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CN-122000553-A - Battery monomer, battery device and power utilization device

CN122000553ACN 122000553 ACN122000553 ACN 122000553ACN-122000553-A

Abstract

The application relates to a battery cell, a battery device and an electric device, wherein the battery cell comprises a positive electrode plate, a separator, an electrolyte and a negative electrode plate, at least one of the positive electrode plate, the separator, the electrolyte and the negative electrode plate contains an additive, the additive is selected from organic micromolecules, organic polymers or organic salts with S=C (R) -S functional groups, wherein R is hydrogen, substituted or unsubstituted straight-chain or branched-chain alkyl, alkoxyalkyl, aryl, heteroaryl and cycloalkyl, or R and a sulfur atom in a carbon-sulfur single bond form a substituted or unsubstituted saturated or unsaturated cycloalkyl. By applying the additive, the effect of chelating transition metal ions is achieved, the negative effect caused by dissolution of transition metal is reduced, and the capacity retention rate of the battery under the conditions of circulation and storage is improved.

Inventors

  • ZHENG SHIBING
  • JIN CHAO
  • DAI ZHIPENG
  • ZHANG XIN

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (14)

  1. 1. The battery cell is characterized by comprising a positive electrode plate, a separator, electrolyte and a negative electrode plate; At least one of the positive electrode plate, the separator, the electrolyte and the negative electrode plate contains an additive, wherein the additive is selected from small organic molecules, organic polymers or organic salts with S=C (R) -S functional groups; wherein R is hydrogen, substituted or unsubstituted straight-chain or branched-chain alkyl, alkoxy, alkyl, aryl, heteroaryl, cycloalkyl or R and a sulfur atom in a carbon-sulfur single bond form a substituted or unsubstituted saturated or unsaturated cycloalkyl.
  2. 2. The battery cell of claim 1, wherein the additive comprises a small organic molecule having S = C (R) -S functionality; Wherein, R is hydrogen, substituted or unsubstituted straight or branched (C 1 -C 6 ) alkyl, (C 1 -C 6 ) alkoxyalkyl, aryl, heteroaryl, (C 3 -C 6 ) cycloalkyl; Or R together with the sulfur atom in the carbon-sulfur single bond forms a substituted or unsubstituted saturated or unsaturated (C 3 -C 6 ) cycloalkyl group.
  3. 3. The battery cell of claim 1, wherein the additive comprises an organic polymer having S = C (R) -S functional groups; The organic polymer takes polyacrylic acid as a main chain, and/or the weight average molecular weight of the organic polymer is 5000-100000.
  4. 4. The battery cell of claim 1, wherein the additive comprises an organic salt having S = C (R) -S functionality; the organic salt comprises a metal cation M selected from lithium ion, sodium ion, potassium ion, zinc ion, ammonium ion, and/or, The R is hydrogen, substituted or unsubstituted straight or branched (C 1 -C 6 ) alkyl, (C 1 -C 6 ) alkoxyalkyl, aryl, heteroaryl, (C 3 -C 6 ) cycloalkyl; Or R together with the sulfur atom in the carbon-sulfur single bond forms a substituted or unsubstituted saturated or unsaturated (C 3 -C 6 ) cycloalkyl group.
  5. 5. The battery cell of any one of claims 1-4, wherein the substitution is substitution of hydrogen or carbon in R with at least one of nitrogen, oxygen, or sulfur.
  6. 6. The battery cell of any one of claims 1-5, wherein the additive is selected from at least one of the group consisting of: Wherein M is a metal cation.
  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 arranged 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, and the additive accounts for 0.3-1% of the positive electrode material layer by mass.
  8. 8. The battery cell according to claim 7, wherein the additive has a particle size Dv50 of less than or equal to the particle size Dv50 of the positive electrode active material.
  9. 9. The battery cell of claim 7 or 8, wherein the positive electrode active material comprises a high nickel positive electrode material and/or a lithium manganese iron phosphate positive electrode material; The chemical formula of the high-nickel positive electrode material is Li 1+a [Ni x Co y Mn z M1 b ]O 2 , wherein, x <1,0< y <0.3,0< z <0.3,0< a <0.2,0< B <0.2, x+y+z+b=0.6 1, M1 is one or more than two of Mg, ca, sb, ce, ti, zr, sr, al, zn, mo and B; The chemical formula of the lithium iron manganese phosphate positive electrode material is (LiMn p Fe 1-p-q M2 q PO 4 ), wherein p is more than or equal to 0.1 and less than or equal to 0.9, q is more than or equal to 0.05, and M2 is one or more than two of V, ti, mg, ni, fe.
  10. 10. The battery cell according to any one of claims 1 to 9, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer arranged on at least one surface of the negative electrode current collector, the negative electrode material layer contains the additive, and the additive accounts for 0.2% -1.0% of the negative electrode material layer by mass.
  11. 11. The battery cell according to any one of claims 1 to 10, wherein the separator comprises a base film and a film layer disposed on at least one surface of the base film, the film layer contains the additive, and the ratio of the additive to the film layer is 2 to 5mg/50 x 100mm 2 .
  12. 12. The battery cell according to any one of claims 1 to 11, wherein the electrolyte comprises the additive in an amount of 0.5 to 5% by mass of the electrolyte.
  13. 13. A battery device comprising the battery cell according to any one of claims 1 to 12.
  14. 14. An electrical device comprising the battery cell of any one of claims 1 to 12 or the battery device of claim 13.

