CN113241437A - Negative plate and lithium ion battery comprising same - Google Patents
Negative plate and lithium ion battery comprising same Download PDFInfo
- Publication number
- CN113241437A CN113241437A CN202110502040.6A CN202110502040A CN113241437A CN 113241437 A CN113241437 A CN 113241437A CN 202110502040 A CN202110502040 A CN 202110502040A CN 113241437 A CN113241437 A CN 113241437A
- Authority
- CN
- China
- Prior art keywords
- negative electrode
- active material
- negative
- negative plate
- material layer
- 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.)
- Pending
Links
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 29
- 239000007773 negative electrode material Substances 0.000 claims abstract description 28
- 229920001046 Nanocellulose Polymers 0.000 claims abstract description 25
- 239000011230 binding agent Substances 0.000 claims description 22
- 239000006258 conductive agent Substances 0.000 claims description 18
- 239000002562 thickening agent Substances 0.000 claims description 17
- 239000000463 material Substances 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical group [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- 239000004480 active ingredient Substances 0.000 claims description 2
- 229920002678 cellulose Polymers 0.000 abstract description 20
- 239000001913 cellulose Substances 0.000 abstract description 20
- 239000011883 electrode binding agent Substances 0.000 abstract description 4
- 238000003860 storage Methods 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 16
- 229920003048 styrene butadiene rubber Polymers 0.000 description 16
- 238000012360 testing method Methods 0.000 description 14
- 239000001768 carboxy methyl cellulose Substances 0.000 description 13
- 239000002174 Styrene-butadiene Substances 0.000 description 12
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 11
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 11
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 11
- 229910021383 artificial graphite Inorganic materials 0.000 description 10
- 239000003792 electrolyte Substances 0.000 description 8
- 238000007599 discharging Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 239000002002 slurry Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 239000006183 anode active material Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 239000011267 electrode slurry Substances 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- -1 polytetrafluoroethylene Polymers 0.000 description 4
- 238000005096 rolling process Methods 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 2
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 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 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 239000002390 adhesive tape Substances 0.000 description 2
- 239000002041 carbon nanotube Substances 0.000 description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 2
- 239000000017 hydrogel Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 239000002985 plastic film Substances 0.000 description 2
- 229920006255 plastic film Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 239000007774 positive electrode material Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 2
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- FHVDTGUDJYJELY-UHFFFAOYSA-N 6-{[2-carboxy-4,5-dihydroxy-6-(phosphanyloxy)oxan-3-yl]oxy}-4,5-dihydroxy-3-phosphanyloxane-2-carboxylic acid Chemical compound O1C(C(O)=O)C(P)C(O)C(O)C1OC1C(C(O)=O)OC(OP)C(O)C1O FHVDTGUDJYJELY-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910032387 LiCoO2 Inorganic materials 0.000 description 1
- 229910001290 LiPF6 Inorganic materials 0.000 description 1
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 239000005062 Polybutadiene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 229940072056 alginate Drugs 0.000 description 1
- 235000010443 alginic acid Nutrition 0.000 description 1
- 229920000615 alginic acid Polymers 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000000418 atomic force spectrum Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- MTAZNLWOLGHBHU-UHFFFAOYSA-N butadiene-styrene rubber Chemical compound C=CC=C.C=CC1=CC=CC=C1 MTAZNLWOLGHBHU-UHFFFAOYSA-N 0.000 description 1
- KVNRLNFWIYMESJ-UHFFFAOYSA-N butyronitrile Chemical compound CCCC#N KVNRLNFWIYMESJ-UHFFFAOYSA-N 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000002134 carbon nanofiber Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 229920006026 co-polymeric resin Polymers 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229920001973 fluoroelastomer Polymers 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002121 nanofiber Substances 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 229920002857 polybutadiene Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920000128 polypyrrole Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 229920000123 polythiophene Polymers 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000000661 sodium alginate Substances 0.000 description 1
- 235000010413 sodium alginate Nutrition 0.000 description 1
- 229940005550 sodium alginate Drugs 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000011115 styrene butadiene Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 230000002522 swelling effect Effects 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 239000011366 tin-based material Substances 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 238000009461 vacuum packaging Methods 0.000 description 1
- 238000004804 winding Methods 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
- H01M4/36—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
-
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- 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)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a negative plate and a lithium ion battery comprising the same; the negative plate comprises the nano-cellulose, and the nano-cellulose is light in weight and high in strength, so that the structure of the negative plate can be enhanced, and the rebound of the negative plate is reduced; meanwhile, the nanocellulose is smaller in volume, the coverage of the negative electrode active material is smaller, and the large bulk phase impedance is not brought like the traditional negative electrode binder. The lithium ion battery comprising the negative plate has excellent low-temperature charge and discharge performance, high-temperature storage performance and high-temperature stability.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a negative plate and a lithium ion battery comprising the same.
