WO2016192389A1 - 一种锂硫电池复合正极材料及其制备方法 - Google Patents

一种锂硫电池复合正极材料及其制备方法 Download PDF

Info

Publication number
WO2016192389A1
WO2016192389A1 PCT/CN2015/099570 CN2015099570W WO2016192389A1 WO 2016192389 A1 WO2016192389 A1 WO 2016192389A1 CN 2015099570 W CN2015099570 W CN 2015099570W WO 2016192389 A1 WO2016192389 A1 WO 2016192389A1
Authority
WO
WIPO (PCT)
Prior art keywords
sulfur
lithium
conductive agent
sulfur battery
positive electrode
Prior art date
Application number
PCT/CN2015/099570
Other languages
English (en)
French (fr)
Inventor
周成冈
周吟
闫允潘
韩波
吴金平
Original Assignee
中国地质大学（武汉）
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 中国地质大学（武汉） filed Critical 中国地质大学（武汉）
Publication of WO2016192389A1 publication Critical patent/WO2016192389A1/zh

Links

Images

Classifications

    • 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
    • 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
    • H01M4/625—Carbon or graphite
    • 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
    • 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 invention relates to the technical field of lithium-sulfur batteries, in particular to a lithium-sulfur battery composite cathode material and a preparation method thereof.
  • the monosulfide cathode material is electrochemically reacted with S 8 +16Li ⁇ 8Li 2 S, and its specific capacity is as high as 1675 mAh ⁇ g -1 . It is the highest energy density in the known solid cathode material, and the sulfur is abundant in reserves, low in price and safe. Low toxicity, so it has a very broad application prospects.
  • the sulfur element is an electronic insulator (5 ⁇ 10 -30 S ⁇ cm -1 , 25 ° C)
  • the high-valent lithium polysulfide formed during the discharge process the lithium-sulfur battery is at different discharge voltages, lithium reacts with sulfur to form Lithium polysulfide with different valence sulfur
  • the products formed from high valence state to low valence state are Li 2 S 8 , Li 2 S 6 , Li 2 S 4 , Li 2 S 3 , Li 2 S 2 , Li 2 S ) Soluble in the electrolyte, forming a so-called "shuttle effect" which seriously affects the battery life and affects the application of lithium-sulfur batteries in actual production.
  • the shuttle effect caused by the dissolution of polysulfide significantly reduces sulfur utilization, specific capacity and cycle performance, while increasing the viscosity of the electrolyte and the migration resistance of ions; as the discharge progresses, the final product of the poor conductivity discharge Li 2 S and Li 2 S 2 may cover the surface of the positive electrode active material in the form of a solid film, thereby hindering the electrochemical reaction between the electrolyte and the electrode active material. Therefore, how to suppress the diffusion of polysulfide and improve the conductivity during the sulfur cathode cycle is the research focus of lithium-sulfur battery cathode materials.
  • the technical problem to be solved by the present invention is to provide a lithium-sulfur battery composite positive electrode material having a high initial capacity and good cycle performance at a high discharge rate and a preparation method thereof, in view of the above-mentioned deficiencies in the prior art.
  • the technical solution provided by the present invention is:
  • a lithium-sulfur battery composite cathode material comprising a conductive agent having a mesoporous structure, sulfur and a modifier dispersed in a pore of a conductive agent, wherein the modifier is chemically bonded and electrically conductive
  • the pores of the agent are connected, and the mass ratio of each component is 30 to 59.4% of the conductive agent, 40 to 60% of the sulfur, and 0.1 to 10% of the modifier.
  • the conductive agent is a mesoporous carbon material having a pore size distribution of 2-10 nm, a specific surface area of 500-800 m 2 /g, and a hydrophilic functional group at the opening of the cell;
  • the modifier is glucose, galactose One of deoxyribose.
  • the mesoporous carbon material is obtained by activation of a carbon material by preparing a solid KOH and a carbon material uniformly mixed at a mass ratio of 1-5:1, and then placing it in a tube furnace with hydrogen gas and The mixed gas of nitrogen is a protective atmosphere in which the volume ratio of hydrogen is 1-5%, calcined at 650-850 ° C for 0.5-1.5 h, and then the calcined product is washed successively with dilute hydrochloric acid and deionized water until neutral, and finally dried to obtain a medium. Hole carbon material.
  • the carbon material is a multi-walled carbon nanotube, a carbon nanofiber or a carbon nanosphere.
  • the hydrophilic functional group is a hydroxyl group or a carboxyl group.
  • the invention also provides a preparation method of the above lithium-sulfur battery composite cathode material, the steps of which are as follows:
  • the conductive agent in the step 1) is a mesoporous carbon material having a pore diameter of 2-10 nm, a specific surface area of 500-800 m 2 /g, and a hydrophilic functional group at the opening of the pore.
  • the modifying agent is a polyhydroxy sugar.
  • the modifying agent is selected from the group consisting of a monosaccharide, a disaccharide, an oligosaccharide, or a combination thereof.
  • the modifying agent is one of glucose, galactose, and deoxyribose.
  • the mesoporous carbon material is obtained by activation of a carbon material by preparing a solid KOH and a carbon material uniformly mixed at a mass ratio of 1-5:1, and then placing it in a tube furnace with hydrogen gas and The mixed gas of nitrogen is a protective atmosphere in which the volume ratio of hydrogen is 1-5%, calcined at 650-850 ° C for 0.5-1.5 h, and then the calcined product is washed successively with dilute hydrochloric acid and deionized water until neutral, and finally dried to obtain a medium. Hole carbon material.
  • the carbon material is a multi-walled carbon nanotube, a carbon nanofiber or a carbon nanosphere.
  • the hydrophilic functional group is a hydroxyl group and a carboxyl group.
  • the sonication time of step 2) is 30-60 min, and the ultrasonic frequency is 20-25 kHz.
  • the principle of the invention is that the conductive agent of the invention is a mesoporous structure, the electrochemically active substance sulfur is dispersed in the pores of the conductive agent, and the modifying agent (sugar) is chemically bonded to the active part of the orifice of the conductive agent. Connect to adjust the performance of the orifice.
  • the modification of the composite by the saccharide radical generated by the hydrothermal reaction of glucose and the like ensures that the lithium-sulfur cathode material selectively allows passage of lithium ions and inhibits the passage of polysulfide ions.
  • the sugar radicals at the pores have a certain adsorption effect on the lithium polysulfide, which prevents the polysulfide from overflowing from the pores and dissolves;
  • the hydrophilic radicals of the carbohydrate radicals and the mesoporous carbon pores The chemical bonding has a shrinkage effect, and the size of the orifice is adjusted to some extent, and the passage of polysulfide is inhibited to some extent without affecting the free passage of lithium ions having a small radius, thereby hindering the dissolution of lithium polysulfide.
  • the present invention mainly has the following advantages: First, the modifier (saccharide) used in the experiment can be achieved when the content is very low (the mass ratio in the composite positive electrode material is 0.6%). Very good cycle stability effect, which greatly reduces the loss of energy density of the positive electrode material; second, hydrothermal decomposition of sugars into hydrophilic radicals of mesoporous carbon material orifices for orientation Chemical bonding can ensure the uniform dispersion and distribution of carbohydrate radicals on the positive electrode material. Third, the chemical bonding of the carbohydrate free radicals with the hydrophilic functional groups of mesoporous carbon pores can ensure the efficiency of carbohydrate free radicals. The use of the channel selectively allows lithium ions to be efficiently embedded and removed to inhibit the passage of polysulfide ions, thereby improving the cycle performance of the lithium-sulfur battery.
  • the beneficial effects of the invention are as follows: 1.
  • the preparation method of the invention is simple, and the prepared lithium-sulfur battery composite cathode material is chemically bonded with a hydrophilic radical generated by a saccharide decomposition reaction such as glucose and a hydrophilic functional group at a mesoporous carbon hole. Effectively inhibiting the dissolution of polysulfide under the premise of free passage of lithium ions; 2.