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 electric device, wherein the battery monomer plays a role of chelating transition metal ions by applying an additive with S=C (R) -S functional groups, 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, the application provides a battery cell comprising a positive electrode sheet, a separator, an electrolyte, and a negative electrode sheet; At least one of the positive electrode plate, the separator, the electrolyte and the negative electrode plate contains an additive, wherein the additive is selected from small organic molecules, organic polymers or organic salts with S=C (R) -S functional groups; Wherein R is hydrogen, substituted or unsubstituted straight-chain or branched-chain alkyl, alkoxyalkyl, aryl, heteroaryl, cycloalkyl, or R and sulfur atoms in the carbon-sulfur single bond form a substituted or unsubstituted saturated or unsaturated cycloalkyl. Sulfur has a larger charge radius, is more capable of adsorbing transition metals, and has better oxidation resistance than other elements used to sequester transition metals (e.g., nitrogen). In an embodiment of the present application, an additive having a s=c (R) -S functional group is used, in which the same carbon has both a carbon-sulfur double bond and a carbon-sulfur single bond, whereby the functional group can form a 4-coordinated disulfide chelate structure with a transition metal ion. Therefore, by applying the additive to at least one of the positive electrode plate, the separator, the electrolyte 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 is achieved. In some embodiments, the additive is a small organic molecule having s=c (R) -S functionality; Wherein, R is hydrogen, substituted or unsubstituted straight or branched (C 1-C6) alkyl, (C 1-C6) alkoxyalkyl, aryl, heteroaryl, (C 3-C6) cycloalkyl; Or R together with the sulfur atom in the carbon-sulfur single bond forms a substituted or unsubstituted saturated or unsaturated (C 3-C6) cycloalkyl group. In some embodiments, the additive is an organic polymer having s=c (R) -S functional groups; The organic polymer takes polyacrylic acid as a main chain, and/or the weight average molecular weight of the organic polymer is 5000-100000. In some embodiments, the additive is an organic salt having s=c (R) -S functionality; the organic salt comprises a metal cation M selected from lithium ion, sodium ion, potassium ion, zinc ion, and/or, The R is hydrogen, substituted or unsubstituted straight or branched (C 1-C6) alkyl, (C 1-C6) alkoxyalkyl, aryl, heteroaryl, (C 3-C6) cycloalkyl; Or R together with the sulfur atom in the carbon-sulfur single bond forms a substituted or unsubstituted saturated or unsaturated (C 3-C6) cycloalkyl group. When the organic micromolecule, the organic polymer or the organic salt is adopted as the additive, the system of the battery is matched, and the chelation effect on the transition metal is improved under the condition of not negatively affecting the function of the battery. In some embodiments, the substitution refers to substitution of hydrogen or carbon in R with at least one of nitrogen, oxygen, or sulfur. When the additive also contains nitrogen, oxygen atoms or additional sulfur atoms, the additive is favorable for increasing the sites with complexation on transition metal, more effectively chelating transition metal ions and reducing adverse interface reactio