CN117038856A - Negative pole piece, battery pack and electric equipment - Google Patents
Negative pole piece, battery pack and electric equipment Download PDFInfo
- Publication number
- CN117038856A CN117038856A CN202311210057.XA CN202311210057A CN117038856A CN 117038856 A CN117038856 A CN 117038856A CN 202311210057 A CN202311210057 A CN 202311210057A CN 117038856 A CN117038856 A CN 117038856A
- Authority
- CN
- China
- Prior art keywords
- negative electrode
- material layer
- active
- active material
- battery
- 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
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 121
- 239000011149 active material Substances 0.000 claims abstract description 79
- 239000000463 material Substances 0.000 claims abstract description 72
- 239000003575 carbonaceous material Substances 0.000 claims abstract description 35
- 238000005087 graphitization Methods 0.000 claims abstract description 28
- 239000007773 negative electrode material Substances 0.000 claims abstract description 12
- 229910021385 hard carbon Inorganic materials 0.000 claims description 15
- 229910021384 soft carbon Inorganic materials 0.000 claims description 7
- 229910021383 artificial graphite Inorganic materials 0.000 claims description 6
- 229910021382 natural graphite Inorganic materials 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 238000005056 compaction Methods 0.000 description 25
- 150000002500 ions Chemical class 0.000 description 23
- 230000009286 beneficial effect Effects 0.000 description 20
- 239000003792 electrolyte Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 14
- -1 polytetrafluoroethylene Polymers 0.000 description 14
- 230000005540 biological transmission Effects 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 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 11
- 239000006258 conductive agent Substances 0.000 description 11
- 238000001556 precipitation Methods 0.000 description 11
- 229910052708 sodium Inorganic materials 0.000 description 11
- 239000011734 sodium Substances 0.000 description 11
- 239000002245 particle Substances 0.000 description 10
- 229910001415 sodium ion Inorganic materials 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 9
- 239000011267 electrode slurry Substances 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 239000011230 binding agent Substances 0.000 description 8
- 239000007774 positive electrode material Substances 0.000 description 8
- 239000006183 anode active material Substances 0.000 description 6
- XKRFYHLGVUSROY-UHFFFAOYSA-N argon Substances [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 230000007547 defect Effects 0.000 description 6
- 229920003048 styrene butadiene rubber Polymers 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 238000001237 Raman spectrum Methods 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 229910052786 argon Inorganic materials 0.000 description 5
- 239000011888 foil Substances 0.000 description 5
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 4
- 239000002033 PVDF binder Substances 0.000 description 4
- 239000011889 copper foil Substances 0.000 description 4
- 210000001787 dendrite Anatomy 0.000 description 4
- 238000003795 desorption Methods 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 230000002349 favourable effect Effects 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000006245 Carbon black Super-P Substances 0.000 description 3
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 239000001768 carboxy methyl cellulose Substances 0.000 description 3
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 3
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000011883 electrode binding agent Substances 0.000 description 3
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 229910044991 metal oxide Inorganic materials 0.000 description 3
- 239000011812 mixed powder Substances 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 229920002239 polyacrylonitrile Polymers 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 description 3
- 229910001414 potassium ion Inorganic materials 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 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 2
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 description 2
- 229920002125 Sokalan® Polymers 0.000 description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 239000006230 acetylene black Substances 0.000 description 2
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 2
- 239000006256 anode slurry Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 description 2
- 239000002041 carbon nanotube Substances 0.000 description 2
- 210000004027 cell Anatomy 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 2
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 229920003063 hydroxymethyl cellulose Polymers 0.000 description 2
- 229940031574 hydroxymethyl cellulose Drugs 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 229920000058 polyacrylate Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000007086 side reaction Methods 0.000 description 2
- 239000000661 sodium alginate Substances 0.000 description 2
- 235000010413 sodium alginate Nutrition 0.000 description 2
- 229940005550 sodium alginate Drugs 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- DCYOBGZUOMKFPA-UHFFFAOYSA-N iron(2+);iron(3+);octadecacyanide Chemical compound [Fe+2].[Fe+2].[Fe+2].[Fe+3].[Fe+3].[Fe+3].[Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] DCYOBGZUOMKFPA-UHFFFAOYSA-N 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920000620 organic polymer Polymers 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
- 229920000447 polyanionic polymer Polymers 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000002633 protecting effect Effects 0.000 description 1
- 229960003351 prussian blue Drugs 0.000 description 1
- 239000013225 prussian blue Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 238000009461 vacuum packaging Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- 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
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
-
- 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
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- 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
Abstract
The application provides a negative pole piece, a battery pack and electric equipment. The negative electrode plate comprises a negative electrode current collector and a negative electrode material layer, the negative electrode material layer comprises a second active material layer and a first active material layer arranged between the negative electrode current collector and the second active material layer, the material of the first active material layer comprises a first active carbon material, the material of the second active material layer comprises a second active carbon material, and d 1 ≥d 2 ，P 1 ＜P 2 ，G 1 ＜G 2 ，d 1 、d 2 The thickness of the first active material layer and the second active material layer is expressed as mu m and P 1 、P 2 Holes of the first active carbon material and the second active carbon materialGap ratio, 1/G 1 、1/G 2 The negative electrode plate meets at least one of the following conditions for graphitization degree of the first active carbon material and the second active carbon material: (1) 0.18 ∈100×G 1 ×P 1 /d 1 ≤0.68；(2)0.82≤100×G 2 ×P 2 /d 2 ≤2.96。
Description
Technical Field
The application belongs to the technical field of batteries, and particularly relates to a negative pole piece, a battery pack and electric equipment.
Background
With the continued development of batteries, researchers have begun to pursue batteries with higher energy densities and more excellent cycle performance. The negative electrode plate is used as a key component in the battery, plays an important role in improving the performance of the battery, however, the selection of a negative electrode material is often focused in the related technology, the design of the whole structure of the negative electrode plate is less researched, and the improvement of the performance of the battery is limited.
