CN220627852U - Negative plate, lithium ion battery and electricity utilization device - Google Patents
Negative plate, lithium ion battery and electricity utilization device Download PDFInfo
- Publication number
- CN220627852U CN220627852U CN202322133574.3U CN202322133574U CN220627852U CN 220627852 U CN220627852 U CN 220627852U CN 202322133574 U CN202322133574 U CN 202322133574U CN 220627852 U CN220627852 U CN 220627852U
- Authority
- CN
- China
- Prior art keywords
- silicon
- current collector
- negative electrode
- layer
- thickness
- 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
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 18
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 18
- 230000005611 electricity Effects 0.000 title abstract description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 85
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 42
- 239000002210 silicon-based material Substances 0.000 claims abstract description 39
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 34
- 239000010439 graphite Substances 0.000 claims abstract description 34
- 239000011148 porous material Substances 0.000 claims description 12
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- 239000011889 copper foil Substances 0.000 claims description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 15
- 239000010703 silicon Substances 0.000 abstract description 15
- 229910052710 silicon Inorganic materials 0.000 abstract description 15
- 239000011230 binding agent Substances 0.000 description 12
- 239000002002 slurry Substances 0.000 description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 9
- 229910052744 lithium Inorganic materials 0.000 description 9
- 239000006258 conductive agent Substances 0.000 description 8
- 239000002245 particle Substances 0.000 description 8
- 229910021393 carbon nanotube Inorganic materials 0.000 description 7
- 239000002041 carbon nanotube Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 7
- 239000004810 polytetrafluoroethylene Substances 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 238000002156 mixing Methods 0.000 description 6
- 229920002401 polyacrylamide Polymers 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 5
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 229920002125 Sokalan® Polymers 0.000 description 4
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000011856 silicon-based particle Substances 0.000 description 4
- 229920003048 styrene butadiene rubber Polymers 0.000 description 4
- 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 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 3
- 239000002033 PVDF binder Substances 0.000 description 3
- 125000005396 acrylic acid ester group Chemical group 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000001768 carboxy methyl cellulose Substances 0.000 description 3
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 230000002687 intercalation Effects 0.000 description 3
- 238000009830 intercalation Methods 0.000 description 3
- -1 polytetrafluoroethylene Polymers 0.000 description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 3
- 238000004537 pulping Methods 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- 239000000661 sodium alginate Substances 0.000 description 3
- 235000010413 sodium alginate Nutrition 0.000 description 3
- 229940005550 sodium alginate Drugs 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910052787 antimony Inorganic materials 0.000 description 2
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 2
- 229910052788 barium Inorganic materials 0.000 description 2
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052790 beryllium Inorganic materials 0.000 description 2
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 238000010280 constant potential charging Methods 0.000 description 2
- 238000010277 constant-current charging Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052732 germanium Inorganic materials 0.000 description 2
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229910052712 strontium Inorganic materials 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- 229910052718 tin Inorganic materials 0.000 description 2
- 239000011135 tin Substances 0.000 description 2
- 229910052727 yttrium Inorganic materials 0.000 description 2
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 229920006184 cellulose methylcellulose Polymers 0.000 description 1
- 238000007600 charging Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 1
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- 239000005543 nano-size silicon particle Substances 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The utility model provides a negative plate, a lithium ion battery and an electricity utilization device, and belongs to the field of new energy. The negative electrode plate comprises a current collector and a silicon-based material layer, a porous carbon layer and a graphite layer which are sequentially laminated on at least one surface of the current collector, wherein the current collector has a porous structure, so that the volume expansion of a silicon-based negative electrode is effectively slowed down, and the cycle performance is improved; and meanwhile, the dynamic performance of the battery is improved.
Description
Technical Field
The utility model belongs to the field of new energy, and particularly relates to a negative plate, a lithium ion battery and an electric device.
