CN114784365B - Secondary battery - Google Patents
Secondary battery Download PDFInfo
- Publication number
- CN114784365B CN114784365B CN202210421459.3A CN202210421459A CN114784365B CN 114784365 B CN114784365 B CN 114784365B CN 202210421459 A CN202210421459 A CN 202210421459A CN 114784365 B CN114784365 B CN 114784365B
- Authority
- CN
- China
- Prior art keywords
- negative electrode
- lithium
- secondary battery
- battery
- battery according
- 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
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 49
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 47
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 35
- 238000006138 lithiation reaction Methods 0.000 claims abstract description 32
- 230000001502 supplementing effect Effects 0.000 claims abstract description 17
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 16
- 239000000126 substance Substances 0.000 claims abstract description 16
- 239000007773 negative electrode material Substances 0.000 claims description 17
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 15
- -1 alkyl lithium Chemical compound 0.000 claims description 15
- 239000011230 binding agent Substances 0.000 claims description 14
- 239000006258 conductive agent Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 14
- 239000007774 positive electrode material Substances 0.000 claims description 14
- 239000003795 chemical substances by application Substances 0.000 claims description 12
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 11
- 238000005097 cold rolling Methods 0.000 claims description 11
- 229910003002 lithium salt Inorganic materials 0.000 claims description 9
- 159000000002 lithium salts Chemical class 0.000 claims description 9
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 claims description 7
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 claims description 7
- 229920003048 styrene butadiene rubber Polymers 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000012937 correction Methods 0.000 claims description 6
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 239000011572 manganese Substances 0.000 claims description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 3
- 239000006183 anode active material Substances 0.000 claims description 3
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 3
- 239000002041 carbon nanotube Substances 0.000 claims description 3
- 229910021389 graphene Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 3
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 3
- 238000011068 loading method Methods 0.000 claims description 3
- 239000002994 raw material Substances 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052710 silicon Inorganic materials 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- 239000010405 anode material Substances 0.000 claims 1
- 239000002002 slurry Substances 0.000 abstract description 21
- 239000013589 supplement Substances 0.000 abstract description 8
- 230000000694 effects Effects 0.000 abstract description 7
- 230000005684 electric field Effects 0.000 abstract description 3
- 230000001681 protective effect Effects 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 38
- 239000003792 electrolyte Substances 0.000 description 29
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 23
- 229910001416 lithium ion Inorganic materials 0.000 description 23
- 238000001035 drying Methods 0.000 description 19
- 239000011248 coating agent Substances 0.000 description 18
- 238000000576 coating method Methods 0.000 description 18
- 238000003466 welding Methods 0.000 description 16
- 238000012360 testing method Methods 0.000 description 13
- 239000011888 foil Substances 0.000 description 12
- 238000004806 packaging method and process Methods 0.000 description 12
- 229910052782 aluminium Inorganic materials 0.000 description 11
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 11
- 229910002804 graphite Inorganic materials 0.000 description 11
- 239000010439 graphite Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 11
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 9
- 239000002033 PVDF binder Substances 0.000 description 9
- 239000000654 additive Substances 0.000 description 9
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 9
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 9
- 238000002360 preparation method Methods 0.000 description 9
- 239000006245 Carbon black Super-P Substances 0.000 description 8
- 238000005520 cutting process Methods 0.000 description 8
- 238000009966 trimming Methods 0.000 description 8
- 238000002156 mixing Methods 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 229910013872 LiPF Inorganic materials 0.000 description 5
- 101150058243 Lipf gene Proteins 0.000 description 5
- 239000004743 Polypropylene Substances 0.000 description 5
- 230000000996 additive effect Effects 0.000 description 5
- 239000011889 copper foil Substances 0.000 description 5
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 5
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 5
- 229920001155 polypropylene Polymers 0.000 description 5
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 4
- 239000011149 active material Substances 0.000 description 4
- 239000006256 anode slurry Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 4
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000012046 mixed solvent Substances 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 238000003825 pressing Methods 0.000 description 4
- 230000002035 prolonged effect Effects 0.000 description 4
- 230000009469 supplementation Effects 0.000 description 4
- 239000002562 thickening agent Substances 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- 229910013188 LiBOB Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- 241000526754 Pannonibacter phragmitetus Species 0.000 description 2
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000002985 plastic film Substances 0.000 description 2
- 229920006255 plastic film Polymers 0.000 description 2
- 239000002210 silicon-based material Substances 0.000 description 2
- 239000011366 tin-based material Substances 0.000 description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- HSBKFSPNDWWPSL-CAHLUQPWSA-N 4-amino-5-fluoro-1-[(2r,5s)-5-(hydroxymethyl)-2,5-dihydrofuran-2-yl]pyrimidin-2-one Chemical compound C1=C(F)C(N)=NC(=O)N1[C@H]1C=C[C@@H](CO)O1 HSBKFSPNDWWPSL-CAHLUQPWSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910011281 LiCoPO 4 Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
- 229910002099 LiNi0.5Mn1.5O4 Inorganic materials 0.000 description 1
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 1
- 229910013086 LiNiPO Inorganic materials 0.000 description 1
- 229910003289 NiMn Inorganic materials 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- QSNQXZYQEIKDPU-UHFFFAOYSA-N [Li].[Fe] Chemical compound [Li].[Fe] QSNQXZYQEIKDPU-UHFFFAOYSA-N 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 150000001733 carboxylic acid esters Chemical class 0.000 description 1
- 239000006257 cathode slurry Substances 0.000 description 1
- 150000005678 chain carbonates Chemical class 0.000 description 1
- 239000002482 conductive additive Substances 0.000 description 1
- 150000005676 cyclic carbonates Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 239000007788 liquid 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
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 230000000153 supplemental effect Effects 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 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
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
-
- 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)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
Abstract
The invention belongs to the technical field of secondary batteries, and particularly relates to a secondary battery which comprises a positive plate and a negative plate, wherein the negative plate meets one of the following relations: formula A is less than or equal to 0.7 ((Q) C1 +(CB‑1)Q D1 )*M 1 L 1 +x*A*3800)/(Q D2 *M 2 L 2 ) Is less than or equal to 1; b, ((Q) C1 +(CB‑1+G)Q D1 )*M 1 L 1 +x*A*3800)/((1+G)Q D2 *M 2 L 2 )<1. The secondary battery of the invention supplements according to the formula A or the formula B, the lithium supplementing agent can be driven by an electric field, the pre-lithiation activity rate is high, the energy density of the battery is obviously improved, meanwhile, the pre-lithiation agent has low inorganic protective shell content, the slurry also contains substances such as active carbon and the like, and after the excessive supplement, the secondary battery has a slow release function in the battery, can prolong the service life of the battery, and has higher energy density and longer cycle life.