Disclosure of Invention
In view of the above, the application provides a negative electrode plate, a battery pack and electric equipment, wherein the negative electrode plate has good compaction density and dynamic performance, can improve the energy density and cycle performance of the battery, and is beneficial to the use of the battery, the battery pack and the electric equipment.
In a first aspect, the present application provides a negative electrode tab, including a negative electrode current collector and a negative electrode material layer disposed on a surface of the negative electrode current collector, where the negative electrode material layer includes a first active material layer and a second active material layer disposed in a stacked manner, the first active material layer is disposed between the negative electrode current collector and the second active material layer, a material of the first active material layer includes a first activated carbon material, a material of the second active material layer includes a second activated carbon material, and a thickness of the first active material layer is d 1 The thickness of the second active material layer is d 2 ，d 1 ≥d 2 ，d 1 And d 2 Is in μm; the first activated carbon material has a porosity of P 1 The second activated carbon material has a porosity of P 2 ，P 1 ＜P 2 The method comprises the steps of carrying out a first treatment on the surface of the The first activated carbon materialIs 1/G 1 The graphitization degree of the second activated carbon material is 1/G 2 ，G 1 ＜G 2 The method comprises the steps of carrying out a first treatment on the surface of the Wherein, calculated with the numerical value of each parameter, the negative electrode sheet satisfies at least one of the following conditions: (1) 0.18 ∈100×G 1 ×P 1 /d 1 ≤0.68；(2)0.82≤100×G 2 ×P 2 /d 2 ≤2.96。
The first active material layer and the second active material layer in the negative electrode plate are matched with each other, so that the negative electrode plate has excellent compaction density and dynamic performance, and the precipitation condition of active ions on the surface of the negative electrode during high-rate charging can be reduced, thereby being beneficial to improving the energy density, the cycle rate and the cycle life of the battery, and simultaneously ensuring the use safety of the battery.
Optionally, the d 1 Said P 1 And the G 1 The values of (2) satisfy: 0.26 ∈100×G 1 ×P 1 /d 1 Less than or equal to 0.52. The arrangement is favorable for further improving the compaction density of the negative electrode plate, and further improving the energy density and the cycle performance of the battery.
Optionally, the d 2 Said P 2 And the G 2 The values of (2) satisfy: 1.06 ∈100×G 2 ×P 2 /d 2 And is less than or equal to 2.42. The arrangement is beneficial to further improving the dynamic performance of the negative electrode plate, and further improving the multiplying power performance of the battery.
Optionally, the d 1 And d is equal to 2 The ratio of (2) is 1.4-4.5. The arrangement can further reduce the transmission time of active ions on the second active material layer, so that the active ions can reach the first active material layer more quickly, dendrite precipitation caused by accumulation of the active ions on the surface of the pole piece is avoided, and the quick charging performance and the safety performance of the negative pole piece and the battery are further improved.
Optionally, the d 1 35-100 μm, said d 2 15-50 μm. The arrangement ensures the content of the first active carbon material and the second active carbon material in the negative electrode plate, and is beneficial to improving the performance of the negative electrode plate.
Alternatively to this, the method may comprise,the G is 1 With said G 2 The ratio of (2) is 0.52-0.80. The arrangement is beneficial to further improving the compaction density of the negative electrode plate, and improving the dynamic performance of the negative electrode plate, so that the energy density, the multiplying power performance and the cycle performance of the battery are improved.
Optionally, the G 1 0.84 to 1.2, G is as follows 2 1.32 to 1.82. The arrangement is beneficial to further improving the compaction density and the dynamic performance of the negative electrode plate.
Optionally, the P 1 With said P 2 The ratio of (2) is 0.36-0.84. The arrangement is beneficial to further improving the compaction density and the dynamic performance of the negative electrode plate, and further improving the energy density, the multiplying power performance and the cycle performance of the battery.
Optionally, the P 1 10 to 25 percent of the P 2 20% -40%. The arrangement is beneficial to further improving the dynamic performance of the negative electrode plate.
Optionally, the first activated carbon material includes at least one of soft carbon, hard carbon, natural graphite, and artificial graphite; the second activated carbon material includes at least one of soft carbon, hard carbon, natural graphite, and artificial graphite.
In a second aspect, the application provides a battery comprising a positive electrode sheet and a negative electrode sheet according to the first aspect. The battery with the negative electrode plate has excellent energy density, rate capability and cycle performance, and high use safety.
In a third aspect, the present application provides a battery pack comprising a case and at least one battery according to the second aspect, the battery being housed in the case. The battery pack with the battery has excellent performance and is beneficial to the use of the battery pack.
In a fourth aspect, the application provides a powered device, which comprises the battery according to the second aspect or the battery pack according to the third aspect. The product competitiveness and the service performance of the electric equipment are improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic cross-sectional view of a negative electrode tab according to an embodiment of the present application.
Detailed Description
The technical solutions of the present application will be clearly and completely described in conjunction with the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, are intended to fall within the scope of the present application.
