WO2007086264A1 - Nonaqueous electrolyte secondary battery - Google Patents

Nonaqueous electrolyte secondary battery Download PDF

Info

Publication number
WO2007086264A1
WO2007086264A1 PCT/JP2007/050384 JP2007050384W WO2007086264A1 WO 2007086264 A1 WO2007086264 A1 WO 2007086264A1 JP 2007050384 W JP2007050384 W JP 2007050384W WO 2007086264 A1 WO2007086264 A1 WO 2007086264A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
secondary battery
negative electrode
lithium
particles
Prior art date
Application number
PCT/JP2007/050384
Other languages
French (fr)
Japanese (ja)
Inventor
Yanko Marinov Todorov
Yoshiki Sakaguchi
Kiyotaka Yasuda
Original Assignee
Mitsui Mining & Smelting Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsui Mining & Smelting Co., Ltd. filed Critical Mitsui Mining & Smelting Co., Ltd.
Publication of WO2007086264A1 publication Critical patent/WO2007086264A1/en

Links

Classifications

    • 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
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M6/00—Primary cells; Manufacture thereof
    • H01M6/14—Cells with non-aqueous electrolyte
    • H01M6/16—Cells with non-aqueous electrolyte with organic electrolyte
    • H01M6/162—Cells with non-aqueous electrolyte with organic electrolyte characterised by the electrolyte
    • H01M6/168—Cells with non-aqueous electrolyte with organic electrolyte characterised by the electrolyte by additives
    • 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
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • 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
    • H01M4/139—Processes of manufacture
    • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
    • 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