Background
Graphite is the most widely used cathode material of the lithium ion battery in the current commercialization because of excellent conductivity, low and stable lithium intercalation point, low cost, rich natural storage capacity and the like. However, the theoretical capacity of graphite is only 372mAh/g, and the energy density of the next-generation lithium ion battery cannot be met in the market. Silicon has an ultra-high theoretical capacity and is considered to be the most likely alternative to graphite as the negative electrode material for the next-generation commercial lithium ion batteries. However, the silicon-based negative electrode has serious volume expansion in the lithium intercalation process, so that not only is the pole piece cracked or even pulverized, and the cohesiveness between particles and a current collector is poor, but also the SEI film formed on the surface is damaged, and finally, the cycle performance is poor, which limits the commercialized application of the silicon-based negative electrode. At present, the volume expansion of silicon is relieved mainly by compounding silicon with elements such as carbon, oxygen and the like and adjusting the structure of a silicon material, but the silicon-based negative electrodes still have remarkable volume expansion in the use process, and the thickness and the cycle performance of the battery core are affected. Therefore, how to effectively slow down the volume expansion of the silicon-based anode is a technical problem to be solved.
Disclosure of Invention
In order to overcome the defects and shortcomings in the prior art, the utility model aims to provide a negative plate, a lithium ion battery and an electric device, so as to effectively slow down the volume expansion of a silicon-based negative electrode and improve the cycle performance.
In order to achieve the above object, a first aspect of the present utility model provides a negative electrode sheet including a current collector having a porous structure, and a silicon-based material layer, a porous carbon layer, and a graphite layer sequentially stacked on at least one side of the current collector.
Further, the aperture of the current collector is 0.5-5 mu m, and the porosity is 30-50%.
Further, the pore diameter of the porous carbon layer is 0.01-1 mu m, and the porosity is 50% -80%.
Further, the thickness of the current collector is 3-8 μm.
Further, the thickness of the silicon-based material layer is 1-20 μm.
Further, the thickness of the porous carbon layer is 1 to 30 μm.
Further, the thickness of the graphite layer is 50-80 μm.
Further, the current collector is a porous copper foil.
The second aspect of the utility model provides a lithium ion battery, which comprises the negative plate.
Compared with the prior art, the utility model has the beneficial effects that: according to the utility model, the space for reserving volume expansion for the silicon-based material is utilized by the current collector with the porous structure and the porous carbon layer, so that the thickness expansion of the pole piece caused by the volume expansion of the silicon-based material is slowed down, and the thickness expansion of the pole piece caused by the silicon-based material is blocked by the graphite layer, so that the battery has good cycle performance; meanwhile, more interfaces contacted with the electrolyte are provided by the porous carbon layer, so that the lithium ion transmission distance is shortened, and the dynamic performance of the battery cell is improved.
Drawings
FIG. 1 is a schematic diagram of a negative plate according to an embodiment of the present utility model;
FIG. 2 is a schematic diagram of a negative electrode sheet according to another embodiment of the present utility model;
Detailed Description
The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the utility model, but not all embodiments, and all other embodiments obtained by those skilled in the art without making creative efforts based on the embodiments of the present utility model are all within the protection scope of the present utility model.
According to a first aspect of the present utility model, there is provided a negative electrode sheet, referring to fig. 1 and 2, comprising a current collector 1 and a silicon-based material layer 2, a porous carbon layer 3, and a graphite layer 4 sequentially stacked on at least one side of the current collector, wherein the current collector 1 has a porous structure. The negative electrode plate utilizes a current collector 1 with a porous structure and a porous carbon layer 3 to reserve a volume expansion space for a silicon-based material, so that the thickness expansion of a pole piece caused by the volume expansion of the silicon-based material is slowed down, and a graphite layer 4 is utilized to buffer the thickness expansion of the pole piece caused by the silicon-based material, so that the battery has good cycle performance; meanwhile, the porous carbon layer 3 can provide more interfaces in contact with electrolyte, so that the lithium ion transmission distance is shortened, and the dynamic performance of the battery cell is improved.