Background
The negative plate is an important component of the lithium ion battery and is one of important factors influencing the overall dynamic performance of the lithium ion battery; meanwhile, in the use process of the lithium ion battery, particularly in a high-temperature environment, the conditions of thickness increase, deformation and other structural changes exist, so that the battery expands and the impedance of the battery core increases. This increase in thickness is generally believed to be primarily due to the negative plate bounce, and optimization of the negative plate formulation is an important approach to reducing cell impedance and battery swelling.
Currently, a negative electrode sheet for a lithium ion battery is generally composed of a negative electrode active material, a negative electrode binder, a thickener and a conductive agent, wherein the negative electrode binder used mostly employs Styrene Butadiene Rubber (SBR) obtained by copolymerizing butadiene and styrene and a modified material thereof, such as SBR modified or copolymerized by acrylic acid, acrylonitrile, butyronitrile, acrylate, and the like. Although the binding property and the ionic conductivity of the negative plate prepared from the styrene-butadiene rubber can be improved by modifying the pure styrene-butadiene rubber, the swelling property of the binder to the electrolyte is increased (namely, the liquid absorption property of the binder is improved), and the binding strength of the binder is reduced, so that the expansion rate of the negative plate is increased.
Disclosure of Invention
In order to overcome the defects of large resistance, large expansion rate and the like of a negative plate in the prior art, the invention provides the negative plate and the lithium ion battery comprising the negative plate.
The purpose of the invention is realized by the following technical scheme:
a negative plate comprises a negative current collector and a negative active material layer, wherein the negative active material layer is arranged on at least one side surface of the negative current collector; the negative electrode active material layer includes nanocellulose.
According to the present invention, the main active ingredient of the nanocellulose is α -cellulose.
According to the invention, the nanocellulose is a nanotubular material, the nanocellulose having a diameter of 5 to 200nm, such as 5nm, 10nm, 20nm, 30nm, 50nm, 80nm, 90nm, 100nm, 120nm, 150nm, 160nm, 180nm or 200 nm; the length is 1 to 20 μm, for example, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 12 μm, 14 μm, 15 μm, 18 μm or 20 μm.
According to the invention, in order to ensure dispersion, the form of the nano-cellulose can be a hydrogel form which is relatively easy to disperse, and the nano-cellulose in the hydrogel form is more easy to disperse in the negative electrode slurry, so that the performance of the nano-cellulose is ensured.
According to the invention, the nano-cellulose has certain cohesiveness and thickening property, can replace or partially replace the function of a binder or a thickening agent, and can play a role in enhancing the cohesive strength and improving the dispersion of slurry in a negative electrode active material layer; meanwhile, the cellulose with the nano structure has very high strength, and can play a role in enhancing the effect with a binder in the negative plate, thereby improving the structural strength of the negative plate and reducing the chemical or electrochemical expansion of the negative plate after the negative plate is assembled into a battery; in addition, polar functional groups such as-OH and the like contained in the negative electrode plate added with the nano-cellulose can improve the adsorption effect on the electrolyte, play a capillary-like effect, improve the capacity and speed of absorbing the electrolyte and reduce the migration impedance of lithium ions.