Description
Technical Field
The invention belongs to the technical field of secondary batteries, and particularly relates to a secondary battery.
Background
In recent years, national policies have greatly encouraged the development of new energy industries, the capital market has unprecedented huge investment enthusiasm for new energy industries, and the traditional automobile industries have been transformed, so that the industry competition is aggravated. Can occupy the technical high point and the market.
High energy density and long service life are main directions of future power battery development, and currently, the main development direction is the pre-lithiation technology. The pre-lithiation technique is divided into positive pre-lithiation and negative pre-lithiation. The positive electrode pre-lithiation is to use decomposable lithium salt as an additive, so that the problems of low lithiation efficiency, more impurities, gas production of a battery cell and the like exist; the negative electrode pre-chemical takes lithium powder, lithium-containing slurry, lithium strip and other substances containing simple substance lithium as pre-lithiation agents, and has the advantage of high lithiation efficiency compared with positive electrode pre-lithiation, but has the advantages of complex process and poor safety. Through years of development, the anode pre-lithiation technology is more mature than the cathode pre-lithiation technology, but the problems of low energy density, short cycle life and the like still exist.
Disclosure of Invention
One of the objects of the present invention is: in order to overcome the defects of the prior art, a secondary battery is provided, which has higher energy density and longer cycle life.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
a secondary battery comprising a positive electrode sheet and a negative electrode sheet, the negative electrode sheet satisfying one of the following relations:
A、0.7≤((Q C1 +(CB-1)Q D1 )*M 1 L 1 +x*A*3800)/(Q D2 *M 2 L 2 )≤1；
B、((Q C1 +(CB-1+G)Q D1 )*M 1 L 1 +x*A*3800)/((1+G)Q D2 *M 2 L 2 )<1；
wherein Q is C1 Half-cell charge gram capacity representing positive electrode, unit mAh g-1, Q C2 Half cell charge gram capacity mAh g-1, Q representing negative electrode D1 The discharge gram capacity of the half battery of the positive electrode is represented, and the unit mAh is g-1; q (Q) D2 The discharge gram capacity of the half cell of the negative electrode is represented by the unit mAh g-1; m is M 1 The unit mass of the positive electrode material of the positive electrode plate is as follows, and the unit g is cm 2 ，M 2 Is the unit mass of the negative electrode material of the negative electrode plate, L 1 Represents the loading percentage of the positive electrode material on the pole piece, L 2 Represents the load percentage unit g cm of the negative electrode material in the pole piece 2 The method comprises the steps of carrying out a first treatment on the surface of the CB represents the capacity excess coefficient of the battery, and the value of CB is (Q C2 *M 2 L 2 )/(Q D1 *M 1 L 1 ) The method comprises the steps of carrying out a first treatment on the surface of the x represents the content of simple substance lithium in the negative electrode lithium supplementing agent; a represents a correction coefficient of 0.4<A<0.9, G represents an excess factor, wherein 0<G<0.7。
Preferably, the negative electrode sheet includes a negative electrode current collector, a first negative electrode active material layer and a second pre-lithiation layer, wherein the first negative electrode active material layer is disposed on at least one surface of the negative electrode current collector, and the second pre-lithiation layer is disposed on one surface of the first negative electrode active material layer far away from the negative electrode current collector.
Preferably, the negative electrode sheet satisfies the following relationship: 0.13< (D3-D1) S2/(D2-D1) S1<2.0; wherein D1 represents the thickness of the negative electrode sheet without the pre-lithiation layer, and D2 represents the thickness of the negative electrode sheet with the pre-lithiation layer and without cold rolling; d3 represents the thickness of the anode sheet with the pre-lithiation layer and after cold rolling; s1 represents the area of the cathode plate, S2 represents the area of the prelithiation layer, wherein 50 μm < D2-D1<100 μm,10 μm < D3-D1<50 μm,0.3< S2/S1<1.
Preferably, the negative electrode sheet satisfies the following relationship: 0.28< (D3-D1) ×S2/(D2-D1) ×S1<0.44.
Preferably, the first anode active material layer includes a carbonaceous or siliceous material.
Preferably, the second pre-physical layer comprises the following raw materials in parts by weight: 5-20 parts of lithium salt, 5-20 parts of conductive agent and 5-25 parts of binder.
Preferably, the lithium salt is one or more of lithium carbonate, lithium fluoride or alkyl lithium.
Preferably, the conductive agent is one or more of conductive carbon, carbon nanotubes and graphene.
Preferably, the binder is one or more of styrene-butadiene rubber and sodium carboxymethyl cellulose.
Preferably, the positive electrode sheet includes one or more of nickel-containing oxide, manganese-containing oxide, or iron-containing oxide.
Compared with the prior art, the invention has the beneficial effects that: when one of the relations A or B is satisfied after lithium is supplemented, the lithium supplementing agent can be driven by an electric field, the pre-lithiation activity rate is high, the energy density of the battery is obviously improved, meanwhile, the inorganic protective shell in the pre-lithiation agent has low content, the slurry also contains substances such as active carbon and the like, and after the excessive supplement, the lithium supplementing agent has a slow release effect in the battery, so that the service life of the battery can be prolonged.