In one embodiment of the present utility model, the pore diameter of the current collector 1 is 0.5 to 5 μm. When the pore diameter of the current collector 1 is within this range, small particle silicon is suitably embedded inside the pores, which is advantageous in alleviating particle expansion.
In one embodiment of the present utility model, the porosity of the current collector 1 is 30% to 50%. When the porosity of the current collector 1 is within this range, both embedding of small particle silicon and tensile strength can be achieved.
In one embodiment of the present utility model, the pore size of the porous carbon layer 2 is 0.01 to 1 μm, and on the one hand, the pore size is suitable for embedding a part of small particle silicon to alleviate the expansion of silicon particles; on the other hand, the electrolyte is beneficial to enter the micropores to contact with the active substance particles, so that the migration distance of lithium ions is shortened.
In one embodiment of the present utility model, the porous carbon layer 2 has a porosity of 50 to 80%. When the porosity of the porous carbon layer 2 is within this range, rapid infiltration of the electrolyte is facilitated, and the distance of lithium ions migrating to silicon and graphite particles is greatly shortened.
In one embodiment of the present utility model, the thickness of the current collector 1 is 3 to 8 μm. The thickness of the current collector 1 is too large, so that the mass and the volume of the battery cell are occupied, and the energy density of the battery cell is affected; the thickness of the current collector 1 is too small, the pore diameter is difficult to embed in silicon particles, and wrinkling is easy, so that the thickness of the current collector 1 is preferably within the aforementioned range.
In one embodiment of the present utility model, the thickness of the silicon-based material layer 2 is 1 to 20 μm. The thickness of the silicon-based material layer 2 is too large, the volume expansion is too large after lithium intercalation, and the pore structures of the current collector 1 and the porous carbon layer 2 cannot absorb the expansion of particles; the thickness of the silicon-based material layer 2 is too small, the silicon particles are small in proportion, and the capacity advantage is not significantly exerted, so that it is preferable that the thickness of the silicon-based material layer 2 is within the aforementioned range.
In one embodiment of the present utility model, the porous carbon layer 3 has a thickness of 1 to 30 μm. The thickness of the porous carbon layer 3 is too large, so that the lithium storage function is not exerted, and the energy density is affected; the thickness of the porous carbon layer 3 is too small, and the expansion space reserved for the silicon particles is insufficient, so that it is preferable that the thickness of the porous carbon layer 3 is within the aforementioned range.
In one embodiment of the present utility model, the thickness of the graphite layer 4 is 50 to 80 μm. The thickness of the graphite layer 4 is too large, so that the overall thickness of the pole piece is increased, and the lithium ion migration is influenced; the thickness of the graphite layer 4 is too small to buffer macroscopic expansion of the pole piece, so it is preferable that the thickness of the graphite layer 4 is within the aforementioned range.
The material selection of the current collector 1 is not particularly limited. As one example, the material of the current collector 1 is selected from at least one of metals, alloys, etc., wherein the metals are selected from any one of copper, chromium, magnesium, iron, zinc, lithium, aluminum, calcium, silver, gold, neodymium, lead, antimony, strontium, yttrium, lanthanum, germanium, nickel, tin, cobalt, cerium, beryllium, barium, etc., and the alloys are selected from metal alloys containing at least one of copper, chromium, magnesium, iron, zinc, lithium, aluminum, calcium, silver, gold, neodymium, lead, antimony, strontium, yttrium, lanthanum, germanium, nickel, tin, cobalt, cerium, beryllium, barium, etc. The choice of material for the current collector 1 is not limited thereto. The material of the current collector 1 is preferably copper, i.e., the current collector 1 is preferably copper foil.
The silicon-based material layer 2 contains a silicon-based material. Wherein the selection of the silicon-based material is not particularly limited. As one example, the silicon-based material in the silicon-based material layer 2 is selected from at least one of nano silicon, silicon oxygen, silicon carbide, and the like. The selection of the silicon-based material in the silicon-based material layer 2 is not limited thereto. The mass fraction of the silicon-based material in the silicon-based material layer 2 is 93% to 97%, for example 93%,95%,97%, or a range of any two of these values.