According to the invention, the negative plate is a low-impedance and low-expansion-rate negative plate.
According to the invention, the resistance of the negative plate is 1-3 omega.
According to the invention, the stripping force of the negative plate is 4-20N/m.
According to the present invention, the amount of the nanocellulose accounts for 0.1 wt% to 2 wt%, for example, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, or 2 wt% of the total mass of the anode active material layer.
According to the present invention, the anode active material layer further includes an anode active material and a conductive agent.
According to the present invention, the negative active material is selected from one or more of artificial graphite, natural graphite, hard carbon, a silicon-based material, or a tin-based material.
According to the present invention, the conductive agent is selected from one or more of acetylene black, conductive carbon black (Super P, Super S, 350G, etc.), carbon fiber (VGCF), Carbon Nanotube (CNT), ketjen black.
According to the invention, the amount of the conductive agent accounts for 0.01-10 wt% of the total mass of the negative electrode active material layer.
According to the invention, the amount of the negative electrode active material is 90-99 wt% of the total mass of the negative electrode active material layer.
According to the present invention, the anode active material layer further includes a binder and a thickener.
According to the invention, the amount of the binder accounts for 0-8 wt% of the total mass of the negative electrode active material layer.
According to the invention, the amount of the thickening agent accounts for 0-8 wt% of the total mass of the negative electrode active material layer.
According to the invention, the binder is selected from one or more of polythiophene, polypyrrole, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polystyrene, polyacrylamide, ethylene-propylene-diene copolymer resin, styrene butadiene rubber, polybutadiene, fluororubber, nitrile rubber, polyethylene oxide, polyvinylpyrrolidone, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, polyethylene oxide, sodium carboxymethylcellulose (CMC), and styrene butadiene latex (SBR).
According to the invention, the thickening agent is selected from one or more of sodium carboxymethylcellulose (CMC-Na), lithium carboxymethylcellulose (CMC-Li), polyacrylic acid (PAA), sodium Alginate (ALG) and polyvinyl alcohol.
According to the present invention, the thickness of the negative electrode active material layer is 20 to 180 μm, preferably 20 to 150 μm, for example, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm.
The invention also provides a preparation method of the negative plate, which comprises the following steps:
1) preparing slurry for forming a negative electrode active material layer, wherein the slurry comprises nano-cellulose;
2) and coating the slurry for forming the negative electrode active material layer on at least one side surface of the negative electrode current collector to prepare the negative electrode sheet.
Exemplarily, step 1) comprises the steps of:
adding a certain proportion of a conductive agent and nanocellulose, optionally adding or not adding a binder, optionally adding or not adding a thickening agent, and then adjusting with water to prepare a negative electrode slurry with proper solid content.
Exemplarily, the step 2) comprises the steps of:
and coating the negative electrode slurry on a negative electrode current collector, drying, rolling, slitting and preparing a sheet to obtain the negative electrode sheet.
The invention also provides a lithium ion battery which comprises the negative plate.
According to the invention, the lithium ion battery also comprises a positive plate, electrolyte, a diaphragm and an aluminum plastic film.
According to the present invention, the positive electrode active material in the positive electrode sheet is lithium cobaltate.
The invention has the beneficial effects that:
the invention provides a negative plate and a lithium ion battery comprising the same; the negative plate comprises the nano-cellulose, and the nano-cellulose is light in weight and high in strength, so that the structure of the negative plate can be enhanced, and the rebound of the negative plate is reduced; meanwhile, the nanocellulose is smaller in volume, the coverage of the negative electrode active material is smaller, and the large bulk phase impedance is not brought like the traditional negative electrode binder. The lithium ion battery comprising the negative plate has excellent low-temperature charge and discharge performance, high-temperature storage performance and high-temperature stability.
Drawings
FIG. 1 is a topographical view of nanocellulose according to the present invention.
Detailed Description
The preparation method of the present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.