Detailed Description
A secondary battery comprising a positive electrode sheet and a negative electrode sheet, the negative electrode sheet satisfying one of the following relations:
A、0.7≤((Q C1 +(CB-1)Q D1 )*M 1 L 1 +x*A*3800)/(Q D2 *M 2 L 2 )≤1；
B、((Q C1 +(CB-1+G)Q D1 )*M 1 L 1 +x*A*3800)/((1+G)Q D2 *M 2 L 2 )<1；
wherein Q is C1 Half-cell charge gram capacity representing positive electrode, unit mAh g-1, Q C2 Half cell charge gram capacity mAh g-1, Q representing negative electrode D1 The discharge gram capacity of the half battery of the positive electrode is represented, and the unit mAh is g-1; q (Q) D2 The discharge gram capacity of the half cell of the negative electrode is represented by the unit mAh g-1; m is M 1 The unit mass of the positive electrode material of the positive electrode plate is as follows, and the unit g is cm 2 ，M 2 Is the unit mass of the negative electrode material of the negative electrode plate, L 1 Represents the loading percentage of the positive electrode material on the pole piece, L 2 Represents the load percentage unit g cm of the negative electrode material in the pole piece 2 The method comprises the steps of carrying out a first treatment on the surface of the CB represents the capacity excess coefficient of the battery, and the value of CB is (Q C2 *M 2 L 2 )/(Q D1 *M 1 L 1 ) The method comprises the steps of carrying out a first treatment on the surface of the x represents the content of simple substance lithium in the negative electrode lithium supplementing agent; a represents a correction coefficient of 0.4<A<0.9, G represents an excess factor, wherein 0<G<0.7。
When designing the battery, the positive electrode and the negative electrode of the battery need to be matched, so that the positive electrode is designed and determined, and then the negative electrode and the lithium supplementing are correspondingly changed according to the positive electrode. And the positive electrode plate and the negative electrode plate obtained by treatment have a certain matching relationship. When the negative electrode sheet is designed, the negative electrode sheet can be used for satisfying one of the relational expression A and the relational expression B, and when the relational expression A is satisfied, the battery has the advantages of high energy density and long service life compared with the battery without supplementing lithium. When the relation B is satisfied, the battery exhibits a higher energy density and a longer life than the group without lithium addition, and the energy density is somewhat reduced but the life is somewhat prolonged than the group without lithium addition. Since the defined lithium-supplementing agent contains a certain amount of inactive substances, the excessive amount of the inactive substances and the excessive amount of the lithium supplement (the capacity capable of being charged and discharged is determined by the amount of the positive electrode, and the excessive capacity can exist in the negative electrode for the positive electrode to consume) can cause the reduction of the energy density of the battery.
The invention uses coating, spraying and other modes to coat the slurry containing metal lithium on the anode plate, dries the solution, then carries out secondary cold rolling, activates lithium powder, winds the pole piece, injects liquid, and the crushed lithium and active substances spontaneously react to form an interface passivation film (SEI) to compensate irreversible lithium ion consumption on the cathode plate.
Compared with the existing lithium strip lithium supplementing process, the existing coating equipment can be used for production, and meanwhile, the safety is higher; compared with the stabilized lithium powder lithium ion supplement, the safety is higher. Compared with the positive electrode lithium supplement, the lithium supplement efficiency is high, and the process is simpler
Preferably, the negative electrode sheet includes a negative electrode current collector, a first negative electrode active material layer and a second pre-lithiation layer, wherein the first negative electrode active material layer is disposed on at least one surface of the negative electrode current collector, and the second pre-lithiation layer is disposed on one surface of the first negative electrode active material layer far away from the negative electrode current collector.
Preferably, the negative electrode sheet satisfies the following relationship: 0.13< (D3-D1) S2/(D2-D1) S1<2.0; wherein D1 represents the thickness of the negative electrode sheet without the pre-lithiation layer, and D2 represents the thickness of the negative electrode sheet with the pre-lithiation layer and without cold rolling; d3 represents the thickness of the anode sheet with the pre-lithiation layer and after cold rolling; s1 represents the area of the cathode plate, S2 represents the area of the prelithiation layer, wherein 50 μm < D2-D1<100 μm,10 μm < D3-D1<50 μm,0.3< S2/S1<1.
Preferably, the negative electrode sheet satisfies the following relationship: 0.28< (D3-D1) ×S2/(D2-D1) ×S1<0.44.
Preferably, the first anode active material layer includes a carbonaceous or siliceous material.
Preferably, the second pre-physical layer comprises the following raw materials in parts by weight: 5-20 parts of lithium salt, 5-20 parts of conductive agent and 5-25 parts of binder.
Preferably, the lithium salt is one or more of lithium carbonate, lithium fluoride or alkyl lithium.
Preferably, the conductive agent is one or more of conductive carbon, carbon nanotubes and graphene.
Preferably, the binder is one or more of styrene-butadiene rubber and sodium carboxymethyl cellulose.
Preferably, the positive electrode sheet includes one or more of nickel-containing oxide, manganese-containing oxide, or iron-containing oxide.
When one of the relations A or B is satisfied after lithium is supplemented, the lithium supplementing agent can be driven by an electric field, the pre-lithiation activity rate is high, the energy density of the battery is obviously improved, meanwhile, the inorganic protective shell in the pre-lithiation agent has low content, the slurry also contains substances such as active carbon and the like, and after the excessive supplement, the lithium supplementing agent has a slow release effect in the battery, so that the service life of the battery can be prolonged. In particular, when the relation a is satisfied, the advantage of the battery is manifested as high energy density and long life as compared to the non-supplemental lithium group. When the relation b is satisfied, the battery has higher energy density and longer service life than the group without lithium supplementation, and the energy density of the group without lithium supplementation is reduced to a certain extent, but the service life is prolonged to a certain extent. Because the defined lithium supplementing agent contains a certain amount of inactive substances, excessive substances and excessive lithium supplementing (capacity capable of being charged and discharged is determined by the amount of the positive electrode, and the excessive capacity can exist as a negative electrode for the positive electrode to consume) can lead to the reduction of the energy density of the battery, and the specific capacity and the first efficiency are high. When the negative electrode sheet after lithium supplementation meets the relation A or B, the lithium supplementation effect is obvious, the battery capacity is increased, the potential of the negative electrode is stable, the impedance of the negative electrode can be reduced, and the impedance of the whole battery is further reduced. The lithium supplementing slurry has the viscosity similar to that of the cathode slurry, is stable in air, contains a layer of organic matters on the surface, can exist stably at the relative humidity of 20%, can be compatible with the existing cathode coating equipment, and has higher safety.
The following secondary battery is exemplified by a lithium ion battery including a positive electrode sheet, a negative electrode sheet, a separator, an electrolyte, and a case for housing the positive electrode sheet, the negative electrode sheet, the separator, and the electrolyte. The negative plate is the negative plate.
The positive plate comprises a positive current collector and a positive active material layer arranged on at least one surface of the positive current collector, wherein the positive active material layer comprises a positive active material, and the positive active material can be a compound with a chemical formula as Li a Ni x Co y M z O 2-b N b (wherein 0.95.ltoreq.a.ltoreq.1.2, x)>0, y.gtoreq.0, z.gtoreq.0, and x+y+z.ltoreq.1, 0.ltoreq.b.ltoreq.1, M is selected from combinations of one or more of Mn, al, N is selected from combinations of one or more of F, P, S), the positive electrode active material may also be a combination of one or more of compounds including but not limited to LiCoO 2 、LiNiO 2 、LiVO 2 、LiCrO 2 、LiMn 2 O 4 、LiCoMnO 4 、Li 2 NiMn 3 O 8 、LiNi 0.5 Mn 1.5 O 4 、LiCoPO 4 、LiMnPO 4 、LiFePO 4 、LiNiPO 4 、LiCoFSO 4 、CuS 2 、FeS 2 、MoS 2 、NiS、TiS 2 And the like. The positive electrode active material may be further subjected to a modification treatment, and a method for modifying the positive electrode active material should be known to those skilled in the art, for example, the positive electrode active material may be modified by coating, doping, or the like, and the material used for the modification treatment may be one or more combinations including, but not limited to, al, B, P, zr, si, ti, ge, sn, mg, ce, W, or the like. The positive current collector is usually a structure or a part for collecting current, and the positive current collector may be various materials suitable for being used as a positive current collector of a lithium ion battery in the field, for example, the positive current collector may be a metal foil, and the like, and more particularly may include, but is not limited to, an aluminum foil, and the like.
The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer arranged on the surface of the negative electrode current collector, wherein the negative electrode active material layer comprises a negative electrode active material, and the negative electrode active material can be one or more of graphite, soft carbon, hard carbon, carbon fiber, mesophase carbon microsphere, silicon-based material, tin-based material, lithium titanate or other metals capable of forming alloy with lithium. Wherein, the graphite can be selected from one or more of artificial graphite, natural graphite and modified graphite; the silicon-based material can be one or more selected from simple substance silicon, silicon oxygen compound, silicon carbon compound and silicon alloy; the tin-based material can be selected from one or more of elemental tin, tin oxide and tin alloy. The negative current collector is typically a structure or part that collects current, and may be any of a variety of materials suitable in the art for use as a negative current collector for a lithium ion battery, for example, the negative current collector may be a material including, but not limited to, a metal foil, etc., and more particularly may be a material including, but not limited to, a copper foil, etc.
The lithium ion battery also includes an electrolyte comprising an organic solvent, an electrolyte lithium salt, and an additive. Wherein the electrolyte lithium salt can be LiPF used in high-temperature electrolyte 6 And/or LiBOB; liBF used in the low-temperature electrolyte may be used 4 、LiBOB、LiPF 6 At least one of (a) and (b); liBF used in the overcharge-preventing electrolyte may also be used 4 、LiBOB、LiPF 6 At least one of LiTFSI; liClO may also be 4 、LiAsF 6 、LiCF 3 SO 3 、LiN(CF 3 SO 2 ) 2 At least one of them. And the organic solvent may be a cyclic carbonate, including PC, EC; chain carbonates, including DFC, DMC, or EMC; carboxylic esters, including MF, MA, EA, MP, and the like, are also contemplated. And additives include, but are not limited to, film forming additives, conductive additives, flame retardant additives, overcharge prevention additives, and control of H in electrolytes 2 At least one of an additive for O and HF content, an additive for improving low temperature performance, and a multifunctional additive.
The separator may be a variety of materials suitable for lithium ion battery separators in the art, and may be, for example, a combination of one or more of polyethylene, polypropylene, polyvinylidene fluoride, aramid, polyethylene terephthalate, polytetrafluoroethylene, polyacrylonitrile, polyimide, polyamide, polyester, natural fibers, and the like, including but not limited to.
Preferably, the shell is made of one of stainless steel and aluminum plastic film. More preferably, the housing is an aluminum plastic film.
The present invention will be described in further detail with reference to the following specific embodiments, but the embodiments of the present invention are not limited thereto.
Example 1
The secondary battery comprises a positive plate, a negative plate, a diaphragm, electrolyte and a shell, wherein the diaphragm separates the positive plate from the negative plate, and the shell is used for packaging the positive plate, the diaphragm, the negative plate and the electrolyte.
In this example, the non-lithium-supplemented group was set as the A1 group, and the lithium-supplemented group was set as the B1 group. The negative electrode sheet of group B1 satisfies the relation a: 0.7-0% C1 +(CB-1)Q D1 )*M 1 L 1 +x*A*3800)/(Q D2 *M 2 L 2 ) Is less than or equal to 1; wherein Qc 1 ＝158mAh/g，Q D1 ＝155mAh/g，M 1 ＝20mg/cm 2 ，M 2 ＝6mg/cm 2 ，Q C2 ＝650mAh/g，Q D2 ＝850mAh/g，CB＝1.68，x＝0.23mg/cm 2 A=60%. Wherein L1 is 96.5%, L2 is 94.3%, and L2 in A1 and B1 are the same.
Wherein, the positive plate is prepared from lithium iron phosphate material, the coating density is 20.0 milligrams per square centimeter, and the L1 is 96.5 percent. The first charge and discharge efficiency is 92%, the gram capacity is 350 milliamp hour per gram of graphite and the first charge and discharge efficiency is 74%, and the gram capacity is 1350 milliamp hour per gram of silicon oxygen (SiOx) according to the mass ratio of 25:75, preparing a negative plate. The areal density of the negative electrode sheets of group A1 was 6 milligrams per square centimeter. The surface density of the cathode sheet of the B1 group is 6 milligrams per square centimeter, a layer of lithium supplementing slurry is coated on the cathode sheet, the thickness of the pre-lithium layer after drying is 24 micrometers, the thickness of the pre-lithium layer after cold rolling is about 10 micrometers, the coating area is 60 percent of the area of the cathode sheet, and the surface density is 0.23 milligrams per square centimeter. The correction factor a is 0.6.
Preparing a positive plate and a negative plate according to the arrangement:
lithium iron phosphate, conductive agent superconducting carbon (Super-P) and binder polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 97:1.5:1.5, uniformly mixing to prepare lithium ion battery anode slurry with certain viscosity, coating the slurry on a current collector aluminum foil, drying at 85 ℃ and then cold pressing; then trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum after splitting, and welding the tab to prepare the lithium ion battery positive plate.
Preparing a negative plate:
graphite, conductive agent superconducting carbon (Super-P), thickener sodium carboxymethyl cellulose (CMC) and binder Styrene Butadiene Rubber (SBR) are mixed according to the mass ratio of 96:2.0:1.0:1.0 preparing slurry, coating on a current collector copper foil, drying at 85 ℃, trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum condition after splitting, and welding electrode lugs to prepare the lithium ion battery negative plate.
Preparation of electrolyte:
lithium hexafluorophosphate (LiPF) 6 ) Dissolved in a mixed solvent composed of Ethylene Carbonate (EC), dimethyl carbonate (DMC) and Ethyl Methyl Carbonate (EMC) (the mass ratio of the three is 1:2: 1) An electrolyte having a concentration of 1mol/L was obtained.
The diaphragm is a polypropylene diaphragm.
Preparation of the battery:
winding the positive plate, the diaphragm and the negative plate into a battery cell, wherein the diaphragm is positioned between the positive plate and the negative plate, the positive electrode is led out by spot welding of an aluminum tab, and the negative electrode is led out by spot welding of a nickel tab; and then placing the battery core in an aluminum-plastic packaging bag, injecting the electrolyte, and performing procedures such as packaging, formation, capacity and the like to prepare the lithium ion battery.
Example 2
The secondary battery comprises a positive plate, a negative plate, a diaphragm, electrolyte and a shell, wherein the diaphragm separates the positive plate from the negative plate, and the shell is used for packaging the positive plate, the diaphragm, the negative plate and the electrolyte.
In this example, the non-lithium-supplemented group was set as the A2 group, and the lithium-supplemented group was set as the B2 group. The negative electrode sheet of group B2 satisfies the relationship B, ((Q) C1 +(CB-1+G)Q D1 )*M 1 L 1 +x*A*3800)/((1+G)Q D2 *M 2 L 2 )<1, a step of; wherein Qc 1 ＝158mAh/g，Q D1 ＝155mAh/g，M 1 ＝20mg/cm 2 A2 and B2 groups share the positive plate, Q C2 ＝650mAh/g，Q D2 =850 mAh/g, where group a M 2 ＝4.4mg/cm 2 Group B M 2 ＝7.6mg/cm 2 Wherein group a is based, group B satisfies formula B, x=1.4 mg/cm 2 The excess coefficient g=0.5, cb=1.50, the uncoated slurry anode sheet thickness 124 microns (without foil thickness), L2 93.4%, L2 being the same in A1, B1. L1 was 96.5%. The anode sheet was prepared by mixing graphite having a capacity of 350 milliamp hours per gram with graphite having a capacity of 74 percent, silicon oxide (SiOx) having a capacity of 1350 milliamp hours per gram, in a mass ratio of 25 to 75, wherein the anode sheet had an L2 of 96.5%, the L2 of A2 and B2 was the same, the areal density of A2 group was 4.4 mg per square centimeter, the areal density of B2 group was 7.6 mg per square centimeter, and a layer of lithium-compensating paste was coated thereon, the thickness of the pre-lithiated layer after drying was 88 micrometers, the thickness of the coating layer on the anode sheet after cold rolling was about 25 micrometers, the coating area was 90% of the area of the cathode sheet, and the areal density was 1.4mg per square centimeter. The correction coefficient A was 0.6 and the excess coefficient B was 0.3. The group B2 satisfies the formula B, qc 1 ＝158mAh/g，Q D1 ＝155mAh/g，M 1 ＝20mg/cm 2 The A, B group shares a cathode. A. Group B anode Q C2 ＝650mAh/g，Q D2 =850 mAh/g, where group a M 2 ＝4.4mg/cm 2 Group B M 2 ＝7.6mg/cm 2 Wherein group a is based, group B satisfies formula B, x=1.4 mg/cm2, excess factor g=0.5, cb=1.50, a=60%, uncoated slurry anode sheet thickness 124 microns (no foil thickness)).
Preparing a positive plate and a negative plate according to the arrangement:
preparation of a positive plate:
lithium iron phosphate, conductive agent superconducting carbon (Super-P) and binder polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 97:1.5:1.5, uniformly mixing to prepare lithium ion battery anode slurry with certain viscosity, coating the slurry on a current collector aluminum foil, drying at 85 ℃ and then cold pressing; then trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum after splitting, and welding the tab to prepare the lithium ion battery positive plate.
Preparing a negative plate:
graphite, conductive agent superconducting carbon (Super-P), thickener sodium carboxymethyl cellulose (CMC) and binder Styrene Butadiene Rubber (SBR) are mixed according to the mass ratio of 96:2.0:1.0:1.0 preparing slurry, coating on a current collector copper foil, drying at 85 ℃, trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum condition after splitting, and welding electrode lugs to prepare the lithium ion battery negative plate.
Preparation of electrolyte:
lithium hexafluorophosphate (LiPF) 6 ) Dissolved in a mixed solvent composed of Ethylene Carbonate (EC), dimethyl carbonate (DMC) and Ethyl Methyl Carbonate (EMC) (the mass ratio of the three is 1:2: 1) An electrolyte having a concentration of 1mol/L was obtained.
The diaphragm is a polypropylene diaphragm.
Preparation of the battery:
winding the positive plate, the diaphragm and the negative plate into a battery cell, wherein the diaphragm is positioned between the positive plate and the negative plate, the positive electrode is led out by spot welding of an aluminum tab, and the negative electrode is led out by spot welding of a nickel tab; and then placing the battery core in an aluminum-plastic packaging bag, injecting the electrolyte, and performing procedures such as packaging, formation, capacity and the like to prepare the lithium ion battery.
Example 3
The secondary battery comprises a positive plate, a negative plate, a diaphragm, electrolyte and a shell, wherein the diaphragm separates the positive plate from the negative plate, and the shell is used for packaging the positive plate, the diaphragm, the negative plate and the electrolyte.
In this example, the non-lithium-supplemented group was set as the A3 group, and the lithium-supplemented group was set as the B3 group. The negative electrode sheet of group B3 satisfies the relation a: 0.7-0% C1 +(CB-1)Q D1 )*M 1 L 1 +x*A*3800)/(Q D2 *M 2 L 2 )≤1；
Wherein Qc 1 ＝235mAh/g，Q D1 ＝205mAh/g，M 1 ＝20.4mg/cm 2 ：M 2 ＝7.6mg/cm 2 ，Q C2 ＝650mAh/g，Q D2 ＝850mAh/g；CB＝145，x＝0.23mg/cm 2 The anode sheets of the two groups a, B3 were identical in areal density and compacted, and the cathode sheet was prepared with NCM811 material with a pre-lithiated layer thickness of 102mm (no foil thickness) and a coated areal density of 20.4 milligrams per square centimeter and L1 of 96.5%. The first charge and discharge efficiency is 92 percent, and the gram capacity is 350 milliamp hours per timeThe anode sheet was prepared by mixing graphite in a mass ratio of 25 to 75 with a first charge/discharge efficiency of 74% and a gram capacity of 1350 milliamperes per gram of silicon oxide (SiOx), and had an L2 of 94.3% and the same groups A3 and B3 of L2. The areal density of the negative electrode sheets of group A3 was 7.6 milligrams per square centimeter. The surface density of the negative electrode sheet of the B3 group is 7.6 milligrams, the thickness of the pre-lithium layer is 24 micrometers after a layer of lithium supplementing slurry is coated on the negative electrode sheet and dried, the thickness of the pre-lithium layer is about 10 micrometers after cold rolling, the coating area is 60 percent of the area of the positive electrode sheet, and the surface density is 0.23 milligrams per square centimeter.
Preparing a positive plate and a negative plate according to the arrangement:
lithium iron phosphate, conductive agent superconducting carbon (Super-P) and binder polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 97:1.5:1.5, uniformly mixing to prepare lithium ion battery anode slurry with certain viscosity, coating the slurry on a current collector aluminum foil, drying at 85 ℃ and then cold pressing; then trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum after splitting, and welding the tab to prepare the lithium ion battery positive plate.
Preparing a negative plate:
graphite, conductive agent superconducting carbon (Super-P), thickener sodium carboxymethyl cellulose (CMC) and binder Styrene Butadiene Rubber (SBR) are mixed according to the mass ratio of 96:2.0:1.0:1.0 preparing slurry, coating on a current collector copper foil, drying at 85 ℃, trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum condition after splitting, and welding electrode lugs to prepare the lithium ion battery negative plate.
Preparation of electrolyte:
lithium hexafluorophosphate (LiPF) 6 ) Dissolved in a mixed solvent composed of Ethylene Carbonate (EC), dimethyl carbonate (DMC) and Ethyl Methyl Carbonate (EMC) (the mass ratio of the three is 1:2: 1) An electrolyte having a concentration of 1mol/L was obtained.
The diaphragm is a polypropylene diaphragm.
Preparation of the battery:
winding the positive plate, the diaphragm and the negative plate into a battery cell, wherein the diaphragm is positioned between the positive plate and the negative plate, the positive electrode is led out by spot welding of an aluminum tab, and the negative electrode is led out by spot welding of a nickel tab; and then placing the battery core in an aluminum-plastic packaging bag, injecting the electrolyte, and performing procedures such as packaging, formation, capacity and the like to prepare the lithium ion battery.
Example 4
The secondary battery comprises a positive plate, a negative plate, a diaphragm, electrolyte and a shell, wherein the diaphragm separates the positive plate from the negative plate, and the shell is used for packaging the positive plate, the diaphragm, the negative plate and the electrolyte.
In this example, the non-lithium-supplemented group was set as the A4 group, and the lithium-supplemented group was set as the B4 group. The negative electrode sheet of group B4 satisfies the relation B: ((Q) C1 +(CB-1+G)Q D1 )*M 1 L 1 +x*A*3800)/((1+G)Q D2 *M 2 L 2 )<1；
Wherein Qc 1 ＝235mAh/g，Q D1 ＝205mAh/g，M 1 ＝16.5mg/cm 2 The A, B group shares a cathode. A. B group negative plate Q C2 ＝650mAh/g，Q D2 =850 mAh/g, where group a M 2 ＝5.3mg/cm 2 Group B M 2 ＝8.1mg/cm 2 Wherein group a is a reference group, group B satisfies formula B, x=1.3 mg/cm 2 The coefficient of excess b=0.5, cb=1.76, the uncoated slurry anode sheet thickness 133 microns (without foil thickness).
In this example, the non-lithium-supplemented group was set as the A4 group, and the lithium-supplemented group was set as the B4 group. Specifically, positive plates were prepared with NCM811 material, with a coating areal density of 16.5 milligrams per square centimeter, L1 of 96.5%. The anode sheet was prepared with a mass ratio of 25 to 75 for silicon oxide (SiOx) with a capacity of 1350 milliamperes per gram, with a capacity of 92% for first charge and discharge, and a capacity of 350 milliamperes per gram of graphite with a capacity of 74% for first charge and discharge, with L2 of 94.3% for L2 in A4, B4. Group A4 anode areal density was 5.3 milligrams per square centimeter. The anode of the B4 group has an areal density of 8.1 mg, a layer of lithium supplementing slurry is coated on the anode, the thickness of the pre-lithiation layer is 88 micrometers after drying, and the thickness of the coating layer on the anode sheet is about 40 micrometers after cold rolling, the coating area is 100% of the area of the anode sheet, and the areal density is 1.3mg per square centimeter. Correction coefficient a is 0.6, excess coefficient B is 0.5 negative electrode sheet in group B4 in example four satisfies formula B, qd1=235 mAh-g，Q D1 ＝205mAh/g，M 1 ＝16.5mg/cm 2 The A, B group shares a cathode. A. Group B anode Q C2 ＝650mAh/g，Q D2 =850 mAh/g, where group a M 2 ＝5.3mg/cm 2 Group B M 2 ＝8.1mg/cm 2 Wherein group A4 is a reference group, group B4 satisfies formula B, x=1.3 mg/cm 2 The coefficient of excess b=0.5, cb2=1.76, the uncoated slurry anode sheet thickness 133 microns (without foil thickness)).
Preparing a positive plate and a negative plate according to the arrangement:
lithium iron phosphate, conductive agent superconducting carbon (Super-P) and binder polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 97:1.5:1.5, uniformly mixing to prepare lithium ion battery anode slurry with certain viscosity, coating the slurry on a current collector aluminum foil, drying at 85 ℃ and then cold pressing; then trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum after splitting, and welding the tab to prepare the lithium ion battery positive plate.
Preparing a negative plate:
graphite, conductive agent superconducting carbon (Super-P), thickener sodium carboxymethyl cellulose (CMC) and binder Styrene Butadiene Rubber (SBR) are mixed according to the mass ratio of 96:2.0:1.0:1.0 preparing slurry, coating on a current collector copper foil, drying at 85 ℃, trimming, cutting pieces, splitting, drying at 110 ℃ for 4 hours under vacuum condition after splitting, and welding electrode lugs to prepare the lithium ion battery negative plate.
Preparation of electrolyte:
lithium hexafluorophosphate (LiPF) 6 ) Dissolved in a mixed solvent composed of Ethylene Carbonate (EC), dimethyl carbonate (DMC) and Ethyl Methyl Carbonate (EMC) (the mass ratio of the three is 1:2: 1) An electrolyte having a concentration of 1mol/L was obtained.
The diaphragm is a polypropylene diaphragm.
Preparation of the battery:
winding the positive plate, the diaphragm and the negative plate into a battery cell, wherein the diaphragm is positioned between the positive plate and the negative plate, the positive electrode is led out by spot welding of an aluminum tab, and the negative electrode is led out by spot welding of a nickel tab; and then placing the battery core in an aluminum-plastic packaging bag, injecting the electrolyte, and performing procedures such as packaging, formation, capacity and the like to prepare the lithium ion battery.
Performance test: the following performance tests were performed on groups A and B of examples 1-4 above.
Button cell measurement conditions:
1. the negative electrode test voltage is in the range of 0.005-2.5V, the active material load is 7.9mg/cm <2 >, the test flow is that 0.05C is discharged to 0.005V, standing is carried out for 30min,50uA is discharged to 0.005V, standing is carried out for 30min, and 0.1C is charged to 2.5V.
2. The ternary test voltage of the positive electrode ranges from 2.7V to 4.35V, the active material load is 9.7mg/cm <2 >, the test flow is that 0.5C is charged to 4.35V,4.35V is charged to 0.05C at constant voltage, standing is carried out for 30min,0.5C is discharged to 2.7V, standing is carried out for 5min, and 0.1C is discharged to 2.7V; the test voltage range of the positive pole iron lithium is 2.0-3.75V, the active material load is 8.2mg/cm <2 >, the test flow is that 0.1C is charged to 3.75V,3.75V is charged to 0.05C at a constant voltage, and the test flow stands for 30min, and 0.1C is discharged to 2.0V.
3. Gram Capacity & first Effect test:
gram capacity is the total charge of 0.5C discharge, 0.1C discharge, 0.01C discharge divided by the amount of active material; the first efficiency is the first total discharge amount divided by the first charge amount.
4. The DCR test is to discharge the battery for 20s at the multiplying power of 2C, and the voltage drop is divided by the current to obtain DCR; the energy density test is the terminal voltage in DCR test discharge current/cell mass.
5. The cycle test is a 0.5C charge, 1C discharge, full SOC test.
TABLE 1
TABLE 2
As can be seen from the comparison of tables 1 and 2, when the negative electrode sheet is set to satisfy the relation A or the relation B, the prepared battery has higher gram capacity, first efficiency, energy density, longer cycle life and lower DCR impedance.
Variations and modifications of the above embodiments will occur to those skilled in the art to which the invention pertains from the foregoing disclosure and teachings. Therefore, the present invention is not limited to the above-described embodiments, but is intended to be capable of modification, substitution or variation in light thereof, which will be apparent to those skilled in the art in light of the present teachings. In addition, although specific terms are used in the present specification, these terms are for convenience of description only and do not limit the present invention in any way.
Claims (10)
1. A secondary battery comprising a positive electrode sheet and a negative electrode sheet, wherein the negative electrode sheet satisfies one of the following relations:
A、0.7≤((Q C1 +(CB-1)Q D1 )*M 1 L 1 +x*A*3800)/(Q D2 *M 2 L 2 )≤1；
B、((Q C1 +(CB-1+G)Q D1 )*M 1 L 1 +x*A*3800)/((1+G)Q D2 *M 2 L 2 )<1；
wherein Q is C1 Half-cell charge gram capacity representing positive electrode, unit mah×g -1 ，Q C2 Half cell charge gram capacity mAh x g representing negative electrode -1 ，Q D1 Half cell discharge gram capacity representing positive electrode, unit mAh g -1 ；Q D2 Half cell discharge gram capacity representing negative electrode, unit mAh g -1 ；M 1 The unit mass of the positive electrode material of the positive electrode plate is as follows, and the unit g is cm 2 ，M 2 The unit mass of the negative electrode material of the negative electrode plate is as follows, and the unit g is cm 2 ，L 1 Represents the loading percentage of the positive electrode material on the pole piece, L 2 Representing the load percentage of the anode material in the pole piece; CB represents the excess of battery capacityThe value of the coefficient of quantity, CB, is (Q C2 *M 2 L 2 )/(Q D1 *M 1 L 1 ) The method comprises the steps of carrying out a first treatment on the surface of the x represents the content of simple substance lithium in the negative electrode lithium supplementing agent; a represents a correction coefficient of 0.4<A<0.9, G represents an excess factor, wherein 0<G<0.7。
2. The secondary battery according to claim 1, wherein the negative electrode sheet includes a negative electrode current collector, a first negative electrode active material layer provided on at least one surface of the negative electrode current collector, and a second pre-lithiation layer provided on one surface of the first negative electrode active material layer remote from the negative electrode current collector.
3. The secondary battery according to claim 2, wherein the negative electrode sheet satisfies the following relation: 0.13< (D3-D1) S2/[ (D2-D1) S1] <2.0; wherein D1 represents the thickness of the negative electrode sheet without the pre-lithiation layer, and D2 represents the thickness of the negative electrode sheet with the pre-lithiation layer and without cold rolling; d3 represents the thickness of the anode sheet with the pre-lithiation layer and after cold rolling; s1 represents the area of the cathode plate, S2 represents the area of the prelithiation layer, wherein 50 μm < D2-D1<100 μm,10 μm < D3-D1<50 μm,0.3< S2/S1<1.
4. The secondary battery according to claim 2, wherein the negative electrode sheet satisfies the following relation: 0.28< (D3-D1) ×s2/[ (D2-D1) ×s1] <0.44.
5. The secondary battery according to claim 2, wherein the first anode active material layer includes a carbon-containing or silicon-containing substance.
6. The secondary battery according to claim 2, wherein the second pre-physical layer comprises the following raw materials in parts by weight: 5-20 parts of lithium salt, 5-20 parts of conductive agent and 5-25 parts of binder.
7. The secondary battery according to claim 6, wherein the lithium salt is one or more of lithium carbonate, lithium fluoride, or alkyl lithium.
8. The secondary battery according to claim 6, wherein the conductive agent is one or more of conductive carbon, carbon nanotubes, and graphene.
9. The secondary battery according to claim 6, wherein the binder is one or more of styrene-butadiene rubber and sodium carboxymethyl cellulose.
10. The secondary battery according to claim 1, wherein the positive electrode sheet includes one or more of a nickel-containing oxide, a manganese-containing oxide, or an iron-containing oxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210421459.3A CN114784365B (en) | 2022-04-21 | 2022-04-21 | Secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210421459.3A CN114784365B (en) | 2022-04-21 | 2022-04-21 | Secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114784365A CN114784365A (en) | 2022-07-22 |
| CN114784365B true CN114784365B (en) | 2024-04-09 |
Family
ID=82431406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210421459.3A Active CN114784365B (en) | 2022-04-21 | 2022-04-21 | Secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114784365B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115241519B (en) * | 2022-08-09 | 2024-07-16 | 江苏正力新能电池技术有限公司 | Lithium ion battery |
| CN115566255B (en) * | 2022-10-27 | 2023-08-15 | 欣旺达电动汽车电池有限公司 | Secondary battery and electric equipment |
| CN115632175B (en) * | 2022-11-02 | 2023-12-15 | 江苏正力新能电池技术有限公司 | Negative electrode lithium supplementing quick-charging pole piece and quick-charging battery |
| CN116344745A (en) * | 2023-05-30 | 2023-06-27 | 江苏正力新能电池技术有限公司 | Negative electrode plate, manufacturing method thereof, lithium battery and electric equipment |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109103496A (en) * | 2018-08-24 | 2018-12-28 | 上海空间电源研究所 | A kind of long storage life lithium ion battery and preparation method thereof |
| CN112701277A (en) * | 2020-12-24 | 2021-04-23 | 中国科学院宁波材料技术与工程研究所 | Lithium ion battery prelithiation additive and application thereof |
| CN113161602A (en) * | 2021-06-01 | 2021-07-23 | 湖南立方新能源科技有限责任公司 | Lithium ion battery cell, lithium ion battery and preparation method |
| WO2022021608A1 (en) * | 2020-07-29 | 2022-02-03 | 深圳市研一新材料有限责任公司 | Lithium-ion battery positive electrode lithium supplement additive, preparation method therefor, and lithium-ion battery |
| CN114141981A (en) * | 2021-11-24 | 2022-03-04 | 蜂巢能源科技有限公司 | Positive pole piece and preparation method and application thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114530604A (en) * | 2019-08-07 | 2022-05-24 | 宁德新能源科技有限公司 | Anode material, and electrochemical device and electronic device including same |
-
2022
- 2022-04-21 CN CN202210421459.3A patent/CN114784365B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109103496A (en) * | 2018-08-24 | 2018-12-28 | 上海空间电源研究所 | A kind of long storage life lithium ion battery and preparation method thereof |
| WO2022021608A1 (en) * | 2020-07-29 | 2022-02-03 | 深圳市研一新材料有限责任公司 | Lithium-ion battery positive electrode lithium supplement additive, preparation method therefor, and lithium-ion battery |
| CN112701277A (en) * | 2020-12-24 | 2021-04-23 | 中国科学院宁波材料技术与工程研究所 | Lithium ion battery prelithiation additive and application thereof |
| CN113161602A (en) * | 2021-06-01 | 2021-07-23 | 湖南立方新能源科技有限责任公司 | Lithium ion battery cell, lithium ion battery and preparation method |
| CN114141981A (en) * | 2021-11-24 | 2022-03-04 | 蜂巢能源科技有限公司 | Positive pole piece and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114784365A (en) | 2022-07-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110854382B (en) | Positive electrode lithium supplement material, positive electrode containing positive electrode lithium supplement material and preparation method of positive electrode lithium supplement material | |
| CN114784365B (en) | Secondary battery | |
| CN108172823A (en) | Lithium-rich manganese material, lithium ion battery cathode material, lithium ion battery cathode sheet, lithium ion battery and preparation method thereof | |
| CN105552344A (en) | Positive plate of lithium ion battery, lithium ion battery and preparation method of lithium ion battery | |
| CN112490518B (en) | Positive electrode lithium supplement additive, preparation method thereof, positive electrode and lithium ion battery | |
| CN113488637B (en) | Composite negative electrode material, negative plate and lithium ion battery | |
| CN111370695A (en) | Negative electrode active material, and electrochemical device and electronic device using same | |
| CN113394370B (en) | Electrode plate and battery containing same | |
| CN102244288B (en) | Lithium-phosphorus secondary battery | |
| CN104253275B (en) | Binder, pole piece, manufacturing method and battery for lithium battery or lithium-sulfur battery | |
| CN114597350A (en) | Calculation method of lithium supplementing time of lithium supplementing electrode, lithium supplementing method and lithium ion battery | |
| CN115336068A (en) | Electrochemical device and electronic device including same | |
| WO2024159825A1 (en) | Positive electrode lithium supplementing material, preparation method therefor, positive electrode material, positive pole piece, and secondary battery | |
| CN115528208B (en) | Lithium supplementing negative electrode plate and secondary battery | |
| CN116487577A (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN116420259B (en) | Electrolyte, secondary battery, battery module, battery pack and power-consuming device | |
| WO2022257146A1 (en) | Composite positive electrode material and preparation method therefor, secondary battery and battery set comprising same, and electrical device | |
| CN115172680A (en) | High-capacity high-rate lithium ion battery and preparation method thereof | |
| CN114400321A (en) | A low-temperature charge-discharge lithium-ion battery and its negative electrode material | |
| CN114497483B (en) | Negative plate, preparation method thereof and lithium ion battery | |
| CN114614009B (en) | Composite material, preparation method thereof, negative electrode plate and secondary battery | |
| WO2022193122A1 (en) | Lithium replenishment additive, electrochemical apparatus comprising same, and electronic device | |
| CN115172878A (en) | Electrolyte, preparation method thereof and secondary battery | |
| WO2023123427A1 (en) | Electrochemical device and electronic device comprising same | |
| CN113690412A (en) | Active slurry, preparation method thereof, positive plate and lithium ion battery |
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 | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 215500 No. 68, Xin'anjiang Road, Southeast street, Changshu, Suzhou, Jiangsu Patentee after: Jiangsu Zhengli New Energy Battery Technology Co.,Ltd. Country or region after: China Address before: 215500 No. 68, Xin'anjiang Road, Southeast street, Changshu, Suzhou, Jiangsu Patentee before: Jiangsu Zenergy Battery Technologies Co.,ltd Country or region before: China |