Referring to fig. 1, a schematic cross-sectional view of a negative electrode sheet according to an embodiment of the present application is provided, the negative electrode sheet 100 includes a negative electrode current collector 10 and a negative electrode material layer 20 disposed on a surface of the negative electrode current collector 10, the negative electrode material layer 20 includes a first active material layer 21 and a second active material layer 22 disposed in a stacked manner, the first active material layer 21 is disposed between the negative electrode current collector 10 and the second active material layer 22, a material of the first active material layer 21 includes a first active carbon material, a material of the second active material layer 22 includes a second active carbon material, and a thickness d of the first active material layer 21 1 The second active material layer 22 has a thickness d 2 ，d 1 ≥d 2 ，d 1 And d 2 Is in μm; the first activated carbon material has a porosity of P 1 The second activated carbon material has a porosity of P 2 ，P 1 ＜P 2 The method comprises the steps of carrying out a first treatment on the surface of the The graphitization degree of the first activated carbon material is 1/G 1 The graphitization degree of the second activated carbon material is 1/G 2 ，G 1 ＜G 2 The method comprises the steps of carrying out a first treatment on the surface of the Wherein, calculated by the numerical value of each parameter, the negative electrode tab 100 satisfies at least one of the following conditions: (1) 0.18 ∈100×G 1 ×P 1 /d 1 ≤0.68；(2)0.82≤100×G 2 ×P 2 /d 2 ≤2.96。
In the negative electrode plate, the thickness of the second active material layer is smaller than or equal to that of the first active material layer, so that active ions (lithium ions, sodium ions, potassium ions and the like) can pass through the second active material layer and enter the first active material layer in a short time in the charge-discharge process, and further, the active ions are prevented from being separated out on the surface of the second active material layer, and the quick charge capacity is improved; the porosity of the first activated carbon material is less than the porosity of the second activated carbon material, that is, the pores within the first activated carbon material are relatively few, the layers of internal graphite microchip are tightly stacked, the compacted density is relatively high, the pores within the second activated carbon material are relatively many, and the compacted density is relatively low; the graphitization degree of the first activated carbon material is greater than that of the second activated carbon material, that is, the first activated carbon material has relatively fewer defects, the formed graphite crystallite structure has relatively higher order degree and higher compaction density, the second activated carbon material has relatively more defects, the formed graphite crystallite structure has relatively higher disorder degree and the compaction density is relatively lower. Namely, the low porosity and the high graphitization degree of the first activated carbon material are beneficial to improving the compaction density, the defects are fewer, the first-week coulomb efficiency can be improved due to low surface activity, and a stable and compact solid electrolyte membrane (SEI film) is easy to form in the circulation process, so that the improvement of the circulation performance is facilitated; the high porosity and low graphitization degree of the second active carbon material facilitate rapid transmission of active ions in the second active material layer, reduce transmission resistance, and improve diffusion rate, so that the second active material layer has better dynamic performance. In the present application, the values of the parameters are calculated (that is, d 1 、d 2 Is a numerical calculation of (c), the negative electrode tab satisfies at least one of the following conditions: (1) 0.18 ∈100×G 1 ×P 1 /d 1 ≤0.68；(2)0.82≤100×G 2 ×P 2 /d 2 Less than or equal to 2.96; that is, the first active material layer satisfies 0.18.ltoreq.100×G 1 ×P 1 /d 1 Not more than 0.68, and/or the second active material layer satisfies 0.82 not more than 100 XG 2 ×P 2 /d 2 And is less than or equal to 2.96. When 100 XG 1 ×P 1 /d 1 When the value of (2) is smaller than 0.18, the graphitization degree of the first active carbon material is larger, the porosity is lower and/or the thickness of the first active material layer is larger, so that the electrolyte is difficult to infiltrate the negative electrode plate, the ion transmission resistance is increased, the liquid phase transmission path of the active ions is increased, the polarization is increased, and the rate performance and the cycle performance of the battery are affected; when 100 XG 1 ×P 1 /d 1 When the value of (2) is larger than 0.68, the graphitization degree of the first active carbon material is smaller, the porosity is higher and/or the thickness of the first active material layer is smaller, so that the compaction density of the negative electrode plate is reduced, and the energy density of the battery is influenced; thus, when the first active material layer satisfies 0.18.ltoreq.100×G 1 ×P 1 /d 1 And when the energy density is less than or equal to 0.68, the negative electrode plate compaction density is improved, so that the energy density and the cycle performance of the battery are improved, and the use of the battery is facilitated. When 100 XG 2 ×P 2 /d 2 When the value of (2) is smaller than 0.82, the graphitization degree of the second active carbon material is larger, the porosity is lower and/or the thickness of the second active material layer is larger, so that the anode piece is relatively difficult to infiltrate into electrolyte, the ion transmission resistance is increased, the liquid phase transmission path of active ions is increased, the polarization is increased, the dynamic performance of the second active material layer is reduced, active ions are easily accumulated on the surface of the second active material layer to precipitate dendrites, and the rate performance, the cycle performance and the safety of the battery are affected; when 100 XG 2 ×P 2 /d 2 When the value of (2) is larger than 2.96, the graphitization degree of the second active carbon material is smaller, the porosity is higher and/or the thickness of the second active material layer is smaller, so that the defects of the second active carbon material are increased, the surface activity is increased, the contact area with the electrolyte is increased, the side reaction with the electrolyte is increased, the SEI film is continuously broken and repaired in the circulation process, the loss of active ions is increased, and the initial cycle coulomb efficiency and the cycle life of the battery are influenced; thus, when the second active material layer satisfies 0.82.ltoreq.100×G 2 ×P 2 /d 2 When the temperature is less than or equal to 2.96, the dynamic performance of the negative electrode plate is improved, and meanwhile, the side reaction with electrolyte is less, so that the battery is improvedRate capability and cycle life. Therefore, the negative electrode plate provided by the application has excellent compaction density and dynamic performance, and can reduce the precipitation condition of active ions on the surface of the negative electrode during high-rate charging, thereby being beneficial to improving the energy density, the cycle rate and the cycle life of the battery and ensuring the use safety of the battery.
In one embodiment of the present application, the thickness d of the first active material layer 1 35-100 μm. Specifically, d 1 May be, but is not limited to, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 58 μm, 60 μm, 65 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc. In one embodiment of the application, d 1 May be 50 μm to 100. Mu.m. In another embodiment of the present application, d 1 May be 60 μm to 80. Mu.m. In one embodiment of the present application, the thickness d of the second active material layer 2 15-50 μm. Specifically, d 2 May be, but is not limited to, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. In one embodiment of the application, d 2 May be 15 μm to 45. Mu.m. In another embodiment of the present application, d 2 May be 20 μm to 35. Mu.m. In one embodiment of the application, d 1 Is 35-100 μm, d 2 15-50 μm. Due to d 1 ≥d 2 The content of the first active carbon material and the second active carbon material in the negative electrode plate is ensured by the arrangement, and the improvement of the performance of the negative electrode plate is facilitated. In one embodiment of the application, d 1 50 μm to 100 μm, d 2 15-45 μm. In another embodiment of the present application, d 1 Is 60-80 mu m, d 2 20-35 μm.