Example 1
Preparing a negative plate, namely mixing 96.3% of artificial graphite, a thickening agent CMC, a binder SBR, a conductive agent SP and nano-cellulose (the diameter is 10-50nm, and the length is 1-5 mu m) in parts by weight: 1.5%: 1.5%: 0.5%: mixing 0.2% by weight, adding deionized water, stirring uniformly, preparing into negative electrode slurry, coating on both sides of a copper foil (thickness of 6 μm) of a negative current collector, drying, rolling, slitting, and welding negative electrode tabs to obtain a negative electrode sheet.
② preparing the positive plate, according to the weight portion, 98.0 percent of positive active material LiCoO2Adding 1.0% of positive binder polyvinylidene fluoride and 1.0% of positive conductive agent SP into NMP, uniformly stirring, coating on two sides of a positive current collector aluminum foil (the thickness is 9 mu m), drying, rolling, slitting and welding positive lugs to obtain the positive plate.
Preparing electrolyte, mixing Ethylene Carbonate (EC), Propylene Carbonate (PC) and Ethyl Methyl Carbonate (EMC) uniformly according to the volume ratio of 1:1:1, adding LiPF6To prepare 1mol/L of an electrolyte.
Fourthly, manufacturing a full battery, namely winding the prepared negative plate, the positive electrode and the diaphragm (12 mu m polyethylene porous bare film) into a bare cell in a conventional mode, placing the bare cell in an aluminum plastic film punched with pits after hot pressing, and performing vacuum drying for 24 hours after pre-packaging; and testing that the moisture of the positive plate, the negative plate and the diaphragm is below 200ppm, injecting electrolyte, carrying out vacuum packaging and formation (the formation temperature is 80 ℃, the formation pressure is 422kg. f, the lithium ion battery is pre-charged to 4.0V at a low current of 0.5C, and then cold pressing and shaping) to obtain the lithium ion battery.
Examples 2 to 7
The lithium ion batteries of examples 2 to 7 were prepared in the same manner as in example 1, except that the nanocellulose was different in size, as shown in table 1.
Example 8
The lithium ion battery of example 8 was prepared in the same manner as in example 1 except that the synthetic graphite, the thickener CMC, the binder SBR, the conductive agent SP, and the nanocellulose (diameter ranging from 10 to 50nm and length ranging from 1 to 5 μm) were mixed in an amount of 96.0%: 1.5%: 1.5%: 0.5%: 0.5% by weight.
Example 9
The lithium ion battery of example 9 was prepared in the same manner as in example 1 except that the synthetic graphite, the thickener CMC, the binder SBR, the conductive agent SP, and the nanocellulose (diameter ranging from 10 to 50nm and length ranging from 1 to 5 μm) were mixed in a ratio of 96.5%: 1.5%: 1.0%: 0.5%: 0.5% by weight.
Example 10
The lithium ion battery of example 10 was prepared in the same manner as in example 1 except that the synthetic graphite, the thickener CMC, the binder SBR, the conductive agent SP, and the nanocellulose (diameter ranging from 10 to 50nm and length ranging from 1 to 5 μm) were mixed in a ratio of 96.5%: 1.0%: 1.0%: 0.5%: mixing at a weight ratio of 1%.
Comparative example 1
The lithium ion battery of comparative example 1 was prepared in the same manner as in example 1, except that the synthetic graphite, the thickener CMC, the binder SBR, and the conductive agent SP were mixed in an amount of 96.5%: 1.5%: 1.5%: 0.5% by weight.
Comparative example 2
The lithium ion battery of comparative example 2 was prepared in the same manner as in example 1, except that the contents of artificial graphite, the thickener CMC, the binder SBR, the conductive agent SP and the nanocellulose (diameter range 300-: 1.5%: 1.5%: 0.5%: 0.2% by weight.
Comparative example 3
The lithium ion battery of comparative example 3 was prepared in the same manner as in example 1, except that the synthetic graphite, the thickener CMC, the binder SBR, the conductive agent SP, and the nanocellulose (diameter range 300-: 1.5%: 1.5%: 0.5%: 0.5% by weight.