In some embodiments of the present utility model, the silicon-based material layer 2 further includes at least one of a binder, a conductive agent, and the like. The binder in the silicon-based material layer 2 is not particularly limited, and as an example, it is selected from at least one of polyacrylic acid (PAA), polyacrylamide (PAM), polyvinylidene fluoride, polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), acrylic acid ester, sodium alginate, sodium/lithium carboxymethyl cellulose, and the like. The choice of the binder in the silicon-based material layer 2 is not limited thereto. The mass fraction of the binder in the silicon-based material layer 2 is 2% to 4%, for example, 2%,3%,4%, or a range of any two of these values. The choice of the conductive agent in the silicon-based material layer 2 is not particularly limited, and as one example, it is selected from at least one of carbon black (such as SP and the like), graphene, carbon Nanotubes (CNT), carbon fibers and the like. The choice of the conductive agent in the silicon-based material layer 2 is not limited thereto. The mass fraction of the conductive agent in the silicon-based material layer 2 is 1% to 3%, for example, 1%,2%,3%, or a range of any two of these values.
The porous carbon layer 3 contains porous carbon. The choice of porous carbon is not particularly limited. As one example, the porous carbon is selected from at least one of hard carbon, soft carbon, carbon nanotubes, carbon molecular sieves, and the like. The choice of porous carbon is not limited thereto. The mass fraction of the porous carbon in the porous carbon layer 3 is 90% to 95%, for example, 90%,92%,95%, or a range of any two of these values.
In some embodiments of the present utility model, the porous carbon layer 3 further comprises at least one of a binder and the like. The binder in the porous carbon layer 3 is not particularly limited, and as one example, it is selected from at least one of polyacrylic acid (PAA), polyacrylamide (PAM), polyvinylidene fluoride, polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), acrylic acid ester, sodium alginate, sodium/lithium carboxymethyl cellulose, and the like. The choice of binder in the porous carbon layer 3 is not limited thereto. The mass fraction of the binder in the porous carbon layer 3 is 5% to 10%, for example, 5%,7%,10%, or a range of any two of these values.
The graphite layer 4 comprises graphite. The choice of porous carbon is not particularly limited. The mass fraction of graphite in the graphite layer 4 is 95% to 97%, for example, 90%,93%,97%, or a range of any two of these values.
In some embodiments of the present utility model, the graphite layer 4 further comprises at least one of a binder, a conductive agent, and the like. The binder in the graphite layer 4 is not particularly limited, and as an example, it is selected from at least one of polyacrylic acid (PAA), polyacrylamide (PAM), polyvinylidene fluoride, polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), acrylic acid ester, sodium alginate, sodium/lithium carboxymethyl cellulose, and the like. The choice of binder in the graphite layer 4 is not limited thereto. The mass fraction of the binder in the graphite layer 4 is 1% to 2%, for example 1%,1.5%,2%, or a range of any two of these values. The choice of the conductive agent in the graphite layer 4 is not particularly limited, and as one example, it is selected from at least one of carbon black (such as SP and the like), graphene, carbon Nanotubes (CNT), carbon fibers and the like. However, the choice of the conductive agent in the graphite layer 4 is not limited thereto. The mass fraction of the conductive agent in the graphite layer 4 is 1% to 3%, for example, 1%,2%,3%, or a range of any two of these values.
Illustratively, the method for preparing the negative electrode sheet comprises the following steps:
uniformly mixing all the raw materials of the silicon-based material layer 2 to obtain first slurry;
uniformly mixing the raw materials of the porous carbon layer 3 to obtain second slurry;
uniformly mixing all the raw materials of the graphite layer 4 to obtain third slurry;
coating the first slurry on at least one surface of a current collector 1, and drying to form a silicon-based material layer 2;
coating the second slurry on the surface of the silicon-based material layer 2 facing away from the current collector 1, and drying to form a porous carbon layer 3;
and coating the third slurry on the surface of the porous carbon layer 3, which is away from the current collector 1, and drying to form a graphite layer 4, thereby obtaining the negative plate.
