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CN-122000555-A - Battery monomer, battery device and power utilization device

CN122000555ACN 122000555 ACN122000555 ACN 122000555ACN-122000555-A

Abstract

The application relates to a battery monomer, a battery device and an electric device, wherein the battery monomer comprises a positive electrode plate, a separator and a negative electrode plate, at least one of the positive electrode plate, the separator and the negative electrode plate contains an additive, the additive is an organic micromolecule, an organic polymer or an organic salt with a functional group A, the functional group A comprises at least two chelating groups, and each chelating group is independently selected from a phosphate group or a phosphate group. The battery monomer plays a role of chelating transition metal ions by applying the additive, reduces negative effects caused by dissolution of transition metal, and is beneficial to improving the capacity retention rate of the battery under the conditions of circulation and storage.

Inventors

  • ZHENG SHIBING
  • JIN CHAO
  • Yan Guanfusheng

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (20)

  1. 1. The battery cell is characterized by comprising a positive electrode plate, a separator and a negative electrode plate; At least one of the positive electrode plate, the separator and the negative electrode plate contains an additive; the additive is small organic molecules with functional groups A, organic polymers or organic salts; the functional group a comprises at least two chelating groups, each chelating group being independently selected from a phosphate group or a phosphate group.
  2. 2. The battery cell of claim 1, wherein the number of functional groups a in the additive is at least two.
  3. 3. The battery cell of claim 1 or 2, wherein each chelating group in the functional group a is coupled to the same atom X, either directly or through an alkylene group, X being selected from one of O, N, S.
  4. 4. The battery cell of any one of claims 1-3, wherein the phosphate group comprises at least one of a lithium phosphate group, a sodium phosphate group, a potassium phosphate group, an ammonium phosphate group, and a zinc phosphate group.
  5. 5. The battery cell of any one of claims 1-4, wherein the functional group a is-X- ((CH 2 ) n -PO 3 M1 a H b ) c ), wherein X is selected from one of O, N, S, n is an integer from 0 to 2, M1 is selected from one of cations Li + 、Na + 、K + 、NH 4 + 、Zn 2+ having a valence of M, (a X M) +b=2, c=2, or 3.
  6. 6. The battery cell of any one of claims 1-5, wherein the additive comprises at least one of hydroxyethylidene diphosphate or a salt thereof, aminotrimethylene phosphate or a salt thereof, ethylenediamine tetramethylene phosphonic acid or a salt thereof, hexamethylenediamine tetramethylene phosphonic acid or a salt thereof, bis 1, 6-hexylene triamine pentamethylene phosphonic acid or a salt thereof, lithium p-phenolate-2 ethyl diphosphate.
  7. 7. The battery cell according to any one of claims 1 to 6, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer disposed on at least one surface of the positive electrode current collector, the positive electrode material layer comprising a positive electrode active material; the positive electrode active material comprises at least one of compounds shown in a formula (I) and a formula (II); li 1+d [Ni x Co y Mn z M2 e ]O 2 type (I) Wherein x <1,0< y <0.3,0< z <0.3, -0.1< d <0.2,0< e <0.2, x+y+z+e=1, m2 comprises one or more than two of Mg, ca, sb, ce, ti, zr, sr, al, zn, mo, Y, W, ta, F and B; (LiMn p Fe 1-p-q M3 q PO 4 ) formula (II) Wherein, the p is more than or equal to 0.1 and less than or equal to 0.9, and 0 is more than or equal to 0 q is less than or equal to 0.05, M3 comprises V, ti, mg, ni, fe, sn, F, one or two or more kinds of the above-mentioned materials.
  8. 8. The battery cell according to any one of claims 1 to 7, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer provided on at least one surface of the positive electrode current collector, the positive electrode material layer contains a positive electrode active material and the additive, the mass ratio of the additive in the positive electrode material layer is 0.2% -1.0%, and/or, The negative electrode plate comprises a negative electrode current collector and a negative electrode material layer arranged on at least one surface of the negative electrode current collector, wherein the negative electrode material layer comprises a negative electrode active material and an additive, the mass ratio of the additive in the negative electrode material layer is 0.2% -1.0%, and/or, The separator comprises a base film and a film layer arranged on at least one surface of the base film, wherein the film layer contains the additive, and the mass ratio of the additive in the film layer is 0.05% -0.2%.
  9. 9. The positive electrode plate is characterized by comprising a positive electrode current collector and a positive electrode material layer arranged on at least one surface of the positive electrode current collector, wherein the positive electrode material layer comprises a positive electrode active material and an additive; the additive is small organic molecules with functional groups A, organic polymers or organic salts; the functional group a comprises at least two chelating groups, each chelating group being independently selected from a phosphate group or a phosphate group.
  10. 10. The positive electrode sheet according to claim 9, wherein the mass ratio of the additive in the positive electrode material layer is 0.2% -1.0%.
  11. 11. The positive electrode sheet according to claim 9 or 10, wherein the number of the functional groups a in the additive is at least two.
  12. 12. The positive electrode sheet according to any one of claims 9 to 11, wherein each chelating group in the functional group a is coupled to the same atom X directly or through an alkylene group, X being selected from one of O, N, S.
  13. 13. The positive electrode sheet of any one of claims 9 to 12, wherein the phosphate group comprises at least one of a lithium phosphate group, a sodium phosphate group, a potassium phosphate group, an ammonium phosphate group, and a zinc phosphate group.
  14. 14. The positive electrode sheet of any one of claims 9-13, wherein the functional group a is-X- ((CH 2 ) n -PO 3 M1 a H b ) c ), wherein X is selected from one of O, N, S, n is an integer from 0 to 2, M1 is selected from one of cations Li + 、Na + 、K + 、NH 4 + 、Zn 2+ having a valence of M, (a X M) +b=2, c=2 or 3.
  15. 15. The positive electrode sheet of any one of claims 9 to 14, wherein the additive comprises at least one of hydroxyethylidene diphosphate or a salt thereof, aminotrimethylene phosphate or a salt thereof, ethylenediamine tetramethylene phosphonic acid or a salt thereof, hexamethylenediamine tetramethylene phosphonic acid or a salt thereof, bis 1, 6-hexylene triamine pentamethylene phosphonic acid or a salt thereof, lithium p-phenolate-2 ethyl lithium diphosphate.
  16. 16. The positive electrode sheet according to any one of claims 9 to 15, wherein the positive electrode active material comprises at least one of compounds represented by formula (I) and formula (II); li 1+d [Ni x Co y Mn z M2 e ]O 2 type (I) Wherein x <1,0< y <0.3,0< z <0.3, -0.1< d <0.2,0< e <0.2, x+y+z+e=1, m2 comprises one or more than two of Mg, ca, sb, ce, ti, zr, sr, al, zn, mo, Y, W, ta, F and B; (LiMn p Fe 1-p-q M3 q PO 4 ) formula (II) Wherein, the p is more than or equal to 0.1 and less than or equal to 0.9, and 0 is more than or equal to 0 q is less than or equal to 0.05, M3 comprises V, ti, mg, ni, fe, sn, F, one or two or more kinds of the above-mentioned materials.
  17. 17. A preparation method of a positive electrode plate is characterized by comprising the following steps of, Providing a positive electrode current collector; Providing a positive electrode material layer on at least one surface of the positive electrode current collector, wherein the positive electrode material layer comprises a positive electrode active material and an additive; the additive is small organic molecules with functional groups A, organic polymers or organic salts; the functional group a comprises at least two chelating groups, each chelating group being independently selected from a phosphate group or a phosphate group.
  18. 18. The negative electrode plate is characterized by comprising a negative electrode current collector and a negative electrode material layer arranged on at least one surface of the negative electrode current collector, wherein the negative electrode material layer comprises a negative electrode active material and an additive; the additive is small organic molecules with functional groups A, organic polymers or organic salts; the functional group a comprises at least two chelating groups, each chelating group being independently selected from a phosphate group or a phosphate group.
  19. 19. The negative electrode sheet of claim 18, wherein the mass ratio of the additive in the negative electrode material layer is 0.2% -1.0%.
  20. 20. The negative electrode sheet of claim 18 or 19, wherein the number of functional groups a in the additive is at least two.

Description

Battery monomer, battery device and power utilization device Technical Field The application relates to the technical field of batteries, in particular to a battery cell, a battery device and an electricity utilization device. Background Secondary batteries represented by lithium ion batteries are widely used in various fields such as energy storage power systems of hydraulic power, thermal power, wind power, solar power stations and the like, electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and the like. In the application process of the secondary battery, higher demands are also put on the performance thereof. When the secondary battery uses the positive electrode active material containing the transition metal oxide, the transition metal easily shuttles to the negative electrode during charge and discharge, and reduction occurs on the surface of the negative electrode, which in turn may cause adverse reactions such as breaking and reconstruction of the SEI film, and further deteriorate the battery performance. Disclosure of Invention The application aims to provide a battery monomer, a battery device and an electricity utilization device, wherein the battery monomer plays a role of chelating transition metal ions by applying an additive, reduces negative effects caused by dissolution of transition metal, and is beneficial to improving the capacity retention rate of a battery under the conditions of circulation and storage. To this end, a first aspect of the present application provides a battery cell including a positive electrode tab, a separator, and a negative electrode tab; At least one of the positive electrode plate, the separator and the negative electrode plate contains an additive; the additive is small organic molecules with functional groups A, organic polymers or organic salts; the functional group a comprises at least two chelating groups, each chelating group being independently selected from a phosphate group or a phosphate group. The above additive contains a functional group comprising at least two phosphate groups or phosphate groups, wherein p=o can be chelated with transition metal ions, which has the advantage of better thermal stability and oxidation resistance than other elements used for chelating transition metals (e.g. nitrogen). Therefore, by applying the additive to at least one of the positive electrode plate, the separator and the negative electrode plate of the battery cell, transition metal ions can be obviously and effectively chelated, so that adverse reactions caused by shuttling of the transition metal ions can be eliminated or reduced, and the function of optimizing the capacity retention rate of the battery under the conditions of circulation and storage can be achieved. In some embodiments, the number of functional groups a in the additive is at least two. When the additive contains at least two functional groups A, a chelating structure with more teeth can be formed aiming at transition metal ions, so that the chelating stability is improved, and the adverse effect caused by the transition metal ions is better eliminated. In some embodiments, each chelating group is coupled to the same atom X, either directly or through an alkylene group, X being selected from one of O, N, S. When the functional group A has the characteristics, the X element can also participate in chelation, so that the chelation stability is improved. In particular, X is matched with a chelating group, and can form a hexadentate chelating structure with transition metal ions, and compared with a tetradentate chelating structure formed when a nitrogen element is singly used for chelating the transition metal element, the hexadentate chelating structure has better stability. In some embodiments, the phosphate groups include at least one of the group consisting of lithium phosphate groups, sodium phosphate groups, potassium phosphate groups, ammonium phosphate groups, zinc phosphate groups. The phosphate group has a structure of p=o metal cation (e.g., p=o-Li +, etc.), which is advantageous in enhancing ion transport ability, thereby reducing charge transfer resistance, and giving a battery cell more excellent rate performance. In some embodiments, the functional group a is-X- ((CH 2)n-PO3M1aHb)c) wherein X is selected from one of O, N, S, n is an integer from 0 to 2, and M1 is selected from one of cations Li +、Na+、K+、NH4+、Zn2+ having a valence of M, (a X M) +b=2, c=2 or 3. When the functional group has the chemical formula, the whole structure is more reasonable (including the length of alkylene, the type of X element, the type of cation and the like), which is beneficial to improving the stability of chelating transition metal ions and further improving the capacity retention rate of the battery under the conditions of circulation and storage. In some embodiments, the additive comprises at least one of hydroxyethylidene diphosphate (HEDP) or