WO2013151209A1 - Cathode active material for lithium ion capacitor and method for manufacturing same - Google Patents

Cathode active material for lithium ion capacitor and method for manufacturing same Download PDF

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Publication number
WO2013151209A1
WO2013151209A1 PCT/KR2012/003860 KR2012003860W WO2013151209A1 WO 2013151209 A1 WO2013151209 A1 WO 2013151209A1 KR 2012003860 W KR2012003860 W KR 2012003860W WO 2013151209 A1 WO2013151209 A1 WO 2013151209A1
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Prior art keywords
lithium
metal oxide
composite metal
active material
ion capacitor
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PCT/KR2012/003860
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French (fr)
Korean (ko)
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박민식
김점수
김영준
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전자부품연구원
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Publication of WO2013151209A1 publication Critical patent/WO2013151209A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/004—Details
    • H01G9/04—Electrodes or formation of dielectric layers thereon
    • H01G9/042—Electrodes or formation of dielectric layers thereon characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/46—Metal oxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/50—Electrodes characterised by their material specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/13—Energy storage using capacitors

Definitions

  • the present invention relates to a lithium ion capacitor having excellent capacity characteristics and high energy density. More specifically, the present invention uses a specific lithium composite metal oxide as a positive electrode additive in a carbon-based material applied as a positive electrode active material, and a lithium ion capacitor positive electrode active material which is electrochemically doped with lithium and further improves energy density, and its preparation It is about a method.
  • a lithium ion capacitor is a new concept of a secondary battery system that combines the high power / long life characteristics of an existing electric double layer capacitor (EDLC) with the high energy density of a lithium ion battery.
  • EDLC electric double layer capacitor
  • Electrode double layer capacitors that use physical adsorption reactions of electrical charges in electrical double layers are limited to various applications due to their low energy density despite their excellent output and lifetime characteristics.
  • a hybrid capacitor having improved energy density using a material capable of inserting and detaching lithium ions as a positive electrode or a negative electrode active material has been proposed.
  • Lithium ion capacitors have been proposed that use a carbon-based material that can be used to insert and detach lithium ions as a negative electrode active material. For example, as shown in FIG.
  • an electric double layer capacitor exhibits excellent output characteristics by using charge bonding and desorption of charges using an activated carbon material having a large specific surface area symmetrically on the anode and the cathode, but has a low energy density (E a).
  • E a energy density
  • hybrid capacitors use a high capacity transition metal oxide as the anode material to increase capacity (),
  • the capacitor is characterized by improving the energy density (E d ) performance by using a carbon-based material capable of reversible insertion and removal of lithium ions as a cathode material.
  • the lithium ion capacitor may improve performance of energy density compared to other hybrid capacitors due to the property of using a material capable of inserting and detaching lithium ions at a low reaction potential as a negative electrode active material.
  • the lithium ion capacitor can be doped with a large amount of ion ion lithium ion in advance to significantly lower the potential of the negative electrode, the cell voltage is also possible to achieve a high voltage of 3.8 V or more improved significantly compared to the 2.5 V of the conventional electric double layer capacitor Energy density can be improved compared to other hybrid capacitors.
  • the electrons are transferred to the carbon-based material of the negative electrode during layer transfer, and the carbon-based material becomes negatively charged.
  • the negative electrode is inserted into the carbonaceous material of the negative electrode, and on the contrary, during discharge, lithium ions inserted into the carbonaceous material of the negative electrode are released, and the negative ions are again adsorbed to the positive electrode.
  • the lithium ion capacitor is a system that combines the energy storage capacity of the lithium ion battery with the output characteristics of the capacitor.
  • the lithium ion capacitor adopts a material capable of isochronizing two functions to show the characteristics of the capacitor at the time of high power use and to maintain the device. It is a future battery system that extends the usage time to the lithium ion battery level.
  • lithium ion capacitor requires a lithium doping process for insertion and desorption reaction of lithium as well as electrochemical adsorption and desorption reaction.
  • the conventional technique of doping lithium to the negative electrode in order to implement such a lithium silver capacitor is a metal laminated by the potential difference between the negative electrode and the metal lithium only by laminating the metal lithium on the electrode and then adding an electrolyte to short the negative electrode and the metal lithium. Lithium is melted into the cathode.
  • the present invention is to provide a cathode active material for a lithium ion capacitor can be doped with lithium in an electrochemical manner without using metal lithium, and can further improve the capacitor capacity and energy density.
  • the present invention also provides a method for producing a cathode active material for a lithium ion capacitor.
  • the present invention also provides a lithium ion capacitor including the cathode active material.
  • the present invention provides a cathode active material for a lithium ion capacitor comprising a first lithium composite metal oxide represented by Formula 1 below, a second lithium composite metal oxide represented by Formula 2 below, and a carbon-based material.
  • a, b, c, d, e, and f represent 0 ⁇ a ⁇ 6, 0 ⁇ b ⁇ 3, 0 ⁇ c ⁇ 4, 0 ⁇ d ⁇ 2, 0 ⁇ e ⁇ 3, and 0 ⁇ f ⁇ 4, respectively.
  • M 1 is one or more selected from the group consisting of Mo, Fe, and Co,
  • M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
  • the present invention also provides a lithium composite metal oxide precursor represented by the following Chemical Formula 3 by a) mixing and heat treating a transition metal compound containing at least one selected from the group consisting of a) a lithium compound and Mo, Fe, and Co.
  • a, b, and c satisfy 0 ⁇ a ⁇ 6, 0 ⁇ b ⁇ 3, 0 ⁇ c ⁇ 4, respectively,
  • a ', b * , and c' satisfy 0 ⁇ a ' ⁇ 6, 0 ⁇ b' ⁇ 3, l ⁇ c ' ⁇ 5, respectively
  • M 1 and M 1 ' are each one or more selected from the group consisting of Mo, Fe, and Co;
  • M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
  • the present invention also provides a lithium ion capacitor including the cathode active material.
  • a cathode active material for a lithium ion capacitor and a method of manufacturing the same, and a lithium ion capacitor including the same will be described in detail.
  • this is presented as an example of the invention, whereby the scope of the invention is not limited, it is apparent to those skilled in the art that various modifications to the embodiments are possible within the scope of the invention.
  • Constant refers to including any component (or component) without particular limitation and should not be construed to exclude the addition of other components (or components).
  • lithium ion capacitor is used to improve the capacitance characteristics by using different asymmetric electrodes for the positive electrode and the negative electrode, and the opposite pole using the high-capacity electrode material.
  • These lithium ion capacitors generally have a large capacity as a negative electrode material and a carbon-based material capable of inserting and desorbing lithium ions such as graphite, hard carbon, and soft carbon.
  • Lithium-ion capacitors are half of electric double layer capacitors and hybrid capacitors of about 3.0V Whereas with a potential having a high banung potential of 4.2V, is characterized in that expression of a high energy density as much excellent capacity characteristic ().
  • the lithium ion capacitor requires a lithium doping process for insertion and desorption reaction of lithium as well as an electrochemical adsorption and desorption reaction, and a doping method in which a conventional metal lithium is laminated on an electrode and electrically shorted. It is difficult to control the amount of silver lithium doped to the negative electrode, and it is difficult to maintain safety due to the lithium metal generated in the doping process.
  • the present invention by adding a specific positive electrode additive as a lithium source to the carbon-based material applied as the positive electrode active material, by electrochemically doping lithium to the negative electrode to significantly improve the doping efficiency and safety, It is possible to obtain a process improvement effect that ensures excellent safety enough for mass production.
  • a lithium ion capacitor is manufactured using a cathode active material including a lithium composite metal oxide having predetermined characteristics as a cathode additive, an excellent capacitor characteristic when used at high power, and excellent output with high energy density. It has been shown that it shows the characteristics and lifespan, and can replace the doping process using lithium metal, thereby ensuring excellent process safety.
  • a cathode active material for a lithium ion capacitor including a cathode additive having predetermined characteristics includes a specific cathode additive, that is, a first lithium composite metal oxide represented by the following Chemical Formula 1, and a second lithium composite metal oxide represented by the following Chemical Formula 2 in the carbon-based material.
  • a, b, c, d, e, and f represent 0 ⁇ a ⁇ 6, 0 ⁇ b ⁇ 3, 0 ⁇ c ⁇ 4, 0 ⁇ d ⁇ 2, 0 ⁇ e ⁇ 3, and 0 ⁇ £ ⁇ 4, respectively.
  • M 1 is one or more selected from the group consisting of Mo, Fe, and Co,
  • M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
  • the positive electrode active material for a lithium ion capacitor of the present invention uses a specific positive electrode additive (the first lithium composite metal oxide) having a large initial irreversible capacity to a carbon-based material that is applied as the positive electrode active material. Doping improves fairness and safety by replacing lithium metal in the existing lithium ion doping method, and at the same time, the specific positive electrode additive (the second lithium composite metal oxide) having high reversibility in the operating potential region of the lithium ion capacitor To further increase the capacitor's capacity and energy density It is characterized by improving.
  • the specific positive electrode additive the second lithium composite metal oxide
  • the lithium metal used as a lithium source for doping lithium to the existing negative electrode, and the first lithium composite metal oxide as a positive electrode additive to be a lithium source in the present invention is represented by the formula (1).
  • the first lithium composite metal oxide of the present invention is characterized in that the initial capacity and the irreversible capacity are large, and can effectively and effectively do the lithium to the cathode of the lithium ion capacitor electrochemically.
  • the metal component Ml forming the oxide together with lithium in the first lithium composite metal oxide may be Mo, Fe, Co, or the like.
  • the Mo, Fe, Co and the like correspond to the transition metal
  • the positive electrode additive containing such a transition metalol is a transition metal oxide.
  • the Mo, Fe, Co and the like has an advantage that can more effectively induce the insertion and desorption of lithium electrochemical in crystal structure.
  • the first lithium composite metal oxide may have a crystal structure such as Rhombohedral, Monoclinic, Orthorhombic, or the like.
  • the first lithium composite metal oxide is 0V to 5V, preferably
  • the lithium composite metal oxide has a large initial irreversible capacity to supply lithium ions to the cathode in an electrochemical manner without using metal lithium.
  • the first lithium composite metal oxide may have an initial layer discharge efficiency () of 50% or less or 0% to 50%, preferably 40% or less or 0) to 40%, more preferably, according to Formula 1 below. Can be up to 30% or from 0% to 30%.
  • Q E represents the initial charge and discharge efficiency of the first lithium composite metal oxide
  • QD is the discharge capacity (mAh / g) at Li / Li + cut-off at a discharge voltage of 2.3 V
  • Qc shows the layer capacitance (mAh / g) at Li / Li + cut-off at the layer voltage 4.7 V.
  • the initial layer discharge efficiency Q E of the first lithium composite metal oxide is constant current or constant voltage in an electrochemical manner under a half cell condition in which lithium is opposed to a voltage of 2.3.
  • Discharge capacity per unit weight of the cathode active material at Li / Li + cut-off at V (Q D , mAh / g) and cathode active material at Li / Li + cut-of at 4.7 V The layer charge capacity (Qc, mAh / g) per unit weight of can be measured and calculated according to the above formula (1).
  • the discharge capacity per unit weight (QD) relative to the total weight of the lithium composite metal oxide at Li / Li + cut-off at a voltage of 2.3 V of the first lithium composite metal oxide is 135 mAh / g or less or 0 to 135 mAh / g, preferably 110 mAh / g or less or 0 to 110 mAh / g, more preferably 85 mAh / g or less or 0 to 85 mAh / g.
  • the charge capacity per unit weight (Qc) relative to the total weight of the first lithium composite metal oxide at a Li / Li + cut-off at a voltage of 4.7 V of the first lithium composite metal oxide is 200 mAh / g or more, preferably Preferably 230 mAh / g or more, more preferably 250 mAh / g or more or 250 to 700 mAh / g, and in some cases 700 mAh / g or less, 500 mAh / g or less, or 300 mAh / g or less Can be
  • Discharge capacity at Li / Li + cut-off at 2.3 V (Q D , mAh / g) and Layer capacity at Li / Li + cut-off at voltage 4.7 V (Qc, mAh / g ) Preferably maintains the range as described above in terms of capacity.
  • the cathode active material of the present invention includes a second lithium composite metal oxide represented by Chemical Formula 2 together with the first lithium composite metal oxide as a cathode additive serving as a lithium source.
  • the second lithium composite metal oxide corresponds to a high capacity transition metal oxide having a high reversibility in the operating potential region of the lithium ion capacitor, and can improve the energy density limit per volume and further improve the energy density of the conventional lithium ion capacitor. have.
  • M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
  • the metal component M 2 forming the oxide together with lithium in the second lithium composite metal oxide may be Mn ⁇ Ti, Ru, Ir, Pt, Sn, Zr, or the like.
  • the Mn, Ti, Ru, Ir, Pt, Sn, Zr and the like correspond to a transition metal
  • the positive electrode additive containing such a transition metal is a transition metal oxide.
  • the Mn, Ti, Ru, Ir, Pt, Sn, and Zr has the advantage of more effectively inducing the insertion and desorption of the electrochemical lithium in the operating potential region of the lithium ion capacitor in the crystal structure.
  • the second lithium composite metal oxide may have a crystal structure such as Rhombohedral, Monocl inic, Orthorhombic, or the like.
  • the second lithium composite metal oxide has a characteristic of reversibly inserting or detaching lithium ions in a voltage range of IV to 5V, preferably 2.5V to 5V, more preferably 2V to 5V.
  • the second lithium composite metal oxide may improve the energy density limit per volume of the lithium ion capacitor according to the conventional lithium metal doping and further increase the energy density. It has a high reversibility characteristic in the operating potential region of a lithium ion capacitor.
  • the second lithium composite metal oxide has a layer discharge efficiency (,) of 503 ⁇ 4 or more or 50% to 100%, preferably 60% or more, more preferably, under a 2.3V to 4.7V potential according to the following Equation 2. May be greater than 70%.
  • 3 ⁇ 4 ⁇ is the charge and discharge efficiency under the 2.3V to 4.7V potential of the second lithium composite metal oxide
  • QD represents discharge capacity (mAh / g) at Li / Li + cut-off at a discharge voltage of 2.3 V
  • Qc ' represents the layer capacitance (mAh / g) at Li / Li + cut-off at the layer voltage 4.7V.
  • the layer discharge efficiency under the 2.3 V to 4.7 V potential of the second lithium composite metal oxide is determined by a constant current or a constant voltage method by an electrochemical method under a half cell condition with lithium as a counter electrode.
  • Discharge capacity per unit weight of positive electrode active material (, mAh / g) at Li / Li + cut-off at 2.3 V, and positive electrode active material at Li / Li + cut-off at 4.7 V The layer charge capacity (, mAh / g) per unit weight of can be measured and calculated according to the above formula (2).
  • the discharge capacity per unit weight (QD,) relative to the total weight of the lithium composite metal oxide at the Li / Li + cut-off at a voltage of 2.3 V of the lithium composite metal oxide is 100 mAh / g or more or 100 to 300 mAh / g, preferably 130 mAh / g or more, more preferably 150 mAh / g or more.
  • the layered capacity per unit weight (Qc is 150 mAh / g or more, preferably 170 mAh, for the total weight of the lithium composite metal oxide at Li / Li + cut-off at a voltage of 4/7 V of the lithium composite metal oxide).
  • lithium composite metal oxide is Li 2 Mn0 3, Li 2 Ti0 3, Li 2 Ru0 3 (
  • Li 2 Ir0 3L Li 2 Pt0 3) Li 2 Sn0 3) and Li 2 Zr can be used.
  • the positive electrode active material for a lithium ion capacitor of the present invention uses a specific first lithium composite metal oxide and a crab 2 lithium composite metal oxide as a positive electrode additive to a carbon-based material to be used as the positive electrode active material.
  • the energy density per volume can be improved and the safety of the doping process can be achieved simultaneously.
  • the conventional lithium ion capacitor laminates lithium metal on an electrode to form a lithium source for transferring lithium ions to the cathode through an electrical short circuit.
  • the lithium ion capacitor of the present invention as shown in Figure 3, by adding a specific positive electrode additive, such as Li 2 Mo0 3 and Li 2 Ru0 3 to the positive electrode active material to use as a lithium source, a separate lithium metal laminate layer It is characterized in that to effectively transfer the lithium ions toward the cathode and to improve the capacity and energy density of the capacitor without forming a.
  • the carbon-based material used as the positive electrode active material for lithium ion capacitor of the present invention refers to activated carbon having a large specific surface area, the specific surface area of 500 m7g or more, preferably 700 m 2 / g or more, more preferably 1,000 m 2 It may be more than / g or 1,000 to 3,000 m 2 / g, in some cases may be less than 2500 m 2 / g, 2,000 m 2 / g or less.
  • Such carbon-based materials may be used at least one of activated carbon, activated carbon and metal oxide composite, activated carbon and conductive polymer composite, and among these, activated carbon is preferable for the conductive aspect.
  • the positive electrode active material for a lithium ion capacitor according to the present invention is a positive electrode additive, that is, the lithium composite metal as a lithium source of a negative electrode material to a carbon-based material
  • the oxides have a composition mixed together.
  • the cathode active material for a lithium ion capacitor according to the present invention may include 0.5 to 49.5% by weight of the first lithium composite metal oxide, 0.5 to 49.5% by weight of the second lithium composite metal oxide, and 50 to 99% by weight of a carbon-based material. Can be.
  • the first lithium composite metal oxide, 1 to 34% by weight of the second lithium composite metal oxide, and 65 to 98% by weight of the carbon-based material are preferably, 1.5 to 18.5 weight% U lithium composite metal oxide, 1.5 to 18.5 weight% second lithium composite metal oxide, and 80 to 97 weight% carbonaceous materials.
  • the first lithium composite metal oxide, the second lithium composite metal oxide, and the carbon-based material are 0.5 weight 3 ⁇ 4 or more, 0.5 weight 3 ⁇ 4>, and 99 weight%, respectively, so as to effectively dope lithium to the negative electrode. It may be included in the following, in terms of ensuring excellent conductivity may be included in each of 49.5% by weight or less, 49.5% by weight or less, and 50% by weight or more.
  • the weight ratio of the two positive electrode additives that is, the weight ratio of the first lithium composite metal oxide to the second lithium composite metal oxide is 90:10 to 10:90, preferably 80:20 to 20:80, more preferably. May be from 70:30 to 30:70.
  • the first lithium composite metal oxide and the second lithium composite metal oxide may be used in a weight ratio of 90:10 or more in terms of improving negative electrode doping capacity, and may be used in a weight ratio of 10:90 or less in terms of improving energy density.
  • first lithium composite metal oxide and the second lithium composite metal oxide may be uniformly mixed throughout the carbon-based material or locally mixed only in part depending on the amount added to the carbon-based material.
  • the weight ratio of the total weight of the first lithium composite metal oxide and the second lithium composite metal oxide to the carbonaceous material is 10:90 to 90:10, preferably 15:85 to 85:15, and more preferably 20:80 to 80:20.
  • the weight ratio of the carbon-based material to the total weight of the first lithium composite metal oxide and the second lithium composite metal oxide may be 10:90 or more in terms of energy density improvement, and 90:10 or less in terms of power density improvement. .
  • the positive electrode additive according to the present invention that is, the first lithium composite metal oxide of Formula 1 and the second lithium composite metal of Formula 2
  • the oxide may be electrochemically doped with lithium on the carbon-based anode active material, and the doped lithium ions contribute to the capacitor characteristics, thereby lowering the Sal voltage, thereby significantly improving the capacity and energy density of the lithium ion capacitor.
  • a method of manufacturing the positive electrode active material for the lithium ion capacitor is provided.
  • the method of manufacturing a cathode active material for a lithium ion capacitor includes a) a first compound represented by the following Chemical Formula 3 by mixing and heat-treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and Mo, Fe, and Co.
  • a lithium composite metal oxide precursor Generating a lithium composite metal oxide precursor; b) reducing the first lithium composite metal oxide precursor represented by Formula 3 to produce a first lithium composite metal oxide represented by Formula 1 below; c) a second lithium composite metal represented by the following Chemical Formula 2 by mixing and heat-treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and Mn, Ti, Ru, Ir, Pt, Sn, and Zr Producing an oxide; And d) mixing the first lithium composite metal oxide and the low 12 lithium composite metal oxide with a carbonaceous material.
  • a, b, and c are each 0 ⁇ a ⁇ 6, 0 ⁇ b ⁇ 3, 0 ⁇ c ⁇ 5, and preferably 0 ⁇ a ⁇ 5
  • a ', b', c ' is 0 ⁇ a' ⁇ 6, 0 ⁇ b' ⁇ 3, l ⁇ c' ⁇ 5, preferably 0 ⁇ a' ⁇ 5, 0 ⁇ b ' ⁇ 2, 0 ⁇ c' ⁇ 4 More preferably, 0 ⁇ a ' ⁇ 5, 0 ⁇ b' ⁇ 1, 0 ⁇ c ' ⁇ 4.
  • M 1 and M 1 ′ are each one or more selected from the group consisting of Mo, Fe, and Co
  • M 2 is selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr 1 or more types.
  • a first lithium composite metal oxide and a precursor thereof, a second lithium composite metal oxide, and a carbon-based material as a cathode active material are described above with reference to the cathode active material for a lithium ion capacitor. As applicable.
  • the first lithium composite metal oxide precursor of Chemical Formula 3 is formed of a lithium compound such as Li 2 CO 3 , LiOH, Li, Mo0 3> ⁇ 0 2) ( ⁇ 4 ) 6 ⁇ 7 ⁇ 2 4 ⁇ 4H 2 0, MoS 2) Mo, FeO, Fe 2 0 3 , Fe 3 0 4) Transition metal compounds such as Fe, CoO, Co can be mixed to prepare a heat treatment process.
  • the lithium compound, Mo, Fe, Co itself and the transition metal compound containing the same, the exponential value a, b, c, a ', b', c ', etc.
  • the heat treatment process may be performed at 400 to 1,000 ° C., preferably 500 to 900 ° C., more preferably 500 to 800 ° C.
  • the lithium The heat treatment process for the compound and the composite metal compound may be performed for 0.5 to 20 hours, preferably 1 to 15 hours, more preferably 2 to 10 hours.
  • the heat treatment process for the lithium compound and the composite metal compound may be performed in an oxygen or air atmosphere.
  • Reducing the first lithium composite metal oxide precursor of Formula 3 in step b) may be carried out by heat treatment at 500 to 1,000 ° C, preferably 700 to 900 ° C, more preferably 700 to 800 ° C. have.
  • the heat treatment process may be performed for 2 to 50 hours, preferably 5 to 30 hours, more preferably 10 to 20 hours. Such heat treatment process By maintaining the temperature and time, it is possible to effectively convert the first lithium composite metal oxide precursor of Formula 3 to the first lithium composite metal oxide of Formula 1.