Definitions

  • the present invention relates to a nonaqueous electrolyte secondary battery such as a lithium secondary battery.
  • a lithium secondary battery using metallic lithium as a negative electrode active material in relation to a non-aqueous electrolyte containing an aromatic compound pyrrole, a kind of aromatic compound, is added at a concentration of 0.2 mol / l or less. It has been proposed to contain it in a non-aqueous electrolyte (see Patent Document 2).
  • the purpose of adding pyrrole is to adsorb pyrrole on the surface of lithium metal, which is the negative electrode active material, to change the self-discharge reaction between the electrolyte and lithium and the lithium precipitation form, thereby improving charge and discharge efficiency. It is said that there is.
  • this technology is based on the premise that metallic lithium is used as the negative electrode active material. Therefore, when a negative electrode active material other than metallic lithium, for example, a metal that can occlude lithium, such as silicon tin, is used, the desired effect is obtained. Not played.
  • Patent Document 3 Japanese Patent Application Laid-Open No. 2005-135906
  • Patent Document 2 Japanese Patent Publication No. 5-64429
  • Patent Document 3 US5556721A
  • An object of the present invention is to provide a non-aqueous electrolyte secondary battery in which various performances are further improved as compared with conventional non-aqueous electrolyte secondary batteries.
  • the present invention provides a non-aqueous electrolyte secondary battery characterized by using an electrolyte containing 0.2 to 2 mol Zl of pyrrole.
  • FIG. 1 is a drawing showing an example of a charge / discharge curve in the nonaqueous electrolyte secondary battery of the present invention.
  • the nonaqueous electrolyte secondary battery of the present invention typically includes a negative electrode, a positive electrode, and a separator interposed between both electrodes.
  • a non-aqueous electrolyte exists between the negative electrode and the positive electrode.
  • the negative electrode has an active material layer formed on at least one surface of a current collector.
  • the active material layer includes a negative electrode active material.
  • As the negative electrode active material a material capable of occluding lithium can be used without particular limitation.
  • the material that can store lithium does not include metallic lithium itself.
  • substances that can occlude lithium include carbon-based materials such as graphite, simple substances of group 14 elements such as silicon, soot, and germanium, alloys, intermetallic compounds, oxides, nitrides, borides, etc.
  • a single group 13 element such as aluminum, an alloy, an intermetallic compound, an oxide, a nitride, or a boride can be used.
  • a material containing silicon or tin is used as the negative electrode active material, it is currently used as a negative electrode material for non-aqueous electrolyte secondary batteries! /
  • a material containing silicon is used as the negative electrode active material.
  • the material is a material containing silicon.
  • alloys of silicon and other metals intermetallic compounds of silicon and other metals, silicon oxide, silicon nitride, silicon boride, etc. can be used.
  • other metals include metals having low ability to form lithium compounds such as Co, Ni, Cu, Fe, V, Ti, Mn, Cr, W, Mg, and Nd.
  • low ability to form a lithium compound means that lithium does not form an intermetallic compound or solid solution, or even if formed, the lithium is in a very small force or very unstable. Li can also be used as another metal.
  • the negative electrode active material may be, for example, in the form of a thin film.
  • an active material layer made of a thin film is formed on at least one surface of the current collector by various thin film forming means such as chemical vapor deposition, physical vapor deposition, and sputtering.
  • the thin film may be etched to form a large number of voids extending in the thickness direction.
  • a dry etching method using a dry gas, plasma, or the like can be employed for etching.
  • the negative electrode active material may be in the form of particles.
  • the particles for example, those described in US2006Z051675A1 related to the previous application of the present applicant can be used. Specifically, ii) particles of silicon alone, mouth) mixed particles of silicon particles and carbon particles, ii) mixed particles of silicon particles and metal particles, 2) compound particles of silicon and metal, E) Mixed particles of silicon and metal compound particles and metal particles.
  • the particles are applied to at least one surface of the current collector in a slurry state mixed with a binder, a solvent, and the like. As a result, an active material layer made of the slurry coating is formed.
  • the coating film may be fired to sinter the particles.
  • a method described in US2004 / 043294A1 can be used as a sintering method of particles containing silicon.
  • the lithium compound has a low ability to form a lithium and the metal penetrates between the particles.
  • the permeation of the metal between the particles can effectively prevent the pulverized active material from falling off due to the volume change caused by charging and discharging.
  • the term “penetration” as used herein refers to a state in which a metal compound with a low lithium compound forming ability exists in the space between particles so as to cover the surface of the particle, and the space between the particles is filled with the metal material. You don't need to be exhausted.
  • the metal material preferably covers the surface of the particles so that there is a space between the particles.
  • the metal material force S The existence of such a state has an advantage that the electrolyte solution surely reaches the deep part of the active material layer. Also occluded lithium There is also an advantage that the increase in volume caused by the expansion of the particles is alleviated.
  • electrolytic coating is performed on the coating film of the slurry to deposit a metal having a low lithium compound forming ability between the particles.
  • electrolytic plating for example, the method described in US2006Z11 5735A1 according to the previous application of the present applicant can be used.
  • a coating film is formed by applying a slurry containing active material particles on a current collector.
  • the slurry contains active material particles, conductive carbon material particles, a binder, a diluent solvent, and the like.
  • the binder polyvinylidene fluoride, polyethylene, ethylene propylene monomer, styrene butadiene rubber or the like is used. Diluent solvents such as N-methylpyrrolidone and cyclohexane are used.
  • a plating bath containing a metal material having a low lithium compound forming ability to perform electroplating.
  • the electrolytic plating conditions may be as follows: the copper concentration is 30 to: LOOgZl, the sulfuric acid concentration is 50 to 200 gZl, and the chlorine concentration is 30 ppm or less.
  • the positive electrode has an active material layer formed on at least one surface of a current collector.
  • the active material layer contains a positive electrode active material.
  • a Li-containing compound is used as the positive electrode active material.
  • the Li-containing compound a substance capable of electrochemically absorbing and releasing lithium is used.
  • LiCoO or LiNiO which are layered compounds containing lithium can be used.
  • LiMo 2 O which is a spinel structure compound containing lithium, can be used. Life
  • the material layer is formed by applying these positive electrode active material particles to at least one surface of a current collector in a slurry state in which the particles are mixed with a binder and a solvent.
  • the current collector that supports the active material layer on the negative electrode is generally composed of a metal material having a low ability to form a lithium compound.
  • a metal material include copper, nickel, iron, cobalt, and alloys thereof.
  • the active material layer is supported in the positive electrode.
  • an aluminum foil is generally used as the current collector to be held.
  • separator that separates the positive electrode and the negative electrode
  • separator As that conventionally used as this type of material can be used.
  • a synthetic resin nonwoven fabric, a polyethylene or polypropylene porous film, or the like is preferably used.
  • nonaqueous electrolytic solution a solution obtained by dissolving a supporting electrolyte in a nonaqueous solvent is used.
  • Nonaqueous solvents include ethylene carbonate, propylene carbonate, butylene carbonate, jetyl carbonate, dimethyl carbonate and the like. These non-aqueous solvents can be used in combination of two or more.
  • PC propylene carbonate
  • DEC! / jetyl carbonate
  • DAC dimethyl carbonate
  • PC and DAC can be mixed within a wide range of volume ratios.
  • the volume ratio of PC to DAC (the former: the latter) in the mixed solvent is preferably 5:95 to 95: 5, more preferably 20:80 to 70:30.
  • the volume ratio of the PC exceeds 95%, the non-aqueous electrolyte secondary battery tends to have low wettability with a separator that is generally used, and the electrolyte distribution may not be smooth. is there.
  • the volume ratio of DAC exceeds 95%, the polarity of the entire mixed solvent may decrease, making it difficult to dissolve the electrolyte.
  • Jetyl carbonate is particularly preferable because it allows the battery to be used below freezing point where the freezing point is low.
  • the non-aqueous electrolyte contains a predetermined concentration of pyrrole.
  • a predetermined concentration of pyrrole By containing a predetermined concentration of pyrrole, a high discharge voltage can be obtained, and the cycle characteristics can be improved. The reason for this is as follows.
  • the produced polypyrrole takes various forms depending on the type of the supporting electrolyte. For example, when LiPF is used as the supporting electrolyte, [(C H N +) PF forms
  • the voltage at which pyrrole is electrolyzed is about 2.5-3.2 V (vs. Li). This is shown in Figure 1.
  • the negative electrode lithium ions present in the non-aqueous electrolyte are occluded by silicon.
  • the discharge cut'off voltage is set to about 2.9-3.3V, which is higher than the voltage of electrolytic deposition of pyrrole, and the state force in which Li is occluded in the silicon is second.
  • the second and subsequent charging / discharging is almost 100% reversible.
  • Charging silicon in a state in which Li is occluded means that the same state as in the case where Li is occluded in the pre-load silicon incorporated into the battery is realized.
  • a higher discharge voltage is obtained than in the first discharge.
  • the fact that the same state as that in which Li is occluded in silicon before being incorporated in the battery is realized in the present invention is extremely advantageous in that Li can be occluded in silicon easily and with high productivity. is there
  • the high-temperature storage stability of the positive electrode active material is enhanced by the coating formed on the surface of the positive electrode by electrolytic deposition of pyrrole.
  • elution of manganese during high-temperature storage can be effectively prevented even when lithium manganate, which is a material that is difficult to store at high temperatures, is used as the positive electrode active material.
  • the concentration of the supporting electrolyte contained in the electrolytic solution is set higher than the concentration of the supporting electrolyte in the conventional non-aqueous electrolyte secondary battery. Specifically, 0.5 to 2 molZl, particularly 1 to 2 molZl is preferable.
  • the types of supporting electrolytes are as described above. Among them, it is preferable to use LiPF for the point of formation of polypyrrole.
  • the concentration of pyrrole in the electrolytic solution is set to 0.2 to 2 molZl as described above, preferably 0.5 to 2 molZl, and more preferably 1 to 2 molZl. If the pyrrole concentration is less than 0.2 molZl, lithium will not be sufficiently supplied to the negative electrode active material. On the other hand, if the concentration of pyrrole exceeds 2 molZl, the amount of pyrrole will be excessive relative to the amount of lithium in the electrolyte.
  • the form of the secondary battery of the present invention may be a coin type, a cylindrical type, or a square type.
  • a separator is interposed between the negative electrode and the positive electrode, these three members are wound to form a wound body, and the wound body is accommodated in a battery container.
  • a roll type battery (cylindrical battery or prismatic battery) can be used.
  • the current collector on which the coating film is formed is immersed in a copper pyrophosphate bath having the following bath composition, and copper is deposited between particles in the coating film by electrolysis to form an active material layer. did. By this electrolytic plating, copper was deposited over the entire thickness direction of the coating film. In this way, a negative electrode was produced.
  • the electrolysis conditions were as follows. DSE was used for the anode. A DC power source was used as the power source.
  • LiCoO powder having an average particle size of 20 / z m was used as the positive electrode active material. 90 parts of this powder,
  • a slurry was obtained by mixing 5 parts of acetylene black as a conductive agent with a 5% N-methylpyrrolidone solution containing 5 parts of polyvinylidene fluoride as a binder. This slurry was applied onto an aluminum foil as a current collector, dried, and then rolled to produce a positive electrode.
  • the obtained negative electrode and positive electrode were opposed to each other through a separator having a polyethylene porous film force and accommodated in a battery case.
  • a solution obtained by dissolving the supporting electrolyte shown in Table 1 in a mixed solvent in which PC and DEC were mixed at a volume ratio shown in Table 1 at a concentration shown in the same table was used.
  • the electrolyte solution contained pyrrole at the concentrations shown in Table 1.
  • the discharge capacity after 100 cycles was measured, and the value was divided by the maximum negative electrode discharge capacity and multiplied by 100.
  • the discharge cut-off voltage was 2.7V.
  • Charging was performed in the constant current mode and the constant voltage mode for the first time, and in the constant current mode for the second and subsequent times.
  • Discharge was in constant current 'constant voltage mode for the first time and in constant current mode for the second and subsequent times.
  • a secondary battery was obtained in the same manner as in Example 1 except that the solvents shown in Table 1 were used as the solvent and the supporting electrolyte in the electrolytic solution.
  • the obtained secondary battery was evaluated in the same manner as in Example 1. The results are shown in Table 1.
  • the secondary batteries of the examples in which pyrrole is contained in the electrolytic solution contain pyrrole and are compared with the secondary batteries of comparative examples. It can be seen that the cycle characteristics are improved. Further, as is clear from the comparison between Examples 1 and 2 and Examples 3 and 4, it can be seen that the cycle characteristics are further improved by using a mixed solvent of PC and DEC as the non-aqueous solvent.
  • the nonaqueous electrolyte secondary battery of the present invention As described above, according to the nonaqueous electrolyte secondary battery of the present invention, a high discharge voltage can be obtained and the cycle characteristics can be improved.

Abstract

Disclosed is a nonaqueous electrolyte secondary battery which is characterized by using an electrolyte solution containing pyrrole. The pyrrole concentration in the electrolyte solution is 0.2-2 mol/l. The supporting electrolyte concentration in the electrolyte solution is preferably 0.5-2 mol/l. It is also preferable that LiPF6 is used as the supporting electrolyte. A substance capable of adsorbing lithium is preferably used as a negative electrode active material. It is further preferable that a material containing silicon or tin is used as the negative electrode active material.