  • the invention greatly increases the transmission channel of lithium ions by activating carbon materials (carbon nanotubes, carbon nanofibers or carbon nanospheres).
  • the lithium ion can be quickly embedded and removed, so that the material can be quickly charged and discharged, and has high rate performance, and the use of the modifier makes the lithium-sulfur battery using the composite positive electrode material prepared by the invention have high rate stability performance and can effectively reduce the capacity.
  • the loss and the "shuttle effect” caused by the “shuttle effect” caused by the dissolution of lithium polysulfide caused the corrosion of the lithium negative electrode and the rapid decay of the capacity, thereby significantly improving the cycle performance of the lithium-sulfur battery (the capacity retention rate was increased from 48.64% to 64.01-92.26%).
  • Example 1 is a discharge cycle test chart of a battery assembled with a lithium-sulfur battery composite positive electrode material prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3, and Example 2;
  • Example 2 is a cycle test diagram of a battery assembled with a composite positive electrode material of a high-rate performance lithium-sulfur battery prepared in Example 1, Example 2, Example 3, and Example 4;
  • Example 3 is a battery discharge cycle test chart of a composite positive electrode material of a high-rate performance lithium-sulfur battery prepared in Example 5;
  • FIG. 4 is a graph showing the discharge rate of a battery assembled with a composite positive electrode material of a high-rate performance lithium-sulfur battery prepared in Example 6.
  • FIG. 4 is a graph showing the discharge rate of a battery assembled with a composite positive electrode material of a high-rate performance lithium-sulfur battery prepared in Example 6.
  • a conductive agent/sulfur composite cathode material is prepared as follows:
  • the conductive agent and sulfur are ground and mixed uniformly, they are placed in a tube furnace, with N 2 as the shielding gas, the gas flow rate is set to 50 mL/min, and the temperature is raised to 155 ° C at a rate of 10 ° C/min at room temperature. 10h, then heated to 190 ° C at a rate of 10 ° C / min for 3h, then naturally cooled to obtain a conductive agent / sulfur composite (o-CNT / S);
  • the above conductive agent/sulfur composite material is prepared into a positive electrode sheet by the following method:
  • the above conductive agent/sulfur composite material (o-CNT/S) and binder (polyvinylidene fluoride) were uniformly mixed at a mass ratio of 9:1, and then dispersed in N-methylpyrrolidone for magnetic stirring for 12 hours to obtain a positive electrode.
  • the slurry; the obtained positive electrode slurry was coated on an aluminum foil to form a sheet, dried, rolled, and sliced to obtain a desired positive electrode sheet, and the thickness of the positive electrode sheet was 100 ⁇ m.
  • the above positive electrode sheet is assembled into a battery as follows:
  • the positive electrode is made of the above positive electrode sheet
  • the negative electrode is made of a lithium foil having a thickness of about 50 ⁇ m
  • the separator is a Celegard 2400 polypropylene film
  • the electrolyte is dissolved in lithium bistrifluoromethanesulfonate (LiN(CF 3 SO 2 ) 2 ).
  • the battery assembled in this comparative example was subjected to constant current charge and discharge test at a current density of 1 C.
  • the battery test temperature was around room temperature 25 ° C.
  • the test results showed that the first discharge specific capacity of the battery was 712 mAh/g, and the discharge was performed after 200 cycles.
  • the specific capacity was 291 mAh/g, and the results are shown in Fig. 1.
  • a conductive agent/sulfur/glucose composite positive electrode material using glucose as a modifier wherein the components are used in an amount of 59.4% by weight of a conductive agent, 40% by weight of sulfur, and 0.6% by weight of a modifier.
  • the conductive agent and sulfur are ground and mixed uniformly, they are placed in a tube furnace, with N 2 as the shielding gas, the gas flow rate is set to 50 mL/min, and the temperature is raised to 155 ° C at a rate of 10 ° C/min at room temperature. 10h, then heated to 190 ° C at a rate of 10 ° C / min for 3h, then naturally cooled to obtain a conductive agent / sulfur composite (o-CNT / S);
  • the methods for preparing the positive electrode sheet, assembling the battery, and testing the battery in this example were the same as in Comparative Example 1.
  • the battery charge and discharge test results show that the first charge-discharge specific capacity of the battery is 664 mAh/g at 1 C discharge rate, and the specific capacity is 471 mAh/g after 200 cycles.
  • the results are shown in Fig. 1.
  • the cycle performance is greatly improved, and the electrochemical performance of the battery is also improved. It indicates that the hydrophilic functional group at the pore opening of the multi-walled carbon nanotubes is bonded to the glucose radical to improve the cycle performance of the battery.
  • a lithium-sulfur battery composite cathode material is prepared as follows:
  • the above porous multi-walled carbon nanotubes are prepared by using solid potassium hydroxide and multi-walled carbon nanotubes (pore size 2-5 nm, specific surface area 324 m 2 /g, pore volume 0.40 cm 3 /g) to 5
  • the mass ratio of 1: is uniformly mixed, and then placed in a tube furnace, with a mixed gas of hydrogen and nitrogen as a protective atmosphere, wherein the volume ratio of hydrogen is 5%, calcined at 850 ° C for 1.5 h, and then the calcined product is taken out, After washing with 1 mol/L of dilute hydrochloric acid, it is washed with deionized water until neutral.
  • porous multi-walled carbon nanotubes which is a mesoporous carbon material (pore size is 2-10 nm).
  • the specific surface area was 800 m 2 /g, and the pore volume was 1.06 cm 3 /g).
  • the conductive agent and sulfur are ground and mixed uniformly, they are placed in a tube furnace, with N 2 as the shielding gas, the gas flow rate is set to 50 mL/min, and the temperature is raised to 155 ° C at a rate of 10 ° C/min at room temperature. After 10 h, the temperature was raised to 190 ° C for 3 h at a rate of 10 ° C / min, and then naturally cooled to obtain a conductive agent / sulfur composite material (h-CNT / S).
  • the methods for preparing the positive electrode sheet, assembling the battery, and testing the battery were the same as in Comparative Example 1. It can be seen from Fig. 1 that the first charge-discharge specific capacity of the battery prepared in this example is 1184 mAh/g at a 1 C rate, and the specific capacity after 510 cycles is 576 mAh/g. Compared with Comparative Example 1, the initial capacity of discharge is greatly improved. This is because the carbon material multi-walled carbon nanotubes have a rich pore structure after activation, which accelerates the efficient migration and removal of lithium ions.
  • the above porous multi-walled carbon nanotubes are prepared by solid potassium hydroxide and multi-walled carbon nanotubes (pore size 2-5 nm, specific surface area 324 m 2 /g, pore volume 0.40 cm 3 /g, Nanjing Xian
  • the product is uniformly mixed at a mass ratio of 5:1, and then placed in a tube furnace with a mixture of hydrogen and nitrogen as a protective atmosphere, wherein the volume ratio of hydrogen is 5% and calcined at 850 °C. After 1.5 h, the calcined product was taken out, washed with 1 mol/L of dilute hydrochloric acid, and then washed with deionized water until neutral.
  • porous multi-walled carbon nanotubes That is, a mesoporous carbon material (having a pore diameter of 2 to 10 nm, a specific surface area of 800 m 2 /g, and a pore volume of 1.06 cm 3 /g).
  • the specific preparation method is as follows:
  • step 2) The conductive agent and sulfur weighed in step 1) are ground and uniformly mixed, and then placed in a tube furnace, with N 2 as a shielding gas, the gas flow rate is set to 50 mL/min, and the temperature is 10 ° C/min at room temperature. Heating to 155 ° C, holding for 10 h, then heating at a rate of 10 ° C / min to 190 ° C for 3 h, then naturally cooled to obtain a conductive agent / sulfur composite (o-CNT / S);
  • porous multi-walled carbon nanotube/sulfur composite prepared by dissolving glucose in 100 mL of ultrapure water to obtain 2.22 ⁇ 10 -5 mol/L aqueous glucose solution and adding to glucose aqueous solution in step 2)
  • Ultrasonic cleaning with ultrasonic cleaning device to uniformly disperse in aqueous glucose solution, sonication time is 30min, frequency is 20-25kHz; after ultrasonic completion, the solution is transferred to the reaction kettle, reacted at 140 ° C for 24h, the preparation will be The product is filtered and dried to give a mesoporous carbon/sulfur/glucose composite.
  • the methods for preparing the positive electrode sheet, assembling the battery, and testing the battery in this example were the same as in Comparative Example 1.
  • the battery charge and discharge test results show that the first charge-discharge specific capacity of the battery is 1088 mAh/g at 1 C discharge rate, and the specific capacity is 697 mAh/g after 200 cycles.
  • the results are shown in Fig. 2.
  • the first charge-discharge specific capacity is slightly smaller, but the cycle performance is greatly improved. This is because the modification of porous multi-walled carbon nanotubes/sulfur composites hinders the insertion and removal of lithium ions.
  • the effect because the modifier content is low, the inhibition effect on lithium ion insertion and removal is relatively weak, and the initial capacity is slightly decreased from 1184 mAh/g to 1088 mAh/g.
  • a porous multi-walled carbon nanotube/sulfur/glucose composite positive electrode material prepared by using glucose as a modifier, wherein the amount of each component is as follows: conductive agent porous multi-walled carbon nanotubes 59.4 wt%, electrochemically active substance Sulfur 40% by weight, modifier glucose 0.6% by weight.
  • the above porous multi-walled carbon nanotubes are prepared by solid potassium hydroxide and multi-walled carbon nanotubes (pore size 2-5 nm, specific surface area 324 m 2 /g, pore volume 0.40 cm 3 /g, Nanjing Xian
  • the product is uniformly mixed at a mass ratio of 5:1, and then placed in a tube furnace with a mixture of hydrogen and nitrogen as a protective atmosphere, wherein the volume ratio of hydrogen is 5% and calcined at 650 °C. After 1.5 h, the calcined product was taken out, washed with 1 mol/L of dilute hydrochloric acid, and then washed with deionized water until neutral.
  • porous multi-walled carbon nanotubes h-CNT
  • infrared test shows that a large number of hydrophilic functional group hydroxyl groups are formed around the surface pores of the mesoporous carbon material.
  • the specific preparation method is as follows:
  • step 2) The conductive agent and sulfur weighed in step 1) are ground and uniformly mixed, and then placed in a tube furnace with N 2 as a shielding gas, the gas flow rate is set to 50 mL/min, and the temperature is 5 ° C/min at room temperature. Heating to 160 ° C, holding for 5 h, then heating at a rate of 5 ° C / min to 210 ° C for 5 h, then naturally cooled to obtain a conductive agent / sulfur composite (o-CNT / S);
  • porous multi-walled carbon nanotube/sulfur composite material prepared by dissolving glucose in 60 mL of ultrapure water to obtain 2.22 ⁇ 10 -3 mol/L aqueous glucose solution and adding to glucose aqueous solution in step 2) (h-CNT/ S), ultrasonically ultrasonically sprayed to uniformly disperse in the aqueous glucose solution, the ultrasonic treatment time is 30 min, the frequency is 20-25 kHz; after the completion of the ultrasonication, the solution is transferred to the reaction kettle, and reacted at 100 ° C for 4 h, The prepared product is filtered and dried to finally obtain a mesoporous carbon/sulfur/glucose composite.
  • the methods for preparing the positive electrode sheet, assembling the battery, and testing the battery in this example were the same as in Comparative Example 1.
  • the battery charge and discharge test results show that the first charge-discharge specific capacity of the battery prepared in this example is 1005mAh/g at 1C rate, and the specific capacity is 793mAh/g after 200 cycles.
  • the cycle test chart of the battery is shown in Figure 2. . Compared with Example 1, a suitable amount of glucose free radicals further enhances its stability.
  • a porous multi-walled carbon nanotube/sulfur/glucose composite cathode material prepared by using glucose as a modifier is similar to that of Example 1, except that the amount of each component is determined by mass percentage: conductive porous multi-wall carbon nanometer
  • the tube was 50% by weight, the electrochemically active substance sulfur was 49.2% by weight, and the modifier glucose was 0.8% by weight.
  • the preparation method of the composite positive electrode material, the preparation of the positive electrode sheet, the assembly battery and the battery test method in this embodiment are the same as those in the first embodiment.
  • the battery charge and discharge test results show that the first charge and discharge of the battery prepared in this embodiment is at 1 C rate.
  • the specific capacity is 754mAh/g, and the specific capacity is 561mAh/g after 200 cycles.
  • the cycle test chart of the battery is shown in Figure 2. The increase in the glucose content compared to Example 2 resulted in a significant decrease in the initial capacity of the battery system, but the cycle performance was substantially unchanged, and the specific capacity reduction ratio was similar after 200 cycles.
  • a porous multi-walled carbon nanotube/sulfur/glucose composite cathode material prepared by using glucose as a modifier is similar to that of Example 1, except that the amount of each component is determined by mass percentage: conductive porous multi-wall carbon nanometer
  • the tube is 30% by weight, the electrochemically active substance sulfur is 60% by weight, and the modifier glucose is 10% by weight.
  • the preparation method of the composite positive electrode material, the preparation of the positive electrode sheet, the assembly battery and the battery test method in this embodiment are the same as those in the first embodiment.
  • the battery charge and discharge test results show that the first charge and discharge of the battery prepared in this embodiment is at 1 C rate.
  • the specific capacity is 363 mAh/g, and the specific capacity is 284 mAh/g after 200 cycles.
  • the cycle test chart of the battery is shown in Fig. 2.
  • a porous carbon nanofiber/sulfur/galactose composite cathode material prepared by using galactose as a modifier is similar to that of Example 1, except that the carbon material is carbon nanofiber, the sugar is galactose, and the solid potassium hydroxide is used.
  • carbon nanofibers pore size 2-5 nm, specific surface area 300 m 2 /g, pore volume 0.30 cm 3 /g
  • a mixed atmosphere of hydrogen and nitrogen is used as a protective atmosphere, wherein
  • the volume ratio of hydrogen is 1%, calcined at 650 ° C for 0.5 h to obtain porous carbon nanofibers (pore size 2-10 nm, specific surface area 500 m 2 /g, pore volume 0.74 cm 3 /g), the amount of each component
  • the conductive agent porous carbon nanofibers are 40% by weight
  • the electrochemically active substance sulfur is 59.4% by weight
  • the modifier galactose is 0.6% by weight.
  • the preparation of the composite positive electrode material, the preparation of the positive electrode sheet, the assembled battery, and the battery test method are the same as in the first embodiment, and the constant current charge and discharge test is performed at a current density of 3 C, and the test temperature is 25 ° C at room temperature.
  • the first discharge specific capacity of the battery prepared in this example was 931 mAh/g, and the discharge specific capacity was 859 mAh/g after 200 cycles, and the battery discharge cycle test chart is shown in FIG. Discharge at 3C rate, battery capacity attenuation is small, battery cycle performance is very good.
  • a porous carbon nanosphere/sulfur/deoxyribose composite cathode material prepared by using deoxyribose as a modifier is similar to that of Example 1, except that the carbon material is carbon nanosphere (pore size 2-6 nm, specific surface area 280 m 2 ) /g, pore volume is 0.44 cm 3 /g), the sugar is deoxyribose, and porous carbon nanospheres are obtained by activation (pore size is 2-8 nm, specific surface area is 580 m 2 /g, pore volume is 0.78 cm 3 /g) The amount of each component is determined by mass percentage: 50 wt% of conductive agent porous carbon nanospheres, 49.4 wt% of electrochemically active substance sulfur, and 0.6 wt% of modifier deoxyribose.
  • the preparation of the composite positive electrode material, the preparation of the positive electrode sheet, the assembly battery and the battery test method in this embodiment are the same as those in the first embodiment, respectively, at 0.5C, 1C, 2C, 3C, 4C, 5C, 6C, 7C, 8C, 9C.
  • the corresponding capacity is 1084mAh / g, 1010mAh / g, 973mAh / g, 928mAh / g, 812mAh / g, 751mAh / g, 683mAh/g, 644mAh/g, 587mAh/g, 539mAh/g, 511mAh/g, it can be seen that the magnification is reduced from 10C to 0.5C, the capacity is 870mAh/g, the capacity retention rate is 80.25%, and the high rate performance of the battery. Good, the discharge rate diagram of the battery is shown in Figure 4.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

本发明涉及一种锂硫电池复合正极材料及其制备方法，它由具有介孔结构的导电剂、硫以及修饰剂组成，所述硫分散于导电剂的孔洞中，所述修饰剂通过化学键合的方式与导电剂的孔口连接，各组分质量比为：导电剂30～59.4％，硫40～60％，修饰剂0.1～10％。其制备方法为采用熔融吸入法将硫灌入导电剂中，得到导电剂/硫复合材料；然后对所得导电剂/硫复合材料进行修饰得到锂硫电池复合正极材料。该复合正极材料不仅可以实现优秀的高倍率稳定性能，并且可以有效降低活性物质的损失以及由多硫化锂的溶解造成的"穿梭效应"所导致的锂负极腐蚀、容量衰减迅速等影响，显著提高锂硫电池的循环性能。

Description

一种锂硫电池复合正极材料及其制备方法 技术领域
本发明涉及锂硫电池技术领域，具体涉及一种锂硫电池复合正极材料及其制备方法。
背景技术
单硫正极材料按电化学反应S8+16Li→8Li2S计，其比容量高达1675mAh·g-1，是已知固体正极材料中能量密度最高的，且硫单质储量丰富、价格低廉、安全低毒，因而具有十分广阔的应用前景。但因硫单质是电子绝缘体(5×10-30S·cm-1，25℃)，且放电过程形成的高价态的多硫化锂(锂硫电池处于不同的放电电压时，锂与硫反应生成不同价态硫的多硫化锂，具体生成的产物从高价态到低价态分别为Li2S8，Li2S6，Li2S4，Li2S3，Li2S2，Li2S)易溶于电解液，形成所谓的“穿梭效应”从而严重影响电池寿命，影响了锂硫电池在实际生产中的应用。多硫化物的溶解导致的穿梭效应显著降低了硫的利用率、比容量和循环性能，同时增加了电解液的粘度和离子的迁移阻力；随着放电过程的进行，导电性差的放电最终产物Li2S和Li2S2会以固态膜的形式覆盖到正极活性材料的表面，从而阻碍电解质与电极活性材料间的电化学反应。为此，如何抑制多硫化物的扩散、提高硫正极循环过程中的导电性是锂硫电池正极材料的研究重点。
针对正极材料的研究，在低放电倍率下提高锂硫电池的循环性能已经取得了很好的效果，为了解决由于充放电过程中体积变化导致的正极结构不稳定的问题也采取了一系列措施。但是，在高放电倍率下，保持高的初始容量并提高循环性能仍然没有得到很好的解决。这主要是因为随着放电倍率提高，电化学极化与浓差极化程度将会严重影响电极的效率，因此，为了保证锂硫电池正极材料在高倍率下正常工作，就必须对正极材料进行设计，不仅需要提供大量的离子传输通道，使锂离子高效的嵌入脱出，同时还需要抑制多硫化物的溶解损失，提高正极材料的循环性能。
发明内容
本发明所要解决的技术问题是针对现有技术中存在的上述不足，提供一种在高放电倍率下具有高的初始容量并且循环性能良好的锂硫电池复合正极材料及其制备方法。
为解决上述技术问题，本发明提供的技术方案是：
提供一种锂硫电池复合正极材料，它由具有介孔结构的导电剂、硫以及修饰剂组成，所述硫分散于导电剂的孔洞中，所述修饰剂通过化学键合的方式与导电 剂的孔口连接，各组分质量比为：导电剂30～59.4％，硫40～60％，修饰剂0.1～10％。
按上述方案，所述导电剂为介孔碳材料，孔径分布为2-10nm，比表面积为500-800m2/g，且孔道开口处具有亲水性官能团；所述修饰剂为葡萄糖、半乳糖、脱氧核糖中的一种。
按上述方案，所述介孔碳材料由碳材料活化得到，其制备方法为：将固态的KOH与碳材料按质量比1-5：1混合均匀，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为1-5％，于650-850℃煅烧0.5-1.5h，然后将煅烧产物先后用稀盐酸和去离子水清洗至中性，最后干燥得到介孔碳材料。
按上述方案，所述碳材料为多壁碳纳米管、碳纳米纤维或碳纳米球。
按上述方案，所述亲水性官能团为羟基或羧基。
本发明还提供了上述锂硫电池复合正极材料的制备方法，其步骤如下：
1)制备导电剂/硫复合材料：将导电剂和硫研磨后混合均匀，置于N2气氛下，在室温下以5-10℃/min的速率升温至155-160℃，保温5-10h，然后以5-10℃/min的速率升温至190-210℃保温3-5h，自然冷却得到导电剂/硫复合材料，导电剂/硫复合材料中导电剂与硫质量比为0.5-1.5：1；
2)制备锂硫电池复合正极材料：将修饰剂溶于超纯水中得到浓度为2.22×10-5-2.22×10-3mol/L的修饰剂水溶液，向该修饰剂水溶液中加入步骤1)所得导电剂/硫复合材料，并经超声处理将导电剂/硫复合材料均匀分散于修饰剂水溶液中，得到均匀的分散液，将所得分散液转移至水热反应釜中，于100-140℃反应4-24h，反应完成后分离出固体产物即得到锂硫电池复合正极材料，锂硫电池复合正极材料中各组分质量比为：导电剂30～59.4％，硫40～60％，修饰剂0.1～10％。
按上述方案，步骤1)所述导电剂为介孔碳材料，孔径为2-10nm，比表面积为500-800m2/g，且孔道开口处具有亲水性官能团。
在另一优选例中，所述修饰剂为多羟基糖。
在另一优选例中，所述修饰剂选自下组：单糖、双糖、寡糖、或其组合。
在另一优选例中，所述修饰剂为葡萄糖、半乳糖、脱氧核糖中的一种。
按上述方案，所述介孔碳材料由碳材料活化得到，其制备方法为：将固态的KOH与碳材料按质量比1-5：1混合均匀，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为1-5％，于650-850℃煅烧0.5-1.5h，然后将煅烧产物先后用稀盐酸和去离子水清洗至中性，最后干燥得到介孔碳材料。
按上述方案，所述碳材料为多壁碳纳米管、碳纳米纤维或碳纳米球。
按上述方案，所述亲水性官能团为羟基和羧基。
按上述方案，步骤2)所述超声处理时间为30-60min，超声频率为20-25kHz。
本发明的原理在于：本发明所述导电剂为介孔结构，电化学活性物质硫分散于导电剂的孔洞中，修饰剂(糖类)以化学键合的方式与导电剂的孔口的活性部位 相连接以调节孔口的性能。葡萄糖等糖类水热反应产生的糖类自由基对复合材料的修饰保证了该锂硫正极材料选择性的允许锂离子通过，而抑制多硫离子的通过。一方面，处于孔洞处的糖类自由基对多硫化锂有一定的吸附作用，阻碍多硫化物从孔口溢出而溶解；另一方面，糖类自由基与介孔碳孔口的亲水官能团的化学键合作用具有缩孔效应，在一定程度上调节孔口的大小，在不影响半径小的锂离子自由通过的同时在一定程度上抑制多硫化物的通过，从而阻碍多硫化锂的溶解。
应理解，在本发明中，上述作用机理仅用于说明本发明，但是本发明的所述正极材料的作用机理并不限于上述解释。
与现有技术相比，本发明主要有以下优点：第一，本实验所采用的修饰剂(糖类)在含量很低时(在复合正极材料中所占质量比为0.6％)就可以达到很好的循环稳定性效果，这大大减小了正极材料能量密度的损失；第二，采用水热法将糖类分解为糖类自由基与介孔碳材料孔口的亲水官能团进行定向的化学键合，可以保证糖类自由基在正极材料上的均匀分散与分布；第三，糖类自由基与介孔碳孔口的亲水官能团进行定向的化学键合作用能够保证糖类自由基的高效利用，通过该通道选择性的允许锂离子高效嵌入脱出而抑制多硫离子的通过，从而提高锂硫电池的循环性能。
本发明的有益效果在于：1、本发明制备方法简单，所制备的锂硫电池复合正极材料利用葡萄糖等糖类分解反应产生的糖类自由基与介孔碳孔洞处的亲水官能团化学键合，保证锂离子自由通过的前提下有效的抑制多硫化物的溶解；2、本发明通过对碳材料(碳纳米管、碳纳米纤维或碳纳米球)的活化，大大增加了锂离子的传输通道，使锂离子能够快速嵌入脱出，因此材料能够快速充放电，具有高倍率性能，而采用修饰剂使得采用本发明所制备的复合正极材料的锂硫电池具备高倍率稳定性能，能够有效的降低容量的损失及对多硫化锂的溶解造成的“穿梭效应”所导致的锂负极腐蚀、容量衰减迅速等影响，从而显著提高锂硫电池的循环性能(容量保有率从48.64％提升至64.01-92.26％)。
附图说明
图1为对比例1、对比例2、对比例3、实施例2制备的锂硫电池复合正极材料所组装电池的放电循环测试图；
图2为实施例1、实施例2、实施例3、实施例4制备的高倍率性能锂硫电池的复合正极材料所组装电池的循环测试图；
图3为实施例5制备的高倍率性能锂硫电池的复合正极材料所组装电池放电循环测试图；
图4为实施例6制备的高倍率性能锂硫电池的复合正极材料所组装电池的放电倍率图。
具体实施方式
为使本领域技术人员更好地理解本发明的技术方案，下面结合附图对本发明作进一步详细描述。
对比例1
导电剂/硫复合正极材料，其制备方法如下：
1)称取0.2g多壁碳纳米管(孔径为2-5nm，比表面积为324m2/g、孔容为0.40cm3/g)作为导电剂(C)，称取0.2g电化学活性物质硫(S)；
2)将导电剂和硫研磨后混合均匀后置于管式炉中，以N2为保护气，气流量设为50mL/min，在室温下以10℃/min的速率升温至155℃，保温10h，然后以10℃/min的速率升温至190℃保温3h，之后自然冷却制备得到导电剂/硫复合材料(o-CNT/S)；
将上述导电剂/硫复合材料制备成正极片，方法如下：
将上述导电剂/硫复合材料(o-CNT/S)和粘结剂(聚偏氟乙烯)按质量比9:1混合均匀，然后分散在N-甲基吡咯烷酮中磁力搅拌12h后制得到正极浆料；所得正极浆料涂覆在铝箔上制成片，烘干、滚压、切片，即得到所需的正极片，正极片的厚度为100μm。
将上述正极片进行电池组装，方法如下：
正极采用上述正极片，负极采用厚度约为50μm的锂箔，隔膜采用的是Celegard2400聚丙烯膜，电解液为双三氟甲基磺酸亚酰胺锂(LiN(CF3SO2)2)溶于二甲氧基乙烷(DME)和1,3-二氧戊环(DOL)的混合溶液中(注：电解液中二甲氧基乙烷与1,3-二氧戊环的体积比为1:1，双三氟甲基磺酸亚酰胺锂在其中的浓度为1mol/L)；将上述组件以正极/隔膜/负极的结构组装在柱状电池中，整个电池组装过程均在手套箱中完成。
对本对比例所组装的电池以1C的电流密度下进行恒流充放电测试，电池测试温度在室温25℃附近，测试结果表明：该电池首次放电比容量为712mAh/g，经过200次循环后放电比容量为291mAh/g，结果如图1所示。
对比例2
以葡萄糖为修饰剂的导电剂/硫/葡萄糖复合正极材料，其中，各组分的用量按质量百分比计为：导电剂59.4wt％，硫40wt％，修饰剂0.6wt％。
具体步骤如下：
1)称取0.2g多壁碳纳米管(o-CNT)(孔径为2-5nm，比表面积为324m2/g、孔容为0.40cm3/g)作为导电剂，称取0.134g电化学活性物质硫；
2)将导电剂和硫研磨后混合均匀后置于管式炉中，以N2为保护气，气流量设为50mL/min，在室温下以10℃/min的速率升温至155℃，保温10h，然后以10 ℃/min的速率升温至190℃保温3h，之后自然冷却制备得到导电剂/硫复合材料(o-CNT/S)；
3)将葡萄糖溶于100mL的超纯水中得到浓度为3.33×10-5mol/L的葡萄糖水溶液，向葡萄糖水溶液加入100mg步骤2)制备的多壁碳纳米管/硫复合材料，用超声清洗仪处理使其均匀分散于葡萄糖水溶液中，超声处理时间为30min，超声频率为20-25kHz；超声完成后将此溶液转移至水热反应釜中，在140℃下反应24h，将制备得到的产物过滤并干燥，最终得到多壁碳/硫/葡萄糖复合材料。
本实施例中正极片制备、组装电池及电池测试的方法均与对比例1中相同。电池充放电测试结果表明：在1C放电倍率下，该电池的首次充放电比容量为664mAh/g，200次循环后比容量为471mAh/g，结果如图1所示。与对比例1相比，循环性能有较大的提高，电池电化学性能也有所提高，说明多壁碳纳米管孔道开口处亲水性官能团与葡萄糖自由基键合后提高了电池的循环性能。
对比例3
锂硫电池复合正极材料，其制备方法如下：
1)称取0.24g多孔多壁碳纳米管(h-CNT)作为导电剂(C)，称取0.16g电化学活性物质硫(S)；
上述多孔多壁碳纳米管的制备方法为：将固态的氢氧化钾与多壁碳纳米管(孔径为2-5nm，比表面积为324m2/g、孔容为0.40cm3/g)以5:1的质量比均匀混合，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为5％，于850℃煅烧1.5h，然后将煅烧后的产物取出，用1mol/L的稀盐酸清洗后再用去离子水洗至中性，过滤后在80℃干燥12h，得到多孔多壁碳纳米管(h-CNT),即介孔碳材料(孔径为2-10nm，比表面积为800m2/g、孔容为1.06cm3/g)。
2)将导电剂和硫研磨后混合均匀后置于管式炉中，以N2为保护气，气流量设为50mL/min，在室温下以10℃/min的速率升温至155℃，保温10h，然后以10℃/min的速率升温至190℃保温3h，之后自然冷却制备得到导电剂/硫复合材料(h-CNT/S)。
正极片制备、组装电池及电池测试的方法均与对比例1相同。由图1可知：在1C倍率下，本实施例所制备电池的首次充放电比容量为1184mAh/g，200次循环后比容量为576mAh/g。与对比例1相比放电初始容量大大提高，这是因为碳材料多壁碳纳米管经过活化后，具有丰富的孔洞结构，加速了锂离子的高效迁入脱出。
实施例1
制备以葡萄糖为修饰剂的多孔多壁碳纳米管/硫/葡萄糖复合正极材料，其中， 各组分的用量按质量百分比计为：导电剂多孔多壁碳纳米管50wt％，电化学活性物质硫49.9wt％，修饰剂葡萄糖0.1wt％。
上述多孔多壁碳纳米管的制备方法为：将固态的氢氧化钾与多壁碳纳米管(孔径为2-5nm，比表面积为324m2/g、孔容为0.40cm3/g，南京先丰纳米材料科技有限公司所售)以5:1的质量比均匀混合，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为5％，于850℃煅烧1.5h，然后将煅烧后的产物取出，使用1mol/L的稀盐酸清洗后再用去离子水洗至中性，过滤后在80℃干燥12h，得到多孔多壁碳纳米管(h-CNT),即介孔碳材料(孔径为2-10nm，比表面积为800m2/g、孔容为1.06cm3/g)。
具体制备方法如下：
1)称取0.2g多孔多壁碳纳米管(h-CNT)作为导电剂，称取0.198g电化学活性物质硫；
2)将步骤1)称取的导电剂和硫研磨后混合均匀后置于管式炉中，以N2为保护气，气流量设为50mL/min，在室温下以10℃/min的速率升温至155℃，保温10h，然后以10℃/min的速率升温至190℃保温3h，之后自然冷却制备得到导电剂/硫复合材料(o-CNT/S)；
3)水热法将葡萄糖分解产生的自由基负载在多孔多壁碳纳米管/硫复合材料(h-CNT/S)上；
将葡萄糖溶于100mL的超纯水中得到2.22×10-5mol/L葡萄糖水溶液，向葡萄糖水溶液加入的步骤2)制备的100mg多孔多壁碳纳米管/硫复合材料(h-CNT/S)，用超声清洗仪进行超声使其均匀分散于葡萄糖水溶液中，超声处理时间为30min，频率为20-25kHz；超声完成后将此溶液转移至反应釜中，在140℃下反应24h，将制备得到的产物过滤并干燥，最终得到介孔碳/硫/葡萄糖复合材料。
本实施例中正极片制备、组装电池及电池测试的方法均与对比例1相同。电池充放电测试结果表明：在1C放电倍率下，该电池的首次充放电比容量为1088mAh/g，200次循环后比容量为697mAh/g，结果如图2所示。与对比例3相比，首次充放电比容量略小，但循环性能有较大的提高，这是因为葡萄糖对多孔多壁碳纳米管/硫复合材料修饰后，对锂离子的嵌入脱出有阻碍作用，因为修饰剂含量低，对锂离子嵌脱的阻碍作用相对较弱，初始容量稍微下降，由1184mAh/g降为1088mAh/g。
实施例2
制备以葡萄糖为修饰剂的多孔多壁碳纳米管/硫/葡萄糖复合正极材料，其中，各组分的用量按质量百分比计为：导电剂多孔多壁碳纳米管59.4wt％，电化学活性物质硫40wt％，修饰剂葡萄糖0.6wt％。
上述多孔多壁碳纳米管的制备方法为：将固态的氢氧化钾与多壁碳纳米管(孔径为2-5nm，比表面积为324m2/g、孔容为0.40cm3/g，南京先丰纳米材料科技有限公司所售)以5:1的质量比均匀混合，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为5％，于650℃煅烧1.5h，然后将煅烧后的产物取出，用1mol/L的稀盐酸清洗后再用去离子水洗至中性，过滤后在80℃干燥12h，得到多孔多壁碳纳米管(h-CNT),即介孔碳材料，经红外测试表明，介孔碳材料表面孔道周围生成了大量亲水性官能团羟基。
具体制备方法如下：
1)称取2g多孔多壁碳纳米管(h-CNT)作为导电剂，称取1.98g电化学活性物质硫；
2)将步骤1)称取的导电剂和硫研磨后混合均匀后置于管式炉中，以N2为保护气，气流量设为50mL/min，在室温下以5℃/min的速率升温至160℃，保温5h，然后以5℃/min的速率升温至210℃保温5h，之后自然冷却制备得到导电剂/硫复合材料(o-CNT/S)；
3)水热法将葡萄糖分解产生的自由基负载在多孔多壁碳纳米管/硫复合材料(h-CNT/S)上；
将葡萄糖溶于60mL的超纯水中得到2.22×10-3mol/L的葡萄糖水溶液，向葡萄糖水溶液加入的步骤2)制备的3.98g多孔多壁碳纳米管/硫复合材料(h-CNT/S)，用超声清洗仪进行超声使其均匀分散于葡萄糖水溶液中，超声处理时间为30min，频率为20-25kHz；超声完成后将此溶液转移至反应釜中，在100℃下反应4h，将制备得到的产物过滤并干燥，最终得到介孔碳/硫/葡萄糖复合材料。
本实施例中正极片制备、组装电池及电池测试的方法均与对比例1相同。电池充放电测试结果表明：在1C倍率下，本实施例所制备电池的首次充放电比容量为1005mAh/g，200次循环后比容量为793mAh/g，电池的循环测试图如图2所示。与实施例1相比，合适含量葡萄糖自由基使其稳定性进一步提升。
实施例3
制备以葡萄糖为修饰剂的多孔多壁碳纳米管/硫/葡萄糖复合正极材料，方法与实施例1相似，不同之处在于各组分的用量按质量百分比计为：导电剂多孔多壁碳纳米管50wt％，电化学活性物质硫49.2wt％，修饰剂葡萄糖0.8wt％。
本实施例中复合正极材料的制备、正极片制备、组装电池及电池测试的方法均与实施例1相同，电池充放电测试结果表明：在1C倍率下，本实施例所制备电池的首次充放电比容量为754mAh/g，200次循环后比容量为561mAh/g，电池的循环测试图如图2所示。与实施例2相比葡萄糖含量增加使电池体系的初始容量显著降低，但循环性能基本不变，200次循环后比容量下降比例相似。
实施例4
制备以葡萄糖为修饰剂的多孔多壁碳纳米管/硫/葡萄糖复合正极材料，方法与实施例1相似，不同之处在于各组分的用量按质量百分比计为：导电剂多孔多壁碳纳米管30wt％，电化学活性物质硫60wt％，修饰剂葡萄糖10wt％。
本实施例中复合正极材料的制备、正极片制备、组装电池及电池测试的方法均与实施例1相同，电池充放电测试结果表明：在1C倍率下，本实施例所制备电池的首次充放电比容量为363mAh/g，200次循环后比容量为284mAh/g，电池的循环测试图如图2所示。通过与实施例3相比葡萄糖含量的进一步增加使电池体系的初始容量显著降低，但循环稳定性能基本不变，即200次循环后比容量下降比例相似。
实施例5
制备以半乳糖为修饰剂的多孔碳纳米纤维/硫/半乳糖复合正极材料，方法与实施例1相似，不同之处在于碳材料为碳纳米纤维，糖类为半乳糖，固态的氢氧化钾与碳纳米纤维(孔径为2-5nm，比表面积为300m2/g、孔容为0.30cm3/g)以1:1的质量比均匀混合，以氢气和氮气的混合气为保护气氛，其中氢气体积比为1％，于650℃煅烧0.5h在得到多孔的碳纳米纤维(孔径为2-10nm，比表面积为500m2/g、孔容为0.74cm3/g)，各组分的用量按质量百分比计为：导电剂多孔碳纳米纤维40wt％，电化学活性物质硫59.4wt％，修饰剂半乳糖0.6wt％。
本实施例中复合正极材料的制备、正极片制备、组装电池及电池测试的方法均与实施例1相同，以3C的电流密度下进行恒流充放电测试，测试温度在室温25℃，结果表明：本实施例所制备电池首次放电比容量为931mAh/g，经过200次循环后放电比容量为859mAh/g，电池放电循环测试图如图3所示。在3C倍率下放电，电池容量衰减小，电池循环性能很好。
表1 实施例1-6与对比例所制备电池的充放电测试结果
Figure PCTCN2015099570-appb-000001
Figure PCTCN2015099570-appb-000002
由表1可见，各实施例与对比例相比，各实施例的循环性能得到了显著提高。
实施例6
制备以脱氧核糖为修饰剂的多孔碳纳米球/硫/脱氧核糖复合正极材料，方法与实施例1相似，不同之处在于碳材料为碳纳米球(孔径为2-6nm，比表面积为280m2/g、孔容为0.44cm3/g)，糖类为脱氧核糖，通过活化得到多孔碳纳米球(孔径为2-8nm，比表面积为580m2/g、孔容为0.78cm3/g)，各组分的用量按质量百分比计为：导电剂多孔碳纳米球50wt％，电化学活性物质硫49.4wt％，修饰剂脱氧核糖0.6wt％。
本实施例中复合正极材料的制备、正极片制备、组装电池及电池测试的方法均与实施例1相同，分别在0.5C、1C、2C、3C、4C、5C、6C、7C、8C、9C以及10C(每个倍率循环十圈)的电流密度下进行恒流充放电测试，相应的容量分别为1084mAh/g、1010mAh/g、973mAh/g、928mAh/g、812mAh/g、751mAh/g、683mAh/g、644mAh/g、587mAh/g、539mAh/g、511mAh/g，可知将倍率从10C回降至0.5C，容量为870mAh/g，容量保有率为80.25％，什么电池的高倍率性能良好，电池的放电倍率图如图4所示。

Claims (10)

  1. 一种锂硫电池复合正极材料，其特征在于，它由具有介孔结构的导电剂、硫以及修饰剂组成，所述硫分散于导电剂的孔洞中，所述修饰剂通过化学键合的方式与导电剂的孔口连接，各组分质量比为：导电剂30～59.4％，硫40～60％，修饰剂0.1～10％。
  2. 根据权利要求1所述的锂硫电池复合正极材料，其特征在于：所述导电剂为介孔碳材料，孔径为2-10nm，比表面积为500-800m2/g，且孔道开口处具有亲水性官能团；和/或
    所述修饰剂为多羟基糖；和/或
    所述修饰剂选自下组：单糖、双糖、寡糖、或其组合；和/或
    所述修饰剂为葡萄糖、半乳糖、脱氧核糖中的一种。
  3. 根据权利要求2所述的锂硫电池复合正极材料，其特征在于所述介孔碳材料由碳材料活化得到，其制备方法为：将固态的KOH与碳材料按质量比1-5：1混合均匀，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为1-5％，于650-850℃煅烧0.5-1.5h，然后将煅烧产物先后用稀盐酸和去离子水清洗至中性，最后干燥得到介孔碳材料。
  4. 根据权利要求3所述的锂硫电池复合正极材料，其特征在于所述碳材料为多壁碳纳米管、碳纳米纤维或碳纳米球。
  5. 根据权利要求2所述的锂硫电池复合正极材料，其特征在于：所述亲水性官能团为羟基。
  6. 一种锂硫电池复合正极材料的制备方法，其特征在于步骤如下：
    1)制备导电剂/硫复合材料：将导电剂和硫研磨后混合均匀，置于N2气氛下，在室温下以5-10℃/min的速率升温至155-160℃，保温5-10h，然后以5-10℃/min的速率升温至190-210℃保温3-5h，自然冷却得到导电剂/硫复合材料，导电剂/硫复合材料中导电剂与硫质量比为0.5-1.485：1；
    2)制备锂硫电池复合正极材料：将修饰剂溶于超纯水中得到浓度为2.22×10-5-2.22×10-3mol/L的修饰剂水溶液，向该修饰剂水溶液中加入步骤1)所得导电剂/硫复合材料，并经超声处理将导电剂/硫复合材料均匀分散于修饰剂水溶液中，得到均匀的分散液，将所得分散液转移至水热反应釜中，于100-140℃反应4-24h，反应完成后分离出固体产物即得到锂硫电池复合正极材料，锂硫电池复合正极材料中各组分质量比为：导电剂30～59.4％，硫40～60％，修饰剂0.1～10％。
  7. 根据权利要求6所述的锂硫电池复合正极材料的制备方法，其特征在于：步骤1)所述导电剂为介孔碳材料，孔径为2-10nm，比表面积为500-800m2/g，且孔道开口处具有亲水性官能团；所述修饰剂为葡萄糖、半乳糖、脱氧核糖中的一 种。
  8. 根据权利要求7所述的锂硫电池复合正极材料的制备方法，其特征在于：所述介孔碳材料由碳材料活化得到，其制备方法为：将固态的KOH与碳材料按质量比1-5：1混合均匀，然后置于管式炉中，以氢气和氮气的混合气为保护气氛，其中氢气体积比为1-5％，于650-850℃煅烧0.5-1.5h，然后将煅烧产物先后用稀盐酸和去离子水清洗至中性，最后干燥得到介孔碳材料。
  9. 根据权利要求8所述的锂硫电池复合正极材料的制备方法，其特征在于：所述碳材料为多壁碳纳米管、碳纳米纤维或碳纳米球。
  10. 根据权利要求7所述的锂硫电池复合正极材料的制备方法，其特征在于：所述亲水性官能团为羟基。
PCT/CN2015/099570 2015-06-03 2015-12-29 一种锂硫电池复合正极材料及其制备方法 WO2016192389A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201510298671.5 2015-06-03
CN201510298671.5A CN104900880B (zh) 2015-06-03 2015-06-03 一种锂硫电池复合正极材料及其制备方法

Publications (1)

Publication Number Publication Date
WO2016192389A1 true WO2016192389A1 (zh) 2016-12-08

Family

ID=54033397

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/099570 WO2016192389A1 (zh) 2015-06-03 2015-12-29 一种锂硫电池复合正极材料及其制备方法

Country Status (2)

Country Link
CN (1) CN104900880B (zh)
WO (1) WO2016192389A1 (zh)

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111092225A (zh) * 2019-11-25 2020-05-01 华东理工大学 锂电池自支撑电极用多功能包覆层及其制备方法
CN111146415A (zh) * 2019-12-18 2020-05-12 东华大学 一种添加助剂的碳硫复合正极材料的制备方法
CN111362312A (zh) * 2020-03-17 2020-07-03 东北大学秦皇岛分校 一种利用酸洗铁红回收处理得到锂-空气电池正极材料的方法
CN111977703A (zh) * 2020-08-21 2020-11-24 天目湖先进储能技术研究院有限公司 Li2O、Li2CO3包覆过渡金属硫化物基正极材料及制备方法和应用
CN112234205A (zh) * 2020-10-16 2021-01-15 肇庆市华师大光电产业研究院 一种用于锂硫电池的通用电极材料及其制备方法
CN112490413A (zh) * 2019-09-11 2021-03-12 肇庆市华师大光电产业研究院 一种碳纳米管硫正极材料的制备方法及其在钠硫电池中的应用
CN113224281A (zh) * 2021-03-12 2021-08-06 上海电力大学 一种以废弃尿不湿为原料的锂硫电池正极材料及制备方法
CN113270569A (zh) * 2021-05-12 2021-08-17 烟台大学 一种锂硫电池专用多孔复合电极的制备及其应用
CN113346091A (zh) * 2021-06-07 2021-09-03 清华大学深圳国际研究生院 正极及其制备方法、锂硫电池
CN113488638A (zh) * 2021-06-30 2021-10-08 肇庆市华师大光电产业研究院 一种高导电强吸附的锂硫电池正极材料制备方法
CN113735177A (zh) * 2021-09-06 2021-12-03 派尔森环保科技有限公司 一种纳米空心球壳状高倍率性能的LaFeO3锂离子电池负极材料的制备方法
CN114388786A (zh) * 2021-12-21 2022-04-22 西安理工大学 一种木材菌丝共生材料制备碳骨架的方法及载硫储能应用
CN114408923A (zh) * 2022-01-24 2022-04-29 天津大学 一种多孔碳材料孔口调控的方法及其应用
CN114583144A (zh) * 2022-03-07 2022-06-03 西安理工大学 一种微细网络结构的硫碳正极材料的机械热合成方法
CN114583145A (zh) * 2022-03-25 2022-06-03 江西省纳米技术研究院 锂硫电池正极材料、其制备方法及锂硫电池
CN114725347A (zh) * 2022-04-27 2022-07-08 南京邮电大学 一种用于锂硫电池的三维多孔碳复合材料及其制备方法
CN114735673A (zh) * 2022-05-05 2022-07-12 贵州大学 一种交联微介孔碳复合材料的制备方法及其应用
CN114976484A (zh) * 2022-07-11 2022-08-30 大连理工大学 负载Ni2P-Co肖特基节活性位点海胆状碳材料电催化剂、制备方法及其应用
CN114975957A (zh) * 2022-06-22 2022-08-30 桂林理工大学 一种硫/葡萄糖介孔碳球锂硫电池正极材料及其制备方法
CN115000366A (zh) * 2022-05-19 2022-09-02 同济大学 具有核壳结构的柔性自支撑锂硫电池正极薄膜及制备方法
CN115036592A (zh) * 2022-06-21 2022-09-09 中国地质大学（武汉） 双位点黏土矿物基硫还原催化剂及其制备方法和应用
CN115043391A (zh) * 2022-05-27 2022-09-13 合肥学院 一种mof衍生的二维微孔碳纳米片材料及其制备方法
CN115050943A (zh) * 2022-07-12 2022-09-13 北京北化工程技术有限公司 一种高压实密度的硒掺杂硫代三聚硫氰酸材料及其制备方法和电池正极片
CN115332519A (zh) * 2022-09-09 2022-11-11 郑州大学 一种锂硫电池正极材料的制备方法及应用
CN115594229A (zh) * 2022-10-18 2023-01-13 香港理工大学（Hk） 纳米高熵氧化物材料及其制备方法、锂硫电池正极材料
CN115676821A (zh) * 2022-10-14 2023-02-03 电子科技大学长三角研究院(湖州) 一种锂硫电池正极材料的制备方法、正极材料及应用
CN115724426A (zh) * 2022-12-06 2023-03-03 辽宁工程技术大学 一种原位掺氮煤基多孔碳锂硫电池正极材料制备方法
CN116425144A (zh) * 2023-04-13 2023-07-14 哈尔滨理工大学 一种用于钠离子电池的碳纳米管修饰硬碳负极材料的制备方法

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104900880B (zh) * 2015-06-03 2017-07-11 中国地质大学（武汉） 一种锂硫电池复合正极材料及其制备方法
CN105355846B (zh) * 2015-10-16 2018-09-11 广东烛光新能源科技有限公司 一种含硫电极、含有该电极的锂硫电池及其制备方法
CN105374998B (zh) * 2015-10-16 2018-11-16 广东烛光新能源科技有限公司 一种含硫电极材料、含有该电极材料的锂硫电池及含硫电极材料的制备方法
CN109417171B (zh) * 2016-07-06 2023-09-12 香港科技大学 分级多孔纳米碳/硫复合阴极的可调节且可量产的合成
CN107887608A (zh) * 2017-11-09 2018-04-06 天津工业大学 一种碳化丝瓜瓤载硫作为锂硫电池正极材料的制备方法
CN108054377B (zh) * 2017-12-27 2020-08-04 湖南工业大学 一种毛线球状碳/硫复合微球材料的制备方法及锂硫电池
CN108232176B (zh) * 2018-02-07 2020-11-13 中南大学 一种锂硫电池阴极材料及其制备方法
CN110474029B (zh) * 2019-07-11 2022-06-10 江苏师范大学 一种锂硫电池正极复合材料及其制备方法
CN110518201A (zh) * 2019-08-05 2019-11-29 中南大学 一种纳米级碳硫复合材料及其制备方法
CN110444754B (zh) * 2019-09-06 2023-12-19 中南大学 一种碳纳米管限域硫硒复合材料及其制备方法
CN111293275B (zh) * 2020-05-09 2020-09-01 北京小米移动软件有限公司 一种锂离子电池电极、电池及其活化方法
CN111554936B (zh) * 2020-05-18 2021-03-26 齐鲁工业大学 一种锂硫电池用导电mof修饰碳纤维纸插层材料
CN114956035B (zh) * 2022-04-29 2023-09-19 中国地质大学（武汉） 超微孔碳材料、硫正极材料及其在锂硫电池中应用研究

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102324507A (zh) * 2011-09-10 2012-01-18 中南大学 一种锂硫电池复合正极材料制备方法
CN103500847A (zh) * 2013-10-02 2014-01-08 中国地质大学（武汉） 锂硫电池添加剂、含有该添加剂的正极材料及其制备方法
CN103515614A (zh) * 2013-10-02 2014-01-15 中国地质大学（武汉） 一种电池添加剂、含有该添加剂的正极材料及其制备方法
CN104900880A (zh) * 2015-06-03 2015-09-09 中国地质大学（武汉） 一种锂硫电池复合正极材料及其制备方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100484642B1 (ko) * 2002-09-23 2005-04-20 삼성에스디아이 주식회사 리튬-설퍼 전지용 양극 활물질 및 그 제조방법
WO2012100301A1 (en) * 2011-01-27 2012-08-02 The University Of Queensland Sulfur-carbon material and use as cathodes for high energy batteries
CN103199250B (zh) * 2013-04-24 2015-08-05 中国科学院苏州纳米技术与纳米仿生研究所 一种有机硅化物修饰的锂硫电池正极材料的制备方法
CN103515613B (zh) * 2013-10-02 2017-06-30 中国地质大学（武汉） 一种锂硫电池添加剂、含有该添加剂的正极材料
CN104466138B (zh) * 2014-12-24 2017-02-22 华南师范大学 一种锂硫电池球形复合正极材料及其制备方法与应用
CN104577080B (zh) * 2014-12-29 2017-02-22 中国地质大学（武汉） 一种高倍率性能锂硫电池的复合正极材料及制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102324507A (zh) * 2011-09-10 2012-01-18 中南大学 一种锂硫电池复合正极材料制备方法
CN103500847A (zh) * 2013-10-02 2014-01-08 中国地质大学（武汉） 锂硫电池添加剂、含有该添加剂的正极材料及其制备方法
CN103515614A (zh) * 2013-10-02 2014-01-15 中国地质大学（武汉） 一种电池添加剂、含有该添加剂的正极材料及其制备方法
CN104900880A (zh) * 2015-06-03 2015-09-09 中国地质大学（武汉） 一种锂硫电池复合正极材料及其制备方法

Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112490413B (zh) * 2019-09-11 2022-12-23 肇庆市华师大光电产业研究院 一种碳纳米管硫正极材料的制备方法及其在钠硫电池中的应用
CN112490413A (zh) * 2019-09-11 2021-03-12 肇庆市华师大光电产业研究院 一种碳纳米管硫正极材料的制备方法及其在钠硫电池中的应用
CN111092225A (zh) * 2019-11-25 2020-05-01 华东理工大学 锂电池自支撑电极用多功能包覆层及其制备方法
CN111092225B (zh) * 2019-11-25 2022-12-13 华东理工大学 锂硫电池自支撑电极及其制备方法
CN111146415A (zh) * 2019-12-18 2020-05-12 东华大学 一种添加助剂的碳硫复合正极材料的制备方法
CN111362312A (zh) * 2020-03-17 2020-07-03 东北大学秦皇岛分校 一种利用酸洗铁红回收处理得到锂-空气电池正极材料的方法
CN111362312B (zh) * 2020-03-17 2022-03-01 东北大学秦皇岛分校 一种利用酸洗铁红回收处理得到锂-空气电池正极材料的方法
CN111977703B (zh) * 2020-08-21 2023-09-05 天目湖先进储能技术研究院有限公司 Li2O、Li2CO3包覆过渡金属硫化物基正极材料及制备方法和应用
CN111977703A (zh) * 2020-08-21 2020-11-24 天目湖先进储能技术研究院有限公司 Li2O、Li2CO3包覆过渡金属硫化物基正极材料及制备方法和应用
CN112234205B (zh) * 2020-10-16 2022-10-04 肇庆市华师大光电产业研究院 一种用于锂硫电池的通用电极材料及其制备方法
CN112234205A (zh) * 2020-10-16 2021-01-15 肇庆市华师大光电产业研究院 一种用于锂硫电池的通用电极材料及其制备方法
CN113224281A (zh) * 2021-03-12 2021-08-06 上海电力大学 一种以废弃尿不湿为原料的锂硫电池正极材料及制备方法
CN113270569A (zh) * 2021-05-12 2021-08-17 烟台大学 一种锂硫电池专用多孔复合电极的制备及其应用
CN113346091A (zh) * 2021-06-07 2021-09-03 清华大学深圳国际研究生院 正极及其制备方法、锂硫电池
CN113488638B (zh) * 2021-06-30 2022-12-23 肇庆市华师大光电产业研究院 一种高导电强吸附的锂硫电池正极材料制备方法
CN113488638A (zh) * 2021-06-30 2021-10-08 肇庆市华师大光电产业研究院 一种高导电强吸附的锂硫电池正极材料制备方法
CN113735177A (zh) * 2021-09-06 2021-12-03 派尔森环保科技有限公司 一种纳米空心球壳状高倍率性能的LaFeO3锂离子电池负极材料的制备方法
CN114388786A (zh) * 2021-12-21 2022-04-22 西安理工大学 一种木材菌丝共生材料制备碳骨架的方法及载硫储能应用
CN114408923B (zh) * 2022-01-24 2024-01-16 天津大学 一种多孔碳材料孔口调控的方法及其应用
CN114408923A (zh) * 2022-01-24 2022-04-29 天津大学 一种多孔碳材料孔口调控的方法及其应用
CN114583144A (zh) * 2022-03-07 2022-06-03 西安理工大学 一种微细网络结构的硫碳正极材料的机械热合成方法
CN114583145B (zh) * 2022-03-25 2023-11-03 江西省纳米技术研究院 锂硫电池正极材料、其制备方法及锂硫电池
CN114583145A (zh) * 2022-03-25 2022-06-03 江西省纳米技术研究院 锂硫电池正极材料、其制备方法及锂硫电池
CN114725347B (zh) * 2022-04-27 2023-09-08 南京邮电大学 一种用于锂硫电池的三维多孔碳复合材料及其制备方法
CN114725347A (zh) * 2022-04-27 2022-07-08 南京邮电大学 一种用于锂硫电池的三维多孔碳复合材料及其制备方法
CN114735673B (zh) * 2022-05-05 2024-03-01 贵州大学 一种交联微介孔碳复合材料的制备方法及其应用
CN114735673A (zh) * 2022-05-05 2022-07-12 贵州大学 一种交联微介孔碳复合材料的制备方法及其应用
CN115000366A (zh) * 2022-05-19 2022-09-02 同济大学 具有核壳结构的柔性自支撑锂硫电池正极薄膜及制备方法
CN115043391A (zh) * 2022-05-27 2022-09-13 合肥学院 一种mof衍生的二维微孔碳纳米片材料及其制备方法
CN115036592B (zh) * 2022-06-21 2023-08-29 中国地质大学（武汉） 双位点黏土矿物基硫还原催化剂及其制备方法和应用
CN115036592A (zh) * 2022-06-21 2022-09-09 中国地质大学（武汉） 双位点黏土矿物基硫还原催化剂及其制备方法和应用
CN114975957A (zh) * 2022-06-22 2022-08-30 桂林理工大学 一种硫/葡萄糖介孔碳球锂硫电池正极材料及其制备方法
CN114976484B (zh) * 2022-07-11 2023-04-11 大连理工大学 负载Ni2P-Co肖特基结活性位点海胆状碳材料电催化剂、制备方法及其应用
CN114976484A (zh) * 2022-07-11 2022-08-30 大连理工大学 负载Ni2P-Co肖特基节活性位点海胆状碳材料电催化剂、制备方法及其应用
CN115050943A (zh) * 2022-07-12 2022-09-13 北京北化工程技术有限公司 一种高压实密度的硒掺杂硫代三聚硫氰酸材料及其制备方法和电池正极片
CN115332519A (zh) * 2022-09-09 2022-11-11 郑州大学 一种锂硫电池正极材料的制备方法及应用
CN115676821A (zh) * 2022-10-14 2023-02-03 电子科技大学长三角研究院(湖州) 一种锂硫电池正极材料的制备方法、正极材料及应用
CN115594229A (zh) * 2022-10-18 2023-01-13 香港理工大学（Hk） 纳米高熵氧化物材料及其制备方法、锂硫电池正极材料
CN115724426A (zh) * 2022-12-06 2023-03-03 辽宁工程技术大学 一种原位掺氮煤基多孔碳锂硫电池正极材料制备方法
CN116425144A (zh) * 2023-04-13 2023-07-14 哈尔滨理工大学 一种用于钠离子电池的碳纳米管修饰硬碳负极材料的制备方法

Also Published As

Publication number Publication date
CN104900880B (zh) 2017-07-11
CN104900880A (zh) 2015-09-09

Similar Documents

Publication Publication Date Title
WO2016192389A1 (zh) 一种锂硫电池复合正极材料及其制备方法
CN108063232B (zh) 一种硅碳复合负极材料及其制备方法、锂离子电池
CN104192836B (zh) 自支撑多孔石墨烯基薄膜的溶液热制备方法
CN108735969A (zh) 锂离子电池负极及柔性锂离子电池
CN107946570A (zh) 贝壳状结构硅碳复合电极材料
CN104409709B (zh) 一种锂离子电池负极材料、制备方法和锂离子电池
CN112794324B (zh) 一种高介孔率木质素多级孔碳材料及其制备方法与应用
CN108682833B (zh) 一种磷酸铁锂基改性正极材料制备方法
CN111628156B (zh) 一种钼掺杂多孔硅碳复合材料及其制备方法和锂离子电池
CN113299896A (zh) 中空多孔的硅碳@木质素碳纳米球的制备方法及其应用
CN114267493B (zh) 一种基于氮掺杂石墨烯的水性导电浆料及其制备方法和应用
CN110212190A (zh) 一种网状包覆结构的复合电极材料及其制备方法与应用
WO2024031867A1 (zh) 氮掺杂石墨烯包覆硅碳复合材料及其制备方法和应用
CN114447325A (zh) 多孔碳材料、其制备方法、负极和锂金属电池
CN113078322A (zh) 一种锂电池循环稳定性的石墨烯-硅负极材料及制备方法
CN111342010A (zh) 双层碳包覆结构的硅碳复合材料及其制备方法和应用
WO2023173772A1 (zh) 硬碳负极材料的制备方法和应用
CN106299294A (zh) 一种二氧化锡纳米晶/二氧化钛纳米管复合材料的制备方法
KR20210124887A (ko) 사전리튬화된 음극, 그 제조방법 및 사전리튬화된 음극을 포함하는 리튬 이온 전지 및 슈퍼 커패시터
CN115036471A (zh) 一种硅基复合材料及其制备方法、锂电池的负极材料及其制备方法、锂电池
CN111435732A (zh) 锂离子电池的负极材料及其制备方法和锂离子电池
CN112409604B (zh) 石墨烯筛接枝超支化聚氨酯自修复粘结剂及其制备与应用
CN108091866B (zh) 一种用于锂离子电池硅碳负极材料的制备方法
CN107732241B (zh) 锂离子电池正极浆料及其合浆方法
CN113506860A (zh) 一种碳纳米管中管@硒复合材料及其制备方法和应用

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15894032

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15894032

Country of ref document: EP

Kind code of ref document: A1