CN115548320B - Concentration gradient Te x Se y S z Composite positive electrode material, preparation method and application thereof - Google Patents
Concentration gradient Te x Se y S z Composite positive electrode material, preparation method and application thereof Download PDFInfo
- Publication number
- CN115548320B CN115548320B CN202211343318.0A CN202211343318A CN115548320B CN 115548320 B CN115548320 B CN 115548320B CN 202211343318 A CN202211343318 A CN 202211343318A CN 115548320 B CN115548320 B CN 115548320B
- Authority
- CN
- China
- Prior art keywords
- positive electrode
- electrode material
- concentration gradient
- composite positive
- composite
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 89
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 40
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 239000006258 conductive agent Substances 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 15
- 229910052711 selenium Inorganic materials 0.000 claims abstract description 14
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 12
- 238000009826 distribution Methods 0.000 claims abstract description 9
- 238000010438 heat treatment Methods 0.000 claims abstract description 9
- 239000011230 binding agent Substances 0.000 claims abstract description 8
- 238000002156 mixing Methods 0.000 claims abstract description 3
- 238000000576 coating method Methods 0.000 claims description 14
- 238000001035 drying Methods 0.000 claims description 14
- 239000002904 solvent Substances 0.000 claims description 11
- 239000011267 electrode slurry Substances 0.000 claims description 10
- JDZCKJOXGCMJGS-UHFFFAOYSA-N [Li].[S] Chemical compound [Li].[S] JDZCKJOXGCMJGS-UHFFFAOYSA-N 0.000 claims description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 8
- 239000002033 PVDF binder Substances 0.000 claims description 8
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 8
- 239000002041 carbon nanotube Substances 0.000 claims description 8
- 238000005096 rolling process Methods 0.000 claims description 8
- 229910052714 tellurium Inorganic materials 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 5
- 238000000859 sublimation Methods 0.000 claims description 5
- 230000008022 sublimation Effects 0.000 claims description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 4
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 230000001681 protective effect Effects 0.000 claims description 4
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 claims description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 2
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 2
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 2
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 2
- 239000001307 helium Substances 0.000 claims description 2
- 229910052734 helium Inorganic materials 0.000 claims description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 claims description 2
- 239000003273 ketjen black Substances 0.000 claims description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 2
- 229920000638 styrene acrylonitrile Polymers 0.000 claims description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims 1
- 239000010405 anode material Substances 0.000 claims 1
- 239000000835 fiber Substances 0.000 claims 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 15
- 229910052744 lithium Inorganic materials 0.000 abstract description 14
- 239000003792 electrolyte Substances 0.000 abstract description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 abstract description 11
- 230000002441 reversible effect Effects 0.000 abstract description 9
- 239000011593 sulfur Substances 0.000 abstract description 9
- 230000000694 effects Effects 0.000 abstract description 8
- 238000004090 dissolution Methods 0.000 abstract description 5
- 239000013543 active substance Substances 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 3
- 239000007772 electrode material Substances 0.000 abstract description 2
- 239000011669 selenium Substances 0.000 description 41
- 239000000463 material Substances 0.000 description 13
- 238000000498 ball milling Methods 0.000 description 12
- 238000011068 loading method Methods 0.000 description 10
- 238000013329 compounding Methods 0.000 description 8
- 239000012528 membrane Substances 0.000 description 8
- 239000011888 foil Substances 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- 239000006256 anode slurry Substances 0.000 description 6
- 238000007664 blowing Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 6
- OPHUWKNKFYBPDR-UHFFFAOYSA-N copper lithium Chemical compound [Li].[Cu] OPHUWKNKFYBPDR-UHFFFAOYSA-N 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 6
- 239000012982 microporous membrane Substances 0.000 description 6
- -1 polytetrafluoroethylene Polymers 0.000 description 6
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 6
- 239000004810 polytetrafluoroethylene Substances 0.000 description 6
- 239000002356 single layer Substances 0.000 description 6
- 238000005303 weighing Methods 0.000 description 6
- JAWMENYCRQKKJY-UHFFFAOYSA-N [3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-ylmethyl)-1-oxa-2,8-diazaspiro[4.5]dec-2-en-8-yl]-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]methanone Chemical compound N1N=NC=2CN(CCC=21)CC1=NOC2(C1)CCN(CC2)C(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F JAWMENYCRQKKJY-UHFFFAOYSA-N 0.000 description 5
- 229910003003 Li-S Inorganic materials 0.000 description 4
- 239000012300 argon atmosphere Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 238000004806 packaging method and process Methods 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000013067 intermediate product Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 238000004321 preservation Methods 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 239000012785 packaging film Substances 0.000 description 2
- 229920006280 packaging film Polymers 0.000 description 2
- 239000002985 plastic film Substances 0.000 description 2
- 229920006255 plastic film Polymers 0.000 description 2
- 229920001021 polysulfide Polymers 0.000 description 2
- 239000005077 polysulfide Substances 0.000 description 2
- 150000008117 polysulfides Polymers 0.000 description 2
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 241000282326 Felis catus Species 0.000 description 1
- 229910018091 Li 2 S Inorganic materials 0.000 description 1
- 229910001216 Li2S Inorganic materials 0.000 description 1
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- 229910003473 lithium bis(trifluoromethanesulfonyl)imide Inorganic materials 0.000 description 1
- QSZMZKBZAYQGRS-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)azanide Chemical compound [Li+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F QSZMZKBZAYQGRS-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
-
- 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
-
- 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
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0404—Methods of deposition of the material by coating on electrode collectors
-
- 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
- H01M4/04—Processes of manufacture in general
- H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
-
- 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
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
-
- 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
-
- 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
Abstract
The invention belongs to the field of lithium battery electrode materials, and particularly discloses a concentration gradient Te x Se y S z Composite positive electrode material, and preparation method and application thereof. The concentration gradient Te x Se y S z The composite positive electrode material is prepared by uniformly mixing at least one of Se and Te, S, a conductive agent and a binder to prepare the positive electrode material, and heating to sublimate the S so that the positive electrode material forms S element content gradient distribution in the thickness direction. Concentration gradient Te prepared by the invention x Se y S z In the composite positive electrode material, the content of S element is distributed in a gradient manner in the thickness direction, compared with uniform Te x Se y S z Composite anode and concentration gradient Te x Se y S z The composite positive electrode material can more effectively inhibit the dissolution and the shuttle effect of active substances in the charge-discharge cycle process; at the same time is more beneficial to Li + And the electrolyte is conducted from the outer surface to the inner part of the electrode, so that the reversible capacity and the cycle performance of the sulfur-based positive electrode are improved.
Description
Technical Field
The invention belongs to the field of lithium battery electrode materials, and in particular relates to a concentration gradient Te x Se y S z Composite positive electrode material, and preparation method and application thereof.
Background
In order to meet the increasing demand for high power/high energy density applications, the development of Li-S batteries is considered one of the most effective solutions at present. However, some of the problems currently existing with sulfur anodes severely hamper the commercialization process of Li-S batteries. (1) Rapid dissolution and tightening of charge and discharge intermediate product lithium polysulfideThe heavy 'fly shuttle effect' causes poor cycling stability and high self-discharge rate of the Li-S battery; (2) The electron and ion insulativity of sulfur and the discharge end product Li2S results in low sulfur positive electrode utilization and poor rate capacity. In order to solve the problems of the above-mentioned Li-S battery, the methods currently in common use are: the conductive carbon material is used as a carrier to bind sulfur or a proper electrolyte is selected to inhibit the dissolution and loss of the lithium polysulfide. However, the sulfur cathode material of lithium sulfur battery still has low conductivity of insulating sulfur (5×10) -28 S m -1 ) And poor cycle performance.
Disclosure of Invention
The invention provides a concentration gradient Te for a lithium-sulfur battery x Se y S z Composite positive electrode material and preparation method thereof. The concentration gradient Te x Se y S z In the composite positive electrode material, the content of S element is distributed in a gradient manner in the thickness direction, x and y are not less than 0 and are not equal to 0 at the same time, and z is greater than 0. Comprising the following steps: when x is equal to 0, te is x Se y S z The composite positive electrode material is Se y S z Y: z=0.05-0.35:1; when y is equal to 0, te is x Se y S z The composite positive electrode material is Te x S z And x: z=0.05-0.15:1; when x and y are not equal to 0, x: y: z=0.05-0.1:0.05-0.2:1.
Concentration gradient Te of the invention x Se y S z In the composite positive electrode material, the content of S element gradually decreases in the thickness direction, and the element contents of Te/Se (in binary material), te and Se (in ternary material) correspondingly gradually increases. Since the charge and discharge intermediates of Se and Te, lithium polyselenide and lithium polytelluride, dissolve and "fly-shuttle effect" are weaker than lithium polysulfide, are different from conventional uniform Te x Se y S z Composite anode, concentration gradient Te in charge-discharge cycle process x Se y S z The outer surface of the composite positive electrode is rich in intermediate products of the lithium polyselenide and the lithium polytelluride, so that the dissolution of active substances and the flying shuttle effect are effectively inhibited. In addition, since Se and Te are discharge end product solid Li 2 Se and Li 2 Te to S ratioElectric final product solid Li 2 S has higher Li + Ionic conductivity, so is different from the conventional uniform Te x Se y S z Composite anode and concentration gradient Te x Se y S z The outer surface of the composite positive electrode is rich in Li + Solid Li with fast ion conduction 2 Se and Li 2 Te, thereby facilitating Li in electrolyte + And the electrolyte is conducted from the outer surface to the inner part of the electrode, so that the reversible capacity and the cycle performance of the sulfur-based positive electrode are improved.
The invention also provides the concentration gradient Te x Se y S z The preparation method of the composite positive electrode material comprises the following steps:
uniformly mixing at least one of Se and Te, S, a conductive agent, a binder and a solvent to prepare a positive electrode material;
step two, sublimating S by heating to form gradient distribution of S element content in the thickness direction of the positive electrode material, thereby obtaining the concentration gradient Te x Se y S z And (3) compounding a positive electrode material.
Wherein, in the step one of the above preparation method, at least one of Se and Te, and the sum of the mass of S: the mass of the conductive agent: mass of binder = 70-90:20-2:10-8. When x is equal to 0, the molar ratio of Se to S is 0.05-0.35:1-1.2; when y is equal to 0, the molar ratio of Te to S is 0.05-0.15:1-1.2; when x and y are not equal to 0, the mass ratio of Te, se and S is 0.05-0.1:0.05-0.2:1-1.2.
Preferably, the specific process of the step one of the preparation method is as follows: at least one of Se and Te, S, a conductive agent, a binder and a solvent are uniformly mixed to prepare positive electrode slurry, the positive electrode slurry is uniformly coated on a current collector through a coating method, and the positive electrode material is prepared after drying and rolling.
As a further preferred implementation, the specific process of the second step is as follows: heating the positive electrode material in protective gas, and enabling the sublimation speed of S to be higher as the positive electrode material is closer to the outer surface far away from the current collector, so as to form gradient distribution of S element content in the thickness direction, thereby preparing the concentration gradient Te x Se y S z A composite positive electrode material; the protective gas is nitrogen or inert gas. Preferably, the heating conditions include: the temperature is 120-250 ℃ and the time is 1-3600 s; the shielding gas is one of nitrogen, argon and helium.
Preferably, in the above preparation method, the conductive agent is at least one of carbon nanotubes, carbon fibers and ketjen black, the binder is at least one of polyvinylidene fluoride, polyethylene oxide, carboxymethyl cellulose, styrene butadiene rubber and acrylonitrile multipolymer, and the solvent is at least one of N-methyl pyrrolidone, ethanol, isopropanol and water.
The beneficial effects of the invention are as follows: concentration gradient Te prepared by the invention x Se y S z In the composite positive electrode material, the content of S element is distributed in a gradient manner in the thickness direction, compared with uniform Te x Se y S z Composite anode, concentration gradient Te in charge-discharge cycle process x Se y S z The outer surface of the composite anode is rich in intermediate products of lithium polyselenide and lithium polytelluride, so that the dissolution of active substances and the shuttle effect can be more effectively inhibited; meanwhile, concentration gradient type Te x Se y S z The outer surface of the composite positive electrode is rich in Li + Solid Li with fast ion conduction 2 Se and Li 2 Te to make Li in electrolyte more beneficial + And the electrolyte is conducted from the outer surface to the inner part of the electrode, so that the reversible capacity and the cycle performance of the sulfur-based positive electrode are improved.
Drawings
FIG. 1 shows the initial SeS of example 1 10 Composite positive plate and final concentration gradient CG-SeS 8 EDS element analysis result comparison diagrams of different section positions of the composite positive plate;
FIG. 2 shows the concentration gradient type CG-SeS obtained in example 1 8 A charge-discharge curve of the composite positive electrode at 0.05 ℃;
FIG. 3 shows the concentration gradient type CG-SeS obtained in example 1 8 And a cycle performance curve of the composite positive electrode at 0.05 ℃.
Detailed Description
The conception, specific structure, and technical effects produced by the present invention will be clearly and completely described below with reference to the embodiments and the drawings to fully understand the objects, aspects, and effects of the present invention.
Example 1:
respectively weighing 32.10g of sublimed sulfur (1.00 mol), 7.90g of elemental selenium (0.10 mol), 7.50g of carbon nanotube conductive agent, 2.50g of polyvinylidene fluoride binder and 116.00g N-methyl pyrrolidone solvent, placing the materials in a polytetrafluoroethylene ball milling tank, and ball milling for 6 hours at a rotating speed of 400r/min according to a ball material weight ratio of 4:1 to obtain uniform anode slurry; uniformly coating the positive electrode slurry on a current collector Al foil with the thickness of 10um by a coating method, drying for 1h by blowing at 60 ℃ and then drying for 12h in vacuum, and rolling to obtain uniform SeS 10 And (5) compounding the positive electrode. Initial SeS 10 The thickness of the composite positive electrode is 190um, and the loading capacity is 5.5mg (S+Se)/cm 2 。
Initial SeS 10 Cutting the composite anode into anode sheets with the length of 6cm and the width of 4cm, and rapidly putting the anode sheets into an argon atmosphere protection furnace at 180 ℃ to sublimate and diffuse S; the closer to the outer surface of the positive electrode sheet (i.e., the surface far from the current collector Al foil), the faster the S sublimation speed is, thereby forming concentration gradient distribution of Se/S in the thickness direction of the positive electrode sheet; after heat preservation for 10min, rapidly taking out the positive plate for natural cooling, and finally obtaining the concentration gradient SeS 8 Composite positive plate (Concentration gradient SeS) 8 cat hode, abbreviated as CG-SeS 8 ). Final CG-SeS 8 The thickness of the composite positive plate is 180um, the loading capacity is 4.6mg (S+ S e)/cm 2 。
FIG. 1 is an initial SeS 10 Composite positive plate and final concentration gradient CG-SeS 8 E DS element analysis results of different section positions of the composite positive plate are compared. The results show that: initial SeS 10 Se and S elements in the composite positive plate are uniformly distributed, and the molar ratio of Se/S at different section positions is 1/10; concentration gradient CG-SeS obtained after rapid heat treatment 8 The composite positive plate forms concentration gradient distribution of Se/S in the thickness direction of the positive plate; the closer to the current collector, the higher the S element content; the closer to the outside, the higher the Se element content.
Gradient concentration CG-SeS to be obtained 8 After the electrode lugs are welded on the composite positive electrode plate and the lithium copper composite negative electrode plate respectively, a Celgar d 2400 microporous membrane is used as a diaphragm, liTFSI/DOL-DME (volume ratio is 1:1) is used as electrolyte, an aluminum plastic membrane is used as an outer packaging membrane, and the single-layer lithium sulfur soft package battery is manufactured through lamination assembly. FIG. 2 shows a concentration gradient CG-SeS 8 And (3) compounding a charge-discharge curve of the positive plate under the current density of 0.05C. FIG. 3 is a CG-SeS 8 The cycle performance curve of the composite positive electrode material sheet under the current density of 0.05C has the initial discharge capacity of 1140mAh g -1 The method comprises the steps of carrying out a first treatment on the surface of the After 50 times of circulation, the reversible discharge capacity still reaches 971mAh g -1 。
Example 2:
respectively weighing 32.10g of sublimed sulfur (1.0 mol), 7.9g of simple substance tellurium (0.06 mol), 7.50g of carbon nano tube conductive agent, 2.50g of polyvinylidene fluoride binder and 116.00g N-methyl pyrrolidone solvent, placing the materials in a polytetrafluoroethylene ball milling tank, ball milling the materials at a ball weight ratio of 4:1 at a rotating speed of 400r/min for 6 hours to obtain uniform anode slurry; uniformly coating the positive electrode slurry on a current collector Al foil with the thickness of 10um by a coating method, drying for 1h by blowing at 60 ℃ and then drying for 12h in vacuum, and rolling to obtain uniform TeS 16.7 And (5) compounding the positive electrode. Initial TeS 16.7 The thickness of the composite positive electrode is 190um, the loading capacity is 5.7mg (S+Te)/cm 2 。
Will initiate TeS 16.7 Cutting the composite anode into anode sheets with the length of 6cm and the width of 4cm, and rapidly putting the anode sheets into an argon atmosphere protection furnace at 200 ℃ to sublimate and diffuse S; the closer to the outer surface of the positive plate, the faster the S sublimation speed is, so that Te/S concentration gradient distribution is formed in the thickness direction of the positive plate; after heat preservation for 8min, rapidly taking out the positive plate for natural cooling, and finally obtaining the concentration gradient TeS 13.0 Composite positive plate (Concentration gradient TeS) 13.0 cathode, abbreviated as CG-TeS 13.0 ). Final CG-TeS 13.0 The thickness of the composite positive plate is 180um, and the loading capacity is 4.8mg (S+Te)/cm 2 。
Gradient concentration CG-TeS to be obtained 13.0 After the electrode lugs are respectively welded on the composite positive electrode plate and the lithium copper composite negative electrode plate, a Celgard 2400 microporous membrane is used as a diaphragm, and LiTFSI/DOL-DME (volume ratio is 1:1) is used as a diaphragmAnd (3) using the electrolyte and the aluminum plastic film as external packaging films, and assembling the laminated films to obtain the single-layer lithium-sulfur soft-package battery. The results show that the concentration gradient type CG-TeS 13.0 The first discharge capacity of the composite anode at the current density of 0.05C is 1132mAh g -1 The method comprises the steps of carrying out a first treatment on the surface of the After 50 times of circulation, the reversible discharge capacity is still up to 960mAhg -1 。
Example 3:
respectively weighing 32.10g of sublimed sulfur (1.00 mol), 3.02g of elemental selenium (0.04 mol), 4.88g of elemental tellurium (0.04 mol), 7.50g of carbon nanotube conductive agent, 2.50g of polyvinylidene fluoride binder and 116.00g N-methyl pyrrolidone solvent, placing the materials in a polytetrafluoroethylene ball milling tank, ball milling at a ball weight ratio of 4:1 for 6 hours at a rotating speed of 400r/min, and obtaining uniform anode slurry; uniformly coating the positive electrode slurry on a current collector Al foil with the thickness of 10um by a coating method, drying for 1h by blowing at 60 ℃ and then drying for 12h in vacuum, and rolling to obtain uniform TeSeS 25 And (5) compounding the positive electrode. Initial TeSeS 25 The thickness of the composite positive electrode is 190um, the loading capacity is 5.6mg (S+Se+Te)/cm 2 。
Initial TeSeS 25 Cutting the composite anode into anode sheets with the length of 6cm and the width of 4cm, and rapidly putting the anode sheets into an argon atmosphere protection furnace at 160 ℃ to sublimate and diffuse S; the closer to the outer surface of the positive plate, the faster the S sublimation speed is, so that the concentration gradient distribution of Te/Se/S is formed in the thickness direction of the positive plate; after heat preservation for 15min, rapidly taking out the positive plate for natural cooling, and finally obtaining the TeSeS with concentration gradient 20.3 Composite positive plate (Concentration gradient TeSeS) 20.3 cathode, abbreviated as CG-TeSeS 20.3 ). Final CG-TeSeS 20.3 The thickness of the composite positive electrode is 180um, the loading capacity is 4.6mg (S+Se+Te)/cm 2 。
Gradient concentration CG-TeSeS to be obtained 20.3 And after the electrode lugs are respectively welded on the composite positive electrode plate and the lithium copper composite negative electrode plate, a Ce lgard 2400 microporous membrane is used as a diaphragm, liTFSI/DOL-DME (volume ratio is 1:1) is used as electrolyte, an aluminum plastic membrane is used as an outer packaging membrane, and the single-layer lithium sulfur soft package battery is prepared through lamination assembly. The results showed that concentration gradient type CG-TeSeS 20.3 The first discharge capacity of the composite anode at the current density of 0.05C is 1145mAh g -1 The method comprises the steps of carrying out a first treatment on the surface of the After the cycle was completed 50 times,the reversible discharge capacity is still as high as 983mAh g -1 。
Comparative example 1:
respectively weighing 40g of sublimed sulfur, 7.50g of carbon nano tube conductive agent, 2.50g of polyvinylidene fluoride binder and 116.00g N-methyl pyrrolidone solvent, placing the materials in a polytetrafluoroethylene ball milling tank, ball milling the materials for 6 hours at a rotating speed of 400r/min according to the weight ratio of 4:1, and obtaining uniform anode slurry; and uniformly coating the positive electrode slurry on a current collector Al foil with the thickness of 10um by a coating method, drying for 1h by blowing at 60 ℃, drying for 12h in vacuum, and rolling to obtain the uniform S composite positive electrode. The thickness of the S composite positive electrode is 180um, and the loading capacity is 4.7mg (S)/cm 2 。
Cutting the obtained uniform S composite anode into anode sheets with the length of 6cm and the width of 4cm, respectively welding the anode tabs with lithium copper composite cathode sheets, and then assembling the anode sheets by using Celgard 2400 microporous membrane as a diaphragm, liTFSI/DOL-DME (volume ratio of 1:1) as electrolyte and aluminum plastic membrane as an outer packaging membrane, thereby preparing the single-layer lithium sulfur soft package battery. The result shows that the first discharge capacity of the uniform S composite anode at the current density of 0.05C is only 680mAh g -1 The method comprises the steps of carrying out a first treatment on the surface of the After 50 times of circulation, the reversible discharge capacity is reduced to 260mAh g -1 Are all significantly lower than the concentration gradient CG-SeS obtained in example 1 8 Composite positive electrode, concentration gradient type CG-TeS obtained in example 2 13.0 Composite Positive electrode or concentration gradient CG-TeSeS obtained in example 3 20.3 And (5) compounding the positive electrode.
Comparative example 2:
respectively weighing 40g of sublimed sulfur, 7.50g of carbon nano tube conductive agent, 2.50g of polyvinylidene fluoride binder and 116.00g N-methyl pyrrolidone solvent, placing the materials in a polytetrafluoroethylene ball milling tank, ball milling the materials for 6 hours at a rotating speed of 400r/min according to the weight ratio of 4:1, and obtaining uniform anode slurry; and uniformly coating the positive electrode slurry on a current collector Al foil with the thickness of 10um by a coating method, drying for 1h by blowing at 60 ℃, drying for 12h in vacuum, and rolling to obtain the uniform S composite positive electrode. The thickness of the initial S composite positive electrode is 190um, and the loading capacity is 5.6mg (S)/cm 2 。
Cutting the initial S composite positive electrode into positive electrode slices with the length of 6cm and the width of 4cm, rapidly placing the positive electrode slices into an argon atmosphere protection furnace at 170 ℃, and preserving heat for 1 timeAnd after 2min, rapidly taking out the positive plate and naturally cooling. The thickness of the finally obtained S composite anode is 180-u m, and the loading capacity is 4.5mg (S)/cm 2 。
And respectively welding the electrode lugs of the S composite anode and the 50um lithium copper composite cathode plate obtained after the rapid heat treatment, and assembling the electrode lugs by taking a C elgard 2400 microporous membrane as a diaphragm, liTFSI/DOL-DME (volume ratio of 1:1) as an electrolyte and taking an aluminum plastic film as an outer packaging film, thereby preparing the single-layer lithium sulfur soft package battery. The result shows that the first discharge capacity of the S composite positive electrode obtained after the rapid heat treatment at the current density of 0.05C is only 861mAh g -1 The method comprises the steps of carrying out a first treatment on the surface of the After 50 cycles, the reversible discharge capacity is reduced to 526 mAh g -1 Are lower than the concentration gradient CG-SeS obtained in example 1 8 Composite positive electrode (shown in FIG. 3), concentration gradient type CG-TeS obtained in example 2 13.0 Composite Positive electrode or concentration gradient CG-TeSeS obtained in example 3 20.3 The composite positive electrode further proves that the concentration gradient Te of the invention x Se y S z The effective benefit of the composite positive electrode.
Comparative example 3:
respectively weighing 32.10g of sublimed sulfur (1.00 mol), 7.90g of elemental selenium (0.10 mol), 7.50g of carbon nanotube conductive agent, 2.50g of polyvinylidene fluoride binder and 116.00g N-methyl pyrrolidone solvent, placing the materials in a polytetrafluoroethylene ball milling tank, and ball milling for 6 hours at a rotating speed of 400r/min according to a ball material weight ratio of 4:1 to obtain uniform anode slurry; uniformly coating the positive electrode slurry on a current collector Al foil with the thickness of 10um by a coating method, drying for 1h by blowing at 60 ℃ and then drying for 12h in vacuum, and rolling to obtain uniform SeS 10 And (5) compounding the positive electrode. Uniform SeS 10 The thickness of the composite positive electrode is 180um, the loading capacity is 4.6mg (S+Se)/cm 2 。
Will be homogeneous SeS 10 And (3) cutting the composite anode into anode sheets with the length of 6cm and the width of 4cm, respectively welding tabs with lithium copper composite cathode sheets, and then assembling by using Celgard 2400 microporous membrane as a diaphragm, liTFSI/DOL-DME (volume ratio of 1:1) as electrolyte and aluminum plastic membrane as an outer packaging membrane, so as to obtain the single-layer lithium-sulfur soft package battery. The results show that uniform SeS 10 The first discharge capacity of the composite anode at the current density of 0.05C is only 710mAhg -1 The method comprises the steps of carrying out a first treatment on the surface of the After 50 times of circulation, the reversible discharge capacity is reduced to 320mAh g -1 Are all significantly lower than the concentration gradient CG-SeS obtained in example 1 8 Composite positive electrode, concentration gradient type CG-TeS obtained in example 2 13.0 Composite Positive electrode or concentration gradient CG-TeSeS obtained in example 3 20.3 And (5) compounding the positive electrode.
The present invention is not limited to the above embodiments, but is merely preferred embodiments of the present invention, and the present invention should be construed as being limited to the above embodiments as long as the technical effects of the present invention are achieved by the same means. Various modifications and variations are possible in the technical solution and/or in the embodiments within the scope of the invention.