Description

明 細 書  Specification
非水電解液二次電池  Non-aqueous electrolyte secondary battery
技術分野  Technical field
[0001] 本発明は、リチウム二次電池等の非水電解液二次電池に関する。  The present invention relates to a nonaqueous electrolyte secondary battery such as a lithium secondary battery.
背景技術  Background art
[0002] アルキル置換ベンゼン類ゃァリール置換ベンゼン類、ハロゲン置換ァ-ソール類な どの芳香族化合物を含有する非水電解液二次電池用の電解液が提案されている（ 特許文献 1参照)。これらの芳香族化合物を添加する目的は、電池の過充電防止や 高温保存後の充放電特性の低下防止にあるとされている。これらの芳香族化合物は その酸ィ匕分解電圧が低ぐ且つ酸ィ匕分解電流が大きいことに起因して過充電防止作 用を発揮する。し力しこれらの芳香族化合物は、電池のサイクル特性等の向上に寄 与するものではない。  There has been proposed an electrolyte solution for a non-aqueous electrolyte secondary battery containing an aromatic compound such as alkyl-substituted benzenes, aryl-substituted benzenes, and halogen-substituted azoles (see Patent Document 1). The purpose of adding these aromatic compounds is to prevent overcharge of batteries and to prevent deterioration of charge / discharge characteristics after high temperature storage. These aromatic compounds exert an overcharge preventing action due to their low acid decomposition voltage and large acid decomposition current. However, these aromatic compounds do not contribute to improvement of the cycle characteristics of the battery.
[0003] 芳香族化合物を含む非水電解液に関連して、金属リチウムを負極活物質として用 いたリチウム二次電池において、芳香族化合物の一種であるピロールを 0. 2mol/l 以下の濃度で非水電解液に含有させることが提案されて ヽる (特許文献 2参照)。ピ ロールを添加する目的は、負極活物質である金属リチウムの表面にピロールを吸着 させて、電解液とリチウムとの間の自己放電反応やリチウムの析出形態を変化させ、 充放電効率を向上させることにあるとされている。し力しこの技術は、金属リチウムを 負極活物質として用いることが前提なので、金属リチウム以外の負極活物質、例えば シリコンゃスズなどのリチウムを吸蔵可能な金属を用いた場合には所望の効果が奏さ れない。  [0003] In a lithium secondary battery using metallic lithium as a negative electrode active material in relation to a non-aqueous electrolyte containing an aromatic compound, pyrrole, a kind of aromatic compound, is added at a concentration of 0.2 mol / l or less. It has been proposed to contain it in a non-aqueous electrolyte (see Patent Document 2). The purpose of adding pyrrole is to adsorb pyrrole on the surface of lithium metal, which is the negative electrode active material, to change the self-discharge reaction between the electrolyte and lithium and the lithium precipitation form, thereby improving charge and discharge efficiency. It is said that there is. However, this technology is based on the premise that metallic lithium is used as the negative electrode active material. Therefore, when a negative electrode active material other than metallic lithium, for example, a metal that can occlude lithium, such as silicon tin, is used, the desired effect is obtained. Not played.
[0004] ところで、非水電解液二次電池の負極活物質に予めリチウムを吸蔵させておき、電 池のサイクル特性を向上させることが提案されている（特許文献 3参照)。リチウムを 予め吸蔵させるための方法としては、例えば電池外において、負極と金属リチウム等 の対極とを非水電解液に接して対向させ電気化学的セルを構成し、電気化学的にリ チウムを負極に吸蔵させる方法が提案されている。しかしこのような方法は技術的に 容易ではなぐまた生産性が良好でない。 [0005] 特許文献 1 :特開 2005— 135906号公報 [0004] By the way, it has been proposed that lithium be occluded in advance in the negative electrode active material of a non-aqueous electrolyte secondary battery to improve the cycle characteristics of the battery (see Patent Document 3). As a method for preliminarily occluding lithium, for example, outside the battery, a negative electrode and a counter electrode such as metallic lithium are opposed to each other in contact with a nonaqueous electrolytic solution to form an electrochemical cell, and electrochemically lithium is negative electrode. A method of occluding them in the water has been proposed. However, this method is not technically easy and the productivity is not good. Patent Document 1: Japanese Patent Application Laid-Open No. 2005-135906
特許文献 2：特公平 5 - 64429号公報  Patent Document 2: Japanese Patent Publication No. 5-64429
特許文献 3 :US5556721A  Patent Document 3: US5556721A
発明の開示  Disclosure of the invention
[0006] 本発明の目的は、従来の非水電解液二次電池よりも各種性能が一層向上した非 水電解液二次電池を提供することにある。  [0006] An object of the present invention is to provide a non-aqueous electrolyte secondary battery in which various performances are further improved as compared with conventional non-aqueous electrolyte secondary batteries.
[0007] 本発明は、ピロールが 0. 2〜2molZl含有されている電解液を用いたことを特徴と する非水電解液二次電池を提供するものである。 The present invention provides a non-aqueous electrolyte secondary battery characterized by using an electrolyte containing 0.2 to 2 mol Zl of pyrrole.
図面の簡単な説明  Brief Description of Drawings
[0008] [図 1]図 1は、本発明の非水電解液二次電池における充放電曲線の一例を示すダラ フである。  FIG. 1 is a drawing showing an example of a charge / discharge curve in the nonaqueous electrolyte secondary battery of the present invention.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0009] 以下本発明を、その好ましい実施形態に基づき説明する。本発明の非水電解液二 次電池は、典型的には、負極及び正極並びに両極間に介在配置されたセパレータ を備えている。負極と正極との間には非水電解液が存在している。負極は、集電体の 少なくとも一面に活物質層が形成されてなる。活物質層は、負極活物質を含んでい る。負極活物質としては、リチウムの吸蔵が可能な物質を特に制限なく用いることがで きる。ここで言うリチウムの吸蔵が可能な物質には金属リチウムそのものは含まれない 。リチウムの吸蔵が可能な物質の例としてはグラフアイト等の炭素系材料、シリコン、ス ズ、ゲルマニウム等の第 14族元素の単体、合金、金属間化合物、酸化物、窒化物、 ホウ化物等、アルミニウム等の第 13族元素の単体、合金、金属間化合物、酸化物、 窒化物、ホウ化物等を用いることができる。特に負極活物質として、シリコンやスズを 含む材料を用いると、現在非水電解液二次電池の負極材料として用いられて！/ヽるグ ラフアイトに比較して高容量の二次電池を実現できるという利点がある。この観点から 、シリコンを含む材料を負極活物質として用いることがとりわけ好ましい。  Hereinafter, the present invention will be described based on preferred embodiments thereof. The nonaqueous electrolyte secondary battery of the present invention typically includes a negative electrode, a positive electrode, and a separator interposed between both electrodes. A non-aqueous electrolyte exists between the negative electrode and the positive electrode. The negative electrode has an active material layer formed on at least one surface of a current collector. The active material layer includes a negative electrode active material. As the negative electrode active material, a material capable of occluding lithium can be used without particular limitation. The material that can store lithium does not include metallic lithium itself. Examples of substances that can occlude lithium include carbon-based materials such as graphite, simple substances of group 14 elements such as silicon, soot, and germanium, alloys, intermetallic compounds, oxides, nitrides, borides, etc. A single group 13 element such as aluminum, an alloy, an intermetallic compound, an oxide, a nitride, or a boride can be used. In particular, when a material containing silicon or tin is used as the negative electrode active material, it is currently used as a negative electrode material for non-aqueous electrolyte secondary batteries! / There is an advantage that a high-capacity secondary battery can be realized compared to the graphite. From this viewpoint, it is particularly preferable to use a material containing silicon as the negative electrode active material.