  • the reducing process of the first lithium composite metal oxide precursor may be performed under an inert atmosphere of argon (Ar) gas or nitrogen (N 2 ).
  • the inert gas quantum may further include hydrogen () and the like, and in terms of improving overall process efficiency, it is preferable to carry out under a condition containing 3 ⁇ 4 of 5% or less.
  • the first lithium composite metal oxide of Chemical Formula 1 having the characteristics as described above may be generated.
  • the second lithium composite metal oxide having Chemical Formula 2 may be selected from Li 2 CO 3> LiOH, Li, a round lithium compound, and MnO, Mn, Ti0 2 ⁇ Ti, Ru0 2) Ru, IrCl 3 , Ir0 2 , Transition metal compounds such as PtCl 4 , PtCl 2 , Pt0 2 , Pt (C 5 H 7 0 2 ) 2, Pt / C, Sn0 2 , Sn, Zr0 2l Zr may be mixed and prepared by a heat treatment process.
  • the lithium compound and Mn, Ti, Ru, Ir, Pt, Sn, and Zr itself and the transition metal compound containing the same, the molar ratio in consideration of the index values d, e, f, etc. in the second lithium composite metal oxide to be produced Can be mixed, for example, 2: 1 to 3: 1, preferably 2: 1 to 2.5: 1, more preferably 2: 1 to 2.3: 1.
  • the heat treatment process may be performed at 500 to 1,000 ° C, preferably 700 to 900 ° C, more preferably 700 to 800 ° C.
  • the heat treatment process may be performed for 2 to 50 hours, preferably 5 to 30 hours, more preferably 10 to 20 hours.
  • the heat treatment process for the lithium compound and the composite metal compound may be performed in an oxygen or air atmosphere.
  • the step d) of mixing the first lithium composite metal oxide and the second lithium composite metal oxide with a carbon-based material may be performed by various physical mixing methods.
  • the carbon-based material as the first lithium composite metal oxide, the second lithium composite metal oxide, and the positive electrode active material may be mixed at 0.5 to 49.5 weight 3 ⁇ 4>, 0.5 to 49.5 weight%, and 50 to 99 weight%, respectively.
  • a lithium ion capacitor including the cathode active material for the lithium ion capacitor is provided.
  • the lithium ion capacitor forms a separate lithium metal layer by using a specific first lithium composite metal oxide having a large initial irreversible capacity and a second lithium composite metal oxide having a high reversibility as an anode additive in an operating potential region of the lithium ion capacitor. It is characterized in that it can effectively transfer lithium ions to the negative electrode without having to.
  • the lithium ion capacitor according to the present invention can improve the process safety according to the generation of lithium metal by doping lithium ions to the cathode in an electrochemical manner, and at the same time, it is possible to secure the effect of further improving the capacity and energy density of the capacitor. have.
  • the lithium ion capacitor of the present invention includes a cathode including a cathode active material; An anode including an anode active material; And a separator between the anode and the cathode, wherein the cathode may be supplied with lithium ions only from the anode.
  • receiving lithium ions only from the positive electrode is included in a separate lithium ion supply layer for supplying lithium ions to the negative electrode, for example, the negative electrode or on the negative electrode
  • a separate lithium metal layer stacked (coated or laminated) is not included in the capacitor, and the negative electrode may mean that only lithium ions derived from the lithium composite metal oxide included in the positive electrode active material are supplied.
  • the lithium ion capacitor of the present invention is lithium in the voltage range of 0V to 5V It may include a carbon-based negative electrode active material for reversibly inserting or detaching ions.
  • a lithium ion capacitor including a positive electrode active material including the first lithium composite metal oxide and the second lithium composite metal oxide and a carbon-based negative electrode active material reversibly intercalating or deintercalating with lithium ionol may be formed. Characterized in that to effectively doping.
  • the first lithium composite metal oxide or the like according to the present invention is applied as a positive electrode additive to a hybrid capacitor using a conventional activated carbon negative electrode which is not a negative electrode active material of a lithium ion capacitor (positive electrode: activated carbon + Li 2 MoO ⁇ negative electrode: activated carbon) ), Due to the large initial irreversible nature of the positive electrode additive itself may cause a problem that the capacity and life performance of the capacitor is significantly reduced.
  • the second lithium composite metal oxide or the like according to the present invention is applied as a positive electrode additive to the hybrid capacitor or the like (anode: activated carbon + Li 2 Ru0 3 , negative electrode: activated carbon), the reversible lithium ions (Li + ), Due to the insertion and desorption properties, the effect of improving energy density may occur.
  • the lithium ion capacitor according to the present invention has a layer discharge capacity measured by an electrochemical method of 50 F / g or more, preferably 70 F / g or more, more preferably 100 F / g or more or 100 to 800 F /. It may exhibit excellent performance of g, and in some cases, 750 F / g or less, and 700 F / g or less.
  • the lithium ion capacitor according to the present invention uses a lithium composite metal oxide having a large initial irreversible capacity in a positive electrode active material to electrochemically dope lithium in a negative electrode, thereby providing a lithium metal electrode or a lithium metal as a separate lithium source. It can be prepared without using.
  • a specific example of a cathode active material for a lithium ion capacitor and a method of manufacturing a lithium ion capacitor using the same according to the present invention will be described in detail.
  • the second step of synthesizing a first step, and a ready-Li 2 Mo0 Li 2 Mo0 3 processes the reduction of 4 precursor to prepare a Li 2 Mo0 4 precursor, Li A third step of synthesizing 2 Ru0 3 , And a fourth step of mixing the Li 2 Mo 3 and the carbon-based material to form a cathode active material.
  • the first step of preparing the Li 2 Mo 0 4 precursor is more specifically, the first 1-step of mixing Li 2 C0 3 and Mo0 3 in a 1: 1 molar ratio, and the marks of Li 2 C0 3 and Mo0 3
  • the mixture is heat-treated at 400-1000 ° C. for 1-6 hours in air to form the first 1-2 steps to form a Li 2 Mo 4 precursor.
  • the first step 1-2 may be performed in the air.
  • the second step is the 2-1 step of uniformly mixing 10 wt% or less of Super-P in Li 2 Mo0 4 through mechanical milling, and the mixture of Li 2 Mo0 4 and Super-P 10%
  • the mixing step according to the mechanical milling in the 2-1 step may proceed for about 30 minutes.
  • the mechanical milling means for example, a mortar, a ball mill, a vibration mill, a satellite ball mill, a tube mill, a rod mill jet mill, a hammer mill, or the like can be used.
  • the reducing atmosphere according to step 2-2 may be performed under an Ar 2 atmosphere containing 3 ⁇ 4 gas of 5 ⁇ 10>.
  • the third step of synthesizing Li 2 Ru 0 3 is more specifically, the 3-1 step of mixing Li 2 C0 3 and Ru0 2 in a 1: 1 molar ratio, and a mixture of Li 2 C0 3 and Ru0 2 It comprises a 3-2 step of synthesizing Li 2 Ru3 ⁇ 4 by heat treatment at 500 to 1000 ° C for 10 to 30 hours in air. In this case, step 3-2 may be performed in the air.
  • step 3-2 may be performed in the air.
  • Li 2 Mo 0 3 and Li 2 Ru0 3 synthesized in the second and third steps are mixed with a carbon-based material to form a cathode active material for a lithium ion capacitor.
  • the cathode active material for a lithium ion capacitor may be formed by mixing Li 2 Mo0 3 3-50 weight%, Li 2 Ru 3-30 weight%, and carbonaceous material 60 to 94 weight%. Preferably 3 to 30% by weight of Li 2 Mo0 3 , 3 to 10% by weight of Li 2 Ru3 ⁇ 4, 60-94% by weight of the carbon-based material.
  • the electrochemical lithium doping may be performed in a voltage range of 5V or less.
  • a lithium ion capacitor was manufactured as follows. At this time, as described above, 92 wt% of the positive electrode active material prepared according to a specific example of the present invention and binder PVdF were 8 wt%, and a slurry was prepared using NMP as a solvent. The slurry was applied to an aluminum mesh (A1 mesh) having a thickness of 20 ⁇ , dried and compacted by a press, dried for 16 hours at 120 ⁇ : in a vacuum to prepare an electrode with a disc of 12 mm in diameter.
  • A1 mesh aluminum mesh having a thickness of 20 ⁇
  • the counter electrode lithium metal foil punched to a diameter of 12 mm was used, and a PP film was used as the separator.
  • a electrolyte solution a mixed solution in which EC / DMC of 1M LiPF 6 was mixed at 3: 7 was used. After the electrolyte solution was impregnated with the separator, the separator was sandwiched between the working electrode and the counter electrode, and a case of a stainless steel (SUS) product was prepared as a test cell for electrode evaluation, that is, a non-aqueous lithium ion capacitor half cell.
  • SUS stainless steel
  • the negative electrode active material is a crystalline or amorphous carbon such as artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbead, petroleum coke, resinous body, carbon fiber, pyrolytic carbon, etc. At least one of the materials may be used.
  • the positive electrode additive reversibly inserts or detaches lithium ions in a voltage range of 5V or less, and is applicable to a lithium ion capacitor to which a non-aqueous electrolyte is driven in a voltage range of 5V or less.
  • the production of the positive electrode plate is one kind commonly used in the powder of the positive electrode active material containing the positive electrode additive according to the present invention, if necessary, a conductive agent, a binder, a thickener, a filler, a dispersant, an ion conductive agent, a pressure enhancer, etc. Or 2 or more types of addition components are added, and it slurry-pastes with suitable solvents, such as water and an organic solvent.
  • suitable solvents such as water and an organic solvent.
  • the binder may be, for example, a rubber binder such as styrene butadiene rubber (SBR), a fluorine resin such as polyethylene tetrafluoride or polyvinylidene fluoride (PVdF), polypropylene, polyethylene, or the like.
  • SBR styrene butadiene rubber
  • PVdF polyvinylidene fluoride
  • Thermoplastic resins, acrylic resins, etc. can be used.
  • the amount of the binder used is the electrical conductivity of the positive electrode active material, the electrode Although it may vary depending on the shape, it can be used in an amount of 2 to 40 parts by weight based on 100 parts by weight of the positive electrode active material.
  • examples of the conductive agent include alum, carbon black, acetylene black, Ketjen black, carbon fiber, and metal powder.
  • the amount of the conductive material used varies depending on the electrical conductivity, electrode shape, and the like of the positive electrode active material, but may be used in an amount of 2 to 40 parts by weight based on 100 parts by weight of the positive electrode active material.
  • CMC carboxymethyl cellulose
  • the electrode support substrate (also referred to as 'current collector') may be composed of copper, nickel, stainless steel, aluminum, foil, sheet, mesh or carbon fiber.
  • a lithium ion capacitor is manufactured using the anode prepared as described above.
  • the form of the lithium ion capacitor may be any one of a coin, a button, a sheet, a pouch, a cylinder, a square, and the like.
  • the negative electrode, electrolyte, and separator of the lithium ion capacitor may be selected and used in a range known to be applicable to a conventional lithium secondary battery.
  • the electrolyte solution is a non-aqueous electrolyte, an inorganic solid electrolyte, or an inorganic solid electrolyte in which lithium salt is dissolved in an organic solvent.
  • Composite materials, etc. can be used, It is not limited to this.
  • the solvent of the non-aqueous electrolyte solution is carbonate ester. Ethers or ketones may be used.
  • the carbonates include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC) ethylene carbonate (EC), Propylene carbonate (PC) butylene carbonate (BC) and the like can be used.
  • Esters include butyrolactone (BL), decanolide, valerolactone, mevalonolactone, ⁇ "caprolactone n-decyl acetate, n-ethyl acetate, n -Propyl acetate, etc.
  • ether dibutyl ether can be used, etc.
  • ketone polymethylvinyl Ketones can be used.
  • the non-aqueous electrolyte according to the present invention is not limited to the type of non-aqueous organic solvent.
  • lithium salt of the non-aqueous electrolyte solution examples include LiPF 6> LiBF 4 , LiSbF 6 , LiAsF 6 , LiC10 4 , L1CF3SO3, LiN (CF 3 S0 2 ) 2) LiN (C 2 F 5 S0 2 ) 2 , LiA10 4 , LiAlCl 4 > LiN (C x F 2x + 1 S0 2 ) (CyF 2x + 1 S0 2 ) (where x and y are natural numbers) and LiS0 3 CF 3 is selected from the group consisting of one or more Include.
  • a porous film made from polyolefin such as polypropylene (PP) or polyethylene (PE), or a porous material such as nonwoven fabric can be used.
  • an electrochemical is added to a carbon-based material for a positive electrode active material of a lithium ion capacitor by adding a positive electrode additive having a large initial irreversible capacity as a source of lithium and a high reversible positive electrode additive to improve energy density in the operating potential region of the lithium ion capacitor.
  • a positive electrode additive having a large initial irreversible capacity as a source of lithium and a high reversible positive electrode additive to improve energy density in the operating potential region of the lithium ion capacitor.
  • the doping of lithium using the positive electrode additive according to the present invention has the effect of improving the energy density of the lithium ion capacitor by lowering the potential of the negative electrode.
  • a simple lithium doping process has the effect of improving the production efficiency of the lithium ion capacitor.
  • EDLC electric double layer capacitor
  • FIG. 2 is a schematic diagram showing a general structure of a conventional lithium ion capacitor (LIC).
  • LIC lithium ion capacitor
  • UC lithium ion capacitor
  • Figure 4 is a reference graph for the initial layer discharge efficiency of the positive electrode additive according to the present invention.
  • Example 5 is an XRD analysis graph of the positive electrode additives Li 2 Mo3 ⁇ 4 and Li 2 Ru0 3 synthesized according to Example 1 of the present invention.
  • Figure 6 is a FESEM and HRTEM picture of the positive electrode additive Li 2 Mo0 3 and Li 2 Ru0 3 synthesized according to Example 1 of the present invention [a) Li 2 Mo0 3 , b) Li 2 u0 3 , c) Li 2 Mo0 3l d) Li 2 Ru 0 3 , e) Li 2 Mo 0 3 , f) Li 2 Ru 0 3 ].
  • FIG. 7 is a graph illustrating a capacity evaluation result of lithium silver capacitors according to Examples 1 and 2 and Comparative Examples 1 and 2 of the present invention.
  • Example 1 is merely to illustrate the present invention is not limited to the scope of the following examples.
  • a high-performance cathode active material for a lithium ion capacitor including Li 2 Mo0 3 as a lithium source for lithium doping to a negative electrode of a lithium ion capacitor and Li 2 Ru0 3 as an additive for improving energy density was prepared.
  • Single phase Li 2 Mo 3 and Li 2 Ru3 ⁇ 4 were synthesized as follows. First, after mixing Li 2 C0 3 and Mo0 3 in a molar ratio of 1: 1, the mixture of Li 2 C0 3 and Mo0 3 is heat-treated at 600 ° C for 5 hours in air to form a lithium composite metal oxide precursor Li 2 Mo0 4 was synthesized. After uniformly mixing 7 parts by weight of Super-P with mechanical milling with respect to 100 parts by weight of Li 2 Mo0 4 thus synthesized, the mixture of Li 2 Mo0 4 and Super-P was mixed for 10 hours at 700 ° C. in an N 2 atmosphere. Heat treatment was performed to synthesize a first lithium composite metal oxide Li 2 M O 0 3 .
  • Li 2 CO 3 and Ru0 2 were mixed in a molar ratio of 1: 1, the mixture of Li 2 CO 3 and Ru0 2 was heat-treated at 900 ° C. for 12 hours in air to form a second lithium composite.
  • a metal oxide precursor Li 2 Ru 0 3 was synthesized.
  • 3 ⁇ 4 is the initial layer discharge efficiency of the lithium composite metal oxide
  • QD is the charge capacity per unit weight of the positive electrode active material (mAh / g) at the Li / Li + cut-off at a discharge voltage of 2.3 V
  • Q c is the Li / Li + cut-off at a layer voltage of 4.7 V. It shows the layer charge capacity (mAh / g) per unit weight of the positive electrode active material (cut-off).
  • the initial layer discharge efficiency () of the prepared first lithium composite metal oxide Li 2 Mo 0 3 was 43%, and it was confirmed that the initial irreversible capacity had a large characteristic.
  • I is the second layer will showing a discharge efficiency at 2.3V ⁇ 4.7V potential of the lithium-metal composite oxide
  • i is Li / Li + cut in the discharge voltage 2.3 V - off (cut off ⁇ ) when the discharge capacity (mAh / g)
  • Q c ⁇ represents the layer capacitance (mAh / g) at the Li / Li + cut-off at the layer voltage 4.7 V.
  • the layer discharge efficiency (3 ⁇ 4,) is more than 70% under the 2.3V to 4.7V potential of the prepared second lithium composite metal oxide Li 2 Ru0 3 , and has a high reversibility in the operating potential region of the lithium ion capacitor. Confirmed.
  • An active material was prepared.
  • a cathode active material for an ion capacitor was prepared.
  • the compositions of the positive electrode active materials according to Examples 1 and 2 and Comparative Examples 1 and 2 are as shown in Table 1 below.
  • slurries were prepared using N-methylpyrrolidone (NMP) as a solvent using 92% of the cathode active materials 92 3 ⁇ 4> and the binder PVdF according to Examples 1 and 2 and Comparative Examples 1 and 2 as 8%.
  • NMP N-methylpyrrolidone
  • the slurry was applied to an aluminum mesh (A1 mesh) having a thickness of 20, dried, compacted in a press, dried for 16 hours at 120 ° C. in a vacuum, and an electrode was prepared from a disk having a diameter of 12 mm 3.
  • the positive electrode plate was prepared by coating 92% of the active material (activated carbon + Li 2 Mo0 3 + Li 2 Ru0 3 ) with an NMP solution containing 8% PVDF binder and a slurry after coating on an aluminum mesh, hard carbon 80 % And a conductive material (super-P) 10 3 ⁇ 4) was prepared by coating the Cu mesh after preparing a slurry and NMP solution containing 10% PVDF binder.
  • a lithium metal foil punched to a diameter of 12 mm was used as an anode, and a polyethylene (PE) film was used as a separator.
  • PE polyethylene
  • a mixed solution in which ethylene glycol / dimethyl chloride (EC / DMC) of 1 M LiPF 6 was mixed at 3: 7 was used as the electrolyte solution.
  • Comparative Example 1 60% of the cathode capacity was doped in a CV (constant voltage) mode using lithium metal, and Comparative Examples 2 and 1 and 2 were electrochemically 4.7 V vs. Lithium was doped to the cathode through layer conversion with a constant current of 0,1 C up to Li / Li +. The amount of Li 2 Mo0 3 shown in Table 1 was fixed in an amount capable of doping the negative electrode in the negative electrode capacity 603 ⁇ 4> according to Comparative Example 1.
  • FIGS. 7 and 8 graphs of capacity evaluation and 1,000 cycle life of the lithium ion capacitor using the positive electrode active material according to Examples 1 to 2 and Comparative Examples 1-2 are shown in FIGS. 7 and 8, respectively.
  • FIG. 7 compares the layer discharge curves of the third cycle after lithium doping after the layer discharge curves, and it is confirmed that Examples 1 to 2 of Li-ion capacitors including Li 2 Ru0 3 additionally exhibit improved capacity.
  • Figure 8 Li 2 Ru 0 3
  • the lithium ion capacitors of Examples 1 to 2 additionally maintain high capacity without deterioration of life, and it was confirmed that the higher capacity was expressed as the amount of Li 2 Ru0 3 increased.
  • the first lithium composite metal oxide having a large initial irreversible capacity and the second lithium composite metal oxide having high reversibility in the operating potential region of the lithium ion capacitor are used together.
  • the lithium ion capacitor of 2 has a discharge capacity of 652 mF to 697 mF and a discharge capacity of 402 mF to 413 mF after 1,000 cycles.
  • the lithium ion capacitor of Comparative Example 1 has a discharge capacity of 386 mF, and after 1,000 cycles, it can be seen that the discharge capacity remarkably drops to 261 mF.
  • the lithium ion capacitor of Comparative Example 2 has a discharge capacity of 562 mF, and discharge capacity of 362 mF after 1,000 cycles is better than that of Comparative Example 1 but is significantly lower than Examples 1 to 2.
  • lithium could be electrochemically doped to the negative carbon material using the positive electrode additives of the Li 2 Mo0 3 and Li 2 Ru0 3 transition metal oxides according to the present invention. It can be seen that it is effective in securing the improved electrochemical properties of the ion capacitor and significantly increasing the energy density.

Abstract

The present invention relates to a lithium ion capacitor having excellent capacitance characteristics and high energy density, and more particularly, to a cathode active material for a lithium ion capacitor in which lithium mixed metal oxide having high initial irreversible capacity as a lithium supplier for a carbon material applied as the cathode active material and lithium mixed metal oxide having high reversibility in the operating potential area of the lithium ion capacitor for energy density improvement are used together as a cathode additive. The invention further relates to a method for manufacturing same, and to a lithium ion capacitor including same. According to the present invention, the anode can be electrochemically doped with lithium without using metal lithium, and the capacitance characteristics of the lithium ion capacitor and the safety of the lithium doping process can be significantly improved.

Description

【명세서】  【Specification】
【발명의 명칭】  [Name of invention]
리튬 이온 커패시터용 양극 활물질 및 그의 제조 방법  Cathode active material for lithium ion capacitor and manufacturing method thereof
【기술분야】  Technical Field
본 발명은 우수한 용량 특성과 높은 에너지 밀도를 갖는 리튬 이온 커패시터에 관한 것이다. 좀더 상세하게는 본 발명은 양극 활물질로 적용되는 탄소계 재료에 특정의 리튬 복합 금속 산화물을 양극 첨가제로 사용하여 전기화학적으로 리튬을 도핑하며 에너지 밀도를 더욱 향상시킨 리튬 이온 커패시터용 양극 활물질 및 그의 제조 방법에 관한 것이다.  The present invention relates to a lithium ion capacitor having excellent capacity characteristics and high energy density. More specifically, the present invention uses a specific lithium composite metal oxide as a positive electrode additive in a carbon-based material applied as a positive electrode active material, and a lithium ion capacitor positive electrode active material which is electrochemically doped with lithium and further improves energy density, and its preparation It is about a method.
【배경기술】  Background Art
휴대용의 소형 전기 전자기기의 보급이 확산됨에 따라 니켈수소전지나 리튬 이차 전지， 슈퍼 커패시터, 리튬 이온 커패시터라고 하는 신형의 이차 전지 개발이 활발하게 진행되고 있다.  With the proliferation of small portable electronic devices, new secondary batteries such as nickel-metal hydride batteries, lithium secondary batteries, super capacitors, and lithium ion capacitors have been actively developed.