In one embodiment of the application, d 1 And d 2 The ratio of the active ions to the negative electrode plate is 1.4-4.5, so that the transmission time of the active ions in the second active material layer can be further reduced, the active ions can reach the first active material layer more quickly, dendrite precipitation caused by accumulation of the active ions on the surface of the negative electrode plate is avoided, and the quick charging performance and the safety performance of the negative electrode plate and the battery are further improved. Specifically, d 1 And d 2 The ratio of (2) may be, but is not limited to, 1.4, 1.5, 1.7, 2, 2.2, 2.5, 2.8, 3, 3.4, 3.5,3.7, 4, 4.1, 4.3 or 4.5, etc. In one embodiment of the application, d 1 And d 2 The ratio of (2) is 1.5-4. In another embodiment of the present application, d 1 And d 2 The ratio of (2) to (3.5).
The graphitization degree can be obtained by Raman spectrum detection, 1350cm in the Raman spectrum -1 The peak of (C) is D peak, 1585cm -1 The peak of (2) is G peak, and the integral area intensity ratio of G peak and D peak is I G /I D Graphitization degree is I G /I D Is a ratio of (2); i G /I D The larger the graphitization degree is, the higher the graphitization degree is, which shows that the internal defects of the material are fewer, the ordering degree is increased, so that the material has higher compaction density, I G /I D The smaller the graphitization degree is, the lower the graphitization degree is, which indicates that a large number of defects exist in the material, and the formed graphite microcrystalline structure has high disorder degree, so that the compaction density of the material is low. 1/G in the present application 1 I.e., the integrated area intensity ratio (I) of the G peak and the D peak of the first activated carbon material G /I D )，1/G 2 The integral area intensity ratio of the G peak and the D peak of the second active carbon material is obtained; g 1 ＜G 2 Namely, the graphitization degree of the first active carbon material is relatively high, and the graphitization degree of the second active carbon material is relatively low, so that the compaction density of the first active material layer and the dynamics performance of the second active material layer can be improved, and the performance of the negative electrode plate is improved.
In one embodiment of the application, G 1 0.84 to 1.2. That is, the integrated area intensity ratio I of the D peak and the G peak of the first activated carbon material D /I G And the density of the first active material layer and the negative electrode plate is 0.84-1.2, so that the compaction density of the first active material layer and the negative electrode plate is improved, and the improvement of the energy density of the battery is facilitated. Specifically, G 1 May be, but is not limited to, 0.84, 0.87, 0.9, 0.93, 0.95, 0.98, 1, 1.05, 1.1, 1.15, 1.2, etc. In one embodiment of the application, G 1 May be 0.85 to 1.1. In another embodiment of the present application, G 1 May be 0.88 to 1. In one embodiment of the application, G 2 1.32 to 1.82. That is, the integrated area intensity ratio I of the D peak and the G peak of the second activated carbon material D /I G 1.32 to 1.82, is favorable for improving the dynamic performance of the second active material layer, further prevents active ions from accumulating on the surface of the negative electrode plate to separate dendrites, and further improves the safety. Specifically, G 2 May be, but is not limited to, 1.32, 1.35, 1.4, 1.45, 1.5, 1.55, 1.58, 1.62, 1.7, 1.75, or 1.8, etc. In one embodiment of the application, G 2 May be 1.4 to 1.8. In another embodiment of the present application, G 2 May be 1.5 to 1.75. In one embodiment of the application, G 1 0.84 to 1.2, G 2 1.32 to 1.82. Due to G 1 ＜G 2 The arrangement is beneficial to further improving the dynamic performance and the use safety of the negative electrode plate. In one embodiment of the application, G 1 Can be 0.85 to 1.1, G 2 May be 1.4 to 1.8. In another embodiment of the present application, G 1 Can be 0.88 to 1, G 2 May be 1.5 to 1.75.
In one embodiment of the application, G 1 And G 2 The ratio of (2) is 0.52-0.80, which is beneficial to further improving the compaction density of the negative electrode plate and improving the dynamic performance of the negative electrode plate at the same time, thereby being beneficial to improving the energy density, the multiplying power performance and the cycle performance of the battery. Specifically, G 1 And G 2 The ratio of (c) may be, but is not limited to, 0.52, 0.55, 0.6, 0.63, 0.65, 0.68, 0.7, 0.73, 0.75, 0.79, 0.8, 0.83, or 0.85, etc. In one embodiment of the application, G 1 And G 2 The ratio of (2) may be 0.55 to 0.83. In another embodiment of the present application, G 1 And G 2 The ratio of (2) may be 0.6 to 0.78.
The porosity can be obtained by detecting the nitrogen adsorption and desorption method, and P 1 ＜P 2 That is, the first active carbon material has relatively low porosity, and the second active carbon material has relatively high porosity, which is beneficial to improving the compaction density of the first active material layer and promoting the rapid transmission of active ions in the second active material layer, thereby improving the performance of the negative electrode plate.
In one embodiment of the application, P 1 10 to 25 percent. That is, the first activated carbon material has a porosity of 10% to 25%,the first active carbon material has low porosity and high compaction density, and is beneficial to improving the compaction density of the first active material layer and the negative electrode plate. Specifically, P 1 May be, but is not limited to, 10%, 13%, 15%, 18%, 20%, 21%, 23%, 25%, etc. In one embodiment of the application, P 1 Can be 10 to 20 percent. In another embodiment of the present application, P 1 Can be 13 to 18 percent.
In one embodiment of the application, P 2 20% -40%. That is, the porosity of the second activated carbon material is 20% -40%, and the porosity of the second activated carbon material is higher, so that the infiltration of the electrolyte is facilitated, the rapid transmission of active ions is facilitated, and the dynamic performance of the negative electrode plate is improved. Specifically, P 2 May be, but is not limited to, 20%, 23%, 25%, 28%, 30%, 32%, 35%, 37%, 40%, etc. In one embodiment of the application, P 2 May be 25 to 38 percent. In another embodiment of the present application, P 2 Can be 27 to 35 percent.