[0010] 本発明で用いられる負極活物質としてシリコンを含む材料を用いる場合、該材料は When a material containing silicon is used as the negative electrode active material used in the present invention, the material is
、シリコン単体のみならず、シリコンと他の金属との合金、シリコンと他の金属との金属 間化合物、シリコン酸ィ匕物、シリコン窒化物、シリコンホウ化物などを用いることができ る。他の金属としては、 Co、 Ni、 Cu、 Fe、 V、 Ti、 Mn、 Cr、 W、 Mg、 Ndなどのリチウ ム化合物の形成能の低 、金属が挙げられる。「リチウム化合物の形成能の低 、」とは 、リチウムと金属間化合物若しくは固溶体を形成しないか、又は形成したとしてもリチ ゥムが微量である力若しくは非常に不安定であることを意味する。また、他の金属とし て Liを用いることもできる。 In addition to silicon alone, alloys of silicon and other metals, intermetallic compounds of silicon and other metals, silicon oxide, silicon nitride, silicon boride, etc. can be used. The Examples of other metals include metals having low ability to form lithium compounds such as Co, Ni, Cu, Fe, V, Ti, Mn, Cr, W, Mg, and Nd. The phrase “low ability to form a lithium compound” means that lithium does not form an intermetallic compound or solid solution, or even if formed, the lithium is in a very small force or very unstable. Li can also be used as another metal.
[0011] 負極活物質は、例えば薄膜の形状であり得る。この場合、化学気相蒸着法、物理 気相蒸着法、スパッタリング法等の各種薄膜形成手段によって、集電体の少なくとも 一面に薄膜からなる活物質層が形成される。この薄膜をエッチングしてその厚み方 向に延びる空隙を多数形成してもよい。エッチングには、水酸化ナトリウム水溶液等 を用いた湿式エッチング法の他、ドライガスやプラズマ等を用いた乾式エッチング法 が採用できる。 [0011] The negative electrode active material may be, for example, in the form of a thin film. In this case, an active material layer made of a thin film is formed on at least one surface of the current collector by various thin film forming means such as chemical vapor deposition, physical vapor deposition, and sputtering. The thin film may be etched to form a large number of voids extending in the thickness direction. In addition to the wet etching method using an aqueous sodium hydroxide solution, a dry etching method using a dry gas, plasma, or the like can be employed for etching.
[0012] 負極活物質は粒子の形状でもあり得る。粒子としては、例えば本出願人の先の出 願に係る US2006Z051675A1に記載のものを用いることができる。具体的には、 ィ）シリコン単体の粒子、口）シリコンの粒子と炭素の粒子との混合粒子、ノ、）シリコン の粒子と金属の粒子との混合粒子、二）シリコン及び金属の化合物粒子、ホ）シリコン 及び金属の化合物粒子と、金属の粒子との混合粒子などが挙げられる。粒子は、結 着剤及び溶剤等と混合されてなるスラリーの状態で、集電体の少なくとも一面に塗布 される。これによつて該スラリーの塗膜からなる活物質層が形成される。この塗膜を焼 成して粒子どうしを焼結させてもよい。焼結の方法としては、例えば、シリコンを含む 粒子の焼結法として、 US2004/043294A1に記載の方法を用いることができる。 或いは、粒子間にリチウム化合物の形成能の低 、金属が浸透して 、ることも好ま ヽ 。粒子間に金属が浸透していることで、充放電で体積変化することに起因して微粉化 した活物質の脱落を効果的に防ぐことができる。ここで言う浸透とは、リチウム化合物 の形成能の低 ヽ金属材料が、粒子の表面を被覆するように粒子間の空間に存在し ている状態を指し、粒子間の空間が当該金属材料で埋め尽くされていることを要しな い。むしろ当該金属材料は、粒子間に空間が存在するように粒子の表面を被覆して いることが好ましい。当該金属材料力 Sこのような状態で存在していることで、電解液が 活物質層の深部にまで確実に到達するという利点がある。また、リチウムを吸蔵した 粒子が膨張することに起因する体積の増加分が緩和されるという利点もある。 [0012] The negative electrode active material may be in the form of particles. As the particles, for example, those described in US2006Z051675A1 related to the previous application of the present applicant can be used. Specifically, ii) particles of silicon alone, mouth) mixed particles of silicon particles and carbon particles, ii) mixed particles of silicon particles and metal particles, 2) compound particles of silicon and metal, E) Mixed particles of silicon and metal compound particles and metal particles. The particles are applied to at least one surface of the current collector in a slurry state mixed with a binder, a solvent, and the like. As a result, an active material layer made of the slurry coating is formed. The coating film may be fired to sinter the particles. As a sintering method, for example, a method described in US2004 / 043294A1 can be used as a sintering method of particles containing silicon. Alternatively, it is also preferable that the lithium compound has a low ability to form a lithium and the metal penetrates between the particles. The permeation of the metal between the particles can effectively prevent the pulverized active material from falling off due to the volume change caused by charging and discharging. The term “penetration” as used herein refers to a state in which a metal compound with a low lithium compound forming ability exists in the space between particles so as to cover the surface of the particle, and the space between the particles is filled with the metal material. You don't need to be exhausted. Rather, the metal material preferably covers the surface of the particles so that there is a space between the particles. The metal material force S The existence of such a state has an advantage that the electrolyte solution surely reaches the deep part of the active material layer. Also occluded lithium There is also an advantage that the increase in volume caused by the expansion of the particles is alleviated.
[0013] 粒子間に金属を浸透させるには、スラリーの塗膜に対して電解めつきを行い、粒子 間にリチウム化合物の形成能の低い金属を析出させればよい。電解めつきによって 粒子間に金属を析出させるには、例えば本出願人の先の出願に係る US2006Z11 5735A1に記載の方法を用いることができる。具体的には、集電体上に、活物質の 粒子を含むスラリーを塗布して塗膜を形成する。スラリーは、活物質の粒子、導電性 炭素材料の粒子、結着剤及び希釈溶媒などを含んでいる。結着剤としてはポリビ-リ デンフルオライド、ポリエチレン、エチレンプロピレンジェンモノマー、スチレンブタジ ェンラバーなどが用いられる。希釈溶媒としては N—メチルピロリドン、シクロへキサン などが用いられる。スラリーの塗膜の形成後、リチウム化合物の形成能の低い金属材 料を含むめっき浴中に浸漬して電解めつきを行う。電解めつきの条件としては、例え ば銅を用いる場合、硫酸銅系溶液を用いるときには、銅の濃度を 30〜： LOOgZl、硫 酸の濃度を 50〜200gZl、塩素の濃度を 30ppm以下とし、液温を 30〜80°C、電流 密度を 1〜： LOOAZdm2とすればよい。ピロ燐酸銅系溶液を用いる場合には、銅の濃 度 2〜50gZl、ピロ燐酸カリウムの濃度 100〜700gZlとし、液温を 30〜60。C、 pH を 8〜12、電流密度を 1〜： LOAZdm2とすればよい。これらの電解条件を適宜調節 することで、リチウム化合物の形成能の低い金属材料が塗膜内に浸透して、目的とす る活物質層が形成される。 [0013] In order to infiltrate the metal between the particles, electrolytic coating is performed on the coating film of the slurry to deposit a metal having a low lithium compound forming ability between the particles. In order to deposit metal between particles by electrolytic plating, for example, the method described in US2006Z11 5735A1 according to the previous application of the present applicant can be used. Specifically, a coating film is formed by applying a slurry containing active material particles on a current collector. The slurry contains active material particles, conductive carbon material particles, a binder, a diluent solvent, and the like. As the binder, polyvinylidene fluoride, polyethylene, ethylene propylene monomer, styrene butadiene rubber or the like is used. Diluent solvents such as N-methylpyrrolidone and cyclohexane are used. After the slurry coating is formed, it is immersed in a plating bath containing a metal material having a low lithium compound forming ability to perform electroplating. For example, when using copper, or when using a copper sulfate-based solution, the electrolytic plating conditions may be as follows: the copper concentration is 30 to: LOOgZl, the sulfuric acid concentration is 50 to 200 gZl, and the chlorine concentration is 30 ppm or less. 30 ~ 80 ° C, current density 1 ~: LOOAZdm 2 . When using a copper pyrophosphate solution, the copper concentration is 2-50 gZl, the potassium pyrophosphate concentration is 100-700 gZl, and the solution temperature is 30-60. C, pH 8-12, current density 1-: LOAZdm 2 . By appropriately adjusting these electrolysis conditions, a metal material having a low lithium compound forming ability penetrates into the coating film, and a target active material layer is formed.