이 중에서， 리튬 이온 커패시터 (UC: lithium ion capacitor)는 기존 전기 이중층 커패시터 (EDLC: Electric Double Layer Capacitor)의 고출력 /장수명 특성과 리튬 이온 전지의 고에너지 밀도를 결합한 새로운 개념의 이차전지 시스템이다.  Among these, a lithium ion capacitor (UC) is a new concept of a secondary battery system that combines the high power / long life characteristics of an existing electric double layer capacitor (EDLC) with the high energy density of a lithium ion battery.
전기적 이중층 내 전하의 물리적 흡착 반웅을 이용하는 전기 이중층 커패시터는 우수한 출력특성 및 수명특성에도 불구하고 낮은 에너지 밀도 때문에 다양한 응용 분야에 적용이 제한되고 있다. 이러한 전기 이중층 커패시터의 문제점을 해결하는 수단으로서 양극 또는 음극 활물질로서 리튬 이온을 삽입 및 탈리할 수 있는 재료를 이용하여 에너지 밀도가 향상된 하이브리드 커패시터가 제안되었으며， 특히 양극은 기존 전기 이중층 커패시터의 양극 물질을 사용하고 음극 활물질로서 리튬 이온을 삽입 및 탈리할 수 있는 탄소계 재료를 이용하는 리튬 이온 커패시터가 제안되었다. 예컨대， 도 1에 나타낸 바와 같이， 전기 이중층 커패시터는 양극과 음극에 대칭적으로 비표면적이 큰 활성탄 소재를 사용하여 전하의 홉착 및 탈착을 이용하여 우수한 출력 특성을 나타내지만, 낮은 에너지 밀도 (Ea)를 갖는 단점이 있다. 이와는 달리, 하이브리드 커패시터는 양극 소재로 고용량의 전이금속 산화물을 사용하여 용량 ( )를 증가시키고, 리튬 이온 커패시터는 음극 소재로 리튬 이온의 가역적인 삽입 및 탈리가 가능한 탄소계 재료를 사용하여 에너지 밀도 (Ed) 성능을 개선하는 것을 특징으로 한다. Electrical double layer capacitors that use physical adsorption reactions of electrical charges in electrical double layers are limited to various applications due to their low energy density despite their excellent output and lifetime characteristics. As a means to solve the problem of the electric double layer capacitor, a hybrid capacitor having improved energy density using a material capable of inserting and detaching lithium ions as a positive electrode or a negative electrode active material has been proposed. Lithium ion capacitors have been proposed that use a carbon-based material that can be used to insert and detach lithium ions as a negative electrode active material. For example, as shown in FIG. 1, an electric double layer capacitor exhibits excellent output characteristics by using charge bonding and desorption of charges using an activated carbon material having a large specific surface area symmetrically on the anode and the cathode, but has a low energy density (E a). Has the disadvantage of In contrast, hybrid capacitors use a high capacity transition metal oxide as the anode material to increase capacity (), The capacitor is characterized by improving the energy density (E d ) performance by using a carbon-based material capable of reversible insertion and removal of lithium ions as a cathode material.
이 중에서, 리튬 이온 커패시터가 낮은 반웅 전위에서 리튬 이온을 삽입 및 탈리할 수 있는 재료를 음극 활물질로 사용하는 특성으로 인하여, 다른 하이브리드 커패시터에 비해 에너지 밀도의 성능을 개선시킬 수 있다. 특히， 리튬 이온 커패시터는 이온화 경향이 큰 리튬 이온을 음극에 미리 도핑하여 음극의 전위를 대폭적으로 낮출 수 있고， 셀 전압도 종래의 전기 이중층 커패시터의 2.5 V 대비 크게 향상된 3.8 V 이상의 고전압 구현이 가능하며 다른 하이브리드 커패시터에 비해 에너지 밀도를 개선할 수 있다. 리튬 이온이 도핑된 탄소계 재료를 이용해 음극을 구성한 리튬 이온 커패시터의 반응 메카니즘 (mechanism)을 살펴보면， 층전 시에는 음극의 탄소계 소재로 전자가 이송되어 탄소계 소재는 음전하를 띠게 됨으로써， 리튬 이온이 음극의 탄소질 재료에 삽입되고， 반대로 방전 시에는 음극의 탄소계 재료에 삽입되어 있던 리튬 이온이 탈리되고 다시 음이온이 양극에 흡착된다. 이러한 반웅 메카니즘을 이용하는 것으로 음극에서의 리튬 이온의 도핑량을 제어하여 고에너지 밀도를 갖는 리튬 이온 커패시터를 실현할 수 있다. 또한， 이러한 리튬 이온 커패시터는 리튬 이온 전지의 에너지 저장 능력과 커패시터의 출력 특성올 조합한 시스템으로 두 가지 기능을 등시에 발현할 수 있는 소재를 적용하여 고출력 사용 시에 커패시터 특성을 나타내고 기기의 지속 사용 시간을 리튬 이온 전지 수준으로 확장한 미래형 전지시스템이다.  Among them, the lithium ion capacitor may improve performance of energy density compared to other hybrid capacitors due to the property of using a material capable of inserting and detaching lithium ions at a low reaction potential as a negative electrode active material. In particular, the lithium ion capacitor can be doped with a large amount of ion ion lithium ion in advance to significantly lower the potential of the negative electrode, the cell voltage is also possible to achieve a high voltage of 3.8 V or more improved significantly compared to the 2.5 V of the conventional electric double layer capacitor Energy density can be improved compared to other hybrid capacitors. Looking at the reaction mechanism of the lithium ion capacitor constituting the negative electrode using a carbon-based material doped with lithium ions, the electrons are transferred to the carbon-based material of the negative electrode during layer transfer, and the carbon-based material becomes negatively charged. The negative electrode is inserted into the carbonaceous material of the negative electrode, and on the contrary, during discharge, lithium ions inserted into the carbonaceous material of the negative electrode are released, and the negative ions are again adsorbed to the positive electrode. By using such a reaction mechanism, it is possible to realize a lithium ion capacitor having a high energy density by controlling the doping amount of lithium ions at the cathode. In addition, the lithium ion capacitor is a system that combines the energy storage capacity of the lithium ion battery with the output characteristics of the capacitor. The lithium ion capacitor adopts a material capable of isochronizing two functions to show the characteristics of the capacitor at the time of high power use and to maintain the device. It is a future battery system that extends the usage time to the lithium ion battery level.
다만， 이와 같은 리튬 이온 커패시터는 전기화학적 흡탈착 반웅뿐 아니라 리튬의 삽입 및 탈리 반웅을 위한 리튬 도핑 공정이 반드시 필요하게 된다. 이러한 리튬 이은 커패시터를 구현하기 위하여 리튬을 음극에 도핑하는 종래의 기술은, 금속 리튬을 전극에 라미네이트한 후 전해액을 넣어 음극과 금속 리튬을 단락시키는 것만으로 음극과 금속 리륨의 전위차에 의해 라미네이트된 금속 리튬이 음극 속으로 녹아 들어가는 방식을 채용하고 있다. 그러나, 금속 리튬을 전극에 라미네이트하여 전기적 단락을 통해 리튬을 도핑하는 방식의 경우, 리튬이 음극에 도핑되는 양을 제어하기가 어렵고， 도핑공정에서 발생하는 리튬 금속에 따른 안전성을 확보하기 어려우며， 이에 따라 양산에 적용하기 어려운 문제점이 있다. However, such a lithium ion capacitor requires a lithium doping process for insertion and desorption reaction of lithium as well as electrochemical adsorption and desorption reaction. The conventional technique of doping lithium to the negative electrode in order to implement such a lithium silver capacitor is a metal laminated by the potential difference between the negative electrode and the metal lithium only by laminating the metal lithium on the electrode and then adding an electrolyte to short the negative electrode and the metal lithium. Lithium is melted into the cathode. However, in the case of doping lithium through an electrical short by laminating metallic lithium on the electrode, lithium It is difficult to control the amount of the doping to the negative electrode, it is difficult to ensure the safety according to the lithium metal generated in the doping process, there is a problem that is difficult to apply to mass production.
따라서， 고출력 사용시에 우수한 커패시터 특성으로 더욱 높은 에너지 밀도와 함깨 우수한 출력 특성과 수명 특성을 나타내며， 대량 양산에 적합할 정도로 우수한 안전성이 확보되는 리튬 이온 커패시터 제조용 소재 및 공정 개발에 대한 연구가 필요하다.  Therefore, research on the development of materials and processes for manufacturing lithium ion capacitors, which show excellent energy characteristics and excellent output characteristics and lifetime characteristics with high capacitor density when using high power, and ensures excellent safety for mass production, is required.
【발명의 내용】  [Content of invention]
【해결하려는 과제】  [Problem to solve]
본 발명은 금속 리튬을 사용하지 않고 전기화학적 방식으로 리튬을 음극에 도핑할 수 있으며, 커패시터 용량 및 에너지 밀도를 더욱 향상시킬 수 있는 리튬 이온 커패시터용 양극 활물질을 제공하고자 한다.  The present invention is to provide a cathode active material for a lithium ion capacitor can be doped with lithium in an electrochemical manner without using metal lithium, and can further improve the capacitor capacity and energy density.
본 발명은 또한， 상기 리튬 이온 커패시터용 양극 활물질의 제조 방법올 제공하고자 한다.  The present invention also provides a method for producing a cathode active material for a lithium ion capacitor.
본 발명은 또한, 상기 양극 활물질을 포함하는 리튬 이온 커패시터를 제공하고자 한다.  The present invention also provides a lithium ion capacitor including the cathode active material.
【과제의 해결 수단】  [Measures of problem]
본 발명은 하기의 화학식 1로 표시되는 제 1 리튬 복합 금속 산화물， 하기의 화학식 2로 표시되는 제 2 리튬 복합 금속 산화물， 및 탄소계 재료를 포함하는 리튬 이온 커패시터용 양극 활물질올 제공한다.  The present invention provides a cathode active material for a lithium ion capacitor comprising a first lithium composite metal oxide represented by Formula 1 below, a second lithium composite metal oxide represented by Formula 2 below, and a carbon-based material.
[화학식 1]  [Formula 1]
LiaM^Oc Li a M ^ Oc
[화학식 2]  [Formula 2]
LidM2 e0f Li d M 2 e 0 f
식 중，  In the formula
a, b, c, d, e, f는 각각 0<a<6, 0<b<3, 0<c<4, 0<d<2, 0<e<3, 및 0<f≤4를 만족하며 ,  a, b, c, d, e, and f represent 0 <a <6, 0 <b <3, 0 <c <4, 0 <d <2, 0 <e <3, and 0 <f ≦ 4, respectively. Satisfied,
M1은 Mo, Fe, 및 Co로 이루어진 군에서 선택된 1종 이상이고, M 1 is one or more selected from the group consisting of Mo, Fe, and Co,
M2은 Mn, Ti, Ru, Ir, Pt , Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상이다. 본 발명은 또한， a) 리튬 화합물과 Mo, Fe, 및 Co으로 이루어진 군에서 선택된 1종 이상을 함유하는 전이금속 화합물을 흔합하고 열처리하여 하기의 화학식 3으로 표시되는 게 1 리튬 복합 금속 산화물 전구체를 생성시키는 단계; b) 하기의 화학식 3으로 표시되는 제 1 리튬 복합 금속 산화물 전구체를 환원하여 하기의 화학식 1로 표시되는 제 1 리튬 복합 금속 산화물을 생성시키는 단계; c) 리튬 화합물과 Mn, Ti, Ru, Ir, Pt, Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상을 함유하는 전이금속 화합물을 흔합하고 열처리하여 하기의 화학식 2으로 표시되는 제 2 리튬 복합 금속 산화물을 생성시키는 단계; 및 d) 상기 제 1 리튬 복합 금속 산화물 및 제 2 리튬 복합 금속 산화물을 탄소계 재료와 흔합하는 단계;를 포함하는 리튬 이온 커패시터용 양극 활물질의 제조 방법을 제공한다. M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr. The present invention also provides a lithium composite metal oxide precursor represented by the following Chemical Formula 3 by a) mixing and heat treating a transition metal compound containing at least one selected from the group consisting of a) a lithium compound and Mo, Fe, and Co. Generating; b) reducing the first lithium composite metal oxide precursor represented by Formula 3 to produce a first lithium composite metal oxide represented by Formula 1 below; c) a second lithium composite metal represented by the following Chemical Formula 2 by mixing and heat-treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and Mn, Ti, Ru, Ir, Pt, Sn, and Zr Producing an oxide; And d) mixing the first lithium composite metal oxide and the second lithium composite metal oxide with a carbonaceous material; and providing a cathode active material for a lithium ion capacitor.
[화학식 1]  [Formula 1]
LiaM^Oc Li a M ^ O c
[화학식 2]  [Formula 2]
LidM2 e0f Li d M 2 e 0 f
[화학식 3]  [Formula 3]
Lia'Mr b.0cl Lia'M r b .0 cl
식 중,  In the formula,
a, b, c 는 각각 0<a<6, 0<b<3, 0<c<4를 만족하며，  a, b, and c satisfy 0 <a <6, 0 <b <3, 0 <c <4, respectively,
d, e, f는 각각 0<d≤2, 0<e<3, 0^<4를 만족하며 ,  d, e, f satisfy 0 <d≤2, 0 <e <3, 0 ^ <4, respectively,
a' , b* , c'는 각각 0<a'<6, 0<b' <3， l<c' <5를 만족하몌 a ', b * , and c' satisfy 0 <a '<6, 0 <b'<3, l <c '<5, respectively
M1 및 M1'은 각각 Mo, Fe, 및 Co로 이루어진 군에서 선택된 1종 이상이고 M 1 and M 1 ' are each one or more selected from the group consisting of Mo, Fe, and Co;
M2은 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상이다. M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
본 발명은 또한， 상기 양극 활물질을 포함하는 리튬 이온 커패시터를 제공한다. 이하， 발명의 구체적인 구현예에 따른 리튬 이온 커패시터용 양극 활물질 및 그의 제조 방법, 이를 포함하는 리튬 이온 커패시터에 대해 보다 상세히 설명하기로 한다 . 다만 , 이는 발명에 대한 하나의 예시로서 제시되는 것으로, 이에 의해 발명의 권리범위가 한정되는 것은 아니며， 발명의 권리범위 내에서 구현예에 대한 다양한 변형이 가능함은 당업자에게 자명하다 . The present invention also provides a lithium ion capacitor including the cathode active material. Hereinafter, a cathode active material for a lithium ion capacitor and a method of manufacturing the same, and a lithium ion capacitor including the same according to a specific embodiment of the present invention This will be described in detail. However, this is presented as an example of the invention, whereby the scope of the invention is not limited, it is apparent to those skilled in the art that various modifications to the embodiments are possible within the scope of the invention.
추가적으로， 본 명세서 전체에서 특별한 언급이 없는 한 "포함" 또는 In addition, unless otherwise indicated throughout this specification, "including" or
"함유 "라 함은 어떤 구성 요소 (또는 구성 성분)를 별다른 제한 없이 포함함을 지칭하며， 다른 구성 요소 (또는 구성 성분)의 부가를 제외하는 것으로 해석될 수 없다. "Containing" refers to including any component (or component) without particular limitation and should not be construed to exclude the addition of other components (or components).
본 발명에서 "리튬 이온 커패시터' '라 함은 양극과 음극에 서로 다른 비대칭 전극을 사용함으로써 한쪽 극은 고용량 특성의 전극재료를 사용하고， 반대 극은 고출력 특성 전극 재료를 사용하여 용량 특성을 개선하고자 하는 이차 전지 시스템을 말하는 것이다. 이러한 리튬 이온 커패시터는 일반적으로 음극 소재로 용량이 크고 리튬 이온을 삽입 및 탈리할 수 있는 탄소계 재료， 예컨대， 그래파이트 (graphite), 하드 카본 (hard carbon) , 소프트 카본 (soft carbon) 등을 사용하여 전기화학적 흡탈착 반웅뿐만 아니라 낮은 전위에서 리튬의 삽입 및 탈리 반웅을 이용하기 때문에 단위 중량당 에너지 밀도를 향상시키는 특징을 갖는다. 특히， 도 1에 나타낸 바와 같이， 상기 리튬 이온 커패시터는 전기 이중층 커패시터 및 하이브리드 커패시터가 3.0V 정도의 반응 전위를 갖는 데 반해 4.2V의 높은 반웅 전위를 가지며， 훨씬 우수한 용량 특성 ( )으로 높은 에너지 밀도를 발현하는 것을 특징으로 한다.  In the present invention, "lithium ion capacitor" is used to improve the capacitance characteristics by using different asymmetric electrodes for the positive electrode and the negative electrode, and the opposite pole using the high-capacity electrode material. These lithium ion capacitors generally have a large capacity as a negative electrode material and a carbon-based material capable of inserting and desorbing lithium ions such as graphite, hard carbon, and soft carbon. The use of (soft carbon) and the like as well as the electrochemical adsorption and desorption reaction as well as the insertion and desorption reaction of lithium at a low potential to improve the energy density per unit weight, as shown in Figure 1 Lithium-ion capacitors are half of electric double layer capacitors and hybrid capacitors of about 3.0V Whereas with a potential having a high banung potential of 4.2V, is characterized in that expression of a high energy density as much excellent capacity characteristic ().
다만， 전술한 바와 같이, 리튬 이온 커패시터는 전기화학적 흡탈착 반웅뿐 아니라 리튬의 삽입 및 탈리 반웅을 위한 리튬 도핑 공정이 반드시 필요하게 되며， 기존의 금속 리튬을 전극에 라미네이트하여 전기적으로 단락시키는 도핑 방식은 리튬이 음극에 도핑되는 양을 제어하기가 어렵고， 도핑 공정에서 발생하는 리튬 금속에 따른 안전성 유지가 어려운 단점이 있다.  However, as described above, the lithium ion capacitor requires a lithium doping process for insertion and desorption reaction of lithium as well as an electrochemical adsorption and desorption reaction, and a doping method in which a conventional metal lithium is laminated on an electrode and electrically shorted. It is difficult to control the amount of silver lithium doped to the negative electrode, and it is difficult to maintain safety due to the lithium metal generated in the doping process.
이에 따라, 본 발명은 양극 활물질로 적용되는 탄소계 재료에 리튬 공급원으로 특정의 양극 첨가제를 첨가함으로써， 음극에 전기화학적으로 리튬을 안정하게 도핑시켜 도핑 효율과 안전성을 현저히 향상시키며， 대량 양산에 적합할 정도로 우수한 안전성이 보장되는 공정 개선 효과를 얻을 수 있다. Accordingly, the present invention, by adding a specific positive electrode additive as a lithium source to the carbon-based material applied as the positive electrode active material, by electrochemically doping lithium to the negative electrode to significantly improve the doping efficiency and safety, It is possible to obtain a process improvement effect that ensures excellent safety enough for mass production.
특히， 본 발명자들의 실험 결과， 소정의 특성을 갖는 리튬 복합 금속 산화물을 양극 첨가제로 포함하는 양극 활물질을 사용하여 리튬 이온 커패시터를 제조함에 따라， 고출력 사용시에 우수한 커패시터 특성으로 높은 에너지 밀도와 함께 우수한 출력 특성과 수명 특성을 나타내며, 리튬 금속을 사용한 도핑 공정을 대체할 수 있어 우수한 공정 안전성을 확보할 수 있음이 밝혀졌다.  Particularly, as a result of the experiments of the present inventors, as a lithium ion capacitor is manufactured using a cathode active material including a lithium composite metal oxide having predetermined characteristics as a cathode additive, an excellent capacitor characteristic when used at high power, and excellent output with high energy density. It has been shown that it shows the characteristics and lifespan, and can replace the doping process using lithium metal, thereby ensuring excellent process safety.
이에 발명의 일 구현예에 따라， 소정의 특성을 갖는 양극 첨가제를 포함하는 리튬 이온 커패시터용 양극 활물질이 제공된다. 이러한 리튬 이온 커패시터용 양극 활물질은 탄소계 재료에 특정의 양극 첨가제， 즉， 하기의 화학식 1로 표시되는 제 1 리튬 복합 금속 산화물 및 하기의 화학식 2로 표시되는 제 2 리튬 복합 금속 산화물을 포함한다.  Accordingly, according to one embodiment of the present invention, a cathode active material for a lithium ion capacitor including a cathode additive having predetermined characteristics is provided. The cathode active material for a lithium ion capacitor includes a specific cathode additive, that is, a first lithium composite metal oxide represented by the following Chemical Formula 1, and a second lithium composite metal oxide represented by the following Chemical Formula 2 in the carbon-based material.
[화학식 1]  [Formula 1]
LiaM^Oc  LiaM ^ Oc
[화학식 2]  [Formula 2]
LidM2 e0f Li d M 2 e 0 f
식 중,  In the formula,
a, b, c, d, e, f는 각각 0<a<6, 0<b<3, 0<c<4, 0<d<2, 0<e<3, 및 0<£≤4를 만족하며 ,  a, b, c, d, e, and f represent 0 <a <6, 0 <b <3, 0 <c <4, 0 <d <2, 0 <e <3, and 0 <£ ≤4, respectively. Satisfied,
M1은 Mo, Fe, 및 Co로 이루어진 군에서 선택된 1종 이상이고, M 1 is one or more selected from the group consisting of Mo, Fe, and Co,
M2은 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상이다. M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
본 발명의 리튬 이온 커패시터용 양극 활물질은， 양극 활물질로 적용되는 탄소계 재료에 초기 비가역 용량이 큰 특정의 양극 첨가제 (상기 제 1 리튬 복합 금속 산화물)를 사용하여 전기화학적 방식으로 음극에 리튬 이온을 도핑함을 통해 기존 리튬 이온 도핑 방법에서 리튬 금속을 대체함으로 공정성과 안전성을 개선함과 동시에， 리튬이온 커패시터의 작동전위 영역에서 가역성이 높은 특정의 양극 첨가제 (상기 제 2 리튬 복합 금속 산화물)를 함께 사용하여 커패시터의 용량 및 에너지 밀도를 더욱 향상시키는 것을 특징으로 한다. The positive electrode active material for a lithium ion capacitor of the present invention uses a specific positive electrode additive (the first lithium composite metal oxide) having a large initial irreversible capacity to a carbon-based material that is applied as the positive electrode active material. Doping improves fairness and safety by replacing lithium metal in the existing lithium ion doping method, and at the same time, the specific positive electrode additive (the second lithium composite metal oxide) having high reversibility in the operating potential region of the lithium ion capacitor To further increase the capacitor's capacity and energy density It is characterized by improving.
먼저， 기존의 음극에 리튬을 도핑하는 리튬 소스로 사용된 리튬 금속을 대체하며， 본 발명에서 리튬 공급원이 되는 양극 첨가제로서 제 1 리튬 복합 금속 산화물은 상기 화학식 1로 표시되는 것이다. 특히， 본 발명의 제 1 리튬 복합 금속 산화물은 초기용량과 비가역용량이 큰 특징으로， 리튬 이온 커패시터의 음극에 전기화학적으로 리륨을 안정하게 효과적으로 도핑할 수 있다.  First, the lithium metal used as a lithium source for doping lithium to the existing negative electrode, and the first lithium composite metal oxide as a positive electrode additive to be a lithium source in the present invention is represented by the formula (1). In particular, the first lithium composite metal oxide of the present invention is characterized in that the initial capacity and the irreversible capacity are large, and can effectively and effectively do the lithium to the cathode of the lithium ion capacitor electrochemically.
상기 제 1 리튬 복합 금속 산화물의 화학식 1에서 a, b, c는 0<a≤6, 0<b<3, 및 0<c<5이고, 바람직하게는 l<a<5, 0<b<l, 및 0<c<4가 될 수 있고， 좀더 바람직하게는 l<a<2, 0<b<l, 및 0<c<3(또는 a=2, b=l, c=3)이 될 수 있다.  In Formula 1 of the first lithium composite metal oxide, a, b, and c are 0 <a ≦ 6, 0 <b <3, and 0 <c <5, preferably l <a <5, 0 <b < l, and 0 <c <4, more preferably l <a <2, 0 <b <l, and 0 <c <3 (or a = 2, b = l, c = 3) Can be.
또한， 상기 제 1 리튬 복합 금속 산화물에서 리튬과 함께 산화물을 형성하는 금속 성분 Ml은 Mo, Fe, 및 Co 등이 될 수 있다. 상기 Mo, Fe, 및 Co 등은 전이금속에 해당하는 것으로， 이러한 전이금속올 포함하는 양극 첨가제는 전이금속 산화물이다. 상기 Mo, Fe, 및 Co 등은 결정구조상 전기화학적인 리튬의 삽입 및 탈리를 좀더 효과적으로 유도할 수 있는 장점이 있다. 상기 제 1 리튬 복합 금속 산화물은 롬보헤드랄 (Rhombohedral), 모노클리닉 (Monoclinic), 올쏘롬빅 (Orthorhombic) 등의 결정 구조를 갖는 것이 될 수 있다.  In addition, the metal component Ml forming the oxide together with lithium in the first lithium composite metal oxide may be Mo, Fe, Co, or the like. The Mo, Fe, Co and the like correspond to the transition metal, the positive electrode additive containing such a transition metalol is a transition metal oxide. The Mo, Fe, Co and the like has an advantage that can more effectively induce the insertion and desorption of lithium electrochemical in crystal structure. The first lithium composite metal oxide may have a crystal structure such as Rhombohedral, Monoclinic, Orthorhombic, or the like.
또한, 상기 제 1 리튬 복합 금속 산화물은 0V 내지 5V, 바람직하게는 In addition, the first lithium composite metal oxide is 0V to 5V, preferably
2V 내지 5V, 좀더 바람직하는 2.3V 내지 5V의 전압영역에서 리튬 이온을 삽입 또는 탈리하는 특성을 갖는다. 특히， 상기 리튬 복합 금속 산화물은 금속 리튬을 사용하지 않고 전기화학적 방식으로 리튬 이온을 음극에 공급할 수 있도록 초기 비가역 용량이 큰 특징을 갖는다. It has a characteristic of inserting or detaching lithium ions in a voltage range of 2V to 5V, more preferably 2.3V to 5V. In particular, the lithium composite metal oxide has a large initial irreversible capacity to supply lithium ions to the cathode in an electrochemical manner without using metal lithium.
이에 따라, 상기 제 1 리튬 복합 금속 산화물은 하기의 계산식 1에 따른 초기 층방전 효율 ( )이 50% 이하 또는 0% 내지 50%， 바람직하게는 40% 이하 또는 0 ) 내지 40%， 좀더 바람직하게는 30% 이하 또는 0% 내지 30%가 될 수 있다.  Accordingly, the first lithium composite metal oxide may have an initial layer discharge efficiency () of 50% or less or 0% to 50%, preferably 40% or less or 0) to 40%, more preferably, according to Formula 1 below. Can be up to 30% or from 0% to 30%.
[계산식 1]  [Calculation 1]
QE = (QD/QC) X 100 식 중， Q E = (QD / QC) X 100 In the formula
QE는 제 1 리튬 복합 금속 산화물의 초기 충방전 효율을 나타낸 것이고, Q E represents the initial charge and discharge efficiency of the first lithium composite metal oxide,
QD는 방전 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut-off)시 방전 용량 (mAh/g)을 나타낸 것이고，  QD is the discharge capacity (mAh / g) at Li / Li + cut-off at a discharge voltage of 2.3 V,
Qc는 층전 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off)시 층전 용량 (mAh/g)을 나타낸 것이다.  Qc shows the layer capacitance (mAh / g) at Li / Li + cut-off at the layer voltage 4.7 V.
상기 제 1 리튬 복합 금속 산화물의 초기 층방전 효율 (QE)은 도 4에 나타낸 바와 같이， 리튬을 대극으로 하는 하프셀 (half cell) 조건 하에서 전기화학적인 방법으로 정전류 또는 정전압 방식으로， 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut-off)시 양극 활물질의 단위 중량당 방전 용량 (QD, mAh/g) 및 전압 4.7V에서 Li/Li+ 컷 -오프 (cut—of f)시 양극 활물질의 단위 중량당 층전 용량 (Qc, mAh/g)을 측정하여 상기 계산식 1에 따라 산측할 수 있다. As shown in FIG. 4, the initial layer discharge efficiency Q E of the first lithium composite metal oxide is constant current or constant voltage in an electrochemical manner under a half cell condition in which lithium is opposed to a voltage of 2.3. Discharge capacity per unit weight of the cathode active material at Li / Li + cut-off at V (Q D , mAh / g) and cathode active material at Li / Li + cut-of at 4.7 V The layer charge capacity (Qc, mAh / g) per unit weight of can be measured and calculated according to the above formula (1).
여기서， 제 1 리튬 복합 금속 산화물의 전압 2.3 V에서 Li/Li+ 컷- 오프 (cut— off)시 리튬 복합 금속 산화물 총중량에 대한 단위 중량당 방전 용량 (QD)은 135 mAh/g 이하 또는 0 내지 135 mAh/g, 바람직하게는 110 mAh/g 이하 또는 0 내지 110 mAh/g, 좀더 바람직하게는 85 mAh/g 이하 또는 0 내지 85 mAh/g가 될 수 있다. 또한， 제 1 리륨 복합 금속 산화물의 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off)시 제 1 리튬 복합 금속 산화물 총중량에 대한 단위 중량당 충전 용량 (Qc)은 200 mAh/g 이상， 바람직하게는 230 mAh/g 이상， 좀더 바람직하게는 250 mAh/g 이상 또는 250 내지 700 mAh/g가 될 수 있으며, 경우에 따라 700 mAh/g 이하， 500 mAh/g 이하， 또는 300 mAh/g 이하가 될 수 있다.  Here, the discharge capacity per unit weight (QD) relative to the total weight of the lithium composite metal oxide at Li / Li + cut-off at a voltage of 2.3 V of the first lithium composite metal oxide is 135 mAh / g or less or 0 to 135 mAh / g, preferably 110 mAh / g or less or 0 to 110 mAh / g, more preferably 85 mAh / g or less or 0 to 85 mAh / g. Further, the charge capacity per unit weight (Qc) relative to the total weight of the first lithium composite metal oxide at a Li / Li + cut-off at a voltage of 4.7 V of the first lithium composite metal oxide is 200 mAh / g or more, preferably Preferably 230 mAh / g or more, more preferably 250 mAh / g or more or 250 to 700 mAh / g, and in some cases 700 mAh / g or less, 500 mAh / g or less, or 300 mAh / g or less Can be
상기 제 1 리튬 복합 금속 산화물의 초기 충방전 효율 ( ) 및 전압 Initial charge and discharge efficiency () and voltage of the first lithium composite metal oxide
2.3 V에서 Li/Li+ 컷 -오프 (cut-off)시 방전 용량 (QD, mAh/g)과 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off)시 층전 용량 (Qc, mAh/g)은 용량 측면에서 상술한 바와 같은 범위를 유지하는 것이 바람직하다. Discharge capacity at Li / Li + cut-off at 2.3 V (Q D , mAh / g) and Layer capacity at Li / Li + cut-off at voltage 4.7 V (Qc, mAh / g ) Preferably maintains the range as described above in terms of capacity.
또한， 이러한 리튬 복합 금속 산화물로는 Li2Mo03, Li5Fe04, Li6Co04로 이루어진 군에서 선택된 1종 이상을 사용할 수 있다. 한편， 본 발명의 양극 활물질은 리튬 공급원이 되는 양극 첨가제로서 제 1 리튬 복합 금속 산화물과 함께 상기 화학식 2로 표시되는 제 2 리륨 복합 금속 산화물을 포함한다. 상기 제 2 리튬 복합 금속 산화물은 리튬이온 커패시터의 작동전위 영역에서 가역성이 높은 고용량 전이금속 산화물에 해당하는 것으로， 기존의 리튬 이온 커패시터 갖는 부피당 에너지 밀도의 한계를 개선하고 에너지 밀도를 추가로 향상시킬 수 있다. In addition, as the lithium composite metal oxide may be at least one selected from the group consisting of Li 2 Mo0 3, Li 5 Fe0 4, Li 6 Co0 4. Meanwhile, the cathode active material of the present invention includes a second lithium composite metal oxide represented by Chemical Formula 2 together with the first lithium composite metal oxide as a cathode additive serving as a lithium source. The second lithium composite metal oxide corresponds to a high capacity transition metal oxide having a high reversibility in the operating potential region of the lithium ion capacitor, and can improve the energy density limit per volume and further improve the energy density of the conventional lithium ion capacitor. have.
상기 제 2 리튬 복합 금속 산화물의 화학식 2에서 d, e, f는 0<d≤2, 0<e<3, 및 0<f≤4이고， 바람직하게는 l≤d≤2, 0<e<2, 및 0 ≤3가 될 수 있고 좀더 바람직하게는 (1=2， e=l, f=3이 될 수 있다. 즉， 상기 제 2 리튬 복합 금속 산화물은 좀더 바람직하게는 다음 화학식 4로 표시되는 것일 수 있다.  In Formula 2 of the second lithium composite metal oxide, d, e, and f are 0 <d ≦ 2, 0 <e <3, and 0 <f ≦ 4, preferably l ≦ d ≦ 2, 0 <e < 2, and 0 ≦ 3 and more preferably (1 = 2, e = l, f = 3. That is, the second lithium composite metal oxide is more preferably represented by the following formula (4): It may be.
[화학식 4]  [Formula 4]
Li2M203 Li 2 M 2 0 3
식 중， M2은 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상이다. In the formula, M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
또한， 상기 제 2 리튬 복합 금속 산화물에서 리튬과 함께 산화물을 형성하는 금속 성분 M2은 Mnᅳ Ti, Ru, Ir, Pt , Sn, 및 Zr 등이 될 수 있다. 상기 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr 등은 전이금속에 해당하는 것으로， 이러한 전이금속을 포함하는 양극 첨가제는 전이금속 산화물이다. 상기 Mn, Ti, Ru, Ir, Pt, Sn, 및 Zr 등은 결정구조상 리튬이온 커패시터의 작동전위 영역에서 전기화학적인 리튬의 삽입 및 탈리를 좀더 효과적으로 유도할 수 있는 장점이 있다. 상기 제 2 리튬 복합 금속 산화물은 름보헤드랄 (Rhombohedral), 모노클리닉 (Monocl inic) , 올쏘롬빅 (Orthorhombic) 등의 결정 구조를 갖는 것이 될 수 있다. In addition, the metal component M 2 forming the oxide together with lithium in the second lithium composite metal oxide may be Mn ᅳ Ti, Ru, Ir, Pt, Sn, Zr, or the like. The Mn, Ti, Ru, Ir, Pt, Sn, Zr and the like correspond to a transition metal, the positive electrode additive containing such a transition metal is a transition metal oxide. The Mn, Ti, Ru, Ir, Pt, Sn, and Zr has the advantage of more effectively inducing the insertion and desorption of the electrochemical lithium in the operating potential region of the lithium ion capacitor in the crystal structure. The second lithium composite metal oxide may have a crystal structure such as Rhombohedral, Monocl inic, Orthorhombic, or the like.
상기 제 2 리튬 복합 금속 산화물은 IV 내지 5V, 바람직하게는 2V 내지 5Vᅳ 좀더 바람직하는 2.5V 내지 5V의 전압영역에서 리튬 이온을 가역적으로 삽입 또는 탈리하는 특성을 갖는다. 특히， 상기 제 2 리튬 복합 금속 산화물은 기존의 리튬 금속 도핑에 따른 리튬 이온 커패시터의 부피당 에너지 밀도 한계를 개선하고 에너지 밀도를 추가로 향상시킬 수 있도록 리튬 이온 커패시터의 작동 전위 영역에서 가역성이 높은 특징을 갖는다. 이에 따라， 상기 제 2 리튬 복합 금속 산화물은 하기의 계산식 2에 따른 2.3V 내지 4.7V 전위 하에서 층방전 효율 ( ,)이 50¾ 이상 또는 50% 내지 100%, 바람직하게는 60% 이상， 좀더 바람직하게는 70% 이상이 될 수 있다. The second lithium composite metal oxide has a characteristic of reversibly inserting or detaching lithium ions in a voltage range of IV to 5V, preferably 2.5V to 5V, more preferably 2V to 5V. In particular, the second lithium composite metal oxide may improve the energy density limit per volume of the lithium ion capacitor according to the conventional lithium metal doping and further increase the energy density. It has a high reversibility characteristic in the operating potential region of a lithium ion capacitor. Accordingly, the second lithium composite metal oxide has a layer discharge efficiency (,) of 50¾ or more or 50% to 100%, preferably 60% or more, more preferably, under a 2.3V to 4.7V potential according to the following Equation 2. May be greater than 70%.
[계산식 2]  [Calculation 2]
QE' = (QDVQC XIOO  QE '= (QDVQC XIOO
식 중,  In the formula,
¾ᅳ는 제 2 리튬 복합 금속 산화물의 2.3V 내지 4.7V 전위 하에서 충방전 효율을 나타낸 것이고，  ¾ ᅳ is the charge and discharge efficiency under the 2.3V to 4.7V potential of the second lithium composite metal oxide,
QD'는 방전 전압 2.3V에서 Li/Li+ 컷 -오프 (cut-off)시 방전 용량 (mAh/g)을 나타낸 것이고，  QD 'represents discharge capacity (mAh / g) at Li / Li + cut-off at a discharge voltage of 2.3 V,
Qc'는 층전 전압 4.7V에서 Li/Li+ 컷 -오프 (cut-off)시 층전 용량 (mAh/g)을 나타낸 것이다.  Qc 'represents the layer capacitance (mAh / g) at Li / Li + cut-off at the layer voltage 4.7V.
상기 제 2 리튬 복합 금속 산화물의 2.3V 내지 4.7V 전위 하에서 층방전 효율 은 도 4에 나타낸 바와 같이， 리튬을 대극으로 하는 하프샐 (half cell) 조건 하에서 전기화학적인 방법으로 정전류 또는 정전압 방식으로， 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut-off)시 양극 활물질의 단위 중량당 방전 용량 ( ,， mAh/g) 및 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut- off)시 양극 활물질의 단위 중량당 층전 용량 ( , mAh/g)을 측정하여 상기 계산식 2에 따라 산측할 수 있다.  As shown in FIG. 4, the layer discharge efficiency under the 2.3 V to 4.7 V potential of the second lithium composite metal oxide is determined by a constant current or a constant voltage method by an electrochemical method under a half cell condition with lithium as a counter electrode. Discharge capacity per unit weight of positive electrode active material (, mAh / g) at Li / Li + cut-off at 2.3 V, and positive electrode active material at Li / Li + cut-off at 4.7 V The layer charge capacity (, mAh / g) per unit weight of can be measured and calculated according to the above formula (2).
여기서, 리튬 복합 금속 산화물의 전압 2.3 V에서 Li/Li+ 컷- 오프 (cut-off)시 리튬 복합 금속 산화물 총중량에 대한 단위 중량당 방전 용량 (QD,)은 100 mAh/g 이상 또는 100 내지 300 mAh/g, 바람직하게는 130 mAh/g 이상， 좀더 바람직하게는 150 mAh/g 이상이 될 수 있다. 또한 리튬 복합 금속 산화물의 전압 4/7 V에서 Li/Li+ 컷 -오프 (cut-off)시 리튬 복합 금속 산화물 총중량에 대한 단위 중량당 층전 용량 (Qc 은 150 mAh/g 이상, 바람직하게는 170 mAh/g 이상, 좀더 바람직하게는 200 mAh/g 이상 또는 200 내지 300 mAh/g가 될 수 있으며， 경우에 따라 200 mAh/g 이하가 될 수 있다. 상기 리튬 복합 금속 산화물의 2.3V 내지 4.7 V 전위 하에서 층방전 효율 ( ,) 및 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut—off)시 방전 용량 ( ,， mAh/g)과 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off )시 층전 용량 (Qc mAh/g)은 용량 측면에서 상술한 바와 같은 범위를 유지하는 것이 바람직하다. Here, the discharge capacity per unit weight (QD,) relative to the total weight of the lithium composite metal oxide at the Li / Li + cut-off at a voltage of 2.3 V of the lithium composite metal oxide is 100 mAh / g or more or 100 to 300 mAh / g, preferably 130 mAh / g or more, more preferably 150 mAh / g or more. In addition, the layered capacity per unit weight (Qc is 150 mAh / g or more, preferably 170 mAh, for the total weight of the lithium composite metal oxide at Li / Li + cut-off at a voltage of 4/7 V of the lithium composite metal oxide). / g or more, more preferably 200 mAh / g or more, or 200 to 300 mAh / g, and in some cases may be 200 mAh / g or less 2.3V to 4.7V potential of the lithium composite metal oxide. Floor discharge Discharge capacity (, mAh / g) at Li / Li + cut-off at efficiency ( , ) and voltage 2.3 V and Layer capacitance at Li / Li + cut-off at voltage 4.7 V ( Q c mAh / g) preferably maintains the range as described above in terms of capacity.
또한， 이러한 리튬 복합 금속 산화물로는 Li2Mn03, Li2Ti03, Li2Ru03( In addition, as the lithium composite metal oxide is Li 2 Mn0 3, Li 2 Ti0 3, Li 2 Ru0 3 (
Li2Ir03l Li2Pt03) Li2Sn03) 및 Li2Zr 로 이루어진 군에서 선택된 1종 이상을 사용할 수 있다. One or more selected from the group consisting of Li 2 Ir0 3L Li 2 Pt0 3) Li 2 Sn0 3) and Li 2 Zr can be used.
전술한 바와 같이, 본 발명의 리튬 이온 커패시터용 양극 활물질은， 양극 활물질로 적용되는 탄소계 재료에 특정의 제 1 리튬 복합 금속 산화물 및 게 2 리튬 복합 금속 산화물을 양극 첨가제로 사용함으로써， 리튬이온 커패시터의 부피당 에너지 밀도 향상과 도핑 공정상 안전성 확보를 동시에 달성할 수 있다.  As described above, the positive electrode active material for a lithium ion capacitor of the present invention uses a specific first lithium composite metal oxide and a crab 2 lithium composite metal oxide as a positive electrode additive to a carbon-based material to be used as the positive electrode active material. The energy density per volume can be improved and the safety of the doping process can be achieved simultaneously.
즉， 도 2에 나타낸 바와 같이， 기존의 리튬 이온 커패시터는 전극에 리튬 금속을 라미네이트하여 전기적 단락을 통해， 리튬 이온을 음극 쪽으로 전달하는 리튬 공급원을 형성하는 것이다. 그러나, 본 발명의 리튬 이온 커패시터는 도 3에 나타낸 바와 같이， 특정의 양극 첨가제， 예컨대 Li2Mo03 및 Li2Ru03 등을 양극 활물질에 첨가하여 리튬 공급원으로 사용함으로써， 별도의 리튬 금속 라미네이트층을 형성하지 않고도 리튬 이온을 음극 쪽으로 효과적으로 전달하며 커패시터의 용량 및 에너지 밀도를 향상시킬 수 있도톡 하는 것을 특징으로 한다. 한편, 본 발명의 리튬 이온 커패시터용 양극 활물질로 사용되는 탄소계 재료는 비표면적이 큰 활성탄을 말하는 것으로 비표면적이 500 m7g 이상， 바람직하게는 700 m2/g 이상， 좀더 바람직하게는 1,000 m2/g 이상 또는 1,000 내지 3,000 m2/g가 될 수 있으며， 경우에 따라 2,500 m2/g 이하， 2,000 m2/g 이하가 될 수 있다. 이러한 탄소계 재료는 활성탄， 활성탄과 금속 산화물 복합체, 활성탄과 전도성 고분자 복합체 등을 1종 이상 사용할 수 있으며， 이중에서 활성탄이 전도성 측면에 바람직하다. That is, as shown in FIG. 2, the conventional lithium ion capacitor laminates lithium metal on an electrode to form a lithium source for transferring lithium ions to the cathode through an electrical short circuit. However, the lithium ion capacitor of the present invention, as shown in Figure 3, by adding a specific positive electrode additive, such as Li 2 Mo0 3 and Li 2 Ru0 3 to the positive electrode active material to use as a lithium source, a separate lithium metal laminate layer It is characterized in that to effectively transfer the lithium ions toward the cathode and to improve the capacity and energy density of the capacitor without forming a. On the other hand, the carbon-based material used as the positive electrode active material for lithium ion capacitor of the present invention refers to activated carbon having a large specific surface area, the specific surface area of 500 m7g or more, preferably 700 m 2 / g or more, more preferably 1,000 m 2 It may be more than / g or 1,000 to 3,000 m 2 / g, in some cases may be less than 2500 m 2 / g, 2,000 m 2 / g or less. Such carbon-based materials may be used at least one of activated carbon, activated carbon and metal oxide composite, activated carbon and conductive polymer composite, and among these, activated carbon is preferable for the conductive aspect.
본 발명에 따른 리튬 이온 커패시터용 양극 활물질은 탄소계 재료에 음극 재료의 리튬 공급원으로 양극 첨가제, 즉， 상기 리튬 복합 금속 산화물이 함께 흔합된 조성을 갖는다. 특히, 본 발명에 따른 리튬 이온 커패시터용 양극 활물질은 상기 제 1 리튬 복합 금속 산화물 0.5 내지 49.5 증량 %， 제 2 리튬 복합 금속 산화물 0.5 내지 49.5 중량 %， 및 탄소계 재료 50 내지 99 중량 ¾를 포함할 수 있다. 바람직하게는， 제 1 리튬 복합 금속 산화물 1 내지 34 중량 %, 제 2 리륨 복합 금속 산화물 1 내지 34 중량 %， 및 탄소계 재료 65 내지 98 중량 ¾>를 포함할 수 있고， 좀더 바람직하게는， 거 U 리튬 복합 금속 산화물 1.5 내지 18.5 중량 %, 제 2 리튬 복합 금속 산화물 1.5 내지 18.5 중량 %， 및 탄소계 재료 80 내지 97 중량 %를 포함할 수 있다. 여기서, 상기 제 1 리튬 복합 금속 산화물， 제 2 리튬 복합 금속 산화물, 및 탄소계 재료는 음극에 전기화학적으로 리튬을 효과적으로 도핑할 수 있도록 각각 0.5 중량 ¾ 이상, 0.5 중량 ¾> 이상， 및 99 중량 % 이하로 포함될 수 있으며， 우수한 전도도 확보 측면에서 각각 49.5 중량 % 이하， 49.5 중량 % 이하, 및 50 중량 % 이상으로 포함될 수 있다. The positive electrode active material for a lithium ion capacitor according to the present invention is a positive electrode additive, that is, the lithium composite metal as a lithium source of a negative electrode material to a carbon-based material The oxides have a composition mixed together. In particular, the cathode active material for a lithium ion capacitor according to the present invention may include 0.5 to 49.5% by weight of the first lithium composite metal oxide, 0.5 to 49.5% by weight of the second lithium composite metal oxide, and 50 to 99% by weight of a carbon-based material. Can be. Preferably, 1 to 34% by weight of the first lithium composite metal oxide, 1 to 34% by weight of the second lithium composite metal oxide, and 65 to 98% by weight of the carbon-based material, and more preferably, 1.5 to 18.5 weight% U lithium composite metal oxide, 1.5 to 18.5 weight% second lithium composite metal oxide, and 80 to 97 weight% carbonaceous materials. Here, the first lithium composite metal oxide, the second lithium composite metal oxide, and the carbon-based material are 0.5 weight ¾ or more, 0.5 weight ¾>, and 99 weight%, respectively, so as to effectively dope lithium to the negative electrode. It may be included in the following, in terms of ensuring excellent conductivity may be included in each of 49.5% by weight or less, 49.5% by weight or less, and 50% by weight or more.
상기 2종의 양극 첨가제의 중량비， 즉， 상기 제 1 리튬 복합 금속 산화물: 제 2 리튬 복합 금속 산화물의 중량비는 90:10 내지 10:90， 바람직하게는 80:20 내지 20:80, 좀더 바람직하게는 70:30 내지 30 :70가 될 수 있다. 상기 제 1 리튬 복합 금속 산화물과 제 2 리튬 복합 금속 산화물은 음극 도핑 용량 향상 측면에서 90:10 이상의 중량비로 사용할 수 있으며， 에너지 밀도 향상 측면에서 10:90 이하의 중량비로사용할 수 있다.  The weight ratio of the two positive electrode additives, that is, the weight ratio of the first lithium composite metal oxide to the second lithium composite metal oxide is 90:10 to 10:90, preferably 80:20 to 20:80, more preferably. May be from 70:30 to 30:70. The first lithium composite metal oxide and the second lithium composite metal oxide may be used in a weight ratio of 90:10 or more in terms of improving negative electrode doping capacity, and may be used in a weight ratio of 10:90 or less in terms of improving energy density.
한편, 상기 제 1 리튬 복합 금속 산화물 및 제 2 리튬 복합 금속 산화물은 탄소계 재료에 첨가되는 양에 따라 탄소계 재료 전체에 균일하게 흔합될 수도 있고, 일부에만 국부적으로 흔합될 수도 있다.  On the other hand, the first lithium composite metal oxide and the second lithium composite metal oxide may be uniformly mixed throughout the carbon-based material or locally mixed only in part depending on the amount added to the carbon-based material.
상기 제 1 리튬 복합 금속 산화물과 제 2 리튬 복합 금속 산화물의 총중량: 탄소계 재료의 중량비는 10:90 내지 90:10， 바람직하게는 15:85 내지 85:15， 좀더 바람직하게는 20:80 내지 80 :20가 될 수 있다. 상기 제 1 리튬 복합 금속 산화물과 제 2 리튬 복합 금속 산화물의 총중량 대비 탄소계 재료의 중량비는 에너지 밀도 향상 측면에서 10:90 이상이 될 수 있으며， 출력밀도 향상 측면에서 90:10 이하가 될 수 있다.  The weight ratio of the total weight of the first lithium composite metal oxide and the second lithium composite metal oxide to the carbonaceous material is 10:90 to 90:10, preferably 15:85 to 85:15, and more preferably 20:80 to 80:20. The weight ratio of the carbon-based material to the total weight of the first lithium composite metal oxide and the second lithium composite metal oxide may be 10:90 or more in terms of energy density improvement, and 90:10 or less in terms of power density improvement. .
전술한 바와 같이， 본 발명에 따른 양극 첨가제， 즉， 상기 화학식 1의 제 1 리튬 복합 금속 산화물 및 상기 화학식 2의 제 2 리튬 복합 금속 산화물은 전기화학적으로, 탄소계 음극 활물질에 리튬을 도핑할 수 있으며， 도핑된 리튬 이온이 커패시터 특성에 기여함으로써 샐 전압을 낮추어 리튬 이온 커패시터의 용량 및 에너지 밀도를 현저히 향상시킬 수 있다. 한편, 본 발명의 다른 구현예에 따라， 상기 리튬 이온 커패시터용 양극 활물질을 제조하는 방법이 제공된다. 상기 리튬 이온 커패시터용 양극 활물질의 제조 방법은 a) 리튬 화합물과 Mo, Fe, 및 Co으로 이루어진 군에서 선택된 1종 이상을 함유하는 전이금속 화합물을 흔합하고 열처리하여 하기의 화학식 3으로 표시되는 제 1 리튬 복합 금속 산화물 전구체를 생성시키는 단계; b) 하기의 화학식 3으로 표시되는 제 1 리튬 복합 금속 산화물 전구체를 환원하여 하기의 화학식 1로 표시되는 제 1 리튬 복합 금속 산화물을 생성시키는 단계; c) 리튬 화합물과 Mn, Ti, Ru, Ir, Pt, Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상을 함유하는 전이금속 화합물을 흔합하고 열처리하여 하기의 화학식 2으로 표시되는 제 2 리튬 복합 금속 산화물을 생성시키는 단계; 및 d) 상기 제 1 리튬 복합 금속 산화물 및 저 12 리튬 복합 금속 산화물을 탄소계 재료와 흔합하는 단계를 포함할 수 있다. As described above, the positive electrode additive according to the present invention, that is, the first lithium composite metal oxide of Formula 1 and the second lithium composite metal of Formula 2 The oxide may be electrochemically doped with lithium on the carbon-based anode active material, and the doped lithium ions contribute to the capacitor characteristics, thereby lowering the Sal voltage, thereby significantly improving the capacity and energy density of the lithium ion capacitor. On the other hand, according to another embodiment of the present invention, a method of manufacturing the positive electrode active material for the lithium ion capacitor is provided. The method of manufacturing a cathode active material for a lithium ion capacitor includes a) a first compound represented by the following Chemical Formula 3 by mixing and heat-treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and Mo, Fe, and Co. Generating a lithium composite metal oxide precursor; b) reducing the first lithium composite metal oxide precursor represented by Formula 3 to produce a first lithium composite metal oxide represented by Formula 1 below; c) a second lithium composite metal represented by the following Chemical Formula 2 by mixing and heat-treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and Mn, Ti, Ru, Ir, Pt, Sn, and Zr Producing an oxide; And d) mixing the first lithium composite metal oxide and the low 12 lithium composite metal oxide with a carbonaceous material.
[화학식 1]  [Formula 1]
LiaM^Oc  LiaM ^ Oc
[화학식 2]  [Formula 2]
LidM2 e0f Li d M 2 e 0 f
[화학식 3]  [Formula 3]
Lia'M1'b'0c' Li a 'M 1 'b'0c'
식 중,  In the formula,
a, b, c 는 각각 0<a<6, 0<b<3, 0<c<5이고, 바람직하게는 0<a<5 a, b, and c are each 0 <a <6, 0 <b <3, 0 <c <5, and preferably 0 <a <5
0<b<2, 및 0<c≤5, 좀더 바람직하게는 바람직하게는 0≤a≤5, 0<b<l, 및 0<c≤4가 될 수 있다. 0 <b <2, and 0 <c ≦ 5, more preferably 0 ≦ a ≦ 5, 0 <b <l, and 0 <c ≦ 4.
또한， 상기 화학식 2에서 d, e, f는 각각 0<d<2, 0<e<3, 0<£<4를 만족하며， 바람직하게는 l<d≤2, 0<e<2, 0<f<3가 될 수 있고, 좀더 바람직하게는 d=2, e=l, f=3가 될 수 있다. 상기 화학식 3에서 a', b'， c'는 각각 0<a'≤6, 0<b' <3, l<c'≤5이고， 바람직하게는 0≤a'≤5， 0<b' <2, 0<c'<4가 될 수 있고， 좀더 바람직하게는 0<a'<5, 0<b' <1, 0<c'≤4가 될 수 있다. In addition, in Formula 2, d, e, and f satisfy 0 <d <2, 0 <e <3, 0 <£ <4, respectively, and preferably, l <d ≦ 2, 0 <e <2, 0 <f <3, and more preferably d = 2, e = l, f = 3. In Formula 3, a ', b', c 'is 0 <a'≤6, 0 <b'<3, l <c'≤5, preferably 0≤a'≤5, 0 <b '<2, 0 <c'<4 More preferably, 0 <a '<5, 0 <b'<1, 0 <c '≦ 4.
상기 식 중， M1 및 M1'은 각각 Mo, Fe, 및 Co로 이루어진 군에서 선택된 1종 이상이고, M2은 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상이다. Wherein M 1 and M 1 ′ are each one or more selected from the group consisting of Mo, Fe, and Co, and M 2 is selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr 1 or more types.
본 발명에 따른 리튬 이온 커패시터용 양극 활물질의 제조 방법에서 제 1 리튬 복합 금속 산화물 및 그의 전구체， 제 2 리튬 복합 금속 산화물, 양극 활물질로서 탄소계 재료는 상기 리튬 이온 커패시터용 양극 활물질과 관련하여 전술한 바와 같이 적용할 수 있다.  In the method for manufacturing a cathode active material for a lithium ion capacitor according to the present invention, a first lithium composite metal oxide and a precursor thereof, a second lithium composite metal oxide, and a carbon-based material as a cathode active material are described above with reference to the cathode active material for a lithium ion capacitor. As applicable.
상기 a) 단계에서 화학식 3의 제 1 리튬 복합 금속 산화물 전구체는 Li2C03, LiOH, Li , 등의 리튬 화합물과 Mo03> Μο02) (ΝΗ4)6Μο7θ24 · 4H20, MoS2) Mo, FeO, Fe203, Fe304) Fe, CoO, Co 등의 전이금속 화합물을 흔합하여 열처리 공정으로 제조할 수 있다. 이때, 상기 리륨 화합물과 Mo, Fe, Co 자체 및 이를 함유하는 전이금속 화합물은 최종 생성되는 제 1 리튬 복합 금속 산화물 및 그의 전구체에서 지수값 a, b, c, a', b', c' 등을 고려한 몰비로 흔합될 수 있으며， 예컨대， 2:1 내지 7:1， 바람직하게는， 2:1 내지 5:1， 좀더 바람직하게는， 2:1 내지 4:1의 몰비로 흔합될 수 있다. 또한， 상기 리튬 화합물과 복합 금속 화합물을 흔합한 후에 열처리 공정은 400 내지 1,000 °C, 바람직하게는 500 내지 900 °C， 좀더 바람직하게는 500 내지 800 °C에서 수행할 수 있다, 또한， 상기 리튬 화합물과 복합 금속 화합물에 대한 열처리 공정은 0.5 내지 20 시간, 바람직하게는 1 내지 15 시간 좀더 바람직하게는 2 내지 10 시간 동안 수행할 수 있다. 상기 리튬 화합물과 복합 금속 화합물에 대한 열처리 공정은 산소 또는 공기 분위기 하에서 수행할 수 있다. In step a), the first lithium composite metal oxide precursor of Chemical Formula 3 is formed of a lithium compound such as Li 2 CO 3 , LiOH, Li, Mo0 3> Μο0 2) (ΝΗ 4 ) 6 Μο 7 θ2 4 · 4H 2 0, MoS 2) Mo, FeO, Fe 2 0 3 , Fe 3 0 4) Transition metal compounds such as Fe, CoO, Co can be mixed to prepare a heat treatment process. At this time, the lithium compound, Mo, Fe, Co itself and the transition metal compound containing the same, the exponential value a, b, c, a ', b', c ', etc. in the first lithium composite metal oxide and the precursor thereof produced Can be mixed in a molar ratio taking into account, for example, 2: 1 to 7: 1, preferably, 2: 1 to 5: 1, more preferably, in a molar ratio of 2: 1 to 4: 1. . In addition, after mixing the lithium compound and the composite metal compound, the heat treatment process may be performed at 400 to 1,000 ° C., preferably 500 to 900 ° C., more preferably 500 to 800 ° C. In addition, the lithium The heat treatment process for the compound and the composite metal compound may be performed for 0.5 to 20 hours, preferably 1 to 15 hours, more preferably 2 to 10 hours. The heat treatment process for the lithium compound and the composite metal compound may be performed in an oxygen or air atmosphere.
상기 b) 단계에서 화학식 3의 제 1 리튬 복합 금속 산화물 전구체를 환원하는 공정은 500 내지 1,000 °C, 바람직하게는 700 내지 900 °C , 좀더 바람직하게는 700 내지 800 °C에서 열처리하여 수행할 수 있다. 또한， 상기 열처리 공정은 2 내지 50 시간 동안, 바람직하게는 5 내지 30 시간， 좀더 바람직하게는 10 내지 20 시간 동안 수행할 수 있다. 이러한 열처리 공정 온도 및 시간을 유지함으로써 , 상기 화학식 3의 제 1 리튬 복합 금속 산화물 전구체를 화학식 1의 제 1 리튬 복합 금속 산화물로 효과적으로 전환할 수 있다. Reducing the first lithium composite metal oxide precursor of Formula 3 in step b) may be carried out by heat treatment at 500 to 1,000 ° C, preferably 700 to 900 ° C, more preferably 700 to 800 ° C. have. In addition, the heat treatment process may be performed for 2 to 50 hours, preferably 5 to 30 hours, more preferably 10 to 20 hours. Such heat treatment process By maintaining the temperature and time, it is possible to effectively convert the first lithium composite metal oxide precursor of Formula 3 to the first lithium composite metal oxide of Formula 1.
또한， 상기 제 1 리튬 복합 금속 산화물 전구체의 환원 공정은 아르곤 (Ar) 가스이나 질소 (N2) 둥 비활성 분위기 하에서 수행할 수 있다. 또한, 상기 비활성 가스 분위는 수소 ( ) 등이 추가로 포함될 수 있으며, 전체 공정 효율 향상 측면에서 5% 이하의 ¾가 포함된 조건으로 수행하는 것이 바람직하다. In addition, the reducing process of the first lithium composite metal oxide precursor may be performed under an inert atmosphere of argon (Ar) gas or nitrogen (N 2 ). In addition, the inert gas quantum may further include hydrogen () and the like, and in terms of improving overall process efficiency, it is preferable to carry out under a condition containing ¾ of 5% or less.
이러한 환원 공정을 통해， 상술한 바와 같은 특징을 갖는 화학식 1의 제 1 리튬 복합 금속 산화물을 생성시킬 수 있다.  Through this reduction process, the first lithium composite metal oxide of Chemical Formula 1 having the characteristics as described above may be generated.
상기 c) 단계에서 화학식 2를 갖는 제 2 리튬 복합 금속 산화물은 Li2C03> LiOH, Li, 둥의 리륨 화합물과 MnO, Mn, Ti02ᅳ Ti， Ru02) Ru, IrCl3, Ir02, PtCl4, PtCl2, Pt02, Pt(C5H702)2, Pt/C, Sn02, Sn, Zr02l Zr 등의 전이금속 화합물을 흔합하여 열처리 공정으로 제조할 수 있다. 이때， 상기 리튬 화합물과 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr 자체 및 이를 함유하는 전이금속 화합물은 최종 생성되는 제 2 리튬 복합 금속 산화물에서 지수값 d, e, f 등을 고려한 몰비로 흔합될 수 있으며， 예컨대， 2:1 내지 3:1， 바람직하게는， 2:1 내지 2.5:1， 좀더 바람직하게는， 2:1 내지 2.3:1의 몰비로 흔합될 수 있다. In step c), the second lithium composite metal oxide having Chemical Formula 2 may be selected from Li 2 CO 3> LiOH, Li, a round lithium compound, and MnO, Mn, Ti0 2 ᅳ Ti, Ru0 2) Ru, IrCl 3 , Ir0 2 , Transition metal compounds such as PtCl 4 , PtCl 2 , Pt0 2 , Pt (C 5 H 7 0 2 ) 2, Pt / C, Sn0 2 , Sn, Zr0 2l Zr may be mixed and prepared by a heat treatment process. At this time, the lithium compound and Mn, Ti, Ru, Ir, Pt, Sn, and Zr itself and the transition metal compound containing the same, the molar ratio in consideration of the index values d, e, f, etc. in the second lithium composite metal oxide to be produced Can be mixed, for example, 2: 1 to 3: 1, preferably 2: 1 to 2.5: 1, more preferably 2: 1 to 2.3: 1.
또한， 상기 리튬 화합물과 복합 금속 화합물을 흔합한 후에 열처리 공정은 500 내지 1，000 °C, 바람직하게는 700 내지 900 °C , 좀더 바람직하게는 700 내지 800 °C에서 수행할 수 있다, 또한， 상기 열처리 공정은 2 내지 50 시간 동안, 바람직하게는 5 내지 30 시간， 좀더 바람직하게는 10 내지 20 시간 동안 수행할 수 있다. 상기 리튬 화합물과 복합 금속 화합물에 대한 열처리 공정은 산소 또는 공기 분위기 하에서 수행할 수 있다. 이러한 열처리 공정 온도 및 시간을 유지함으로써, 상기 화학식 2의 제 2 리튬 복합 금속 산화물을 효과적으로 생성시킬 수 있다. Further, after mixing the lithium compound and the composite metal compound, the heat treatment process may be performed at 500 to 1,000 ° C, preferably 700 to 900 ° C, more preferably 700 to 800 ° C. The heat treatment process may be performed for 2 to 50 hours, preferably 5 to 30 hours, more preferably 10 to 20 hours. The heat treatment process for the lithium compound and the composite metal compound may be performed in an oxygen or air atmosphere. By maintaining the temperature and time of the heat treatment process, it is possible to effectively produce the second lithium composite metal oxide of the formula (2).
본 발명에 따른 리튬 이온 커패시터용 양극 활물질의 제조 방법에서 상기 계 1 리튬 복합 금속 산화물과 제 2 리튬 복합 금속 산화물을 탄소계 재료와 흔합하는 상기 d) 단계는 다양한 물리적인 흔합 방법으로 수행할 수 있다. 이때， 상기 제 1 리튬 복합 금속 산화물, 제 2 리튬 복합 금속 산화물, 및 양극 활물질로서 탄소계 재료는 각각 0.5 내지 49.5 중량 ¾>， 0.5 내지 49.5 중량 %, 및 50 내지 99 중량 %로 흔합될 수 있다. 또한ᅳ 바람직하게는 제 1 리튬 복합 금속 산화물 1 내지 34 중량 %， 게 2 리륨 복합 금속 산화물 1 내지 34 중량 %, 및 탄소계 재료 65 내지 98 중량 ¾로 흔합될 수 있다. 좀더 바람직하게는, 제 1 리튬 복합 금속 산화물 1.5 내지 18.5 중량 %， 제 2 리튬 복합 금속 산화물 1.5 내지 18.5 중량 ¾, 및 탄소계 재료 80 내지 97 중량 %로 흔합될 수 있다. 한편， 본 발명의 또다른 구현예에 따라， 상기 리튬 이온 커패시터용 양극 활물질을 포함하는 리튬 이온 커패시터가 제공된다. 상기 리튬 이온 커패시터는 초기 비가역 용량이 큰 특정의 제 1 리튬 복합 금속 산화물과 리튬이온 커패시터의 작동전위 영역에서 가역성이 높은 특정의 제 2 리튬 복합 금속 산화물을 양극 첨가제로 사용함으로써 별도의 리튬 금속층을 형성하지 않고도 리튬 이온을 음극 쪽으로 효과적으로 전달할 수 있도록 하는 것을 특징으로 한다. 이로써， 본 발명에 따른 리튬 이온 커패시터는 전기화학적으로 방식으로 음극에 리튬 이온을 도핑하여 리튬 금속 발생에 따른 공정 안전성을 개선함과 동시에， 커패시터의 용량 및 에너지 밀도를 더욱 향상시키는 효과를 확보할 수 있다. In the method of manufacturing a cathode active material for a lithium ion capacitor according to the present invention, the step d) of mixing the first lithium composite metal oxide and the second lithium composite metal oxide with a carbon-based material may be performed by various physical mixing methods. have. In this case, the carbon-based material as the first lithium composite metal oxide, the second lithium composite metal oxide, and the positive electrode active material may be mixed at 0.5 to 49.5 weight ¾>, 0.5 to 49.5 weight%, and 50 to 99 weight%, respectively. . Also preferably 1 to 34% by weight of the first lithium composite metal oxide, 1 to 34% by weight of the germanium lithium composite metal oxide, and 65 to 98% by weight of the carbonaceous material. More preferably, 1.5 to 18.5 wt% of the first lithium composite metal oxide, 1.5 to 18.5 wt% of the second lithium composite metal oxide, and 80 to 97 wt% of the carbonaceous material may be mixed. On the other hand, according to another embodiment of the present invention, a lithium ion capacitor including the cathode active material for the lithium ion capacitor is provided. The lithium ion capacitor forms a separate lithium metal layer by using a specific first lithium composite metal oxide having a large initial irreversible capacity and a second lithium composite metal oxide having a high reversibility as an anode additive in an operating potential region of the lithium ion capacitor. It is characterized in that it can effectively transfer lithium ions to the negative electrode without having to. As a result, the lithium ion capacitor according to the present invention can improve the process safety according to the generation of lithium metal by doping lithium ions to the cathode in an electrochemical manner, and at the same time, it is possible to secure the effect of further improving the capacity and energy density of the capacitor. have.
특히， 본 발명의 리튬 이온 커패시터는 양극 활물질을 포함하는 양극 (cathode); 음극 활물질을 포함하는 음극 (anode); 및 양극 및 음극 사이의 격리막 (separator)을 포함하고， 상기 음극은 양극으로부터만 리튬 이온을 공급받는 것이 될 수 있다.  In particular, the lithium ion capacitor of the present invention includes a cathode including a cathode active material; An anode including an anode active material; And a separator between the anode and the cathode, wherein the cathode may be supplied with lithium ions only from the anode.
이때， "양극으로부터만 리튬 이온을 공급받는 것"이라 함은， 도 3에 나타낸 바와 같이, 음극에 리튬 이온을 공급하기 위한 별도의 리튬 이온 공급층, 예를 들어, 음극에 포함되거나 음극상에 적층 (코팅 또는 라미네이트)되는 별도의 리튬 금속층이 커패시터에 포함되지 않고， 상기 음극은 양극 활물질에 포함된 리튬 복합 금속 산화물에서 유래한 리튬 이온만을 공급받음을 의미할 수 있다.  At this time, "receiving lithium ions only from the positive electrode", as shown in Figure 3, is included in a separate lithium ion supply layer for supplying lithium ions to the negative electrode, for example, the negative electrode or on the negative electrode A separate lithium metal layer stacked (coated or laminated) is not included in the capacitor, and the negative electrode may mean that only lithium ions derived from the lithium composite metal oxide included in the positive electrode active material are supplied.
본 발명의 리튬 이온 커패시터는 0V 내지 5V의 전압영역에서 리튬 이온을 가역적으로 삽입 또는 탈리하는 탄소계 음극 활물질올 포함할 수 있다. The lithium ion capacitor of the present invention is lithium in the voltage range of 0V to 5V It may include a carbon-based negative electrode active material for reversibly inserting or detaching ions.
본 발명에 따라 상기 제 1 리튬 복합 금속 산화물 및 제 2 리튬 복합 금속 산화물을 포함하는 양극 활물질과 리튬 이온올 가역적으로 삽입 또는 탈리하는 탄소계 음극 활물질을 포함하는 리튬 이온 커패시터를 구성하여, 음극에 리튬을 효과적으로 도핑하고자 하는 것을 특징으로 한다. 그러나， 리튬 이온 커패시터의 음극 활물질이 아닌 기존의 활성탄 음극을 사용하는 하이브리드 커패시터 등에 본 발명에 따른 제 1 리튬 복합 금속 산화물 등을 양극 첨가제로 적용하게 되면 (양극: 활성탄 +Li2MoO^ 음극: 활성탄), 상기 양극 첨가제 자체의 큰 초기 비가역 특성 때문에 커패시터의 용량 및 수명 성능이 현저하게 저하되는 문제가 발생할 수 있다. 또한, 본 발명에 따른 제 2 리튬 복합 금속 산화물 등을 상기 하이브리드 커패시터 등에 양극 첨가제로 적용하게 되면 (양극: 활성탄 +Li2Ru03, 음극: 활성탄), 상기 양극 첨가제 자체의 가역적인 리튬 이온 (Li+)의 삽입 및 탈리 특성 때문에 에너지 밀도가 향상 하는 효과가 발생할 수 있다. According to the present invention, a lithium ion capacitor including a positive electrode active material including the first lithium composite metal oxide and the second lithium composite metal oxide and a carbon-based negative electrode active material reversibly intercalating or deintercalating with lithium ionol may be formed. Characterized in that to effectively doping. However, when the first lithium composite metal oxide or the like according to the present invention is applied as a positive electrode additive to a hybrid capacitor using a conventional activated carbon negative electrode which is not a negative electrode active material of a lithium ion capacitor (positive electrode: activated carbon + Li 2 MoO ^ negative electrode: activated carbon) ), Due to the large initial irreversible nature of the positive electrode additive itself may cause a problem that the capacity and life performance of the capacitor is significantly reduced. In addition, when the second lithium composite metal oxide or the like according to the present invention is applied as a positive electrode additive to the hybrid capacitor or the like (anode: activated carbon + Li 2 Ru0 3 , negative electrode: activated carbon), the reversible lithium ions (Li + ), Due to the insertion and desorption properties, the effect of improving energy density may occur.
한편, 본 발명에 따른 리튬 이온 커패시터는 전기화학적 방법으로 측정한 층방전 용량이 50 F/g 이상， 바람직하게는 70 F/g 이상， 좀더 바람직하게는 100 F/g 이상 또는 100 내지 800 F/g의 우수한 성능을 나타낼 수 있으며， 경우에 따라 750 F/g 이하， 700 F/g 이하를 나타낼 수 있다. 본 발명에 따른 리튬 이온 커패시터는 상술한 바와 같이， 양극 활물질에 초기 비가역 용량이 큰 리튬 복합 금속 산화물을 사용하여 음극에 전기화학적으로 리튬을 도핑시킴으로써， 별도의 리튬 공급원으로 리튬 금속 전극이나 리튬 금속 등을 사용하지 않고 제조할 수 있다. 이하 본 발명의 리튬 이온 커패시터용 양극 활물질 및 이를 이용한 리튬 이온 커패시터의 제조 방법에 대한 구체적인 일례를 보다 상세하게 설명하면 다음과 같다.  Meanwhile, the lithium ion capacitor according to the present invention has a layer discharge capacity measured by an electrochemical method of 50 F / g or more, preferably 70 F / g or more, more preferably 100 F / g or more or 100 to 800 F /. It may exhibit excellent performance of g, and in some cases, 750 F / g or less, and 700 F / g or less. As described above, the lithium ion capacitor according to the present invention uses a lithium composite metal oxide having a large initial irreversible capacity in a positive electrode active material to electrochemically dope lithium in a negative electrode, thereby providing a lithium metal electrode or a lithium metal as a separate lithium source. It can be prepared without using. Hereinafter, a specific example of a cathode active material for a lithium ion capacitor and a method of manufacturing a lithium ion capacitor using the same according to the present invention will be described in detail.
본 발명에 따른 리튬 이온 커패시터용 양극 활물질의 제조 방법은 Li2Mo04 전구체를 준비하는 제 1 단계와, 준비된 Li2Mo04 전구체를 환원 처리하여 Li2Mo03를 합성하는 제 2 단계와， Li2Ru03를 합성하는 제 3 단계와, Li2Mo03와 탄소계 재료를 흔합하여 양극 활물질을 형성하는 제 4 단계를 포함한다. And a method of manufacturing the positive electrode active material for a lithium ion capacitor according to the invention the second step of synthesizing a first step, and a ready-Li 2 Mo0 Li 2 Mo0 3 processes the reduction of 4 precursor to prepare a Li 2 Mo0 4 precursor, Li A third step of synthesizing 2 Ru0 3 , And a fourth step of mixing the Li 2 Mo 3 and the carbon-based material to form a cathode active material.
먼저， Li2Mo04 전구체를 준비하는 제 1 단계는 좀더 구체적으로는， Li2C03와 Mo03를 1:1 몰비로 흔합하는 제 1-1 단계와, Li2C03와 Mo03의 흔합물을 공기 중에서 400~1000 °C에서 1~6시간 열처리하여 Li2Mo04 전구체를 형성하는 제 1-2 단계를 포함한다. 이때, 상기 제 1-2 단계는 공기 중에서 진행될 수 있다. First, the first step of preparing the Li 2 Mo 0 4 precursor is more specifically, the first 1-step of mixing Li 2 C0 3 and Mo0 3 in a 1: 1 molar ratio, and the marks of Li 2 C0 3 and Mo0 3 The mixture is heat-treated at 400-1000 ° C. for 1-6 hours in air to form the first 1-2 steps to form a Li 2 Mo 4 precursor. In this case, the first step 1-2 may be performed in the air.
다음으로 상기 제 2 단계는 Li2Mo04에 10중량 % 이하의 Super-P를 기계적 밀링을 통해 균일하게 흔합하는 제 2-1 단계와， Li2Mo04와 Super-P의 흔합물을 10% 이하의 ¾가스가 포함된 Ar 분위기에서 500~1000 °C에서 10~30 시간 열처리하여 Li2Mo03를 합성하는 제 2— 2 단계를 포함한다. 이때, 상기 제 2-1 단계에서 기계적 밀링에 따른 흔합 단계는 30분 정도 진행될 수 있다. 기계적 밀링 수단으로는， 예를 들면， 유발， 볼 밀， 진동 밀， 위성 볼 밀， 튜브 밀， 라드 밀 제트 밀， 헤머 밀 등이 사용될 수 있다. 그리고， 상기 제 2-2 단계에 따른 환원 분위기는 5~10>의 ¾ 가스가 포함된 Ar2 분위기 하에서 수행될 수 있다. Next, the second step is the 2-1 step of uniformly mixing 10 wt% or less of Super-P in Li 2 Mo0 4 through mechanical milling, and the mixture of Li 2 Mo0 4 and Super-P 10% The second to second step of synthesizing Li 2 Mo0 3 by heat treatment at 500 ~ 1000 ° C for 10 to 30 hours in an Ar atmosphere containing the following ¾ gas. At this time, the mixing step according to the mechanical milling in the 2-1 step may proceed for about 30 minutes. As the mechanical milling means, for example, a mortar, a ball mill, a vibration mill, a satellite ball mill, a tube mill, a rod mill jet mill, a hammer mill, or the like can be used. In addition, the reducing atmosphere according to step 2-2 may be performed under an Ar 2 atmosphere containing ¾ gas of 5˜10>.
또한， Li2Ru03를 합성하는 제 3 단계는 좀더 구체적으로는， Li2C03와 Ru02를 1:1 몰비로 흔합하는 제 3-1 단계와， Li2C03와 Ru02의 흔합물을 공기 중에서 500~1000 °C에서 10~30 시간 열처리하여 Li2Ru¾를 합성하는 제 3-2 단계를 포함한다. 이때， 상기 제 3-2단계는 공기 중에서 진행될 수 있다. 그리고， 상기 제 4 단계는 상기 제 2 단계 및 제 3 단계에서 합성된 Li2Mo03 및 Li2Ru03를 탄소계 재료와 흔합하여 리튬 이온 커패시터용 양극 활물질을 형성한다. 이때 리튬 이온 커패시터용 양극 활물질은 Li2Mo033-50 중량 %와, Li2Ru 3-30 중량 %， 탄소계 재료 60~94 중량 %를 흔합하여 형성할 수 있다. 바람직하게는 Li2Mo03 3-30 중량 %와, Li2Ru¾ 3~10 중량 %, 탄소계 재료 60-94 중량 %로 흔합하는 것이다. 그리고 전기화학적 리튬 도핑은 5V 이하의 전압영역에서 진행될 수 있다. Further, the third step of synthesizing Li 2 Ru 0 3 is more specifically, the 3-1 step of mixing Li 2 C0 3 and Ru0 2 in a 1: 1 molar ratio, and a mixture of Li 2 C0 3 and Ru0 2 It comprises a 3-2 step of synthesizing Li 2 Ru¾ by heat treatment at 500 to 1000 ° C for 10 to 30 hours in air. In this case, step 3-2 may be performed in the air. In the fourth step, Li 2 Mo 0 3 and Li 2 Ru0 3 synthesized in the second and third steps are mixed with a carbon-based material to form a cathode active material for a lithium ion capacitor. In this case, the cathode active material for a lithium ion capacitor may be formed by mixing Li 2 Mo0 3 3-50 weight%, Li 2 Ru 3-30 weight%, and carbonaceous material 60 to 94 weight%. Preferably 3 to 30% by weight of Li 2 Mo0 3 , 3 to 10% by weight of Li 2 Ru¾, 60-94% by weight of the carbon-based material. The electrochemical lithium doping may be performed in a voltage range of 5V or less.
이와 같은 본 발명에 따른 양극 첨가제를 이용한 리튬 이온 커패시터용 양극 활물질의 리튬 도핑 특성 및 용량특성을 평가하기 위해서， 아래와 같이 리튬 이온 커패시터를 제조하였다. 이때， 전술한 바와 같이 본 발명의 구체적인 일례에 따라 제조된 양극 활물질 92 중량 %와 바인더 PVdF를 8 중량 %로 하여， NMP을 용매로 슬러리 (slurry)를 제조하였다. 이 슬러리를 두께 20 ΛΠ의 알루미늄 메쉬 (A1 mesh)에 도포하여 건조 후 프레스로 압밀화시켜, 진공상에서 120 \：로 16 시간 동안 건조하여 직경 12 mm의 원판으로 전극을 제조하였다. 상대극으로는 직경 12 mm로 편칭 (punching)을 한 리튬 금속박을， 격리막으로는 PP 필름을 사용하였다. 전해액으로는 1M의 LiPF6의 EC/DMC를 3:7로 배합한 흔합 용액을 사용하였다. 전해액을 격리막에 함침시킨 후, 이 격리막을 작용극과 상대극 사이에 끼운 후 스테인레스 (SUS) 제품의 케이스를 전극 평가용 시험 샐, 즉 비수계 리튬 이온 커패시터 반쪽 셀로 제조하였다. In order to evaluate the lithium doping characteristics and capacity characteristics of the cathode active material for a lithium ion capacitor using the cathode additive according to the present invention, a lithium ion capacitor was manufactured as follows. At this time, as described above, 92 wt% of the positive electrode active material prepared according to a specific example of the present invention and binder PVdF were 8 wt%, and a slurry was prepared using NMP as a solvent. The slurry was applied to an aluminum mesh (A1 mesh) having a thickness of 20 ΛΠ, dried and compacted by a press, dried for 16 hours at 120 \: in a vacuum to prepare an electrode with a disc of 12 mm in diameter. As the counter electrode, lithium metal foil punched to a diameter of 12 mm was used, and a PP film was used as the separator. As a electrolyte solution, a mixed solution in which EC / DMC of 1M LiPF 6 was mixed at 3: 7 was used. After the electrolyte solution was impregnated with the separator, the separator was sandwiched between the working electrode and the counter electrode, and a case of a stainless steel (SUS) product was prepared as a test cell for electrode evaluation, that is, a non-aqueous lithium ion capacitor half cell.
여기서, 풀 셀로 적용할 경우 음극 활물질로 탄소계 재료인 인조혹연， 천연흑연， 흑연화탄소 섬유， 혹연화 메조카본마이크로비드, 석유코크스， 수지소성체， 탄소섬유， 열분해 탄소 등의 결정질이나 비정질 탄소로 이루어진 물질 중에서 적어도 하나가 사용될 수 있다.  Here, when applied as a full cell, the negative electrode active material is a crystalline or amorphous carbon such as artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbead, petroleum coke, resinous body, carbon fiber, pyrolytic carbon, etc. At least one of the materials may be used.
상기 양극 첨가제는 5V 이하의 전압영역에서 가역적으로 리튬 이온은 삽입 또는 탈리하며， 5V 이하의 전압영역에서 구동되는 비수계 전해질이 적용된 리튬 이온 커패시터에 적용이 가능하다.  The positive electrode additive reversibly inserts or detaches lithium ions in a voltage range of 5V or less, and is applicable to a lithium ion capacitor to which a non-aqueous electrolyte is driven in a voltage range of 5V or less.
한편， 양극 극판의 제작은 본 발명에 따른 양극 첨가제를 포함하는 양극 활물질의 분말에, 필요에 따라서， 도전제, 바인더, 증점제， 필러， 분산제， 이온 도전제, 압력 증강제 등과 통상 이용되고 있는 1종 또는 2종 이상의 첨가 성분을 첨가해, 물이나 유기 용매 등의 적당한 용매에 의해 슬러리 내지 페이스트 (paste)화 한다. 이렇게 얻은 슬러리 또는 페이스트를 전극 지지 기판에 닥터 블레이드법 등을 이용해 도포 및 건조한 후, 압연 를 등으로 프레스한 것을 양극 극판으로서 사용한다.  On the other hand, the production of the positive electrode plate is one kind commonly used in the powder of the positive electrode active material containing the positive electrode additive according to the present invention, if necessary, a conductive agent, a binder, a thickener, a filler, a dispersant, an ion conductive agent, a pressure enhancer, etc. Or 2 or more types of addition components are added, and it slurry-pastes with suitable solvents, such as water and an organic solvent. The slurry or paste thus obtained is coated and dried on an electrode support substrate using a doctor blade method or the like, and then pressed by rolling or the like is used as the positive electrode plate.
여기서, 바인더로는 예컨대， 스티렌 부타디엔 러버 (SBR, styrene butadiene rubber) 등의 고무계 바인더나， 폴리에틸렌테트라플루오라이드, 폴리비닐리덴 플루오라이드 (PVdF, polyvinyl i dene fluoride) 등의 불소계 수지, 폴리프로필렌, 폴리에틸렌 등의 열가소성 수지， 아크릴계 수지 등을 사용할 수 있다. 바인더의 사용량은 상기 양극 활물질의 전기 전도도， 전극 형상 등에 따라 달라질 수 있지만， 상기 양극 활물질 100 중량부에 대해 2 내지 40중량부의 함량으로 사용할 수 있다. The binder may be, for example, a rubber binder such as styrene butadiene rubber (SBR), a fluorine resin such as polyethylene tetrafluoride or polyvinylidene fluoride (PVdF), polypropylene, polyethylene, or the like. Thermoplastic resins, acrylic resins, etc. can be used. The amount of the binder used is the electrical conductivity of the positive electrode active material, the electrode Although it may vary depending on the shape, it can be used in an amount of 2 to 40 parts by weight based on 100 parts by weight of the positive electrode active material.
또한, 필요에 따라 도전제로는 혹연， 카본 블랙， 아세틸렌 블랙， 케트젠 블택 (Ketjen Black), 탄소섬유, 금속 분말 등을 들 수 있다. 도전재의 사용량은 양극 활물질의 전기 전도도, 전극 형상 등에 의해 상이하지만， 상기 양극 활물질 100 중량부에 대해 2 내지 40 중량부의 함량으로 사용할 수 있다.  If necessary, examples of the conductive agent include alum, carbon black, acetylene black, Ketjen black, carbon fiber, and metal powder. The amount of the conductive material used varies depending on the electrical conductivity, electrode shape, and the like of the positive electrode active material, but may be used in an amount of 2 to 40 parts by weight based on 100 parts by weight of the positive electrode active material.
이외에， 증점제로 카르복시메틸샐를로오스 (CMC, carboxylmethyl cellulose) 등을 사용할 수 있다.  In addition, carboxymethyl cellulose (CMC) may be used as the thickener.
이때， 전극 지지 기판 ('집전체 : Current Col lector '라고도 함)은, 동, 니켈, 스텐레스 강철, 알루미늄 등의 박, 시트， 메쉬 혹은 탄소섬유 둥으로 구성할 수 있다.  At this time, the electrode support substrate (also referred to as 'current collector') may be composed of copper, nickel, stainless steel, aluminum, foil, sheet, mesh or carbon fiber.
이와 같이 제조된 양극을 이용하여 리튬 이온 커패시터를 제작한다. 리튬 이온 커패시터의 형태는 코인， 버튼, 시트， 파우치, 원통형, 각형 등 어느 것이라도 좋다. 리튬 이온 커패시터의 음극， 전해질, 격리막 둥은 기존 리튬이차전지에 적용할 수 있는 것으로 알려진 범위에서 선택하여 사용할 수 있다.  A lithium ion capacitor is manufactured using the anode prepared as described above. The form of the lithium ion capacitor may be any one of a coin, a button, a sheet, a pouch, a cylinder, a square, and the like. The negative electrode, electrolyte, and separator of the lithium ion capacitor may be selected and used in a range known to be applicable to a conventional lithium secondary battery.
전해액은 유기용매에 리튬염을 용해시킨 비수계 전해액， 무기 고체 전해질, 무기 고체 전해질의. 복합재 등을 사용할 수 있으며, 이것에 한정되는 것은 아니다.  The electrolyte solution is a non-aqueous electrolyte, an inorganic solid electrolyte, or an inorganic solid electrolyte in which lithium salt is dissolved in an organic solvent. Composite materials, etc. can be used, It is not limited to this.
여기서 비수계 전해액의 용매로서는 카보네이트 에스테르，. 에테르 또는 케톤을 사용할 수 있다. 상기 카보네이트로는 디메틸 카보네이트 (DMC), 디에틸 카보네이트 (DEC), 디프로필 카보네이트 (DPC), 메틸프로필 카보네이트 (MPC), 에틸프로필 카보네이트 (EPC), 메틸에틸 카보네이트 (MEC) 에틸렌 카보네이트 (EC), 프로필렌 카보네이트 (PC) 부틸렌 카보네이트 (BC) 등이 사용될 수 있다. 에스테르로는 부티로락톤 (BL), 데카놀라이드 (decanolide), 발레로락톤 (valerolactone) , 메발로노락톤 (mevalonolactone) , ^"프로락톤 (caprolactone) n-데틸 아세테이트, n-에틸 아세테이트， n-프로필 아세테이트 등이 사용될 수 있다. 에테르로는 디부틸 에테르 등이 사용될 수 있다. 케톤으로는 폴리메틸비닐 케톤이 사용될 수 있다. 또한 본 발명에 따른 비수계 전해액은 비수성 유기용매의 종류에 한정되는 것은 아니다. The solvent of the non-aqueous electrolyte solution is carbonate ester. Ethers or ketones may be used. The carbonates include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC) ethylene carbonate (EC), Propylene carbonate (PC) butylene carbonate (BC) and the like can be used. Esters include butyrolactone (BL), decanolide, valerolactone, mevalonolactone, ^ "caprolactone n-decyl acetate, n-ethyl acetate, n -Propyl acetate, etc. As the ether, dibutyl ether can be used, etc. As the ketone, polymethylvinyl Ketones can be used. In addition, the non-aqueous electrolyte according to the present invention is not limited to the type of non-aqueous organic solvent.
비수계 전해액의 리튬염의 예로서는， LiPF6> LiBF4, LiSbF6, LiAsF6, LiC104, L1CF3SO3, LiN(CF3S02)2) LiN(C2F5S02)2, LiA104, LiAlCl4> LiN(CxF2x+1S02)(CyF2x+1S02) (여기서， x 및 y는 자연수임) 및 LiS03CF3로 이루어진 군에서 선택되는 것을 하나 이상 또는 이들의 흔합물을 포함한다. 그리고， 격리막으로는 폴리프로필렌 (PP) 또는 폴리에틸렌 (PE) 등의 폴리올레핀 (Polyolefin)으로부터 제조되는 다공성 필름이나， 부직포 등의 다공성재를 사용할 수 있다. Examples of the lithium salt of the non-aqueous electrolyte solution include LiPF 6> LiBF 4 , LiSbF 6 , LiAsF 6 , LiC10 4 , L1CF3SO3, LiN (CF 3 S0 2 ) 2) LiN (C 2 F 5 S0 2 ) 2 , LiA10 4 , LiAlCl 4 > LiN (C x F 2x + 1 S0 2 ) (CyF 2x + 1 S0 2 ) (where x and y are natural numbers) and LiS0 3 CF 3 is selected from the group consisting of one or more Include. As the separator, a porous film made from polyolefin such as polypropylene (PP) or polyethylene (PE), or a porous material such as nonwoven fabric can be used.
본 발명에 있어서 상기 기재된 내용 이외의 사항은 필요에 따라 가감이 가능한 것이므로, 본 발명에서는 특별히 한정하지 아니한다.  In the present invention, matters other than those described above can be added or subtracted as necessary, and therefore the present invention is not particularly limited.
【발명의 효과】  【Effects of the Invention】
본 발명에 따르면， 리튬 이온 커패시터의 양극 활물질용 탄소계 재료에 리륨 공급원으로 초기 비가역용량이 큰 양극 첨가제와 리튬이온 커패시터의 작동전위 영역에서 에너지 밀도 향상을 위해 가역성이 높은 양극 첨가제를 첨가하여 전기화학적으로 리튬을 탄소계 음극 활물질에 도핑함으로써， 리튬 이온 커패시터의 향상된 층전 및 방전 용량을 확보할 수 있다.  According to the present invention, an electrochemical is added to a carbon-based material for a positive electrode active material of a lithium ion capacitor by adding a positive electrode additive having a large initial irreversible capacity as a source of lithium and a high reversible positive electrode additive to improve energy density in the operating potential region of the lithium ion capacitor. By doping lithium to the carbon-based negative electrode active material, it is possible to ensure improved layer charge and discharge capacity of the lithium ion capacitor.
또한 본 발명에 따른 양극 첨가제를 이용한 리튬의 도핑은 음극의 전위를 낮추어 리튬 이온 커패시터의 에너지 밀도를 향상시킬 수 있는 효과가 있다.  In addition, the doping of lithium using the positive electrode additive according to the present invention has the effect of improving the energy density of the lithium ion capacitor by lowering the potential of the negative electrode.
또한 단순한 리튬 도핑 공정으로 인하여 리튬 이온 커패시터의 생산 효율성 또한 향상시킬 수 있는 효과가 있다.  In addition, a simple lithium doping process has the effect of improving the production efficiency of the lithium ion capacitor.
【도면의 간단한 설명】  [Brief Description of Drawings]
도 1은 전기 이중층 커패시터 (EDLC: Electric Double Layer 1 is an electric double layer capacitor (EDLC)
Capacitor), 하이브리드 커패시터, 및 리튬 이온 커패시터 (UC: lithium ion capacitor)의 일반적인 층방전 특성을 나타낸 모식도이다. It is a schematic diagram showing the general layer discharge characteristics of a capacitor, a hybrid capacitor, and a lithium ion capacitor (UC).
도 2는 종래의 리튬 이온 커패시터 (LIC: lithium ion capacitor)가 갖는 일반적인 구조를 나타낸 모식도이다.  2 is a schematic diagram showing a general structure of a conventional lithium ion capacitor (LIC).
도 3은 본 발명에 따른 리튬 이온 커패시터 (UC: lithium ion capacitor)의 구조를 나타낸 모식도이다. 3 is a lithium ion capacitor (UC: lithium ion) according to the present invention A schematic diagram showing the structure of a capacitor).
도 4는 본 발명에 따른 양극 첨가제의 초기 층방전 효율 관련 참조용 그래프이다.  Figure 4 is a reference graph for the initial layer discharge efficiency of the positive electrode additive according to the present invention.
도 5는 본 발명의 실시예 1에 따라 합성된 양극 첨가제 Li2Mo¾ 및 Li2Ru03에 대한 XRD분석 그래프이다. 5 is an XRD analysis graph of the positive electrode additives Li 2 Mo¾ and Li 2 Ru0 3 synthesized according to Example 1 of the present invention.
도 6는 본 발명의 실시예 1에 따라 합성된 양극 첨가제 Li2Mo03 및 Li2Ru03의 FESEM 및 HRTEM 사진이다 [a) Li2Mo03, b) Li2 u03, c) Li2Mo03l d) Li2Ru03, e) Li2Mo03, f) Li2Ru03] . Figure 6 is a FESEM and HRTEM picture of the positive electrode additive Li 2 Mo0 3 and Li 2 Ru0 3 synthesized according to Example 1 of the present invention [a) Li 2 Mo0 3 , b) Li 2 u0 3 , c) Li 2 Mo0 3l d) Li 2 Ru 0 3 , e) Li 2 Mo 0 3 , f) Li 2 Ru 0 3 ].
도 7은 본 발명의 실시예 1~2 및 비교예 1~2에 따른 리튬 이은 커패시터의 용량 평가 결과를 나타낸 그래프이다.  7 is a graph illustrating a capacity evaluation result of lithium silver capacitors according to Examples 1 and 2 and Comparative Examples 1 and 2 of the present invention.
도 8은 본 발명의 실시예 1~2 및 비교예 1~2에 따른 리튬 이온 커패시터의 1000 cycle수명 평가 결과를 나타낸 그래프이다.  8 is a graph showing the results of 1000 cycle life evaluation of the lithium ion capacitor according to Examples 1 to 2 and Comparative Examples 1 to 2 of the present invention.
【발명을 실시하기 위한 구체적인 내용】  [Specific contents to carry out invention]
이하， 본 발명의 이해를 돕기 위하여 바람직한 실시예를 제시하나ᅳ 하기 실시예는 본 발명을 예시하는 것일 뿐 본 발명의 범위가 하기 실시예에 한정되는 것은 아니다. 실시예 1  Or less, to present a preferred embodiment to aid the understanding of the present invention, the following examples are merely to illustrate the present invention is not limited to the scope of the following examples. Example 1
리튬이온 커패시터의 음극에 리튬 도핑을 위한 리튬 소스로 Li2Mo03와 에너지밀도 향상을 위한 첨가제로 Li2Ru03를 포함하는 리튬이온 커패시터용 고성능 양극 활물질 제조하였다. A high-performance cathode active material for a lithium ion capacitor including Li 2 Mo0 3 as a lithium source for lithium doping to a negative electrode of a lithium ion capacitor and Li 2 Ru0 3 as an additive for improving energy density was prepared.
하기와 같은 방법으로 단상의 Li2Mo03와 Li2Ru¾를 각각 합성하였다. 먼저, Li2C03와 Mo03를 1:1의 몰비로 흔합한 후， Li2C03와 Mo03의 흔합물을 공기 중에서 600 °C에서 5 시간 동안 열처리하여 리튬 복합 금속 산화물 전구체 Li2Mo04를 합성하였다. 이렇게 합성된 Li2Mo04 100 중량부에 대하여 Super-P 7 중량부를 기계적 밀링으로 균일하게 흔합한 후, Li2Mo04와 Super-P의 흔합물을 N2 분위기에서 700 °C에서 10 시간 동안 열처리하여 제 1 리튬 복합 금속 산화물 Li2MO03를 합성하였다. Single phase Li 2 Mo 3 and Li 2 Ru¾ were synthesized as follows. First, after mixing Li 2 C0 3 and Mo0 3 in a molar ratio of 1: 1, the mixture of Li 2 C0 3 and Mo0 3 is heat-treated at 600 ° C for 5 hours in air to form a lithium composite metal oxide precursor Li 2 Mo0 4 was synthesized. After uniformly mixing 7 parts by weight of Super-P with mechanical milling with respect to 100 parts by weight of Li 2 Mo0 4 thus synthesized, the mixture of Li 2 Mo0 4 and Super-P was mixed for 10 hours at 700 ° C. in an N 2 atmosphere. Heat treatment was performed to synthesize a first lithium composite metal oxide Li 2 M O 0 3 .
또한, Li2C03와 Ru02를 1:1의 몰비로 흔합한 후, Li2C03와 Ru02의 흔합물을 공기 중에서 900 °C에서 12 시간 동안 열처리하여 제 2 리튬 복합 금속 산화물 전구체 Li2Ru03를 합성하였다. Further, after mixing Li 2 CO 3 and Ru0 2 in a molar ratio of 1: 1, the mixture of Li 2 CO 3 and Ru0 2 was heat-treated at 900 ° C. for 12 hours in air to form a second lithium composite. A metal oxide precursor Li 2 Ru 0 3 was synthesized.
이렇게 합성된 제 1 리튬 복합 금속 산화물 Li2Mo03 24.2 중량 %와 제 2 리튬 복합 금속 산화물 전구체 Li2Ru03 5 중량 %를 비표면적 1,200 m2/g의 활성탄 62.8 중량 %를 흔합하여 리튬 이온 커패시터용 양극 활물질을 제조하였다. 이때, 상기 활성탄은 평균입자크기가 15 인 것을 사용하였다. 한편， 전술한 바와 같은 방법으로 합성된 제 1 리튬 복합 금속 산화물 Li2Mo03 및 제 2 리튬 복합 금속 산화물 Li2Ru03에 대하여， 도 5에 나타낸 바와 같은 XRD(X-ray diffraction) 분석을 통해 롬보헤드랄 (Rhombohedral)의 결정 구조를 갖는 것임을 확인하였다. 또한， 제 1 리튬 복합 금속 산화물 Li2Mo03 및 제 2 리튬 복합 금속 산화물 Li2Ru03에 대한 미세 구조 및 형상은 도 6에 나타낸 바와 같은 FESEM 및 HRTEM 사진을 통해 확인하였다. This synthesis of the first lithium mixed metal oxide Li 2 Mo0 3 24.2% by weight of the second lithium mixed metal oxide precursor Li 2 Ru0 3 lithium ion capacitor to 5% by weight by adding the activated carbon 62.8% by weight of a specific surface area of 1,200 m 2 / g common A cathode active material for was prepared. At this time, the activated carbon used was an average particle size of 15. On the other hand, for the first lithium composite metal oxide Li 2 Mo0 3 and the second lithium composite metal oxide Li 2 Ru0 3 synthesized in the same manner as described above, through X-ray diffraction (XRD) analysis as shown in FIG. It was confirmed that it had a crystal structure of Rhombohedral. In addition, the microstructure and shape of the first lithium composite metal oxide Li 2 Mo0 3 and the second lithium composite metal oxide Li 2 Ru0 3 were confirmed through FESEM and HRTEM photographs as shown in FIG. 6.
또한, 상기 제 1 리튬 복합 금속 산화물 Li2Mo03에 대하여， 리튬 금속을 대극으로 하는 하프셀을 제작하여 전기화학적인 방법으로 무게당 방전 용량 ( ) 및 무게당 춤전 용량 ( )를 측정하여 하기 계산식 1에 따라 초기 층방전 효율 ( )을 산측하였다. In addition, with respect to the first lithium composite metal oxide Li 2 Mo0 3 , a half cell made of lithium metal as a counter electrode was prepared, and the discharge capacity per weight and the dance capacitance per weight were measured by an electrochemical method. According to the 1, the initial layer discharge efficiency () was estimated.
[계산식 1]  [Calculation 1]
QE = (QD/QC) X 100  QE = (QD / QC) X 100
식 중，  In the formula
¾는 리튬 복합 금속 산화물의 초기 층방전 효율을 나타낸 것이고， ¾ is the initial layer discharge efficiency of the lithium composite metal oxide,
QD는 방전 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut-off)시 양극 활물질의 단위 중량당 충전 용량 (mAh/g)을 나타낸 것이고, Qc는 층전 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off)시 양극 활물질의 단위 중량당 층전 용량 (mAh/g)을 나타낸 것이다. QD is the charge capacity per unit weight of the positive electrode active material (mAh / g) at the Li / Li + cut-off at a discharge voltage of 2.3 V, and Q c is the Li / Li + cut-off at a layer voltage of 4.7 V. It shows the layer charge capacity (mAh / g) per unit weight of the positive electrode active material (cut-off).
이때， 제조된 제 1 리튬 복합 금속 산화물 Li2Mo03의 초기 층방전 효율 ( )은 43%가 되며， 초기 비가역 용량이 큰 특징을 갖는 것을 확인하였다. At this time, the initial layer discharge efficiency () of the prepared first lithium composite metal oxide Li 2 Mo 0 3 was 43%, and it was confirmed that the initial irreversible capacity had a large characteristic.
이와 함께， 상기 제 2 리튬 복합 금속 산화물 Li2Ru03에 대하여， 리튬 금속을 대극으로 하는 하프샐을 제작하여 전기화학적인 방법으로 무게당 방전 용량 (QD) 및 무게당 층전 용량 (Qc)를 측정하여 하기 계산식 2에 따라 2.3V ~ 4.7V 전위 하에서 충방전 효율 (QE.)을 산측하였다. In addition, with respect to the second lithium composite metal oxide Li 2 Ru0 3 , a half cell made of lithium metal as a counter electrode was fabricated, and the discharge capacity per weight (Q D ) and the layer charge capacity (Qc) per weight were obtained by an electrochemical method. Measured according to the following formula 2 The charge and discharge efficiency (Q E. ) Was calculated under a 2.3V to 4.7V potential.
[계산식 2] [Calculation 2]
' = (QD'/QC')X100  '= (QD' / QC ') X100
식 중，  In the formula
ᅵ는 제 2 리튬 복합 금속 산화물의 2.3V ~ 4.7V 전위 하에서 층방전 효율을 나타낸 것이고， ᅵ는 방전 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut¬ off)시 방전 용량 (mAh/g)을 나타낸 것이고， Qc ᅵ는 층전 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut— off)시 층전 용량 (mAh/g)을 나타낸 것이다. I is the second layer will showing a discharge efficiency at 2.3V ~ 4.7V potential of the lithium-metal composite oxide, i is Li / Li + cut in the discharge voltage 2.3 V - off (cut off ¬) when the discharge capacity (mAh / g) Q c ᅵ represents the layer capacitance (mAh / g) at the Li / Li + cut-off at the layer voltage 4.7 V.
이때 제조된 제 2 리튬 복합 금속 산화물 Li2Ru03의 2.3V ~ 4.7V 전위 하에서 층방전 효율 (¾,)은 70% 이상이 되며， 리튬이온 커패시터의 작동전위 영역에서 가역성이 높은 특징을 갖는 것임을 확인하였다. At this time, the layer discharge efficiency (¾,) is more than 70% under the 2.3V to 4.7V potential of the prepared second lithium composite metal oxide Li 2 Ru0 3 , and has a high reversibility in the operating potential region of the lithium ion capacitor. Confirmed.
실시예 2  Example 2
상기 제 1 리튬 복합 금속 산화물 Li2Mo03 22.8 중량 ¾, 제 2 리튬 복합 금속 산화물 Li2Ru03 10 중량 %와 활성탄 59.2 중량 %를 흔합한 것을 제외하고는, 실시예 1과 동일한 방법으로 리튬 이온 커패시터용 양극 활물질을 제조하였다. Lithium ion in the same manner as in Example 1, except that the first lithium composite metal oxide Li 2 Mo0 3 22.8 weight ¾, the second lithium composite metal oxide Li 2 Ru0 3 10% by weight and activated carbon 59.2% by weight A cathode active material for a capacitor was prepared.
비교예 1  Comparative Example 1
기존의 방식으로 리튬 금속을 사용하여 CV (constant voltage) 모드 (mode)로 음극 용량의 60% 도핑을 진행하여 리튬 이온 커패서티를 제조할 수 있도록， 활성탄 92 중량 %를 포함하는 리튬 이온 커패시터용 양극 활물질을 제조하였다.  Cathode for lithium ion capacitors containing 92% by weight of activated carbon, so that lithium metal can be manufactured by doping 60% of the cathode capacity in a constant voltage (CV) mode using lithium metal in a conventional manner. An active material was prepared.
비교예 2  Comparative Example 2
상기 제 2 리튬 복합 금속 산화물 Li2Ru03을 사용하지 않고 게 1 리륨 복합 금속 산화물 Li2Mo03 25.6 중량 ¾>와 활성탄 64.4 중량 %를 흔합한 것을 제외하고는， 실시예 1과 동일한 방법으로 리튬 이온 커패시터용 양극 활물질을 제조하였다. 실시예 1~2 및 비교예 1~2에 따른 양극 활물질의 조성은 하기 표 1에 나타낸 바와 같다. The second lithium mixed metal oxide Li without using 2 Ru0 3 to 1 Lyrium composite metal oxide Li 2 Mo0 3 25.6 wt ¾> as that of, and lithium in the same manner as in Example 1 except that the common sum of the activated carbon 64.4% by weight A cathode active material for an ion capacitor was prepared. The compositions of the positive electrode active materials according to Examples 1 and 2 and Comparative Examples 1 and 2 are as shown in Table 1 below.
- 【표 1】 - Table 1
Figure imgf000027_0001
시험예
Figure imgf000027_0001
Test Example
실시예 1~2 및 비교예 1~2에 따라 양극 활물질올 사용하여 다음과 같은 방법으로 하프셀 리튬 이온 커패시터를 제조한 후에, 이에 대한 전지 성능 평가를 수행하였다. a) 리튬 이온 커패시터 제조  According to Examples 1 and 2 and Comparative Examples 1 and 2, after manufacturing a half cell lithium ion capacitor using the positive electrode active material in the following manner, battery performance evaluation was performed. a) lithium ion capacitor manufacturing
먼저, 실시예 1~2 및 비교예 1~2에 따른 양극 활물질 92 ¾>와 바인더 PVdF를 8 %로 하여， N-메틸피를리돈 (NMP)을 용매로 슬러리 (slurry)를 제조하였다. 이 슬러리를 두께 20 의 알루미늄 메쉬 (A1 mesh)에 도포하여 건조 후 프레스로 압밀화시켜 진공상에서 120 °C로 16 시간 건조하여 직경 12 醒의 원판으로 전극 (cathode)을 제조하였다. 이때， 양극 극판은 활물질 (활성탄 +Li2Mo03+Li2Ru03) 92 %를 PVDF 바인더 8 %를 포함하는 NMP 용액과 슬러리 제조 후 알루미늄 메쉬 (Al mesh)에 코팅하여 제작하였으며， 하드카본 80 %와 도전재 (super-P) 10 ¾)를 PVDF 바인더 10 %를 포함하는 NMP 용액과 슬러리 제조 후 Cu mesh에 코팅하여 제작하였다. First, slurries were prepared using N-methylpyrrolidone (NMP) as a solvent using 92% of the cathode active materials 92 ¾> and the binder PVdF according to Examples 1 and 2 and Comparative Examples 1 and 2 as 8%. The slurry was applied to an aluminum mesh (A1 mesh) having a thickness of 20, dried, compacted in a press, dried for 16 hours at 120 ° C. in a vacuum, and an electrode was prepared from a disk having a diameter of 12 mm 3. At this time, the positive electrode plate was prepared by coating 92% of the active material (activated carbon + Li 2 Mo0 3 + Li 2 Ru0 3 ) with an NMP solution containing 8% PVDF binder and a slurry after coating on an aluminum mesh, hard carbon 80 % And a conductive material (super-P) 10 ¾) was prepared by coating the Cu mesh after preparing a slurry and NMP solution containing 10% PVDF binder.
또한， 상대극 (anode)으로는 직경 12 mm로 펀칭 (punching)을 한 리튬 금속박을， 격리막으로는 폴리에틸렌 (PE) 필름을 사용하였다. 이때 전해액으로는 1M의 LiPF6의 에틸렌글리콜 /디메틸클로라이드 (EC/DMC)를 3 :7로 배합한 흔합 용액을 사용하였다. In addition, a lithium metal foil punched to a diameter of 12 mm was used as an anode, and a polyethylene (PE) film was used as a separator. At this time, a mixed solution in which ethylene glycol / dimethyl chloride (EC / DMC) of 1 M LiPF 6 was mixed at 3: 7 was used as the electrolyte solution.
전해액을 격리막에 함침시킨 후, 이 격리막을 작용극 (cathode)과 상대극 (anode) 사이에 끼운 후 스테인레스스틸 (SUS) 제품의 케이스를 전극 평가용 시험 샐, 즉 비수계 리튬 이온 커패시터 반쪽 셀로 제조하였다. b) 리튬 이온 커패시터의 용량 평가 After the electrolyte was impregnated into the separator, the separator was sandwiched between the cathode and the anode, and then a case of a stainless steel product was manufactured from a test cell for electrode evaluation, that is, a non-aqueous lithium ion capacitor half cell. It was. b) capacity assessment of lithium ion capacitors
비교예 1은 리튬 금속을 사용하여 CV (constant voltage) 모드로 음극 용량의 60% 도핑을 진행하였으며， 비교예 2와 실시예 1 및 2는 전기화학적으로 4.7 V vs. Li/Li+까지 0,1 C의 정전류로 층전을 통해 리튬을 음극에 도핑하였다. 상기 표 1에 나타낸 Li2Mo03의 양은 비교예 1에 맞추어 음극 용량 60¾>에 음극을 도핑할 수 있는 양으로 고정하였다. In Comparative Example 1, 60% of the cathode capacity was doped in a CV (constant voltage) mode using lithium metal, and Comparative Examples 2 and 1 and 2 were electrochemically 4.7 V vs. Lithium was doped to the cathode through layer conversion with a constant current of 0,1 C up to Li / Li +. The amount of Li 2 Mo0 3 shown in Table 1 was fixed in an amount capable of doping the negative electrode in the negative electrode capacity 60¾> according to Comparative Example 1.
c) 리튬 이온 커패시터의 수명 평가  c) life assessment of lithium ion capacitors
상술한 바와 같이 실시예 1~2 및 비교예 1~2에 따른 양극 활물질을 사용하여 제조된 하프셀 리튬 이온 커패시터에 대하며， 1000 cycle 동안 1.5 V ~ 3.9 V의 전위 영역에서 10C의 정전류를 인가하여 층방전을 진행하여 리튬 이온 커패시터의 수명 평가를 수행하였다. 또한, 상기 실시예 1~2 및 비교예 1~2에 따른 양극 활물질을 사용한 리튬 이온 커패시터에 대하여 용량 평가 및 수명 평가 결과를 하기의 표 2에 나타낸 바와 같다.  As described above, for a half-cell lithium ion capacitor manufactured using the cathode active materials according to Examples 1 and 2 and Comparative Examples 1 and 2, a constant current of 10 C is applied in a potential region of 1.5 V to 3.9 V for 1000 cycles. The layer discharge was carried out to evaluate the life of the lithium ion capacitor. In addition, the capacity evaluation and the life evaluation results of the lithium ion capacitors using the cathode active materials according to Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 2 below.
【표 2】 Table 2
Figure imgf000028_0001
또한， 실시예 1~2 및 비교예 1-2에 따른 양극 활물질올 사용한 리튬 이온 커패시터에 대한 용량 평가 그래프 및 1,000 cycle 수명 평가 결과 그래프를 각각 도 7 및 도 8에 나타내었다. 여기서， 도 7은 층방전 곡선 후 리튬 도핑후 3번째 cycle의 층방전 곡선을 비교한 것으로 Li2Ru03를 추가적으로 포함하는 리튬 이온 커패시터 실시예 1~2가 향상된 용량을 나타내는 것을 확인하였다. 또한， 도 8에 나타난 바와 같이 Li2Ru03를 추가적으로 포함하는 실시예 1~2의 리튬 이온 커패시터가 수명 열화 없이 높은 용량을 유지하며， Li2Ru03의 양이 증가할수록 높은 용량을 발현하는 것을 확인할 수 있었다.
Figure imgf000028_0001
In addition, graphs of capacity evaluation and 1,000 cycle life of the lithium ion capacitor using the positive electrode active material according to Examples 1 to 2 and Comparative Examples 1-2 are shown in FIGS. 7 and 8, respectively. Here, FIG. 7 compares the layer discharge curves of the third cycle after lithium doping after the layer discharge curves, and it is confirmed that Examples 1 to 2 of Li-ion capacitors including Li 2 Ru0 3 additionally exhibit improved capacity. In addition, as shown in Figure 8 Li 2 Ru 0 3 In addition, the lithium ion capacitors of Examples 1 to 2 additionally maintain high capacity without deterioration of life, and it was confirmed that the higher capacity was expressed as the amount of Li 2 Ru0 3 increased.
한편， 상기 표 2에 나타낸 바와 같이， 본 발명에 따라 초기 비가역 용량이 큰 제 1 리튬 복합 금속 산화물과 리륨 이온 커패시터의 작동전위 영역에서 가역성이 높은 제 2 리튬 복합 금속 산화물을 함께 사용한 실시예 1~2의 리튬 이온 커패시터는 방전용량이 652 mF 내지 697 mF이며， 1,000 cycle 후 방전용량이 402 mF 내지 413 mF으로 매우 우수한 특성을 갖는 것임을 알 수 있다. 반면에， 비교예 1의 리튬 이온 커패시터는 방전용량이 386 mF이며, 1,000 cycle 후 방전용량이 261 mF로 현저히 떨어지는 것을 알 수 있다. 또한， 비교예 2의 리튬 이온 커패시터는 방전용량이 562 mF이며， 1,000 cycle 후 방전용량이 362 mF으로 비교예 1보다는 우수하지만 실시예 1~2 대비 현저히 떨어지는 것을 알 수 있다.  Meanwhile, as shown in Table 2, according to the present invention, the first lithium composite metal oxide having a large initial irreversible capacity and the second lithium composite metal oxide having high reversibility in the operating potential region of the lithium ion capacitor are used together. It can be seen that the lithium ion capacitor of 2 has a discharge capacity of 652 mF to 697 mF and a discharge capacity of 402 mF to 413 mF after 1,000 cycles. On the other hand, the lithium ion capacitor of Comparative Example 1 has a discharge capacity of 386 mF, and after 1,000 cycles, it can be seen that the discharge capacity remarkably drops to 261 mF. In addition, the lithium ion capacitor of Comparative Example 2 has a discharge capacity of 562 mF, and discharge capacity of 362 mF after 1,000 cycles is better than that of Comparative Example 1 but is significantly lower than Examples 1 to 2.
이로써， 본 발명에 따른 Li2Mo03 및 Li2Ru03 전이금속산화물의 양극 첨가제를 이용하여 전기화학적으로 리튬을 음극 탄소계 소재에 도핑할 수 있었으며， 도끰된 리튬 이온이 커패시터 특성에 기여함으로써 리튬 이온 커패시터의 향상된 전기화학적 특성을 확보하고, 에너지 밀도를 현저히 더욱 증가시키는 데 효과가 있음을 알 수 있다. Thus, lithium could be electrochemically doped to the negative carbon material using the positive electrode additives of the Li 2 Mo0 3 and Li 2 Ru0 3 transition metal oxides according to the present invention. It can be seen that it is effective in securing the improved electrochemical properties of the ion capacitor and significantly increasing the energy density.

Claims

【특허청구범위】 【청구항 1】 하기의 화학식 1로 표시되는 제 1 리튬 복합 금속 산화물, 하기의 화학식 2로 표시되는 게 2 리튬 복합 금속 산화물， 및 탄소계 재료를 포함하는 리튬 이온 커패시터용 양극 활물질: Claims [Claim 1] A cathode active material for a lithium ion capacitor comprising a first lithium composite metal oxide represented by the following Chemical Formula 1, a second lithium composite metal oxide represented by the following Chemical Formula 2, and a carbon-based material :
[화학식 1]  [Formula 1]
LiaM'bOc  LiaM'bOc
[화학식 2]  [Formula 2]
LidM2 e0f Li d M 2 e 0f
식 중，  In the formula
a, b, c, d, e, f는 각각 0<a<6, 0<b<3, 0<c<4, 0<d<2, 0<e<3, 및 0<f≤4를 만족하며，  a, b, c, d, e, and f represent 0 <a <6, 0 <b <3, 0 <c <4, 0 <d <2, 0 <e <3, and 0 <f ≦ 4, respectively. Satisfied,
M1은 Mo, Fe, 및 Co로 이루어진 군에서 선택된 1종 이상이고， M 1 is one or more selected from the group consisting of Mo, Fe, and Co,
M2은 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상임 . M 2 is at least one member selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr.
【청구항 2】  [Claim 2]
제 1항에 있어서,  The method of claim 1,
상기 제 1 리튬 복합 금속 산화물은 하기의 계산식 1에 따른 초기 층방전 효율 ( )이 50% 이하인 리튬 이온 커패시터용 양극 활물질:  The first lithium composite metal oxide is an anode active material for a lithium ion capacitor having an initial layer discharge efficiency () of 50% or less according to Formula 1 below:
[계산식 1]  [Calculation 1]
QE = (QD/QC) X 100  QE = (QD / QC) X 100
식 중，  In the formula
¾는 게 1 리륨 복합 금속 산화물의 초기 층방전 효율을 나타낸 것이고，  ¾ is the initial layer discharge efficiency of the Ge 1 lithium composite metal oxide,
¾는 방전 전압 2.3 V에서 Li/Li+ 컷 -오프 (cut— off)시 방전 용량 (mAh/g)을 나타낸 것이고，  ¾ represents the discharge capacity (mAh / g) at Li / Li + cut-off at a discharge voltage of 2.3 V,
Qc는 층전 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off)시 층전 용량 (mAh/g)을 나타낸 것임.  Qc represents the layer capacitance (mAh / g) at Li / Li + cut-off at the layer voltage 4.7 V.
【청구항 3】  [Claim 3]
제 1항에 있어서, 상기 제 2 리튬 복합 금속 산화물은 2.3V 내지 4.7V 전위 하에서 층방전 효율 ( 이 50% 이상인 리튬 이온 커패시터용 양극 활물질: The method of claim 1, The second lithium composite metal oxide has a layer discharge efficiency at a potential of 2.3 V to 4.7 V (at least 50% of the positive electrode active material for a lithium ion capacitor:
[계산식 2]  [Calculation 2]
QE' = (QD'/QC')X100  QE '= (QD' / QC ') X100
식 중，  In the formula
ᅵ는 제 2 리튬 복합 금속 산화물의 2.3V 내지 4.7V 전위 하에서 층방전 효율을 나타낸 것이고,  ᅵ shows the layer discharge efficiency under the 2.3V to 4.7V potential of the second lithium composite metal oxide,
QD,는 방전 전압 2.3 V에서 Li/Li+ 컷ᅳ오프 (cut-off)시 방전 용량 (mAh/g)을 나타낸 것이고, . QD, represents discharge capacity (mAh / g ) at Li / Li + cut-off at discharge voltage 2.3 V,.
는 층전 전압 4.7 V에서 Li/Li+ 컷 -오프 (cut-off)시 층전 용량 (mAh/g)을 나타낸 것임.  Shows the layer capacity (mAh / g) at Li / Li + cut-off at layer voltage 4.7 V.
【청구항 4】  [Claim 4]
저11항에 있어서,  The method of claim 11,
상기 제 1 리튬 복합 금속 산화물은 Li2Mo03, Li5Fe04, 및 Li6Co04로 이루어진 군에서 선택된 1종 이상인 리튬 이온 커패시터용 양극 활물질. The first lithium composite metal oxide is at least one selected from the group consisting of Li 2 Mo 0 3 , Li 5 Fe0 4 , and Li 6 Co0 4 positive electrode active material for a lithium ion capacitor.
【청구항 5】 [Claim 5]
제 1항에 있어서，  The method of claim 1,
상기 제 2 리튬 복합 금속 산화물은 Li2Mn03, Li2Ti03, Li2Ru03> Li2Ir¾, Li2Pt03, Li2Sn03, 및 Li2Zr¾로 이루어진 군에서 선택된 1종 이상인 리튬 이온 커패시터용 양극 활물질. The second lithium mixed metal oxide is Li 2 Mn0 3, Li 2 Ti0 3, Li 2 Ru0 3> Li 2 Ir¾, Li 2 Pt0 3, Li 2 Sn0 3, and at least one member of lithium selected from the group consisting of Li 2 Zr¾ Cathode active material for ion capacitors.
【청구항 6】  [Claim 6]
게 1항에 있어서,  According to claim 1,
상기 제 1 리튬 복합 금속 산화물은 0V 내지 5V의 전압영역에서 라튬 이은을 삽입 또는 탈리하는 것인 리튬 이온 커패시터용 양극 활물질.  The first lithium composite metal oxide is a positive electrode active material for lithium ion capacitor to insert or detach the lithium silver in the voltage range of 0V to 5V.
【청구항 7】  [Claim 7]
제 1항에 있어서,  The method of claim 1,
상기 제 2 리튬 복합 금속 산화물은 IV 내지 5V의 전압영역에서 리튬 이은을 가역적으로 삽입 또는 탈리하는 것인 리튬 이온 커패시터용 양극 활물질.  The second lithium composite metal oxide is a positive electrode active material for lithium ion capacitor reversibly inserting or detaching lithium silver in the voltage range of IV to 5V.
【청구항 8】 제 1항에 있어서, [Claim 8] The method of claim 1,
상기 탄소계 재료는 비표면적이 500 m2/g 이상인 것을 특징으로 하는 리튬 이온 커패시터용 양극 활물질. The carbon-based material has a specific surface area of 500 m 2 / g or more, the positive electrode active material for lithium ion capacitors.
【청구항 9】  [Claim 9]
제 1항에 있어서，  The method of claim 1,
상기 탄소계 재료는 활성탄， 활성탄과 금속 산화물 복합체， 활성탄과 전도성 고분자 복합체로 이루어진 군에서 선택된 1종 이상인 리튬 이온 커패시터용 양극 활물질.  The carbon-based material is at least one selected from the group consisting of activated carbon, activated carbon and metal oxide composite, activated carbon and conductive polymer composite.
【청구항 10]  [Claim 10]
제 1항에 있어서，  The method of claim 1,
상기 제 1 리튬 복합 금속 산화물 0.5내지 49.5중량 %，  0.5 to 49.5 wt% of the first lithium composite metal oxide;
상기 제 2 리튬 복합 금속 산화물 0.5내지 49.5중량 %ᅳ및  0.5 to 49.5 weight% of the second lithium composite metal oxide; and
상기 탄소계 재료 50 내지 99 중량 %를 포함하는 리튬 이온 커패시터용 양극 활물질.  A cathode active material for a lithium ion capacitor comprising 50 to 99% by weight of the carbonaceous material.
【청구항 11】  [Claim 11]
제 1항에 있어서，  The method of claim 1,
상기 제 1 리튬 복합 금속 산화물: 제 2 리튬 복합 금속 산화물의 중량비는 10:90내지 90:10인 리튬 이온 커패시터용 양극 활물질.  The weight ratio of the first lithium composite metal oxide: second lithium composite metal oxide is 10:90 to 90:10, the positive electrode active material for a lithium ion capacitor.
【청구항 12]  [Claim 12]
a) 리튬 화합물과 M으 Fe, 및 Co으로 이루어진 군에서 선택된 1종 이상을 함유하는 전이금속 화합물을 흔합하고 열처리하여 하기의 화학식 3으로 표시되는 제 1 리튬 복합 금속 산화물 전구체를 생성시키는 단계; b) 하기의 화학식 3으로 표시되는 제 1 리튬 복합 금속 산화물 전구체를 환원하여 하기의 화학식 1로 표시되는 제 1 리튬 복합 금속 산화물을 생성시키는 단계;  a) mixing and heat treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and M as Fe and Co to produce a first lithium composite metal oxide precursor represented by Formula 3 below; b) reducing the first lithium composite metal oxide precursor represented by Formula 3 to produce a first lithium composite metal oxide represented by Formula 1 below;
c) 리튬 화합물과 Mn, Ti, Ru, Ir, Pt， Sn, 및 Zr으로 이루어진 군에서 선택된 1종 이상을 함유하는 전이금속 화합물을 흔합하고 열처리하여 하기의 화학식 2으로 표시되는 제 2 리튬 복합 금속 산화물을 생성시키는 단계; 및  c) a second lithium composite metal represented by the following Chemical Formula 2 by mixing and heat-treating a transition metal compound containing at least one selected from the group consisting of a lithium compound and Mn, Ti, Ru, Ir, Pt, Sn, and Zr Producing an oxide; And
d) 상기 제 1 리튬 복합 금속 산화물 및 제 2 리륨 복합 금속 산화물을 탄소계 재료와흔합하는 단계 ; d) the first lithium composite metal oxide and the second lithium composite metal oxide Mixing with a carbonaceous material;
를 포함하는 리튬 이온 커패시터용 양극 활물질의 제조 방법:  Method for producing a cathode active material for a lithium ion capacitor comprising:
[화학식 1]  [Formula 1]
LiaMV)c Li a MV) c
[화학식 2]  [Formula 2]
LidM2 e0f Li d M 2 e 0 f
[화학식 3]  [Formula 3]
. Lia.Mr b c' . Li a .M r bc ''
식 중，  In the formula
a, b, c 는 각각 0<a<6, 0<b<3, 0<c<4를 만족하며，  a, b, and c satisfy 0 <a <6, 0 <b <3, 0 <c <4, respectively,
d, e, f는 각각 0<d<2, 0<e<3, 0<f<4를 만족하며,  d, e, f satisfy 0 <d <2, 0 <e <3, 0 <f <4, respectively,
a', b' , c'는 각각 0<a'<6, 0<b' <3, 1<('<5를 만족하며，  a ', b' and c 'satisfy 0 <a' <6, 0 <b '<3, 1 <(' <5, respectively,
M1 및 M1'은 각각 Mo, Fe, 및 Co로 이루어진 군에서 선택된 1종 이상이고， M 1 and M 1 ' is at least one selected from the group consisting of Mo, Fe, and Co, respectively,
M2은 Mn, Ti, Ru, Ir, Pt , Sn, 및 Zr으로 이루어진 군에서 선택된M 2 is selected from the group consisting of Mn, Ti, Ru, Ir, Pt, Sn, and Zr
1종 이상임 . One or more species.
【청구항 13】  [Claim 13]
제 12항에 있어서，  The method of claim 12,
상기 a) 단계의 열처리 공정은 400 내지 1,000 °C에서 수행하는 것인 리튬 이온 커패시터용 양극 활물질의 제조 방법. The heat treatment process of step a) is performed at 400 to 1,000 ° C. A method of manufacturing a cathode active material for a lithium ion capacitor.
【청구항 14】  [Claim 14]
제 12항에 있어서，  The method of claim 12,
상기 b) 단계는 제 1 리튬 복합 금속 산화물 전구체를 500 내지 1,000 °C에서 열처리하여 환원시키는 리튬 이온 커패시터용 양극 활물질의 제조 방법 . The step b) is a method of manufacturing a cathode active material for a lithium ion capacitor to reduce the first lithium composite metal oxide precursor by heat treatment at 500 to 1,000 ° C.
【청구항 151  [Claim 151]
제 12항에 있어서，  The method of claim 12,
상기 c) 단계의 열처리 공정은 500 내지 1,000 °C에서 수행하는 것인 리튬 이은 커패시터용 양극 활물질의 제조 방법.  The heat treatment process of step c) is performed at 500 to 1,000 ° C. A method for producing a cathode active material for lithium silver capacitor.
【청구항 16】 제 12항에 있어서， [Claim 16] The method of claim 12,
상기 a) 단계 및 c) 단계의 리튬 화합물은 각각 Li2C03, LiOH, 및 Li로 이루어진 군에서 선택된 1종 이상인 리튬 이온 커패시터용 양극 활물질. The lithium compound of step a) and c) is at least one selected from the group consisting of Li 2 CO 3 , LiOH, and Li, respectively.
【청구항 17】  [Claim 17]
제 12항에 있어서，  The method of claim 12,
상기 a) 단계의 전이금속 화합물은 Mo03, Mo02, (NH4)6Mo7024 · 4¾0， MoS2, Mo, FeO, Fe203, Fe304, Fe, CoO, 및 Co로 이루어진 군에서 선택된 1종 이상인 리튬 이온 커패시터용 양극 활물질. The transition metal compound of step a) is Mo0 3 , Mo0 2 , (NH 4 ) 6 Mo 7 0 24 · 4¾0, MoS 2 , Mo, FeO, Fe 2 0 3 , Fe 3 0 4 , Fe, CoO, and Co A cathode active material for at least one lithium ion capacitor selected from the group consisting of.
【청구항 18】  [Claim 18]
제 12항에 있어서，  The method of claim 12,
상기 c) 단계의 전이금속 화합물은 MnO, Mnᅳ Ti02, Ti， Ru02, Ru, IrCl3, Ir02) PtCl4, PtCl2, Pt02> Pt(C5H702)2, Pt/C, Sn02) Sn, Zr02, 및 Zr로 이루어진 군에서 선택된 1종 이상인 리튬 이온 커패시터용 양극 활물질. The transition metal compound of step c) is MnO, Mn ᅳ Ti0 2 , Ti, Ru0 2 , Ru, IrCl 3 , Ir0 2) PtCl 4 , PtCl 2 , Pt0 2> Pt (C 5 H 7 0 2 ) 2, Pt / C, Sn0 2) A cathode active material for at least one lithium ion capacitor selected from the group consisting of Sn, Zr0 2 , and Zr.
【청구항 19】  [Claim 19]
제 1항 내지 제 11항 중 어느 한 항에 따른 양극 활물질을 포함하는 리튬 이온 커패시터.  A lithium ion capacitor comprising the cathode active material according to any one of claims 1 to 11.
【청구항 20】  [Claim 20]
제 19항에 있어서，  The method of claim 19,
양극 활물질을 포함하는 양극 (cathode);  A cathode including a cathode active material;
음극 활물질을 포함하는 음극 (anode); 및  An anode including an anode active material; And
양극 및 음극 사이의 격리막 (separator)  Separator between anode and cathode
올 포함하고， 상기 음극은 양극으로부터만 리튬 이온을 공급받는 리튬 이온 커패시터.  And a negative electrode is supplied with lithium ions only from the positive electrode.
【청구항 21】  [Claim 21]
제 19항에 있어서,  The method of claim 19,
0V 내지 5V의 전압영역에서 리튬 이온을 가역적으로 삽입 또는 탈리하는 탄소계 음극 활물질을 포함하는 리튬 이온 커패시터.  Lithium ion capacitor comprising a carbon-based negative active material for reversibly inserting or detaching lithium ions in the voltage range of 0V to 5V.
PCT/KR2012/003860 2012-04-04 2012-05-16 Cathode active material for lithium ion capacitor and method for manufacturing same WO2013151209A1 (en)

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Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101892177B1 (en) * 2015-06-30 2018-08-28 전자부품연구원 Additive material for high power energy storage device, and high power energy storage device comprising the same
KR101751213B1 (en) * 2017-02-22 2017-06-28 전자부품연구원 Manufacturing method of additive material for high power energy storage device, additive material for high power energy storage device made by the same, high power energy storage device comprising the same
WO2018236166A1 (en) * 2017-06-21 2018-12-27 주식회사 엘지화학 Lithium secondary battery
KR102115602B1 (en) * 2017-06-21 2020-05-26 주식회사 엘지화학 Lithium secondary battery
WO2018236168A1 (en) * 2017-06-21 2018-12-27 주식회사 엘지화학 Lithium secondary battery
KR102093971B1 (en) 2017-06-21 2020-05-21 주식회사 엘지화학 Lithium secondary battery
US10403929B2 (en) 2017-11-30 2019-09-03 Lg Chem, Ltd. Additive for cathode, method for preparing the same, cathode including the same, and lithium secondary battery including the same
WO2020091428A1 (en) * 2018-10-30 2020-05-07 주식회사 엘지화학 Lithium secondary battery
EP3866224A4 (en) * 2018-11-02 2021-12-08 Lg Energy Solution, Ltd. Lithium secondary battery
WO2020091515A1 (en) * 2018-11-02 2020-05-07 주식회사 엘지화학 Lithium secondary battery
KR102217302B1 (en) * 2018-11-30 2021-02-18 주식회사 포스코 Positive electrode additive material for rechargeable lithium battery, method of preparing the same, positive electrode including the same and rechargeable lithium battery including the same
KR102168789B1 (en) * 2018-12-20 2020-10-22 한국전자기술연구원 Lithium cobalt oxide-carbon composite for positive active material for lithium ion capacitor, positive active material comprising the same, lithium ion capacitor comprising the same, and preparation method thereof
KR20220159129A (en) * 2021-05-25 2022-12-02 주식회사 엘지에너지솔루션 Positive electrode material slurry and positive electrode for lithium secondary battery using the same
KR20220159010A (en) * 2021-05-25 2022-12-02 주식회사 엘지에너지솔루션 Additives for positive electrode and positive electrode for lithium secondary battery containing the same
KR20220161653A (en) * 2021-05-31 2022-12-07 주식회사 엘지에너지솔루션 Master batch containing positive electrode active materials and irreversible additives, and positive electrode slurry for secondary battery containing the same
KR20230024858A (en) * 2021-08-12 2023-02-21 주식회사 엘지에너지솔루션 Cathode for lithium secondary battery comprising cathode additive

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20050049746A (en) * 2003-11-24 2005-05-27 전자부품연구원 Cathode active material for lithium secondary batteries, method for manufacturing the same and lithium secondary batteries containing the same
KR20080081297A (en) * 2005-12-28 2008-09-09 후지 주코교 카부시키카이샤 Lithium ion capacitor
KR20100002107A (en) * 2008-06-25 2010-01-06 삼성에스디아이 주식회사 Lithium secondary battery
KR20120009701A (en) * 2010-07-20 2012-02-02 삼성에스디아이 주식회사 Positive electrode and Lithium battery comprising the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20050049746A (en) * 2003-11-24 2005-05-27 전자부품연구원 Cathode active material for lithium secondary batteries, method for manufacturing the same and lithium secondary batteries containing the same
KR20080081297A (en) * 2005-12-28 2008-09-09 후지 주코교 카부시키카이샤 Lithium ion capacitor
KR20100002107A (en) * 2008-06-25 2010-01-06 삼성에스디아이 주식회사 Lithium secondary battery
KR20120009701A (en) * 2010-07-20 2012-02-02 삼성에스디아이 주식회사 Positive electrode and Lithium battery comprising the same

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