According to a second aspect of the present utility model, there is provided a lithium ion battery comprising the above-described negative electrode sheet.
According to a third aspect of the present utility model, there is provided an electric device comprising the above negative electrode sheet or the above lithium ion battery.
The utility model is further illustrated by the following examples. The raw materials and process parameters used for each parallel test are the same unless specified otherwise.
Example 1
The negative electrode plate comprises a current collector and silicon-based material layers, a porous carbon layer and a graphite layer which are sequentially laminated on two sides of the current collector, wherein the current collector has a porous structure, the pore diameter is 2-4 mu m, the porosity is 46%, and the thickness is 6 mu m; the thickness of the silicon-based material layer is 4 mu m; the pore diameter of the porous carbon layer is 5-500nm, the porosity is 68%, and the thickness is 10 mu m; the graphite layer had a thickness of 70. Mu.m.
The preparation method of the negative electrode plate comprises the following steps:
(1) Silicon-based anode material and PAA, CNT, SP are prepared according to the following proportion of 96.5:2.0:0.9: mixing and pulping in a double planetary mixer according to the mass ratio of 0.6 to obtain slurry I;
(2) CNT, PTFE were mixed as per 9:1, mixing and pulping in a double planetary mixer to obtain slurry II;
(3) Graphite, CMC, SBR, SP, 97:0.9:06: mixing and pulping in a double planetary mixer according to the mass ratio of 1.5 to obtain slurry III;
(4) Coating the slurry I on two sides of a porous copper foil, and drying to obtain a pole piece I;
(5) Coating the slurry II on two sides of the pole piece I, and drying to obtain a pole piece II;
(6) And (3) coating the slurry III on two sides of the pole piece II, and drying to obtain the pole piece III, namely the negative pole piece of the embodiment.
Comparative example 1
The only difference from example 1 is that: no porous carbon layer is contained. The composition, structure, thickness and preparation method of each of the other layers were the same as those of example 1.
Comparative example 2
The only difference from example 1 is that: and does not contain a graphite layer. The composition, structure, thickness and preparation method of each of the other layers were the same as those of example 1.
The negative plates of each example and comparative example were made into batteries, and the specific preparation method was as follows: and assembling the lithium cobalt oxide positive plate, the negative plate, the diaphragm and the aluminum plastic film into a soft package battery cell, injecting electrolyte, and sealing to obtain the battery cell.
The performance test was performed on the negative electrode sheets of the above examples and comparative examples and the battery manufactured, respectively, and the specific test method was as follows:
1. disassembling the battery cells of 0% SOC,50% SOC and 100% SOC respectively, and taking a negative plate to measure the thickness;
2.0.5C constant current charging to 4.45V, constant voltage charging to cut-off current of 0.02C,0.2C discharging to 3.0V, repeating the two steps of charging and discharging;
3. constant current charging to 4.45V, constant voltage charging to 0.02C, and 0.2C discharging to 3.0V are respectively carried out at the multiplying power of 1C/2C/3C.
The test results are shown in tables 1 to 2.
TABLE 1
TABLE 2
As can be seen from tables 1 to 3, in example 1, by adopting the special structure of porous current collector/silicon-based material/porous carbon/graphite, the volume expansion of the silicon-based negative electrode is effectively alleviated, so that the battery has good cycle performance, compared with comparative examples 1 and 2; as can be seen from the ratio discharge capacity retention rate data of comparative example 1 and comparative example 1, the intermediate porous carbon layer can improve the dynamic performance of the battery.
Claims (10)
1. The negative electrode plate is characterized by comprising a current collector and a silicon-based material layer, a porous carbon layer and a graphite layer which are sequentially laminated on at least one surface of the current collector, wherein the current collector has a porous structure.