In one embodiment of the application, P 1 10 to 25 percent of P 2 20% -40%. Due to P 1 ＜P 2 The arrangement is beneficial to further improving the dynamic performance of the negative electrode plate. In one embodiment of the application, P 1 Can be 10 to 20 percent, P 2 May be 25 to 38 percent. In another embodiment of the present application, P 1 Can be 13 to 18 percent, P 2 Can be 27 to 35 percent.
In one embodiment of the application, P 1 And P 2 The ratio of (2) is 0.36-0.84, which is favorable for further improving the compaction density and the dynamic performance of the negative electrode plate, and further improving the energy density, the multiplying power performance and the cycle performance of the battery. Specifically, P 1 And P 2 The ratio of (c) may be, but is not limited to, 0.36, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.55, 0.58, 0.6, 0.65, 0.7, 0.75, 0.8, or 0.82, etc. In one embodiment of the application, P 1 And P 2 The ratio of (2) may be 0.4 to 0.8. In another embodiment of the present application, P 1 And P 2 The ratio of (2) may be 0.45 to 0.75.
In one embodiment of the application, d 1 、P 1 And G 1 The values of (2) satisfy: 0.26 ∈100×G 1 ×P 1 /d 1 And less than or equal to 0.52, thus being beneficial to further improving the compaction density of the negative electrode plate and further improving the energy density and the cycle performance of the battery. Exemplary, 100 XG 1 ×P 1 /d 1 The value of (2) may be, but is not limited to, in the range of 0.27 to 0.5, 0.28 to 0.49, 0.3 to 0.45, or 0.33 to 0.43. Specifically, 100 XG 1 ×P 1 /d 1 The value of (c) may be, but is not limited to, 0.27, 0.29, 0.32, 0.35, 0.39, 0.4, 0.41, 0.44, 0.46, 0.49, or 0.5, etc.
In one embodiment of the application, d 2 、P 2 And G 2 The values of (2) satisfy: 1.06 ∈100×G 2 ×P 2 /d 2 And less than or equal to 2.42, which is favorable for further improving the dynamic performance of the negative electrode plate and further improving the multiplying power performance of the battery. Exemplary, 100 XG 2 ×P 2 /d 2 The value of (2) may be, but is not limited to, in the range of 1.06 to 2.42, 1.1 to 2.5, 1.15 to 2.45, 1.2 to 2.2, 1.3 to 2, or 1.35 to 1.9. Specifically, 100 XG 2 ×P 2 /d 2 The value of (c) may be, but is not limited to, 1.06, 1.08, 1.13, 1.15, 1.2, 1.25, 1.3, 1.36, 1.4, 1.5, 1.6, 1.73, 1.86, 1.9, 2, 2.2, or 2.35, etc.
In one embodiment of the present application, the first activated carbon material may have a particle size of 5 μm to 14 μm, and the particle size is suitable, which is advantageous for further improving the compaction density of the first activated material layer. Specifically, the particle size of the first activated carbon material may be, but is not limited to, 5 μm, 6 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or the like. In one embodiment of the present application, the first activated carbon material may have a particle size of 5 μm to 10 μm. In another embodiment of the present application, the first activated carbon material may have a particle size of 9 μm to 14 μm.
In one embodiment of the present application, the specific surface area of the first activated carbon material may be 1.5m 2 /g～5m 2 And/g, the specific surface area is proper, the electrolyte is facilitated to infiltrate, and the transmission capacity of active ions is improved. Specifically, the first ActivityThe specific surface area of the carbon material may be, but is not limited to, 1.5m 2 /g、1.8m 2 /g、2m 2 /g、2.2m 2 /g、2.5m 2 /g、2.7m 2 /g、2.9m 2 /g、3m 2 /g、3.1m 2 /g、3.5m 2 /g、3.7m 2 /g、4m 2 /g、4.3m 2 /g、4.5m 2 /g、4.8m 2 /g or 5m 2 /g, etc.
In one embodiment of the present application, the second activated carbon material may have a particle size of 3 μm to 8 μm, and the particle size is suitable, which is advantageous for further improving the compaction density of the second activated material layer. Specifically, the particle size of the second activated carbon material may be, but is not limited to, 3 μm, 5 μm, 6 μm, 7 μm, 8 μm, or the like. In one embodiment of the present application, the particle size of the second activated carbon material may be 3 μm to 6 μm. In another embodiment of the present application, the particle size of the second activated carbon material may be 5 μm to 8 μm.
In one embodiment of the application, the specific surface area of the second activated carbon material may be 2m 2 /g～8m 2 And/g, the specific surface area is proper, the electrolyte is facilitated to infiltrate, and the transmission capacity of active ions is improved. In particular, the specific surface area of the second activated carbon material may be, but is not limited to, 2m 2 /g、2.2m 2 /g、2.5m 2 /g、3m 2 /g、3.5m 2 /g、3.7m 2 /g、4m 2 /g、4.3m 2 /g、4.5m 2 /g、5m 2 /g、5.5m 2 /g、5.9m 2 /g、6m 2 /g、6.5m 2 /g or 7m 2 /g, etc.
The first active material layer is made of the first active carbon material with high graphitization degree and low porosity, so that the usability of the negative electrode plate is improved. In one embodiment of the present application, the first activated carbon material comprises at least one of soft carbon, hard carbon, natural graphite, and synthetic graphite. The second active material layer is made of the second active carbon material with low graphitization degree and high porosity, so that the usability of the negative electrode plate is improved. In one embodiment of the present application, the second activated carbon material comprises at least one of soft carbon, hard carbon, natural graphite, and synthetic graphite. In the application, the materials of the first activated carbon material and the second activated carbon material can be the same or different. In one embodiment of the present application, the first activated carbon material and the second activated carbon material are both hard carbon. In the related art, when hard carbon is used as a battery anode active material, the problems of low charge and discharge efficiency, low capacity, poor multiplying power characteristics and the like at the first week of the hard carbon prevent the use of the hard carbon, and the compaction density of the hard carbon material is low, so that the processability of an anode piece and the volumetric energy density of a battery are affected; according to the application, the first active material layer and the second active material layer are matched, so that the anode piece and the battery with excellent electrochemical performance can be improved, and the wide use of hard carbon is facilitated. In another embodiment of the present application, the first activated carbon material may be hard carbon and the second activated carbon material may be soft carbon.
In an embodiment of the present application, the first active material layer further includes at least one of a first binder and a first conductive agent, and the second active material layer further includes at least one of a second binder and a second conductive agent. In an embodiment of the present application, the first binder and the second binder are independently selected from at least one of styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyacrylate, carboxymethyl cellulose (CMC), and sodium alginate. In an embodiment of the present application, the first conductive agent and the second conductive agent are independently selected from at least one of acetylene black, conductive carbon black (e.g., super-P, etc.), carbon nanotubes, carbon fibers, and graphene. In the application, the materials of the first binder and the second binder can be the same or different; the materials of the first conductive agent and the second conductive agent may be the same or different.
The negative electrode material layer is arranged on the surface of the negative electrode current collector, namely, the negative electrode material layer can be arranged in a partial area of one surface of the negative electrode current collector, can be arranged in all areas of one surface of the negative electrode current collector, and can also be arranged on two opposite surfaces of the negative electrode current collector. In an embodiment of the present application, the material of the negative electrode current collector includes at least one of copper and aluminum or stainless steel. In an embodiment of the present application, the negative electrode current collector may include at least one of a copper foil, a stainless steel foil, a copper alloy foil, a carbon coated copper foil, an aluminum foil, and a carbon coated aluminum foil.
The application provides a battery, which comprises a positive electrode plate and a negative electrode plate in any embodiment. The battery with the negative electrode plate has excellent energy density, rate capability and cycle performance, and high use safety.
In the present application, the battery may include at least one of a lithium ion battery, a sodium ion battery, and a potassium ion battery, and specifically, the battery type may be set as required.
In one embodiment of the application, the positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer arranged on the surface of the positive electrode current collector, wherein the positive electrode material layer comprises a positive electrode active material. In an embodiment of the present application, the positive electrode active material may include at least one of a transition metal oxide, a polyanion compound, an organic polymer, and a prussian blue-based material, thus facilitating the use of sodium ion batteries and potassium ion batteries. In another embodiment of the present application, the positive electrode active material may include at least one of lithium cobalt metal oxide, lithium nickel metal oxide, lithium manganese metal oxide, and a polyanionic battery positive electrode material, thus facilitating the use of a lithium ion battery. In an embodiment of the present application, the positive electrode material layer further includes at least one of a positive electrode binder and a positive electrode conductive agent. Specifically, the positive electrode binder comprises at least one of styrene-butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, polyacrylonitrile, polyacrylic acid, polyacrylate, carboxymethyl cellulose and sodium alginate; the positive electrode conductive agent comprises at least one of acetylene black, conductive carbon black (such as Super-P and the like), carbon nanotubes, carbon fibers and graphene.
In one embodiment of the application, the battery further comprises a separator disposed between the positive electrode tab and the negative electrode tab. The separator may be any separator material used in existing batteries. In an embodiment of the present application, the material of the separator includes at least one of polypropylene (PP), polyethylene (PE) and ceramic.
In one embodiment of the application, the battery further comprises an electrolyte, at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet being immersed in the electrolyte. In one embodiment of the application, the electrolyte includes an electrolyte salt and an organic solvent. The specific types and compositions of the electrolyte salt and the organic solvent are all routine choices in the field of batteries, and can be selected according to actual requirements.
The application provides a battery pack, which comprises a box body and at least one battery in any embodiment, wherein the battery is accommodated in the box body. The battery pack with the battery has excellent performance and is beneficial to the use of the battery pack. The battery is accommodated in the box body, so that the fixing and protecting effects on the battery can be improved, and the service life of the battery pack is prolonged. It will be appreciated that the battery pack may have one or more batteries therein, and that when a battery comprises a plurality of batteries, the plurality of batteries may be connected in at least one of parallel and series.
The application provides electric equipment, which comprises the battery or the battery pack in any embodiment, so that the product competitiveness and the service performance of the electric equipment are improved. In one embodiment of the application, the powered device includes a powered device body, and the battery or battery pack is used to power the powered device body. In an embodiment of the application, the electric equipment body comprises an equipment anode and an equipment cathode, the anode piece of the battery or the battery pack is used for being electrically connected with the equipment anode of the electric equipment body, and the cathode piece of the battery or the battery pack is used for being electrically connected with the equipment cathode of the electric equipment body so as to supply power to the electric equipment.
The electric equipment can be, but is not limited to, portable electronic equipment such as mobile phones, tablet computers, notebook computers, desktop computers, intelligent toys, intelligent bracelets, intelligent watches, electronic readers, game machines, toys and the like; the system can also be large-scale equipment such as a battery car, an electric automobile, a ship, a spacecraft and the like.
The effects of the technical scheme of the present application are further described below by means of specific examples.
Examples 1 to 8
Mixing a hard carbon material (first active carbon material) with high graphitization strength and low porosity, a first conductive agent (conductive carbon black) and a first binder (sodium hydroxymethyl cellulose and styrene-butadiene rubber, CMC+SBR) according to the mass ratio of 95.5:1:1.5:2, placing the mixed powder into a vacuum mixer, adding deionized water, stirring to obtain a first negative electrode slurry, uniformly coating the first negative electrode slurry on the surfaces of two opposite sides of a negative electrode current collector, transferring the first negative electrode slurry into an oven, and drying to obtain a first active material layer formed on the surface of the negative electrode current collector.
Mixing a hard carbon material (second active carbon material) with relatively low graphitization strength and high porosity, a second conductive agent (conductive carbon black) and a second binder (sodium hydroxymethyl cellulose and styrene butadiene rubber, CMC+SBR) according to the mass ratio of 95.5:1:1.5:2, placing the mixed powder in a vacuum mixer, adding deionized water, stirring to obtain a second negative electrode slurry, uniformly coating the second negative electrode slurry on the surface of the first active material layer, transferring the second negative electrode slurry into an oven, drying to obtain a second negative electrode active material layer, and rolling and slitting to obtain a negative electrode plate.
The structural parameters of the negative electrode sheets in examples 1 to 8 were different, and specific information is shown in table 1.
Comparative example 1
Substantially the same as in example 1, except that the second anode active material layer was not provided.
Comparative example 2
Substantially the same as in example 1, except that the first anode active material layer was not provided.
Comparative example 3
The method is similar to example 1, except that a second anode slurry is coated on the surface of an anode current collector to form a first anode active material layer, and then the surface of the first anode active material layer is coated with the first anode slurry to form a second anode active material layer, so as to obtain an anode sheet.
And (3) testing parameters of the negative electrode plate:
the thicknesses d of the first active material layer and the second active material layer in the negative electrode sheets prepared in the above examples and comparative examples were measured by scanning electron microscope analysis 1 、d 2 (in μm) for detection, specific test procedure: selecting a negative electrodeAnd the pole piece is used for analyzing the cross section of the negative pole piece by using a scanning electron microscope, and the thicknesses of the first active material layer and the second active material layer are respectively measured and counted. Porosity P of the first and second activated carbon materials in the above examples and comparative examples by the nitrogen adsorption and desorption test method 1 、P 2 Detecting; graphitization degree G of the first and second activated carbon materials in the above examples and comparative examples by Raman spectrum test method 1 、G 2 Detecting; the specific test process comprises the following steps: using an argon ion polishing instrument to ionize argon by using a high-voltage electric field to generate argon ions, polishing the generated argon ions under the action of accelerating voltage to remove a second active material layer of the negative pole piece, soaking the second active material layer in water, removing copper foil after pole piece dressing is removed, filtering an aqueous solution, taking residues, burning the residues in an oxygen atmosphere by using acetylene flame, wherein the burning temperature is 600-800 ℃, the burned residues are first active carbon material powder of the negative pole piece, and performing a porosity test and a Raman spectrum test calculation by using a nitrogen adsorption and desorption method to obtain graphitization degree; and similarly, removing the copper foil and the first active material layer of the negative electrode plate by adopting an argon ion polisher, immersing in water, filtering, taking residues, burning in an oxygen atmosphere by using acetylene flame, wherein the burning temperature is 600-800 ℃, the burned residues are second active carbon material powder of the negative electrode plate, and carrying out a porosity test and a Raman spectrum test calculation by adopting a nitrogen adsorption and desorption method to obtain the graphitization degree. According to d above 1 、d 2 、P 1 、P 2 、G 1 、G 2 Numerical expression 1 (100×G) 1 ×P 1 /d 1 ) And 2 (100 XG) 2 ×P 2 /d 2 ) Is a value of (2). The comparison of the parameters of the examples and comparative examples is shown in Table 1.
Table 1 parameter tables for negative electrode sheets of examples 1 to 8 and comparative examples 1 to 3
The positive electrode active material is preparedNa 3 V 2 (PO 4 ) 3 ) Mixing a positive electrode conductive agent (Super-P) and a positive electrode binder (PVDF) according to a mass ratio of 95:2.5:2.5, placing the mixed powder into a vacuum stirrer, adding N-methylpyrrolidone (NMP), and uniformly stirring to obtain positive electrode slurry; and uniformly coating the positive electrode slurry on the surfaces of two opposite sides of the aluminum foil of the positive electrode current collector, transferring the positive electrode current collector coated with the positive electrode slurry into an oven for drying, and rolling and cutting to obtain the positive electrode plate.
Mixing Ethylene Carbonate (EC), ethylmethyl carbonate (EMC) and diethyl carbonate (DEC) according to a volume ratio of 1:1:1 to obtain a mixed solvent, and adding dried sodium salt NaPF 6 An electrolyte with a concentration of 1mol/L was prepared, and 2% fluoroethylene carbonate (FEC) additive was added.
And sequentially stacking the negative electrode plate, the positive electrode plate and the polypropylene diaphragm prepared in the embodiment and the comparative example, enabling the diaphragm to be positioned between the positive electrode plate and the negative electrode plate, then winding to obtain a bare cell, filling the bare cell into an aluminum plastic film soft package, drying, injecting electrolyte, and carrying out the procedures of vacuum packaging, standing, formation, shaping and the like to obtain the secondary battery. The battery performance was tested as follows:
energy density testing: weighing each sodium ion battery at 25 ℃ by using an electronic balance; charging and discharging each prepared sodium ion battery at the rate of 1C at the temperature of 25 ℃, and recording the actual discharge energy at the moment; the ratio of the actual discharge energy of the sodium ion battery to the weight of the sodium ion battery is the actual energy density of the sodium ion battery.
Testing of cycle performance: each sodium ion battery was charged at 2C rate and discharged at 1C rate, and a full charge discharge cycle test was performed to record the capacity retention after 1000 cycles.
Kinetic performance test: and (3) fully charging each sodium ion battery with nC at 25 ℃, fully discharging with 1C, repeating the charge and discharge cycle for 10 times, then charging the battery to a full state with nC multiplying power, then disassembling the negative electrode plate, and observing the sodium precipitation condition on the surface of the negative electrode plate. Wherein, the area of the sodium precipitation area on the surface of the negative electrode plate is smaller than 2 percent, which is regarded as non-sodium precipitation. The sodium precipitation rate refers to that if sodium is not precipitated on the surface of the negative electrode plate, the charging rate is gradually increased from nC by a gradient of 0.1C, and the test is performed again until sodium is precipitated on the surface of the negative electrode, and the charging rate nC minus 0.1C at this time is the maximum charging rate of the battery under the condition of no sodium precipitation.
The battery performance test results of examples and comparative examples are shown in table 2, and it can be seen that the batteries of examples 1 to 8 have high cycle capacity retention rate, excellent cycle performance, and high sodium precipitation rate, indicating that the kinetic performance is excellent, and the energy density and the first-week charge-discharge efficiency are maintained at higher levels, as compared with comparative examples 1 to 3; moreover, compared with examples 2-8, the battery of example 1 has high energy density, cycle capacity retention, first week charge and discharge efficiency, and sodium precipitation rate, and excellent overall performance, and is beneficial to the use of the battery.
