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CN-122026005-A - Battery cell, battery and electricity utilization device

CN122026005ACN 122026005 ACN122026005 ACN 122026005ACN-122026005-A

Abstract

The application provides a battery monomer, a battery and an electricity utilization device, wherein the battery monomer comprises a positive pole piece, a negative pole piece and an isolating film, the isolating film is arranged between the positive pole piece and the negative pole piece, the isolating film comprises an isolating body and a polymer layer arranged on at least one surface of the isolating body, the polymer layer comprises an aldehyde ketone polymer, the aldehyde ketone polymer is made into a sheet-shaped structure, the sheet-shaped structure is subjected to dynamic frequency scanning test under the condition of (T m +20) DEGC to obtain an elastic modulus G '-energy consumption modulus G' curve, the slope of the elastic modulus G '-energy consumption modulus G' curve is K, K < -.

Inventors

  • PENG LIN
  • Peng Shuangjuan
  • LI BAIQING
  • JIN HAIZU
  • ZHAO FENGGANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260512
Application Date
20230417

Claims (17)

  1. 1. The utility model provides a battery monomer, includes positive pole piece, negative pole piece and barrier film, the barrier film set up in positive pole piece with between the negative pole piece, the barrier film includes: an isolation body; A polymer layer disposed on at least one surface of the separator body, the polymer layer comprising an aldehyde ketone polymer, Wherein, the The aldehyde ketone polymer is made into a sheet structure, the sheet structure is subjected to dynamic frequency scanning test at (T m +20) DEGC to obtain an elastic modulus G '-energy dissipation modulus G' curve, the slope of the elastic modulus G '-energy dissipation modulus G' curve is K, K </infinite > is more than or equal to 0.8, and T m ℃ represents the melting temperature of the aldehyde ketone polymer.
  2. 2. The battery cell of claim 1, wherein 0.8K 100, alternatively 0.8K 10, further alternatively 0.8K 1.
  3. 3. The battery cell of claim 1 or 2, wherein the aldehyde ketone polymer is added to the first solvent at 70 ℃ to form an aldehyde ketone polymer system; the aldehyde ketone polymer system is kept stand for 8 hours at 70 ℃, and after the aldehyde ketone polymer system is kept stand for more than or equal to 24 hours at 25 ℃, the aldehyde ketone polymer system is filtered by a 200-mesh filter screen to obtain a first substance, Wherein the mass of the aldehyde ketone polymer is q, the unit is g, the mass of the first substance is m, the unit is g, the aldehyde ketone polymer and the first substance satisfy that m/q is more than or equal to 5 and less than or equal to 1000, alternatively, m/q is more than or equal to 5 and less than or equal to 20, further alternatively, m/q is more than or equal to 5 and less than or equal to 12.
  4. 4. A battery cell according to any one of claims 1 to 3, wherein the aldehyde ketone polymer has a glass transition temperature Tg in the units of °c, -100 +.tg +.55, -optionally, -100 +.tg +.50, -further optionally, -80 +.tg +.30, further optionally 0 +.tg +.30.
  5. 5. The battery cell according to any one of claims 1 to 4, wherein the aldehyde ketone polymer comprises a structural unit represented by formula (I), Formula (I); In the formula (I) of the present invention, R 1 includes a single bond, a substituted or unsubstituted C1-C6 methylene group, R 2 includes a hydrogen atom, a substituted or unsubstituted C1-C6 alkyl group; Alternatively, R 1 comprises a single bond, a substituted or unsubstituted C1-C2 methylene group; Optionally, R 2 comprises a hydrogen atom, a substituted or unsubstituted C1-C3 alkyl group.
  6. 6. The battery cell according to claim 5, wherein the aldehyde ketone polymer comprises at least one of a structural unit represented by formula (I-1) to a structural unit represented by formula (I-6), A compound of the formula (I-1), A compound of the formula (I-2), A compound of the formula (I-3), A compound of the formula (I-4), A compound of the formula (I-5), Formula (I-6).
  7. 7. The battery cell according to any one of claims 1 to 6, wherein the aldehyde ketone polymer comprises a structural unit represented by formula (II), Formula (II); In the formula (II) of the present invention, R 3 to R 6 each independently comprises a hydrogen atom, a hydroxyl group, a substituted or unsubstituted C1-C3 alkyl group, a substituted or unsubstituted C1-C3 hydroxyalkyl group, or a substituted or unsubstituted C1-C3 alkoxy group, R and s are each independently selected from integers from 0 to 5, and at least one of R and s is selected from positive integers; Alternatively, the process may be carried out in a single-stage, R 3 to R 6 each independently comprise a hydrogen atom, a hydroxyl group, a substituted or unsubstituted C1-C3 alkyl group, a substituted or unsubstituted C1-C2 hydroxyalkyl group, or a substituted or unsubstituted C1-C2 alkoxy group.
  8. 8. The battery cell according to claim 7, wherein the aldehyde ketone polymer comprises at least one of a structural unit represented by formula (II-1) to a structural unit represented by formula (II-4), A compound of the formula (II-1), A compound of the formula (II-2), A compound of the formula (II-3), Formula (II-4).
  9. 9. The battery cell according to any one of claims 5 to 8, wherein, N is selected from a positive integer of 500 to 15000, and/or The molecular weight of the aldehyde ketone polymer is 1.2X10 5 g/mol to 1.0X10 6 g/mol.
  10. 10. The battery cell of any one of claims 1-9, wherein the separator body comprises a substrate, the polymer layer being disposed on at least one surface of the substrate.
  11. 11. The battery cell of any one of claims 1 to 9, wherein the separator body comprises a substrate and a heat resistant coating disposed on at least one surface of the substrate, the heat resistant coating having the polymer layer disposed on a surface facing away from the substrate.
  12. 12. The battery cell of any one of claims 1 to 11, wherein the polymer layer further comprises heat resistant particles; Alternatively, the ratio of the mass percent of the aldehyde ketone polymer to the mass percent of the heat resistant particles is (0.2 to 5): 1, alternatively (0.5 to 2): 1, based on the total mass of the polymer layer.
  13. 13. The battery cell according to any one of claims 1 to 12, wherein, The coating grammage of the polymer layer is 0.5mg/1540.25mm 2 to 5mg/1540.25mm 2 .
  14. 14. The battery cell according to any one of claims 1 to 13, wherein the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, the positive electrode active material layer including at least one of a lithium-containing phosphate compound, a lithium-containing transition metal oxide, a sodium-containing phosphate compound, and a sodium-containing transition metal oxide.
  15. 15. The battery cell according to any one of claims 1 to 14, wherein the negative electrode tab includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer including at least one of natural graphite, artificial graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate.
  16. 16. A battery comprising the battery cell according to any one of claims 1 to 15.
  17. 17. An electrical device comprising the battery of claim 16.

Description

Battery cell, battery and electricity utilization device The application is based on the application number 202380060957.2, the application date 2023, 04 and 17, and the application is a divisional application of the application named as 'isolating film, battery cell, battery and power utilization device' of New energy science and technology Co., ltd in the Ningde era. Technical Field The application relates to the field of batteries, in particular to a battery monomer, a battery and an electric device. Background The battery cell has the characteristics of high capacity, long service life and the like, and is widely applied to electronic equipment such as mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy automobiles, electric toy ships, electric toy airplanes, electric tools and the like. As the battery application range becomes wider, the requirements on the performance of the battery cells become more stringent. However, the storage performance of the battery cells is poor at present, and further improvement is still required. Disclosure of Invention The present application has been made in view of the above problems, and an object thereof is to provide a battery cell, a battery, and an electric device. The first aspect of the application provides a battery cell, which comprises a positive electrode plate, a negative electrode plate and a separation film, wherein the separation film is arranged between the positive electrode plate and the negative electrode plate, the separation film comprises a separation body and a polymer layer arranged on at least one surface of the separation body, the polymer layer comprises an aldehyde ketone polymer, the aldehyde ketone polymer is made into a sheet-shaped structure, the sheet-shaped structure is subjected to dynamic frequency scanning test at (T m +20) DEGC to obtain an elastic modulus G '-energy consumption modulus G' curve, the slope of the elastic modulus G '-energy consumption modulus G' curve is K, K < + > is more than or equal to 0.8, and T m ℃ represents the melting temperature of the aldehyde ketone polymer. When the polymer of the embodiment of the application meets the above range, the polymer can reduce the entanglement state of molecular chains, is favorable for the diffusion of electrolyte between molecular chains, can lock the electrolyte in the polymer and reduce the risk of the polymer being dissolved in the electrolyte, and improves the stability of the performance of the polymer, and the polymer and the electrolyte can construct a three-dimensional communicated interface between the isolating membrane and the pole piece, wherein the interface has a network structure, is favorable for improving the diffusion rate of active ions such as lithium ions from the electrolyte to the pole piece, improves the conductivity of the isolating membrane, reduces concentration polarization, enables the active ions to be quickly embedded into the pole piece and be uniformly deposited, and improves the storage performance of a battery monomer. In some embodiments, 0.8≤K≤100; alternatively, K is more than or equal to 0.8 and less than or equal to 10, and further alternatively, K is more than or equal to 0.8 and less than or equal to 1. In some embodiments, the aldehyde ketone polymer is added to the first solvent at 70 ℃ to form an aldehyde ketone polymer system, the aldehyde ketone polymer system is left at 70 ℃ for 8 hours, after being left at 25 ℃ for more than or equal to 24 hours, the aldehyde ketone polymer system is filtered by a 200 mesh screen to form a first substance, wherein the mass of the aldehyde ketone polymer is q and the unit of the aldehyde ketone polymer is g, the mass of the first substance is m and the unit of the first substance is g, the aldehyde ketone polymer and the first substance satisfy that m/q is less than or equal to 5 and less than or equal to 1000, alternatively, 5 and less than or equal to m/q is less than or equal to 20, further alternatively, 5 and less than or equal to m/q is less than or equal to 12. According to the embodiment of the application, the stretching of the polymer molecular chain can be realized within the safe working temperature range of the battery monomer by increasing the temperature, and the mutual attraction and physical combination of the polymer molecular chain and the electrolyte are promoted. The activity of the aldehyde ketone polymer molecular chain segment is reduced at normal temperature, the surface of the isolation body is kept to be attached, and the electrolyte is locked in the space environment where the polymer is positioned, so that a gel or gel-like state is formed, the transmission rate of active ions such as lithium ions can be improved, and the storage performance is improved. In some embodiments, the aldehyde ketone polymer has a glass transition temperature Tg in units of-100. Ltoreq.Tg≤55, alternatively, -100. Ltore