Comparative example 4
The lithium ion battery of comparative example 4 was prepared in the same manner as in example 1, except that the contents of artificial graphite, the thickener CMC, the binder SBR, the conductive agent SP and the nanocellulose (diameter range 400-: 1.5%: 1.5%: 0.5%: 0.2% by weight.
Comparative example 5
The lithium ion battery of comparative example 5 was prepared in the same manner as in example 1, except that the synthetic graphite, the thickener CMC, the binder SBR, the conductive agent SP, and the nanocellulose (diameter range of 400-800nm, length of 20-50 μm) were mixed in an amount of 96.0%: 1.5%: 1.5%: 0.5%: 0.5% by weight.
Test example 1
And (3) testing the stripping force of the negative plate: the negative electrode sheet was cut into a rectangular shape having a length of 100mm and a width of 10 mm. A stainless steel plate with the width of 25mm is taken, double-faced adhesive tapes (with the width of 11mm) are attached, the cut negative pole piece is attached to the double-faced adhesive tapes on the stainless steel plate, and a 2000g press roller is used for rolling the surface of the negative pole piece back and forth three times (300 mm/min). Bending the negative plate by 180 degrees, manually stripping by 25mm, fixing the sample on a testing machine, keeping the stripping surface consistent with the force line of the testing machine, continuously stripping the testing machine at 300mm/min to obtain a stripping force curve, taking the average value of the stable section as the stripping force F0, and then testing the adhesion of the negative plate: F0/0.01F 0.
Test example 2
Testing the resistance of the negative plate diaphragm: and taking the dried negative plate, and testing the resistance of the diaphragm by using a four-probe tester.
Test example 3
And (3) testing the cycle performance of the battery: and (2) at 45 ℃, carrying out 0.7C charging, 1.0C discharging and 0.05C cutoff current cyclic charging and discharging tests on the battery cell, standing for 10min after each charging and discharging is finished, respectively recording the discharging capacity of the battery cell and the thickness data under full charge under the cyclic times of 100 weeks, 300 weeks and 500 weeks, wherein the ratio of the discharging capacity to the first discharging capacity is a retention rate, and the ratio of the discharging capacity to the first full charge thickness data is a thickness expansion rate.
Test example 4
And (3) battery rate performance test: at 25 ℃, the cell is charged with 0.7C and the cutoff current is fully charged with 0.05C, and the cell is discharged to 3.0V at 0.5C and 3C, respectively, and the discharge capacity ratio at 3C discharge rate to 0.5C is calculated.
Table 1 compositions of negative electrode sheets of examples and comparative examples and performance test results of the negative electrode sheets
As can be seen from table 1, the peeling force of the solution with nanocellulose added in the example is improved and the impedance of the membrane is reduced compared with that of comparative example 1; the nano-cellulose is used as a high molecular material, and-OH groups rich in the structure can form hydrogen bonds with oxygen-containing groups on the surface of a negative electrode active substance or a conductive agent, so that partial binding power is provided, and the contact resistance of particles is reduced; meanwhile, the nanofiber has very high strength, can reinforce the adhesive and provide cohesion; it is understood from comparison of comparative examples 2 to 5 with comparative example 1 that the coarse diameter cellulose does not exert the same effect as nanocellulose, but rather deteriorates the binding power because the coarse cellulose is too poorly hydrophilic to form a good dispersion effect in the aqueous slurry, and at the same time, the coarse cellulose brings a larger volume, adsorbs the binder, and lowers the binding performance.
Table 2 results of performance test of lithium ion batteries of examples and comparative examples
As can be seen from Table 2, the embodiment added with the nanocellulose has higher cycle retention rate and smaller cycle expansion, which corresponds to the data of the adhesive force of the pole piece; the effect of replacing part of the binder and/or the thickening agent with the nano-cellulose is better, and the cyclic expansion is lower; the improvement of the bonding strength caused by the nano-cellulose and the similar capillary effect formed by the nano-structure improve the affinity of the electrolyte and have better rate discharge performance; from comparative example data, the coarse cellulose does not contribute to the cell cycling stability, but rather deteriorates the cell performance, mainly due to the bulk impedance of the coarse cellulose and the dispersion problem that worsens the pole piece peel force and resistance.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A negative plate comprises a negative current collector and a negative active material layer, wherein the negative active material layer is arranged on at least one side surface of the negative current collector; the negative electrode active material layer includes nanocellulose.
2. The negative electrode sheet according to claim 1, wherein the main active ingredient of the nanocellulose is α -cellulose.
3. The negative electrode sheet according to claim 1 or 2, wherein the nanocellulose is a nanotube-shaped material, and the diameter of the nanocellulose is 5 to 200 nm; the length is 1 to 20 μm.
4. The negative electrode sheet according to any one of claims 1 to 3, wherein the resistance of the negative electrode sheet is 1 to 3 Ω.
5. The negative electrode sheet according to any one of claims 1 to 4, wherein the negative electrode sheet has a peel force of 4 to 20N/m.
6. The negative electrode sheet according to any one of claims 1 to 5, wherein the amount of the nanocellulose is 0.1 to 2 wt% of the total mass of the negative electrode active material layer.
7. The negative electrode sheet according to any one of claims 1 to 6, wherein the negative electrode active material layer further comprises a negative electrode active material and a conductive agent, the amount of the conductive agent is 0.01 to 10 wt% of the total mass of the negative electrode active material layer, and the amount of the negative electrode active material is 90 to 99 wt% of the total mass of the negative electrode active material layer.
8. The negative electrode sheet according to any one of claims 1 to 7, wherein the negative electrode active material layer further comprises a binder in an amount of 0 to 8 wt% and a thickener in an amount of 0 to 8 wt% based on the total mass of the negative electrode active material layer.
9. The negative electrode sheet according to any one of claims 1 to 8, wherein the negative electrode active material layer has a thickness of 20 to 180 μm.
10. A lithium ion battery comprising the negative electrode sheet of any one of claims 1 to 9.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110502040.6A CN113241437A (en) | 2021-05-08 | 2021-05-08 | Negative plate and lithium ion battery comprising same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110502040.6A CN113241437A (en) | 2021-05-08 | 2021-05-08 | Negative plate and lithium ion battery comprising same |
Publications (1)
Publication Number | Publication Date |
---|---|
CN113241437A true CN113241437A (en) | 2021-08-10 |
Family
ID=77132781
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110502040.6A Pending CN113241437A (en) | 2021-05-08 | 2021-05-08 | Negative plate and lithium ion battery comprising same |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113241437A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113991108A (en) * | 2021-08-30 | 2022-01-28 | 宁波维科电池有限公司 | High-performance lithium ion battery cell |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2033249A (en) * | 1978-11-09 | 1980-05-21 | Nevamar Corp | Abrasion-resistant Laminate |
US4513019A (en) * | 1983-07-06 | 1985-04-23 | Seppic | Film-forming compositions for enveloping solid forms, particularly pharmaceutical or food products or seeds, and products obtained, coated with said compositions |
EP0689817A2 (en) * | 1994-06-30 | 1996-01-03 | Kimberly-Clark Corporation | Absorbent structure including an adhesive |
CN105637683A (en) * | 2013-10-28 | 2016-06-01 | 日本瑞翁株式会社 | Slurry composition for negative electrodes of lithium ion secondary batteries, negative electrode for lithium ion secondary batteries, and lithium ion secondary battery |
CN109524619A (en) * | 2017-09-19 | 2019-03-26 | 株式会社东芝 | Electrode group, secondary cell, battery pack and vehicle |
CN110192296A (en) * | 2017-01-17 | 2019-08-30 | 株式会社大赛璐 | Electrode slurry, electrode and its manufacturing method and secondary cell |
CN110323414A (en) * | 2018-03-30 | 2019-10-11 | 丰田自动车株式会社 | The manufacturing method of non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery |
CN110970595A (en) * | 2018-10-01 | 2020-04-07 | 丰田自动车株式会社 | Negative electrode, battery, and method for producing negative electrode |
-
2021
- 2021-05-08 CN CN202110502040.6A patent/CN113241437A/en active Pending
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2033249A (en) * | 1978-11-09 | 1980-05-21 | Nevamar Corp | Abrasion-resistant Laminate |
US4513019A (en) * | 1983-07-06 | 1985-04-23 | Seppic | Film-forming compositions for enveloping solid forms, particularly pharmaceutical or food products or seeds, and products obtained, coated with said compositions |
EP0689817A2 (en) * | 1994-06-30 | 1996-01-03 | Kimberly-Clark Corporation | Absorbent structure including an adhesive |
CN105637683A (en) * | 2013-10-28 | 2016-06-01 | 日本瑞翁株式会社 | Slurry composition for negative electrodes of lithium ion secondary batteries, negative electrode for lithium ion secondary batteries, and lithium ion secondary battery |
CN110192296A (en) * | 2017-01-17 | 2019-08-30 | 株式会社大赛璐 | Electrode slurry, electrode and its manufacturing method and secondary cell |
CN109524619A (en) * | 2017-09-19 | 2019-03-26 | 株式会社东芝 | Electrode group, secondary cell, battery pack and vehicle |
CN110323414A (en) * | 2018-03-30 | 2019-10-11 | 丰田自动车株式会社 | The manufacturing method of non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery |
CN110970595A (en) * | 2018-10-01 | 2020-04-07 | 丰田自动车株式会社 | Negative electrode, battery, and method for producing negative electrode |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113991108A (en) * | 2021-08-30 | 2022-01-28 | 宁波维科电池有限公司 | High-performance lithium ion battery cell |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN110148708B (en) | Negative plate and lithium ion battery | |
CN112599723A (en) | Lithium-supplement negative pole piece, preparation method thereof and lithium ion battery | |
WO2022121863A1 (en) | Negative plate and lithium ion battery comprising negative plate | |
CN110556511A (en) | Lithium battery negative pole piece with excellent cycle performance, preparation method thereof and lithium ion battery | |
CN111261874B (en) | Lithium ion battery cathode and preparation method and application thereof | |
CN112002883A (en) | Silicon-based composite material for negative electrode active material, negative electrode plate and lithium ion battery | |
CN103326027A (en) | Lithium ion battery cathode and lithium ion battery | |
CN113659104A (en) | Preparation method of battery active layer, battery pole piece and application | |
CN109687014A (en) | A kind of high-energy density fast charging type lithium-ion-power cell | |
CN113725398A (en) | Lithium ion battery and positive pole piece thereof | |
CN108306006A (en) | Negative material, negative plate and preparation method thereof, lithium ion battery and preparation method thereof | |
CN106299243A (en) | Lithium ion battery positive pole piece containing composite conductive agent | |
CN111293274A (en) | Negative pole piece, preparation method thereof and lithium ion battery | |
CN109860597A (en) | A kind of aqueous compound binding agent of lithium ion battery | |
CN115498164A (en) | Negative electrode material, negative electrode slurry, negative electrode sheet, preparation method and lithium ion battery | |
CN116417658A (en) | Secondary battery and application thereof | |
CN113241437A (en) | Negative plate and lithium ion battery comprising same | |
CN114388869A (en) | Gel polymer battery and preparation method thereof | |
CN113394363B (en) | Preparation method of negative pole piece, battery and electronic device | |
CN220627852U (en) | Negative plate, lithium ion battery and electricity utilization device | |
CN113611917A (en) | Square aluminum shell low-temperature rate lithium ion battery and preparation method thereof | |
CN117334912A (en) | Adhesive for lithium ion battery, preparation method, negative electrode plate and lithium ion battery | |
CN116387472A (en) | Negative electrode slurry of sodium ion battery, negative electrode plate and sodium ion battery | |
CN113193203B (en) | Silicon-carbon negative electrode plate, preparation method thereof and lithium ion battery | |
CN115224237A (en) | Negative pole piece 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 |