Table 2 battery performance test results of examples 1 to 8 and comparative examples 1 to 3
The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.
Claims (13)
1. The negative electrode plate is characterized by comprising a negative electrode current collector and a negative electrode material layer arranged on the surface of the negative electrode current collector, wherein the negative electrode material layer comprises a first active material layer and a second active material layer which are arranged in a stacked manner, the first active material layer is arranged between the negative electrode current collector and the second active material layer, the first active material layer comprises a first active carbon material, the second active material layer comprises a second active carbon material,
the thickness of the first active material layer is d 1 The thickness of the second active material layer is d 2 ，d 1 ≥d 2 ，d 1 And d 2 Is in μm;
the first activated carbon material has a porosity of P 1 The second activated carbon material has a porosity of P 2 ，P 1 ＜P 2 ；
The graphitization degree of the first activated carbon material is 1/G 1 The graphitization degree of the second activated carbon material is 1/G 2 ，G 1 ＜G 2 ；
Wherein, calculated with the numerical value of each parameter, the negative electrode sheet satisfies at least one of the following conditions:
(1)0.18≤100×G 1 ×P 1 /d 1 ≤0.68；
(2)0.82≤100×G 2 ×P 2 /d 2 ≤2.96。
2. the negative electrode tab of claim 1 wherein d 1 Said P 1 And the G 1 The values of (2) satisfy: 0.26 ∈100×G 1 ×P 1 /d 1 ≤0.52。
3. The negative electrode tab of claim 1 wherein d 2 Said P 2 And the G 2 The values of (2) satisfy: 1.06 ∈100×G 2 ×P 2 /d 2 ≤2.42。
4. The negative electrode tab of claim 1 wherein d 1 And d is equal to 2 The ratio of (2) is 1.4-4.5.
5. The negative electrode tab of claim 1 wherein d 1 35-100 μm, said d 2 15-50 μm.
6. As claimed inThe negative electrode sheet of claim 1, wherein the G 1 With said G 2 The ratio of (2) is 0.52-0.80.
7. The negative electrode tab of claim 1 wherein G 1 0.84 to 1.2, G is as follows 2 1.32 to 1.82.
8. The negative electrode tab of claim 1 wherein P 1 With said P 2 The ratio of (2) is 0.36-0.84.
9. The negative electrode tab of claim 1 wherein P 1 10 to 25 percent of the P 2 20% -40%.
10. The negative electrode sheet of claim 1, wherein the first activated carbon material comprises at least one of soft carbon, hard carbon, natural graphite, and synthetic graphite;
the second activated carbon material includes at least one of soft carbon, hard carbon, natural graphite, and artificial graphite.
11. A battery comprising a positive electrode sheet and a negative electrode sheet according to any one of claims 1 to 10.
12. A battery pack comprising a housing and at least one battery of claim 11, the battery being housed in the housing.
13. A powered device comprising the battery of claim 11 or the battery pack of claim 12.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311210057.XA CN117038856A (en) | 2023-09-19 | 2023-09-19 | Negative pole piece, battery pack and electric equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311210057.XA CN117038856A (en) | 2023-09-19 | 2023-09-19 | Negative pole piece, battery pack and electric equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117038856A true CN117038856A (en) | 2023-11-10 |
Family
ID=88624743
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311210057.XA Pending CN117038856A (en) | 2023-09-19 | 2023-09-19 | Negative pole piece, battery pack and electric equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117038856A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117558918A (en) * | 2024-01-12 | 2024-02-13 | 宁德时代新能源科技股份有限公司 | Secondary battery and electricity utilization device |
-
2023
- 2023-09-19 CN CN202311210057.XA patent/CN117038856A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117558918A (en) * | 2024-01-12 | 2024-02-13 | 宁德时代新能源科技股份有限公司 | Secondary battery and electricity utilization device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111987296B (en) | Negative electrode material, and electrochemical device and electronic device using same | |
| US9379387B2 (en) | Cathode current collector coated with primer and magnesium secondary battery comprising the same | |
| EP4199135A1 (en) | Negative electrode plate and secondary battery | |
| JP5800208B2 (en) | Nonaqueous electrolyte secondary battery | |
| JP4088755B2 (en) | Nonaqueous electrolyte secondary battery | |
| CN114665065A (en) | Positive pole piece and preparation method and application thereof | |
| KR101817418B1 (en) | Negative electrode active material and method for preparing the same | |
| CN112151755A (en) | Positive plate and battery | |
| CN113228342A (en) | Negative pole piece, electrochemical device comprising same and electronic device | |
| CN112786949B (en) | Secondary battery, battery module, battery pack and device containing same | |
| CN113437252A (en) | Negative electrode, electrochemical device including the same, and electronic device | |
| CN113161532A (en) | Negative electrode active material, and negative electrode, secondary battery, and electronic device including same | |
| CN117038856A (en) | Negative pole piece, battery pack and electric equipment | |
| CN115911261A (en) | Negative pole piece, secondary battery and power consumption device | |
| JP2023538082A (en) | Negative electrode and secondary battery containing the same | |
| US11545722B2 (en) | Separators for electrochemical cells and methods of making the same | |
| CN109428054B (en) | Anode pole piece, lithium ion secondary battery and preparation method | |
| CN116014225A (en) | Sodium ion battery | |
| KR20230088782A (en) | Composite Separators, Electrochemical Energy Storage Devices and Electrical Devices | |
| JP2024504525A (en) | Secondary batteries and power consumption devices including them | |
| KR102248310B1 (en) | Secondary battery, fuel battery and separator for secondary battery or fuel battery and manufacturing method of separator for secondary battery or fuel battery | |
| CN116487584A (en) | Positive electrode composite material, preparation method thereof, positive electrode and lithium ion secondary battery | |
| KR20130101375A (en) | Preparation method of electrode for litium rechargeable battery | |
| CN117117091A (en) | Negative pole piece, battery pack and electric equipment | |
| CN116632368B (en) | Secondary battery and electronic device |
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 |