2. The negative electrode sheet according to claim 1, wherein the current collector has a pore diameter of 0.5 to 5 μm and a porosity of 30 to 50%.
3. The negative electrode sheet according to claim 1, wherein the porous carbon layer has a pore diameter of 0.01 to 1 μm and a porosity of 50 to 80%.
4. The negative electrode sheet according to claim 1, wherein the thickness of the current collector is 3 to 8 μm.
5. The negative electrode sheet according to claim 1, wherein the silicon-based material layer has a thickness of 1 to 20 μm.
6. The negative electrode sheet of claim 1, wherein the porous carbon layer has a thickness of 1 to 30 μm.
7. The negative electrode sheet of claim 1, characterized in that the graphite layer has a thickness of 50 to 80 μm.
8. The negative electrode sheet of claim 1, wherein the current collector is copper foil.
9. A lithium ion battery comprising the negative electrode sheet according to any one of claims 1 to 8.
10. An electric device comprising the negative electrode sheet according to any one of claims 1 to 8 or the lithium ion battery according to claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322133574.3U CN220627852U (en) | 2023-08-08 | 2023-08-08 | Negative plate, lithium ion battery and electricity utilization device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322133574.3U CN220627852U (en) | 2023-08-08 | 2023-08-08 | Negative plate, lithium ion battery and electricity utilization device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220627852U true CN220627852U (en) | 2024-03-19 |
Family
ID=90215870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322133574.3U Active CN220627852U (en) | 2023-08-08 | 2023-08-08 | Negative plate, lithium ion battery and electricity utilization device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220627852U (en) |
-
2023
- 2023-08-08 CN CN202322133574.3U patent/CN220627852U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103413692A (en) | Lithium ion capacitor positive plate and lithium ion capacitor using same | |
| JP2023519287A (en) | Lithium iron phosphate positive electrode sheet and manufacturing method thereof, lithium iron phosphate lithium ion battery | |
| CN101465416A (en) | High specific capacity composite electrode pole piece for lithium ion battery | |
| CN111916757B (en) | Multilayer electrode, preparation method of multilayer electrode and lithium ion battery | |
| CN112614703B (en) | Negative electrode material of ionic capacitor and preparation method and application thereof | |
| CN113675365B (en) | Negative plate and lithium ion battery | |
| CN108400292A (en) | A kind of preparation method and applications of bismuth simple substance nanometer sheet combination electrode | |
| CN113555541A (en) | High-energy-density lithium ion battery | |
| CN105374982A (en) | Electrode structure of lithium sulfur battery and processing technology therefor | |
| CN114975853A (en) | Composite positive pole piece and preparation method and application thereof | |
| CN112542571A (en) | Novel lithium ion battery positive pole piece and preparation method and application thereof | |
| CN213026226U (en) | Sulfide all-solid-state battery with lithium composite material as negative electrode | |
| CN117497835A (en) | Solid-state battery cell, preparation method thereof and solid-state battery | |
| CN113285050A (en) | Li-M-X-based solid lithium battery anode and preparation method thereof | |
| CN113130907A (en) | Battery cell, preparation method thereof and fast-charging lithium ion battery | |
| CN208674263U (en) | Compound cathode and lithium secondary battery | |
| CN220627852U (en) | Negative plate, lithium ion battery and electricity utilization device | |
| CN112542572A (en) | Novel lithium ion battery positive pole piece and preparation method and application thereof | |
| CN116387472A (en) | Negative electrode slurry of sodium ion battery, negative electrode plate and sodium ion battery | |
| CN114512633A (en) | Negative plate and battery comprising same | |
| CN113161516B (en) | Lithium ion battery | |
| CN113517419A (en) | Negative electrode material, negative electrode slurry, battery cell, quick-charging battery and preparation method thereof | |
| CN114373890A (en) | Novel silicon-containing cathode and lithium ion battery | |
| CN113241437A (en) | Negative plate and lithium ion battery comprising same | |
| KR20220009280A (en) | Electrode for secondary battery and method for preparing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |