CN112635699B - Pre-lithiation method - Google Patents
Pre-lithiation method Download PDFInfo
- Publication number
- CN112635699B CN112635699B CN202011447689.4A CN202011447689A CN112635699B CN 112635699 B CN112635699 B CN 112635699B CN 202011447689 A CN202011447689 A CN 202011447689A CN 112635699 B CN112635699 B CN 112635699B
- Authority
- CN
- China
- Prior art keywords
- battery
- lithium
- positive electrode
- positive
- plate
- 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
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000006138 lithiation reaction Methods 0.000 title claims abstract description 13
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000011267 electrode slurry Substances 0.000 claims abstract description 25
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 25
- 239000011248 coating agent Substances 0.000 claims abstract description 21
- 238000000576 coating method Methods 0.000 claims abstract description 21
- 239000000126 substance Substances 0.000 claims abstract description 20
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims abstract description 14
- 239000002131 composite material Substances 0.000 claims abstract description 11
- 239000003792 electrolyte Substances 0.000 claims abstract description 11
- 230000004913 activation Effects 0.000 claims abstract description 10
- 239000006258 conductive agent Substances 0.000 claims abstract description 10
- 239000002904 solvent Substances 0.000 claims abstract description 10
- 239000007774 positive electrode material Substances 0.000 claims abstract description 9
- 238000002156 mixing Methods 0.000 claims abstract description 8
- 239000012299 nitrogen atmosphere Substances 0.000 claims abstract description 7
- 238000004806 packaging method and process Methods 0.000 claims abstract description 7
- 239000000843 powder Substances 0.000 claims abstract description 7
- 238000003466 welding Methods 0.000 claims abstract description 7
- 239000000853 adhesive Substances 0.000 claims abstract description 6
- 230000001070 adhesive effect Effects 0.000 claims abstract description 6
- 238000005096 rolling process Methods 0.000 claims abstract description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 20
- 239000002109 single walled nanotube Substances 0.000 claims description 14
- 239000002033 PVDF binder Substances 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 9
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 9
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000012528 membrane Substances 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- 239000010703 silicon Substances 0.000 claims description 7
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 4
- 239000011230 binding agent Substances 0.000 claims description 4
- 150000002500 ions Chemical class 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 239000011572 manganese Substances 0.000 claims description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical group CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
- 239000002134 carbon nanofiber Substances 0.000 claims description 3
- 229910021389 graphene Inorganic materials 0.000 claims description 3
- 229910021385 hard carbon Inorganic materials 0.000 claims description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 3
- 238000002848 electrochemical method Methods 0.000 abstract description 4
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 abstract 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 22
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 22
- 229910052757 nitrogen Inorganic materials 0.000 description 11
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 229910052782 aluminium Inorganic materials 0.000 description 7
- 239000011888 foil Substances 0.000 description 7
- BHZCMUVGYXEBMY-UHFFFAOYSA-N trilithium;azanide Chemical compound [Li+].[Li+].[Li+].[NH2-] BHZCMUVGYXEBMY-UHFFFAOYSA-N 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 239000011889 copper foil Substances 0.000 description 6
- 238000007599 discharging Methods 0.000 description 5
- 239000000654 additive Substances 0.000 description 4
- 230000000996 additive effect Effects 0.000 description 4
- 210000004379 membrane Anatomy 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 239000007773 negative electrode material Substances 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000005034 decoration Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- 229910021131 SiyP3−yO12 Inorganic materials 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000006256 anode slurry Substances 0.000 description 1
- 210000002469 basement membrane Anatomy 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- GLNWILHOFOBOFD-UHFFFAOYSA-N lithium sulfide Chemical compound [Li+].[Li+].[S-2] GLNWILHOFOBOFD-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
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
- H01M4/04—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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/043—Processes of manufacture in general involving compressing or compaction
- H01M4/0435—Rolling or calendering
-
- 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
- H01M4/0438—Processes of manufacture in general by electrochemical processing
- H01M4/044—Activating, forming or electrochemical attack of the supporting material
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
The invention provides a prelithiation method, which comprises the following steps: mixing a positive electrode active material, a composite conductive agent, an adhesive, lithium powder and a solvent according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, coating the obtained positive electrode slurry, rolling and tabletting to obtain a positive electrode sheet; reacting the positive plate in a nitrogen atmosphere at the temperature of 50-300 ℃ for 1-48 h to obtain a reacted positive plate; preparing the positive plate, the negative plate and the diaphragm after the reaction into a battery cell, welding, packaging and injecting electrolyte to obtain a battery; and (3) standing the battery, performing charging chemical activation, and inserting the formed lithium ions into the negative electrode to finish the pre-lithiation. The method belongs to electrochemical prelithiation, and is characterized in that lithium nitride is formed and then lithium ions released by the lithium nitride are inserted into a negative electrode by an electrochemical method, and compared with other methods, the method has better uniformity, and an SEI formed in the initial stage is more compact and accurate, so that the first-time efficiency of the battery is high, and the energy density is high.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a prelithiation method.
Background
Lithium ion batteries have received much attention due to their high energy density and good cycle performance. Along with the popularization of mobile internet equipment, the popularization of electric automobiles and other electric vehicles, and the development of aerospace technologies such as unmanned aerial vehicles and space detectors, the performance of lithium ion batteries is facing higher development requirements, and how to improve the volume energy density and the mass energy density of lithium batteries becomes the key breakthrough direction of high-performance lithium ion batteries.
In the technical scheme of the key field of 2025 manufactured by China, namely in the power battery of a new energy automobile, the energy density of the power battery in 2025 years is required to reach 400Wh/kg, and in order to achieve the aim, researchers mostly adopt a high-gram-capacity positive electrode (lithium-rich manganese-based material with NCM811 and NCA or higher gram capacity) and a high-gram-capacity silicon-based negative electrode material with a negative electrode. However, the high-gram-capacity silicon-based negative electrode material has low initial efficiency, and the energy density of 400Wh/kg is difficult to achieve under the design condition of a limit process, so that the method for solving the problem only carries out pre-lithiation on the negative electrode material or the battery cell, and the initial efficiency is improved. In addition, the appropriate pre-lithiation amount can not only improve the gram capacity of the anode and improve the energy density of the battery, but also weaken the early sharp attenuation in the cycle process of the silicon cathode and improve the overall cycle performance of the battery, and can also improve the discharge medium voltage and further improve the energy density.
However, the influence of different prelithiation depths on battery cycle by some existing prelithiation technologies has no systematic research, so that most of the prelithiation technologies only promote first effect, and the cycle is not promoted because the positive irreversible lithium is continuously consumed by the fracture and regeneration of SEI in the charging and discharging processes. China with publication number CN109888274A specially uses positive lithium salt as additive to release lithium ion for pre-lithiation in the first circle, the positive electrode obtained by the method has low gram capacity and limited lithium, and substances added according to the mass conservation principle account for certain mass and can not improve the energy density; journal of Materials Chemistry a Journal 2017, volume 5, No. 27, No. 14286-14293, discloses that an ethanol solution of lithium sulfide is used for soaking into a positive electrode and then pre-lithiation is performed on the negative electrode through charging and discharging, and the method finally generates hydrogen sulfide which is extremely toxic and is not beneficial to production and environment friendliness.
Disclosure of Invention
In view of the above, the present invention aims to provide a prelithiation method, which is simple and the formed SEI is dense.
The invention provides a prelithiation method, which comprises the following steps:
mixing a positive electrode active material, a composite conductive agent, an adhesive, lithium powder and a solvent according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, coating the obtained positive electrode slurry, rolling and tabletting to obtain a positive electrode sheet;
reacting the positive plate in a nitrogen atmosphere at the temperature of 50-300 ℃ for 1-48 h to obtain a reacted positive plate;
preparing the positive plate, the negative plate and the diaphragm after the reaction into a battery cell, welding, packaging and injecting electrolyte to obtain a battery;
and (3) standing the battery, performing charging chemical activation, and inserting the formed lithium ions into the negative electrode to finish the prelithiation.
Preferably, the process of charging chemical activation comprises:
after the battery is kept still for time t1, the battery is charged to U1 by a current constant current of 0.02C, then discharged to U2 by a current constant current of 0.1C, then charged to a current of 0.02C by a voltage constant voltage of U2, kept still for time t2, discharged to U3 by a current constant current of 0.1C, decompressed, pumped and sealed, and subjected to 0.5C circulation after the chemical composition and the capacity are completed, so that the pre-lithiation is completed;
the U1 is 3.0-3.9V, the U2 is 4.5-4.8V, and the U3 is 2-2.5V; t1 is 10-14 h, t2 is 1-5 min.
Preferably, the positive active material includes one or more of single crystal ternary 532, a lithium rich manganese base, and a high voltage lithium cobaltate;
the binder is selected from PVDF;
the solvent is selected from N-methyl pyrrolidone;
the composite conductive agent is selected from any two or more of conductive carbon black SP, SWCNT, CNT, KS-6, VGCF and graphene.
Preferably, the negative plate is selected from a silicon-based negative plate, a tin-based negative plate or a hard carbon negative plate;
the membrane is selected from a LAGP ion coated membrane or an alumina coated membrane.
Preferably, the viscosity of the positive electrode slurry is 3500-8000 Pa.s.
Preferably, the mixing time is 3-6.5 h.
The invention provides a prelithiation method, which comprises the following steps: mixing a positive electrode active material, a composite conductive agent, an adhesive, lithium powder and a solvent according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, coating the obtained positive electrode slurry, rolling and tabletting to obtain a positive electrode sheet; reacting the positive plate in a nitrogen atmosphere at the temperature of 50-300 ℃ for 1-48 h to obtain a reacted positive plate; preparing the positive plate, the negative plate and the diaphragm after the reaction into a battery cell, welding, packaging and injecting electrolyte to obtain a battery; and (3) standing the battery, performing charging chemical activation, and inserting the formed lithium ions into the negative electrode to finish the prelithiation. The method belongs to electrochemical prelithiation, which is characterized in that lithium nitride is formed and then lithium ions released by the lithium nitride are inserted into a negative electrode by an electrochemical method. Compared with the conventional positive electrode additive, the method has the advantages that lithium and nitrogen in the oven are directly generated in the electrode drying process, other procedures are not needed, and the method is efficient and convenient.
Drawings
FIG. 1 is SEM images of a positive electrode plate prepared in example 1 of the present invention before and after heating, wherein a is the SEM image before reaction with nitrogen, and b is the SEM image after reaction with nitrogen;
fig. 2 is a first-turn charge-discharge curve diagram of a battery prepared in example 1 of the present invention;
fig. 3 is a first-turn charge-discharge curve diagram of a battery prepared in example 2 of the present invention;
fig. 4 is a first-turn charge-discharge curve diagram of a battery prepared in example 3 of the present invention.
Detailed Description
The invention provides a prelithiation method, which comprises the following steps:
mixing a positive electrode active material, a composite conductive agent, an adhesive, lithium powder and a solvent according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, coating the obtained positive electrode slurry, rolling and tabletting to obtain a positive electrode sheet;
reacting the positive plate in a nitrogen atmosphere at the temperature of 50-300 ℃ for 1-48 h to obtain a reacted positive plate;
preparing the positive plate, the negative plate and the diaphragm after the reaction into a battery cell, welding, packaging and injecting electrolyte to obtain a battery;
and (3) standing the battery, performing charging chemical activation, and inserting the formed lithium ions into the negative electrode to finish the prelithiation.
According to the invention, a positive electrode active substance, a composite conductive agent, a binder, lithium powder and a solvent are mixed according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, and the obtained positive electrode slurry is coated, rolled and tabletted to obtain a positive electrode sheet. In the invention, the viscosity of the positive electrode slurry is preferably 3500 to 8000 Pa.s. In a specific embodiment, the viscosity of the positive electrode slurry is 4500 pa.s; the solids content was 63%. The thickness of the positive plate is 200 mu m. In the present invention, the positive active material includes one or more of a single crystal ternary 532 (NCM 532), a lithium rich manganese base (LRM), and a high voltage Lithium Cobaltate (LCO);
the binder is selected from PVDF;
the solvent is selected from N-methyl pyrrolidone;
the composite conductive agent is selected from any two or more of conductive carbon black SP, SWCNT, CNT, KS-6, VGCF and graphene.
In a specific embodiment, the positive electrode slurry comprises LRM, SP, SWCNT, PVDF and Li in a mass ratio of 95.5:0.8:0.2:1.5: 2; or LCO, SP, SWCNT, PVDF, and Li in a mass ratio of 95.5:0.8:0.2:1.5: 2; or NCM532, SP, SWCNT, PVDF, and Li in a mass ratio of 95.5:0.8:0.2:1.5: 2.
After the positive plate is obtained, the positive plate is reacted in the nitrogen atmosphere to obtain the reacted positive plate. The reaction temperature is 50-300 ℃, and preferably 100-150 ℃; the time is 1-48 h, preferably 12-24 h. The invention preferably carries out the above reaction in an oven; according to the invention, the oven is preferably vacuumized, then filled with nitrogen, and directly heated for reaction.
The positive plate, the negative plate and the diaphragm after reaction are made into a battery cell, and then the battery cell is welded, packaged, injected with electrolyte and kept stand to obtain the battery.
The silicon-based negative plate is preferably coated by negative slurry and pressed into a sheet to prepare the negative plate.
In the invention, the negative plate is selected from a silicon-based negative plate, a tin-based negative plate or a hard carbon negative plate; the negative electrode slurry comprises SiO, SP, SWCNT and PAA with the mass ratio of 95-96: 1.0-1.1: 0.055-0.065: 3-3.2; in a specific embodiment, the negative electrode slurry is SiO, SP, SWCNT and PAA in a mass ratio of 95.8:1.04:0.06: 3.1.
In the present invention, the separator is selected from a LAGP ion-coated separator or an alumina-coated separator; the basement membrane of the diaphragm is Celgard PP membrane. The LAGP ion coating diaphragm is Li1+x+yAlx(Ti,Ge)2-x SiyP3-yO12(ii) a X is more than 0 and less than 2, and y is more than 0 and less than 3. Ultrasonic welding is preferred for the present invention. The invention preferably adopts aluminum plastic film packaging. The electrolyte is preferably selected from the group consisting of Thailand Wallace 4750 FB.
The battery is statically placed and then is subjected to charging chemical activation, and formed lithium ions are inserted into the negative electrode to complete the pre-lithiation. The standing time is preferably 1-96 h, and the standing temperature is preferably 40-50 ℃. In a specific embodiment, the standing temperature is 45 ℃ and the standing time is 24 h.
In the invention, the process of chemical activation of charging comprises the steps that after the battery is kept still for t1, the battery is charged to U1 by a current constant current of 0.02C, then the battery is charged to U2 by a current constant current of 0.1C, then the battery is charged to a current of 0.02C by a voltage constant voltage of U2, the battery is kept still for t2, the battery is discharged to U3 by a constant current of 0.1C, decompression, air suction and sealing are carried out, and 0.5C circulation is carried out after the chemical composition and partial volume are finished, so that pre-lithiation is finished;
the U1 is 3.0-3.9V, the U2 is 4.5-4.8V, and the U3 is 2-2.5V; t1 is 10-14 h, t2 is 1-5 min.
In specific embodiments, the U1 is 3.5V, the U2 is 4.6V, the U3 is 2.5V, the t1 is 12h, and the t2 is 3 min.
The method provided by the invention belongs to electrochemical pre-lithiation, and is characterized in that lithium nitride is formed and then lithium ions released by the lithium nitride are inserted into a negative electrode by an electrochemical method. Compared with the conventional positive electrode additive, the method has the advantages that lithium and nitrogen in the oven are directly generated in the electrode drying process, other procedures are not needed, and the method is efficient and convenient.
To further illustrate the present invention, a prelithiation method provided by the present invention is described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.
Example 1 lithium-rich cathode material + silicon carbon negative electrode
Coating the positive electrode slurry on an aluminum foil with the thickness of 12 microns, coating the aluminum foil with the thickness of 240 microns, and tabletting to obtain a positive plate with the thickness of 200 microns; the positive electrode slurry was LRM: SP: SWCNT: PVDF: li =95.5%:0.8%:0.2%:1.5%: 2%; the slurry viscosity was 4500 with a solids content of 63%.
Reacting the positive plate in a nitrogen atmosphere at the temperature of 110 ℃ for 12 hours to obtain a reacted positive plate;
coating the negative electrode slurry on a copper foil with the thickness of 6 microns, coating the copper foil with the thickness of 125 microns, and tabletting to obtain a negative electrode plate with the thickness of 110 microns; the negative electrode slurry was SiO: SP: SWCNT: PAA = 95.8%: 1.04%, 0.06% and 3.1%. (the gram volume of the mixture of the silicon monoxide and the graphite is 1000 mAh/g)
And (3) assembling the negative plate, the reacted positive plate, a diaphragm celgard16+4 and electrolyte (China Taihuarong 4750 FB) into a soft-package battery, and standing at a high temperature of 45 ℃ for 24 hours.
After standing at high temperature, the first efficiency and the medium pressure are recorded by carrying out chemical composition volume operation. The method comprises the following specific steps: standing the battery after standing at high temperature for t1, then charging to U1 with a current constant current of 0.02C, then charging to U2 with a current constant current of 0.1C, then charging to a current of 0.02C with a voltage constant voltage of U2, standing for t2, discharging to U3 with a constant current of 0.1C, decompressing, exhausting and sealing, and completing the capacity of chemical components; t1 is 12h, U1 is 3.5V, U2 is 4.6V, U3 is 2.5V, and t2 is 3 min.
And performing 0.5C circulation after the component capacity.
Fig. 1 is SEM images of the positive electrode sheet before and after reaction in nitrogen, and it can be seen from fig. 1 that: the positive plate has almost no pure lithium phase, and is converted into a lithium nitride phase after reaction in nitrogen.
As can be seen from fig. 2: the first efficiency of the lithium + SiO-rich system was 97.2%, the energy density was 428 Wh/kg.
Example 2 high voltage lithium cobaltate + silicon carbon negative electrode
Coating the positive electrode slurry on an aluminum foil with the thickness of 12 microns, coating the aluminum foil with the thickness of 240 microns, and tabletting to obtain a positive plate with the thickness of 200 microns; the anode slurry is LCO: SP: SWCNT: PVDF: LI =95.5%:0.8%:0.2%:1.5%: 2%; the slurry viscosity was 4500 with a solids content of 63%.
Coating the negative electrode slurry on a copper foil with the thickness of 6 microns, coating the copper foil with the thickness of 125 microns, and tabletting to obtain a negative electrode plate with the thickness of 110 microns; the negative electrode slurry was SiO: SP: SWCNT: PAA = 95.8%: 1.04%, 0.06% and 3.1%. (the gram volume of the mixture of the silicon monoxide and the graphite is 1000 mAh/g)
Reacting the positive plate in nitrogen at the temperature of 110 ℃ for 12 hours to obtain a reacted positive plate;
and assembling the negative plate, the reacted positive plate, a diaphragm celgard16+4 and electrolyte (China capacity 4750 FB) into a soft package battery, and standing at the high temperature of 45 ℃ for 24 hours.
After standing at high temperature, the first efficiency and the medium pressure are recorded by carrying out chemical composition volume operation. The method comprises the following specific steps: standing the battery after standing at high temperature for t1, then charging to U1 with a current constant current of 0.02C, then charging to U2 with a current constant current of 0.1C, then charging to a current of 0.02C with a voltage constant voltage of U2, standing for t2, discharging to U3 with a constant current of 0.1C, decompressing, exhausting and sealing, and completing the capacity of chemical components; t1 is 12h, U1 is 3.5V, U2 is 4.4.5V, U3 is 2.5V, and t2 is 3 min.
And performing 0.5C circulation after the component capacity.
As can be seen from fig. 3: the LCO + SiO system has the first efficiency of 96.7 percent and the energy density of 352 Wh/kg.
EXAMPLE 3 Single Crystal NCM532+ silicon carbon negative electrode
Coating the positive electrode slurry on an aluminum foil with the thickness of 12 microns, coating the aluminum foil with the thickness of 240 microns, and tabletting to obtain a positive plate with the thickness of 200 microns; the positive electrode slurry was NCM 532: SP: SWCNT: PVDF: LI =95.5%:0.8%:0.2%:1.5%: 2%; the slurry viscosity was 4500 with a solids content of 63%.
Reacting the positive plate in nitrogen at the temperature of 110 ℃ for 12 hours to obtain a reacted positive plate;
coating the negative electrode slurry on a copper foil with the thickness of 6 microns, coating the copper foil with the thickness of 125 microns, and tabletting to obtain a negative electrode plate with the thickness of 110 microns; the negative electrode slurry was SiO: SP: SWCNT: PAA = 95.8%: 1.04%, 0.06% and 3.1%. (the gram volume of the mixture of the silicon monoxide and the graphite is 1000 mAh/g)
And assembling the negative plate, the reacted positive plate, a diaphragm celgard16+4 and electrolyte (China capacity 4750 FB) into a soft package battery, and standing at the high temperature of 45 ℃ for 24 hours.
After standing at high temperature, the first efficiency and the medium pressure are recorded by carrying out chemical composition volume operation. The method comprises the following specific steps: standing the battery after standing at high temperature for t1, then charging to U1 with a current constant current of 0.02C, then charging to U2 with a current constant current of 0.1C, then charging to a current of 0.02C with a voltage constant voltage of U2, standing for t2, discharging to U3 with a constant current of 0.1C, decompressing, exhausting and sealing, and completing the capacity of chemical components; t1 is 12h, U1 is 3.5V, U2 is 4.6V, U3 is 2.5V, and t2 is 3 min.
And performing 0.5C circulation after the component capacity.
As can be seen from fig. 4: the NCM532+ SiO system has the first efficiency of 96.2 percent and the energy density of 341 Wh/kg.
As can be seen from the above examples, the present invention provides a method of prelithiation comprising the steps of: mixing a positive electrode active material, a composite conductive agent, an adhesive, lithium powder and a solvent according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, coating the obtained positive electrode slurry, rolling and tabletting to obtain a positive electrode sheet; reacting the positive plate in nitrogen at the temperature of 50-300 ℃ for 1-48 h to obtain a reacted positive plate; preparing the positive plate after the reaction, the negative plate of the composite lithium foil and the diaphragm into a battery cell, welding, packaging, injecting electrolyte, and standing to obtain a battery; and (3) standing the battery, performing charging chemical activation, and inserting the formed lithium ions into the negative electrode to finish the prelithiation. The method belongs to electrochemical prelithiation, and is characterized in that lithium nitride is formed and then lithium ions released by the lithium nitride are inserted into a negative electrode by an electrochemical method. Compared with the conventional positive electrode additive, the method has the advantages that lithium and nitrogen in the oven are directly generated in the electrode drying process, other procedures are not needed, and the method is efficient and convenient.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (2)
1. A method of prelithiation comprising the steps of:
mixing a positive electrode active material, a composite conductive agent, an adhesive, lithium powder and a solvent according to a mass ratio of 95-98: 0.7-0.9: 2-3: 8-12: 100-110, coating the obtained positive electrode slurry, rolling and tabletting to obtain a positive electrode sheet; the viscosity of the positive electrode slurry is 3500-8000 Pa.s;
reacting the positive plate in a nitrogen atmosphere at the temperature of 50-300 ℃ for 1-48 h to obtain a reacted positive plate;
preparing the positive plate, the negative plate and the diaphragm after the reaction into a battery cell, welding, packaging, injecting electrolyte, and standing to obtain a battery; the negative plate is selected from a silicon-based negative plate, a tin-based negative plate or a hard carbon negative plate; the membrane is selected from a LAGP ion coating membrane or an alumina coating membrane;
standing the battery, and then performing charging chemical activation to form lithium ions which are inserted into a negative electrode to complete pre-lithiation;
the process of charging chemical activation comprises:
after the battery is kept still for time t1, the battery is charged to U1 by a current constant current of 0.02C, then charged to U2 by a current constant current of 0.1C, then charged to a current of 0.02C by a voltage constant voltage of U2, kept still for time t2, discharged to U3 by a constant current of 0.1C, decompressed, pumped and sealed, and subjected to 0.5C circulation after the chemical composition and the capacity are completed, so that the pre-lithiation is completed;
the U1 is 3.0-3.9V, the U2 is 4.5-4.8V, and the U3 is 2-2.5V; t1 is 10-14 h, t2 is 1-5 min;
the positive active material comprises one or more of monocrystal ternary 532, lithium-rich manganese base and high-voltage lithium cobaltate;
the binder is selected from PVDF;
the solvent is selected from N-methyl pyrrolidone;
the composite conductive agent is selected from any two or more of conductive carbon black SP, SWCNT, CNT, KS-6, VGCF and graphene.
2. The method of claim 1, wherein the mixing time is 3 to 6.5 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011447689.4A CN112635699B (en) | 2020-12-09 | 2020-12-09 | Pre-lithiation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011447689.4A CN112635699B (en) | 2020-12-09 | 2020-12-09 | Pre-lithiation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112635699A CN112635699A (en) | 2021-04-09 |
| CN112635699B true CN112635699B (en) | 2022-03-25 |
Family
ID=75310294
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011447689.4A Active CN112635699B (en) | 2020-12-09 | 2020-12-09 | Pre-lithiation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112635699B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113488610A (en) * | 2021-06-07 | 2021-10-08 | 万向一二三股份公司 | Lithium ion battery anode, lithium ion battery and preparation method of battery |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102916164A (en) * | 2012-09-20 | 2013-02-06 | 东莞新能源科技有限公司 | Method for supplementing lithium to lithium-ion battery positive plate |
| CN109346679A (en) * | 2018-09-21 | 2019-02-15 | 合肥国轩高科动力能源有限公司 | A method of cycle life of lithium ion battery is promoted using lithium nitride |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102916165B (en) * | 2012-09-20 | 2016-05-18 | 东莞新能源科技有限公司 | A kind of method of mending lithium to anode plate for lithium ionic cell |
| US11056679B2 (en) * | 2018-07-31 | 2021-07-06 | GRU Energy Lab Inc. | Positive electrodes with active materials and temporary lithium additives for lithium ion electrochemical cells |
-
2020
- 2020-12-09 CN CN202011447689.4A patent/CN112635699B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102916164A (en) * | 2012-09-20 | 2013-02-06 | 东莞新能源科技有限公司 | Method for supplementing lithium to lithium-ion battery positive plate |
| CN109346679A (en) * | 2018-09-21 | 2019-02-15 | 合肥国轩高科动力能源有限公司 | A method of cycle life of lithium ion battery is promoted using lithium nitride |
Non-Patent Citations (1)
| Title |
|---|
| "Battery prelithiation enabled by lithium fixation on cathode";Si-Yu Yang et al.;《Journal of Power Sources》;20201101;第1-2页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112635699A (en) | 2021-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111261836B (en) | Method for pre-lithiating negative electrode of lithium ion battery and preparation method of pre-lithiated lithium ion battery | |
| CN101937994A (en) | Graphene/aluminum composite cathode material of lithium ion battery and preparation method thereof | |
| CN112133909B (en) | Antimony sulfide-based negative electrode material for lithium ion battery and preparation method thereof | |
| CN100505391C (en) | honeycomb structure spherical LiFePO4 / C composite material preparation method | |
| CN110890545A (en) | PEDOT (polyethylene glycol terephthalate)/PSS (Polybutylece terephthalate)/CMC (carboxymethyl cellulose) composite binder as well as preparation method and application thereof | |
| CN105742592A (en) | Preparation method of W/W2C/Action Carbon-coated cathode material for lithium-ion battery | |
| CN112635699B (en) | Pre-lithiation method | |
| CN106744776A (en) | A kind of preparation method of pure phase titanium phosphate lithium anode material | |
| KR20070091456A (en) | Preparation method of active material for positive electrode of lithium secondary battery and lithium secondary battery thereby | |
| CN103378355A (en) | Alkali metal secondary battery as well as negative active substance, negative material and negative electrode thereof, and preparation method of negative active substance | |
| CN104766958A (en) | Silicon-carbon composite material and preparation method thereof, and lithium ion battery | |
| CN106602049A (en) | Preparation method for lithium-sulfur battery taking carbon-supported boron-lithium alloy as negative electrode material | |
| CN114937770B (en) | Double-layer lithium ion conductor coated modified lithium cobalt oxide positive electrode material, preparation method thereof, lithium ion battery and electric equipment | |
| CN110444734A (en) | Silicon sulphur battery prelithiation method | |
| CN110993912A (en) | Preparation of silicon-carbon negative electrode battery | |
| CN107482181B (en) | Composite lithium ion battery anode material Li3V2(PO4)3/C and preparation method thereof | |
| CN113697787B (en) | Method for preparing lithium ion battery anode material by starch modified coated ferric phosphate | |
| CN105024113B (en) | Preparation method of rechargeable lithium ion oxygen battery based on lithium-intercalated graphite | |
| CN114678494A (en) | Method for pre-lithiating negative electrode and simultaneously obtaining SEI (solid electrolyte interface) film, negative electrode and lithium ion battery | |
| CN110571500B (en) | Lithium-sulfur semi-flow battery | |
| CN110518194B (en) | Method for preparing core-shell silicon/carbon composite material by in-situ carbon coating and application thereof | |
| CN114094081A (en) | Crosslinked nanocarbon sheet loaded boron nitride nanocrystal/sulfur composite material, preparation method thereof, lithium-sulfur battery positive electrode and lithium-sulfur battery | |
| CN109546092B (en) | Lithium-sulfur thin film battery | |
| CN112186174A (en) | Conductive additive and preparation method and application thereof | |
| CN104900871A (en) | Preparation method of LiFePO4 cathode material, lithium ion battery 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 | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20240423 Address after: 315201 No. 1818, Zhong Guan Xi Road, Zhuang City Street, Zhenhai District, Ningbo, Zhejiang. Patentee after: NINGBO GRAPHENE INNOVATION CENTER Co.,Ltd. Country or region after: China Address before: 315201, No. 519, Zhuang Avenue, Zhenhai District, Zhejiang, Ningbo Patentee before: NINGBO INSTITUTE OF MATERIALS TECHNOLOGY & ENGINEERING, CHINESE ACADEMY OF SCIENCES Country or region before: China |
|
| TR01 | Transfer of patent right |