[0014] 一方、正極は、集電体の少なくとも一面に活物質層が形成されてなる。活物質層は 正極活物質を含んでいる。正極活物質としては含 Liィ匕合物が用いられる。含 Li化合 物としては、電気化学的にリチウムを吸蔵 ·放出可能な物質が用いられる。例えば、リ チウムを含む層状化合物である LiCoOや LiNiOなどを用いることができる。或いは  On the other hand, the positive electrode has an active material layer formed on at least one surface of a current collector. The active material layer contains a positive electrode active material. A Li-containing compound is used as the positive electrode active material. As the Li-containing compound, a substance capable of electrochemically absorbing and releasing lithium is used. For example, LiCoO or LiNiO which are layered compounds containing lithium can be used. Or
2 2  twenty two
、リチウムを含むスピネル構造の化合物である LiMo Oなどを用いることができる。活  LiMo 2 O, which is a spinel structure compound containing lithium, can be used. Life
2 4  twenty four
物質層は、これら正極活物質の粒子が、結着剤及び溶剤等と混合されてなるスラリー の状態で、集電体の少なくとも一面に塗布されて形成される。  The material layer is formed by applying these positive electrode active material particles to at least one surface of a current collector in a slurry state in which the particles are mixed with a binder and a solvent.
[0015] 負極にぉ 、て、活物質層を支持する集電体は、リチウム化合物の形成能の低!、金 属材料から一般に構成される。そのような金属材料としては、例えば銅、ニッケル、鉄 、コバルト又はこれらの合金などが挙げられる。一方、正極において、活物質層を支 持する集電体としては、一般にアルミニウム箔が用いられる。 [0015] The current collector that supports the active material layer on the negative electrode is generally composed of a metal material having a low ability to form a lithium compound. Examples of such a metal material include copper, nickel, iron, cobalt, and alloys thereof. On the other hand, the active material layer is supported in the positive electrode. As the current collector to be held, an aluminum foil is generally used.
[0016] 正極と負極とを隔てるセパレータの種類には特に制限はなぐ従来この種の材料と して用いられているものと同様のものを用いることができる。例えば合成樹脂製不織 布、ポリエチレンやポリプロピレンの多孔質フィルム等が好ましく用いられる。  [0016] There are no particular restrictions on the type of separator that separates the positive electrode and the negative electrode, and the same separator as that conventionally used as this type of material can be used. For example, a synthetic resin nonwoven fabric, a polyethylene or polypropylene porous film, or the like is preferably used.
[0017] 非水電解液としては、非水溶媒に支持電解質を溶解してなるものが用いられる。非 水溶媒としては、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネ ート、ジェチルカーボネート、ジメチルカーボネートなどが挙げられる。これらの非水 溶媒は 2種以上を組み合わせて用いることもできる。  [0017] As the nonaqueous electrolytic solution, a solution obtained by dissolving a supporting electrolyte in a nonaqueous solvent is used. Nonaqueous solvents include ethylene carbonate, propylene carbonate, butylene carbonate, jetyl carbonate, dimethyl carbonate and the like. These non-aqueous solvents can be used in combination of two or more.
[0018] 特に、負極活物質としてシリコンを含む材料を用いる場合には、非水電解液の溶媒 として、プロピレンカーボネート（以下、 PCともいう）と、ジェチルカーボネート（以下、 DECとも!/、う）ゃジメチルカーボネートなどのジアルキルカーボネート（以下、 DACと もいう）との混合溶媒を用いることが好ましい。これによつて、温度特性やサイクル特 性を高めることができる。詳細には、 PCを用いることで電池のサイクル特性が向上し 、 DACを用いることで電池の温度特性が向上する。  [0018] In particular, when a material containing silicon is used as the negative electrode active material, propylene carbonate (hereinafter also referred to as PC) and jetyl carbonate (hereinafter also referred to as DEC! /) Are used as a solvent for the non-aqueous electrolyte. It is preferable to use a mixed solvent with dialkyl carbonate such as dimethyl carbonate (hereinafter also referred to as DAC). As a result, temperature characteristics and cycle characteristics can be improved. Specifically, the cycle characteristics of the battery are improved by using a PC, and the temperature characteristics of the battery are improved by using a DAC.
[0019] PCと DACとは広い容積比の範囲で混合可能である。具体的には、混合溶媒にお ける PCと DACとの容積比（前者：後者）は好ましくは 5： 95〜95： 5であり、更に好ま しくは20 : 80〜70 : 30でぁる。 PCの容積比が 95%超になると、非水電解液二次電 池にお 、て一般的に使用されるセパレータとの濡れ性が低くなる傾向にあり、電解質 の流通が円滑にならないことがある。一方、 DACの容積比が 95%超になると、混合 溶媒全体としての極性が低下し、電解質の溶解が困難になる場合がある。  [0019] PC and DAC can be mixed within a wide range of volume ratios. Specifically, the volume ratio of PC to DAC (the former: the latter) in the mixed solvent is preferably 5:95 to 95: 5, more preferably 20:80 to 70:30. When the volume ratio of the PC exceeds 95%, the non-aqueous electrolyte secondary battery tends to have low wettability with a separator that is generally used, and the electrolyte distribution may not be smooth. is there. On the other hand, if the volume ratio of DAC exceeds 95%, the polarity of the entire mixed solvent may decrease, making it difficult to dissolve the electrolyte.
[0020] DACとしては、例えばジェチルカーボネート又はジメチルカーボネートの何れか一 方を用いることもでき、或いは両者を併用することもできる。特にジェチルカーボネー トは凝固点が低ぐ氷点下での電池使用が可能となることから好ましい。  [0020] As the DAC, for example, either jetyl carbonate or dimethyl carbonate can be used, or both can be used in combination. Jetyl carbonate is particularly preferable because it allows the battery to be used below freezing point where the freezing point is low.
[0021] なお、非水電解液の溶媒として PCと DACの混合溶媒を用いる場合、 PC及び DA C以外の溶媒を更に用いることは何ら妨げられない。尤も、 PCと DACの混合溶媒を 用いた場合の効果を最大限発揮させるためには、 PC及び DACのみを用い、且つ他 の非水溶媒は用いな 、ことが最も好まし 、。  [0021] When a mixed solvent of PC and DAC is used as the solvent for the non-aqueous electrolyte, further use of a solvent other than PC and DAC is not hindered. However, in order to maximize the effects of using a mixed solvent of PC and DAC, it is most preferable to use only PC and DAC and no other non-aqueous solvent.
[0022] 非水溶媒に溶解される支持電解質としては、この種の物質として従来用いられて 、 るものと同様のものを特に制限なく用いることができる。例えば LiClO、 LiAlCl、 Li [0022] As a supporting electrolyte dissolved in a non-aqueous solvent, conventionally used as this type of substance, A thing similar to the above can be used without particular limitation. For example, LiClO, LiAlCl, Li
4 4 4 4
PF、 LiAsF、 LiSbF、 LiSCNゝ LiCl、 LiBrゝ Lil、 LiCF SO、 LiC F SO等が挙PF, LiAsF, LiSbF, LiSCN ゝ LiCl, LiBr ゝ Lil, LiCF SO, LiC F SO, etc.
6 6 6 3 3 4 9 3 げられる。これらの支持電解質は単独で、又は 2種以上を組み合わせて用いることが できる。 6 6 6 3 3 4 9 3 These supporting electrolytes can be used alone or in combination of two or more.
[0023] 本発明者らの検討の結果、非水電解液に、所定濃度のピロールを含有させること が有利であることが判明した。所定濃度のピロールを含有させることによって、高い放 電電圧が得られ、またサイクル特性が向上するという効果が奏される。この理由は次 のとおりである。  [0023] As a result of the study by the present inventors, it has been found that it is advantageous that the non-aqueous electrolyte contains a predetermined concentration of pyrrole. By containing a predetermined concentration of pyrrole, a high discharge voltage can be obtained, and the cycle characteristics can be improved. The reason for this is as follows.
[0024] 例えば負極活物質としてシリコンを含む材料を用い、また正極活物質として LiCoO を用いて二次電池を組み、初回の充電を行うと、ピロールの重合体、即ちポリピロ一 [0024] For example, when a secondary battery is assembled using a material containing silicon as the negative electrode active material and LiCoO as the positive electrode active material and charged for the first time, a polymer of pyrrole, that is, polypyrrole
2 2
ルが正極上に電解しその表面に被膜を形成することが本発明者らの検討の結果判 明した。生成したポリピロールは、支持電解質の種類に応じて種々の形態となる。例 えば支持電解質として例えば LiPFを用いた場合には、 [ (C H N+) PFつの形態に  As a result of the study by the present inventors, it was found that the electrolyte was electrolyzed on the positive electrode to form a film on the surface. The produced polypyrrole takes various forms depending on the type of the supporting electrolyte. For example, when LiPF is used as the supporting electrolyte, [(C H N +) PF forms
6 4 3 3 6 X なっている。ピロールが電解する電圧は、約 2. 5— 3. 2V (対 Li)である。この様子を 図 1に示す。この電解に対応して、負極においては、非水電解液中に存在するリチウ ムイオンがシリコンに吸蔵される。初回の充電が完了した後、電池に負荷をかけて放 電を行うと電圧が次第に低下してくる（図 1参照)。この場合、放電のカット'オフ電圧 をピロールの電解析出の電圧よりも高い値である約 2. 9- 3. 3Vに設定して、シリコ ン中に Liが吸蔵された状態力 2回目の充電を開始すると、 2回目以降の充放電が ほぼ 100%可逆的に行われるようになる。 Liが吸蔵された状態にあるシリコンを充電 することは、電池に組み込む前力 シリコンに Liを吸蔵させておいた状態と同じ状態 が実現されることを意味する。これによつて、図 1に示すように、 2回目以降の放電に おいては、初回の放電よりも高い放電電圧が得られる。また、電池に組み込む前から シリコンに Liを吸蔵させておいた状態と同じ状態が本発明において実現されることは 、シリコンへの Liの吸蔵を容易に且つ生産性よく行えるという点で極めて有利である  6 4 3 3 6 X The voltage at which pyrrole is electrolyzed is about 2.5-3.2 V (vs. Li). This is shown in Figure 1. Corresponding to this electrolysis, in the negative electrode, lithium ions present in the non-aqueous electrolyte are occluded by silicon. After the first charge is completed, when the battery is loaded and discharged, the voltage gradually decreases (see Fig. 1). In this case, the discharge cut'off voltage is set to about 2.9-3.3V, which is higher than the voltage of electrolytic deposition of pyrrole, and the state force in which Li is occluded in the silicon is second. When charging starts, the second and subsequent charging / discharging is almost 100% reversible. Charging silicon in a state in which Li is occluded means that the same state as in the case where Li is occluded in the pre-load silicon incorporated into the battery is realized. As a result, as shown in FIG. 1, in the second and subsequent discharges, a higher discharge voltage is obtained than in the first discharge. In addition, the fact that the same state as that in which Li is occluded in silicon before being incorporated in the battery is realized in the present invention is extremely advantageous in that Li can be occluded in silicon easily and with high productivity. is there
[0025] その上、各回の放電時には、シリコン中に Liが常時吸蔵された状態になっているの で、その電子伝導性が常に良好な状態にあり、負極の分極が小さくなる。これによつ て、放電末期における負極の電圧の急激な低下が起こりに《なる。また、正極が 4. 3V以上の高電位にさらされないので、正極の劣化も防止される。これらの結果、電 池のサイクル特性が向上する。 [0025] In addition, at each discharge, Li is always occluded in the silicon, so that the electron conductivity is always in a good state and the polarization of the negative electrode is reduced. This Thus, the voltage of the negative electrode suddenly drops at the end of discharge. Moreover, since the positive electrode is not exposed to a high potential of 4.3 V or more, the deterioration of the positive electrode is prevented. As a result, the cycle characteristics of the battery are improved.
[0026] しかも、ピロールの電解析出によって正極の表面に形成された被膜によって正極活 物質の高温保存性が高くなるという利点もある。特に正極活物質として高温保存性に 難のある物質であるリチウムマンガン酸ィ匕物を用いた場合であっても、高温保存中に おけるマンガンの溶出を効果的に防止できる。  In addition, there is an advantage that the high-temperature storage stability of the positive electrode active material is enhanced by the coating formed on the surface of the positive electrode by electrolytic deposition of pyrrole. In particular, elution of manganese during high-temperature storage can be effectively prevented even when lithium manganate, which is a material that is difficult to store at high temperatures, is used as the positive electrode active material.
[0027] 先に述べたとおり、初回の充電時、負極活物質に吸蔵される Liは、正極活物質から ではなぐ電解液中のリチウムイオン力 供給される。この観点から、電解液中に含ま れる支持電解質の濃度は、従来の非水電解液二次電池における支持電解質の濃度 よりも高めに設定しておくことが好ましい。具体的には、 0. 5〜2molZl、特に l〜2m olZlであることが好ましい。支持電解質の種類は先に述べたとおりである力 それら のうち、ポリピロールの形成性の点力も LiPFを用いることが好ましい。  [0027] As described above, during the initial charge, Li that is occluded in the negative electrode active material is supplied by the lithium ion force in the electrolyte that is different from the positive electrode active material. From this viewpoint, it is preferable that the concentration of the supporting electrolyte contained in the electrolytic solution is set higher than the concentration of the supporting electrolyte in the conventional non-aqueous electrolyte secondary battery. Specifically, 0.5 to 2 molZl, particularly 1 to 2 molZl is preferable. The types of supporting electrolytes are as described above. Among them, it is preferable to use LiPF for the point of formation of polypyrrole.
6  6
[0028] 電解液におけるピロールの濃度は、先に述べたとおり 0. 2〜2molZlに設定し、好 ましくは 0. 5〜2molZl、更に好ましくは l〜2molZlに設定する。ピロールの濃度が 0. 2molZl未満では、リチウムが負極活物質に十分に供給されないこととなってしま う。一方、ピロールの濃度が 2molZl超では、電解液中のリチウム量に対してピロ一 ルの量が過剰になってしまう。  [0028] The concentration of pyrrole in the electrolytic solution is set to 0.2 to 2 molZl as described above, preferably 0.5 to 2 molZl, and more preferably 1 to 2 molZl. If the pyrrole concentration is less than 0.2 molZl, lithium will not be sufficiently supplied to the negative electrode active material. On the other hand, if the concentration of pyrrole exceeds 2 molZl, the amount of pyrrole will be excessive relative to the amount of lithium in the electrolyte.
[0029] 本発明の二次電池の形態は、コイン型や円筒型、角型であり得る。例えば本発明 の二次電池は、負極と正極との間にセパレータを介在させ、これら三者を卷回させて 卷回体を形成し、該卷回体を電池容器内に収容してなるジェリーロールタイプの電 池（円筒型電池や角型電池）とすることができる。  [0029] The form of the secondary battery of the present invention may be a coin type, a cylindrical type, or a square type. For example, in the secondary battery of the present invention, a separator is interposed between the negative electrode and the positive electrode, these three members are wound to form a wound body, and the wound body is accommodated in a battery container. A roll type battery (cylindrical battery or prismatic battery) can be used.
実施例  Example
[0030] 以下、実施例により本発明を更に詳細に説明する。し力しながら本発明の範囲はか 力る実施例に制限されるものではない。特に断らない限り「％」及び「部」はそれぞれ「 重量％」及び「重量部」を意味する。  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such embodiments. Unless otherwise specified, “%” and “part” mean “% by weight” and “part by weight”, respectively.
[0031] 〔実施例 1〕  [Example 1]
(1)負極の製造 厚さ 18 /z mの電解銅箔力もなる集電体を室温で 30秒間酸洗浄した。処理後、 15 秒間純水洗浄した。集電体上に Siの粒子を含むスラリーを膜厚 15 mになるように 塗布し塗膜を形成した。粒子の平均粒径は 2 mであった。スラリーの組成は、粒子: スチレンブタジエンラバー（結着剤） = 100 : 1. 7 (重量比）であった。 (1) Manufacture of negative electrode A current collector having an electrolytic copper foil strength of 18 / zm in thickness was acid-washed at room temperature for 30 seconds. After the treatment, it was washed with pure water for 15 seconds. A slurry containing Si particles was applied on the current collector to a thickness of 15 m to form a coating film. The average particle size was 2 m. The composition of the slurry was particles: styrene butadiene rubber (binder) = 100: 1.7 (weight ratio).
[0032] 塗膜が形成された集電体を、以下の浴組成を有するピロリン酸銅浴に浸漬させ、電 解めつきにより塗膜中の粒子間に銅を析出させて活物質層を形成した。この電解め つきによって塗膜の厚み方向全域にわたって銅が析出した。このようにして負極を製 造した。電解の条件は以下の通りとした。陽極には DSEを用いた。電源は直流電源 を用いた。 [0032] The current collector on which the coating film is formed is immersed in a copper pyrophosphate bath having the following bath composition, and copper is deposited between particles in the coating film by electrolysis to form an active material layer. did. By this electrolytic plating, copper was deposited over the entire thickness direction of the coating film. In this way, a negative electrode was produced. The electrolysis conditions were as follows. DSE was used for the anode. A DC power source was used as the power source.
'ピロリン酸銅三水和物： 105gZl  'Copper pyrophosphate trihydrate: 105gZl
•ピロリン酸カリウム： 450g/l  • Potassium pyrophosphate: 450g / l
'硝酸カリウム： 30gZl  'Potassium nitrate: 30gZl
'浴温度： 50°C  'Bath temperature: 50 ° C
•電流密度： 3AZdm2 • Current density: 3AZdm 2
•pH：アンモニア水とポリリン酸を添カ卩して pH8. 2になるように調整した。  • pH: Ammonia water and polyphosphoric acid were added to adjust to pH 8.2.
[0033] (2)正極の製造 [0033] (2) Production of positive electrode
正極活物質として平均粒径 20 /z mの LiCoOの粉末を用いた。この粉末 90部と、  LiCoO powder having an average particle size of 20 / z m was used as the positive electrode active material. 90 parts of this powder,
2  2
導電剤としてのアセチレンブラック 5部を、結着剤としてのポリフッ化ビ-リデン 5部を 含む 5%の N—メチルピロリドン溶液に混合してスラリーを得た。このスラリーを、集電 体であるアルミニウム箔の上に塗布し、乾燥した後圧延して正極を製造した。  A slurry was obtained by mixing 5 parts of acetylene black as a conductive agent with a 5% N-methylpyrrolidone solution containing 5 parts of polyvinylidene fluoride as a binder. This slurry was applied onto an aluminum foil as a current collector, dried, and then rolled to produce a positive electrode.
[0034] (3)二次電池の製造  [0034] (3) Manufacture of secondary batteries
得られた負極及び正極を、ポリエチレン多孔質フィルム力もなるセパレータを介して 対向させ、電池ケース内に収容した。電解液としては、 PC及び DECを表 1に示す容 積比で混合した混合溶媒に、表 1に示す支持電解質を同表に示す濃度で溶解した ものを用いた。また電解液には、表 1に示す濃度のピロールを含有させておいた。  The obtained negative electrode and positive electrode were opposed to each other through a separator having a polyethylene porous film force and accommodated in a battery case. As the electrolytic solution, a solution obtained by dissolving the supporting electrolyte shown in Table 1 in a mixed solvent in which PC and DEC were mixed at a volume ratio shown in Table 1 at a concentration shown in the same table was used. In addition, the electrolyte solution contained pyrrole at the concentrations shown in Table 1.
[0035] (4)評価  [0035] (4) Evaluation
得られた二次電池につ!、て、 100サイクル容量維持率を以下の方法で測定した。 その結果を表 1に示す。 [0036] 〔100サイクル容量維持率〕 With respect to the obtained secondary battery, the 100 cycle capacity retention rate was measured by the following method. The results are shown in Table 1. [100 cycle capacity maintenance rate]
100サイクル後の放電容量を測定し、その値を最大負極放電容量で除し、 100を 乗じて算出した。放電のカット'オフ電圧は 2. 7Vとした。充電は、初回は定電流 '定 電圧モード、 2回目以降は定電流モードとした。放電は、初回は定電流'定電圧モー ド、 2回目以降は定電流モードとした。  The discharge capacity after 100 cycles was measured, and the value was divided by the maximum negative electrode discharge capacity and multiplied by 100. The discharge cut-off voltage was 2.7V. Charging was performed in the constant current mode and the constant voltage mode for the first time, and in the constant current mode for the second and subsequent times. Discharge was in constant current 'constant voltage mode for the first time and in constant current mode for the second and subsequent times.
[0037] 〔実施例 2ないし 4及び比較例 1〕 [Examples 2 to 4 and Comparative Example 1]
電解液における溶媒及び支持電解質の種類として表 1に示すものを用いた以外は 実施例 1と同様にして二次電池を得た。得られた二次電池につ!/、て実施例 1と同様 の評価を行った。この結果を表 1に示す。  A secondary battery was obtained in the same manner as in Example 1 except that the solvents shown in Table 1 were used as the solvent and the supporting electrolyte in the electrolytic solution. The obtained secondary battery was evaluated in the same manner as in Example 1. The results are shown in Table 1.
[0038] [表 1] [0038] [Table 1]
Figure imgf000011_0001
Figure imgf000011_0001
[0039] 表 1に示す結果から明らかなように、電解液中にピロールが含有されている各実施 例の二次電池は、ピロールが含有されて 、なレ、比較例の二次電池に比べてサイクル 特性が向上することが判る。また、実施例 1及び 2と実施例 3及び 4との対比から明ら かなように、非水溶媒として PCと DECの混合溶媒を用いることで、サイクル特性が一 層向上することが判る。 [0039] As is apparent from the results shown in Table 1, the secondary batteries of the examples in which pyrrole is contained in the electrolytic solution contain pyrrole and are compared with the secondary batteries of comparative examples. It can be seen that the cycle characteristics are improved. Further, as is clear from the comparison between Examples 1 and 2 and Examples 3 and 4, it can be seen that the cycle characteristics are further improved by using a mixed solvent of PC and DEC as the non-aqueous solvent.
産業上の利用可能性  Industrial applicability
[0040] 以上、詳述したとおり、本発明の非水電解液二次電池によれば、高い放電電圧が 得られ、またサイクル特性が向上する。 As described above, according to the nonaqueous electrolyte secondary battery of the present invention, a high discharge voltage can be obtained and the cycle characteristics can be improved.

Claims

請求の範囲 The scope of the claims
[1] ピロールが 0. 2〜2molZl含有されている電解液を用いたことを特徴とする非水電 解液二次電池。  [1] A non-aqueous electrolyte secondary battery using an electrolytic solution containing 0.2 to 2 molZl of pyrrole.
[2] 前記電解液における支持電解質の濃度が 0. 5〜2molZlである請求の範囲第 1 項記載の非水電解液二次電池。  [2] The nonaqueous electrolyte secondary battery according to [1], wherein the concentration of the supporting electrolyte in the electrolyte is 0.5 to 2 molZl.
[3] 前記支持電解質が LiPFである請求の範囲第 2項記載の非水電解液二次電池。 [3] The nonaqueous electrolyte secondary battery according to [2], wherein the supporting electrolyte is LiPF.
6  6
[4] 負極活物質としてリチウムの吸蔵が可能な物質を用いた請求の範囲第 1項記載の 非水電解液二次電池。  [4] The non-aqueous electrolyte secondary battery according to claim 1, wherein a material capable of occluding lithium is used as the negative electrode active material.
[5] 負極活物質としてシリコン又はスズを含む材料を用いた請求の範囲第 4項記載の 非水電解液二次電池。  [5] The nonaqueous electrolyte secondary battery according to claim 4, wherein a material containing silicon or tin is used as the negative electrode active material.
PCT/JP2007/050384 2006-01-30 2007-01-15 Nonaqueous electrolyte secondary battery WO2007086264A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006-021517 2006-01-30
JP2006021517A JP2007207443A (en) 2006-01-30 2006-01-30 Nonaqueous electrolyte secondary battery

Publications (1)

Publication Number Publication Date
WO2007086264A1 true WO2007086264A1 (en) 2007-08-02

Family

ID=38309059

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2007/050384 WO2007086264A1 (en) 2006-01-30 2007-01-15 Nonaqueous electrolyte secondary battery

Country Status (2)

Country Link
JP (1) JP2007207443A (en)
WO (1) WO2007086264A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103715456A (en) * 2013-07-18 2014-04-09 江西优锂新材股份有限公司 Lithium ion battery high-voltage electrolyte preparation method
EP4333131A1 (en) * 2022-08-29 2024-03-06 Toyota Jidosha Kabushiki Kaisha Aqueous potassium ion battery

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5394610B2 (en) * 2007-02-20 2014-01-22 パナソニック株式会社 Nonaqueous electrolyte secondary battery
JP5126570B2 (en) * 2007-03-12 2013-01-23 株式会社デンソー Method for manufacturing lithium secondary battery
CN104332649B (en) * 2014-09-09 2016-12-07 上海纳米技术及应用国家工程研究中心有限公司 A kind of electrolyte and its preparation method and application

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0359963A (en) * 1989-07-27 1991-03-14 Yuasa Battery Co Ltd Lithium secondary battery
JPH087921A (en) * 1994-06-21 1996-01-12 Fujitsu Ltd Electrolyte for secondary cell
JPH08236158A (en) * 1995-02-27 1996-09-13 Fuji Photo Film Co Ltd Non aqueous secondary battery
JP2000090970A (en) * 1998-09-14 2000-03-31 Matsushita Electric Ind Co Ltd Lithium secondary battery
JP2002008719A (en) * 2000-06-27 2002-01-11 Mitsui Chemicals Inc Nonaqueous electrolyte and secondary battery using the same
JP2003297422A (en) * 2002-04-02 2003-10-17 Sony Corp Battery

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0359963A (en) * 1989-07-27 1991-03-14 Yuasa Battery Co Ltd Lithium secondary battery
JPH087921A (en) * 1994-06-21 1996-01-12 Fujitsu Ltd Electrolyte for secondary cell
JPH08236158A (en) * 1995-02-27 1996-09-13 Fuji Photo Film Co Ltd Non aqueous secondary battery
JP2000090970A (en) * 1998-09-14 2000-03-31 Matsushita Electric Ind Co Ltd Lithium secondary battery
JP2002008719A (en) * 2000-06-27 2002-01-11 Mitsui Chemicals Inc Nonaqueous electrolyte and secondary battery using the same
JP2003297422A (en) * 2002-04-02 2003-10-17 Sony Corp Battery

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103715456A (en) * 2013-07-18 2014-04-09 江西优锂新材股份有限公司 Lithium ion battery high-voltage electrolyte preparation method
EP4333131A1 (en) * 2022-08-29 2024-03-06 Toyota Jidosha Kabushiki Kaisha Aqueous potassium ion battery

Also Published As

Publication number Publication date
JP2007207443A (en) 2007-08-16

Similar Documents

Publication Publication Date Title
US11355739B2 (en) Passivation of lithium metal by two-dimensional materials for rechargeable batteries
JP5230904B2 (en) Non-aqueous electrolyte secondary battery
US8697286B2 (en) Anode active material, anode including the anode active material, method of manufacturing the anode, and lithium battery including the anode
TWI521773B (en) Porous silicon-based anode active material, method of preparing the same, and lithium secondary battery including the anode active material
TWI506838B (en) Nonaqueous electrolyte storage battery and manufacturing method thereof
JP4837614B2 (en) Lithium secondary battery
US9831500B2 (en) Porous electrode active material and secondary battery including the same
US20070057228A1 (en) High performance composite electrode materials
US20080226988A1 (en) Nonaqueous electrolyte secondary battery
WO2008038798A1 (en) Non-aqueous electrolyte secondary battery
JP5098192B2 (en) COMPOSITE PARTICLE FOR LITHIUM SECONDARY BATTERY, ITS MANUFACTURING METHOD, AND LITHIUM SECONDARY BATTERY USING THE SAME
JP2002015729A (en) Nonaqueous electrolyte secondary battery
WO2012064531A1 (en) High capacity alloy anodes and lithium-ion electrochemical cells containing same
KR20160081692A (en) Silicon-based anode active material, method of preparing the same, anode including the silicon-based anode active material, and lithium secondary battery including the anode
JP2007184261A (en) Lithium-ion secondary battery
CN112055902A (en) Negative electrode for lithium ion secondary battery
KR20140058928A (en) The non-aqueous and high-capacity lithium secondary battery
JP2007109423A (en) Manufacturing method of nonaqueous electrolyte secondary battery, and its anode
WO2007086264A1 (en) Nonaqueous electrolyte secondary battery
JPH11297311A (en) Negative electrode material for nonaqueous secondary battery
JP2007273224A (en) Nonaqueous electrolyte secondary battery
JP5360860B2 (en) Non-aqueous electrolyte secondary battery
WO2009084329A1 (en) Positive electrode for nonaqueous electrolyte secondary battery
KR101862774B1 (en) Negative electrode active material for rechargable lithium battery, method for manufacturing the same, and rechargable lithium battery including the same
WO2007083583A1 (en) Nonaqueous electrolyte secondary battery

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07706725

Country of ref document: EP

Kind code of ref document: A1