Claims (7)
1. Concentration gradient Te x Se y S z A composite positive electrode material characterized by Te x Se y S z In the composite positive electrode material, the content of the S element is distributed in a gradient manner in the thickness direction, the content of the S element is gradually reduced in the thickness direction, x and y are not less than 0 and are not equal to 0 at the same time, and z is greater than 0: when x is equal to 0, te is x Se y S z The composite positive electrode material is Se y S z Y: z=0.05-0.35:1; when y is equal to 0, te is x Se y S z The composite positive electrode material is Te x S z And x: z=0.05-0.15:1; when x and y are not equal to 0, x: y: z=0.05-0.1:0.05-0.2:1;
the concentration gradient Te x Se y S z The preparation method of the composite positive electrode material comprises the following steps:
uniformly mixing at least one of Se and Te, S, a conductive agent, a binder and a solvent to prepare a positive electrode material;
step two, sublimating S by heating to form gradient distribution of S element content in the thickness direction of the positive electrode material, thereby obtaining the concentration gradient Te x Se y S z A composite positive electrode material;
and the specific process of the second step is as follows: placing the positive electrode material in a protective gasThe closer to the outer surface of the current collector, the faster the S sublimation speed, thereby forming a gradient distribution of the S element content in the thickness direction, thereby producing the concentration gradient Te x Se y S z A composite positive electrode material; the protective gas is nitrogen or inert gas.
2. The concentration gradient Te according to claim 1 x Se y S z The composite positive electrode material is characterized in that in the first step, at least one of Se and Te and the sum of the mass of S: the mass of the conductive agent: mass of binder = 70-90:20-2:10-8.
3. The concentration gradient Te according to claim 2 x Se y S z The composite positive electrode material is characterized in that in the first step, when x is equal to 0, the molar ratio of Se to S is 0.05-0.35:1-1.2; when y is equal to 0, the molar ratio of Te to S is 0.05-0.15:1-1.2; when x and y are not equal to 0, the mass ratio of Te, se and S is 0.05-0.1:0.05-0.2:1-1.2.
4. The concentration gradient Te according to claim 1 x Se y S z The composite positive electrode material is characterized in that the specific process of the first step is as follows: at least one of Se and Te, S, a conductive agent, a binder and a solvent are uniformly mixed to prepare positive electrode slurry, the positive electrode slurry is uniformly coated on a current collector through a coating method, and the positive electrode material is prepared after drying and rolling.
5. The concentration gradient Te according to claim 1 x Se y S z The composite positive electrode material is characterized in that the heating conditions comprise: the temperature is 120-250 ℃ and the time is 1s-3600s; the shielding gas is one of nitrogen, argon and helium.
6. The concentration gradient Te according to claim 1 x Se y S z The composite positive electrode material is characterized in that the conductive agent is carbon nano tube and carbonAt least one of fiber and ketjen black, at least one of polyvinylidene fluoride, polyethylene oxide, carboxymethyl cellulose, styrene-butadiene rubber and acrylonitrile multipolymer, and at least one of N-methyl pyrrolidone, ethanol, isopropanol and water.
7. The concentration gradient Te of claim 1 x Se y S z The application of the composite anode material in preparing the anode of the lithium sulfur battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211343318.0A CN115548320B (en) | 2022-10-31 | 2022-10-31 | Concentration gradient Te x Se y S z Composite positive electrode material, preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211343318.0A CN115548320B (en) | 2022-10-31 | 2022-10-31 | Concentration gradient Te x Se y S z Composite positive electrode material, preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115548320A CN115548320A (en) | 2022-12-30 |
| CN115548320B true CN115548320B (en) | 2023-10-31 |
Family
ID=84718193
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211343318.0A Active CN115548320B (en) | 2022-10-31 | 2022-10-31 | Concentration gradient Te x Se y S z Composite positive electrode material, preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115548320B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106207088A (en) * | 2016-09-30 | 2016-12-07 | 上海空间电源研究所 | A kind of lithium-sulphur cell positive electrode and preparation method thereof |
| CN108461729A (en) * | 2018-03-13 | 2018-08-28 | 温州大学 | A kind of tellurium sulphur complex carbon material and the preparation method and application thereof |
| CN109616634A (en) * | 2018-11-30 | 2019-04-12 | 南昌大学 | One kind being based on hetero atom chalcogen solid solution TexSeySzPositive electrode material of lithium secondary cell and preparation method |
| CN109920957A (en) * | 2019-01-31 | 2019-06-21 | 华中科技大学 | A kind of intercalation material of lithium-sulfur cell |
| CN114725333A (en) * | 2022-03-08 | 2022-07-08 | 华中科技大学 | Lithium-sulfur battery composite positive electrode material, and preparation and application thereof |
| CN114824192A (en) * | 2022-03-14 | 2022-07-29 | 国联汽车动力电池研究院有限责任公司 | Composite positive electrode material, battery positive electrode, lithium battery and application of composite positive electrode material |
| CN115148946A (en) * | 2022-08-05 | 2022-10-04 | 中南大学 | Preparation method of positive pole piece of lithium-sulfur battery and lithium-sulfur battery |
-
2022
- 2022-10-31 CN CN202211343318.0A patent/CN115548320B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106207088A (en) * | 2016-09-30 | 2016-12-07 | 上海空间电源研究所 | A kind of lithium-sulphur cell positive electrode and preparation method thereof |
| CN108461729A (en) * | 2018-03-13 | 2018-08-28 | 温州大学 | A kind of tellurium sulphur complex carbon material and the preparation method and application thereof |
| CN109616634A (en) * | 2018-11-30 | 2019-04-12 | 南昌大学 | One kind being based on hetero atom chalcogen solid solution TexSeySzPositive electrode material of lithium secondary cell and preparation method |
| CN109920957A (en) * | 2019-01-31 | 2019-06-21 | 华中科技大学 | A kind of intercalation material of lithium-sulfur cell |
| CN114725333A (en) * | 2022-03-08 | 2022-07-08 | 华中科技大学 | Lithium-sulfur battery composite positive electrode material, and preparation and application thereof |
| CN114824192A (en) * | 2022-03-14 | 2022-07-29 | 国联汽车动力电池研究院有限责任公司 | Composite positive electrode material, battery positive electrode, lithium battery and application of composite positive electrode material |
| CN115148946A (en) * | 2022-08-05 | 2022-10-04 | 中南大学 | Preparation method of positive pole piece of lithium-sulfur battery and lithium-sulfur battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115548320A (en) | 2022-12-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108123101B (en) | Lithium-sulfur battery adopting pre-lithiated carbon material as negative electrode and preparation method thereof | |
| CN106602063B (en) | Preparation method of graphene flower and application of graphene flower in lithium-sulfur battery | |
| Chung et al. | Low-cost, porous carbon current collector with high sulfur loading for lithium–sulfur batteries | |
| CN110668509B (en) | Selenium-coated high-nickel ternary layered positive electrode material and preparation method thereof | |
| CN108417777A (en) | A kind of porous triple anode composite piece and preparation method thereof and its application | |
| CN108808092B (en) | Active electrolyte, preparation method and application | |
| CN108232111A (en) | A kind of anode composite pole piece of solid state battery and preparation method thereof | |
| CN109449414A (en) | A kind of anode composite material of lithium ion battery and the all-solid-state battery containing the material | |
| CN110611084B (en) | Lithium-sulfur secondary battery with long cycle life and 100% coulombic efficiency | |
| CN112234157A (en) | Composite positive pole piece for solid-state battery and preparation method thereof | |
| CN111370791A (en) | Formation method of lithium-sulfur battery and lithium-sulfur battery prepared by formation method | |
| Yan et al. | Li3N film modified separator with homogenization effect of lithium ions for stable lithium metal battery | |
| Wang et al. | A large-area lithium metal–carbon nanotube film for precise contact prelithiation in lithium-ion batteries | |
| CN113346192A (en) | Lithium ion battery composite diaphragm and preparation method and application thereof | |
| CN115548320B (en) | Concentration gradient Te x Se y S z Composite positive electrode material, preparation method and application thereof | |
| He et al. | Electrochemical characteristics of sulfur composite cathode for reversible lithium storage | |
| CN108039453B (en) | Method for improving cycle performance of negative electrode of lithium battery by using coating | |
| CN113451547B (en) | Composite metal lithium cathode and lithium ion battery comprising same | |
| CN111211303B (en) | Negative electrode active material and preparation method and application thereof | |
| CN114784387A (en) | Dry-method double-electrode lithium battery and preparation method thereof | |
| CN114220962A (en) | Preparation method of graphene modified lithium material and graphene modified lithium material | |
| CN113644235A (en) | Method for constructing LiF protective layer on three-dimensional lithium-carbon composite material and application of LiF protective layer | |
| CN106532024B (en) | Graphene supports the preparation method of the negative electrode material of the lithium ion battery of nanometer boron | |
| CN112759874B (en) | Preparation method of Se-doped sulfurized polyacrylonitrile material | |
| CN114899359B (en) | Improved lithium/silicon/carbon composite negative electrode and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |