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CN-122000418-A - Battery cell, electrolyte, battery device and electricity utilization device

CN122000418ACN 122000418 ACN122000418 ACN 122000418ACN-122000418-A

Abstract

The application provides a battery cell, an electrolyte, a battery device and an electric device. The battery cell comprises an electrolyte, wherein the electrolyte comprises electrolyte salt, an organic solvent and a thioester additive, the mass content of the thioester additive in the electrolyte is 0.001-10%, and the thioester additive comprises a structure shown in any one or more of the formulas (1) to (6): Wherein R1 and R2 each independently comprise a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which is unsubstituted or substituted with a hetero atom, n, m are each integers, n is 1 to 4, and m is 0 to 4. The electrolyte provided by the application can participate in the formation of a solid electrolyte membrane, so that the dynamic performance of the battery monomer is improved, and the battery device and the power utilization device comprising the battery monomer have at least the beneficial effects.

Inventors

  • CHEN HUI
  • Guo Suogang
  • FU CHENGHUA
  • YE YONGHUANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241105

Claims (14)

  1. 1. The battery cell is characterized by comprising an electrolyte, wherein the electrolyte comprises electrolyte salt, an organic solvent and a thioester additive, the mass content of the thioester additive in the electrolyte is 0.001-10%, and the thioester additive comprises a structure shown in any one or more of a formula (1) to a formula (6): Wherein R1 and R2 each independently comprise a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which is unsubstituted or substituted with a hetero atom, n, m are each integers, n is 1 to 4, and m is 0 to 4.
  2. 2. The battery cell according to claim 1, wherein R1 and R2 in the structural formulae represented by the formula (1) and/or the formula (2) each independently include a hydrogen atom and an alkyl group having 1 to 4 carbon atoms.
  3. 3. The battery cell of claim 1 or 2, wherein the thioester additive comprises a structure represented by any one or more of formulas (I-1) to (I-26) 。
  4. 4. The battery cell according to any one of claims 1 to 3, wherein the mass content of the thioester additive in the electrolyte is 0.5% to 2%.
  5. 5. The battery cell of any one of claims 1-4, wherein the electrolyte satisfies one or more of the following conditions: 1) The concentration of the electrolyte salt in the electrolyte is 0.5mol/L to 3mol/L; 2) 60% to 95% of the mass content of the organic solvent in the electrolyte; 3) The mass ratio of the thioester additive to the organic solvent is 1 (5-1000).
  6. 6. The battery cell of any one of claims 1-4, wherein the electrolyte satisfies one or more of the following conditions: 1) The concentration of the electrolyte salt in the electrolyte is 0.8mol/L to 1.2mol/L; 2) 80% to 88% of the mass content of the organic solvent in the electrolyte; 3) The mass ratio of the thioester additive to the organic solvent is 1 (7.8-881).
  7. 7. The battery cell of any one of claims 1-6, wherein the electrolyte satisfies one or more of the following conditions: 1) The electrolyte salt comprises a lithium salt, which is one or more of lithium bis (fluorosulfonyl) imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium (trifluoromethylsulfonyl) imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorobis (oxalato) phosphate, lithium bis (oxalato) borate, lithium difluorooxalato borate, lithium tetrafluorooxalato phosphate, lithium difluorodioxaato phosphate and lithium tetrafluorooxalato phosphate; 2) The organic solvent comprises one or more of carbonic ester, carboxylic ester and ethers.
  8. 8. The battery cell of any one of claims 1-7, wherein the electrolyte is an electrolyte that satisfies one or more of the following conditions: 1) The conductivity of the electrolyte is 10 to 40mS cm -1 ; 2) The viscosity of the electrolyte is 1 to 20 mPas.
  9. 9. The battery cell of any one of claims 1-8, wherein the electrolyte is an electrolyte that satisfies one or more of the following conditions: 1) The conductivity of the electrolyte is 12 to 20mS cm -1 ; 2) The viscosity of the electrolyte is 1.5 to 3 mPas.
  10. 10. The battery cell of any one of claims 1-9, wherein the battery comprises a negative electrode tab comprising a negative electrode active material comprising one or more of silicon carbon, silicon oxygen, natural graphite, artificial graphite, lithium titanate, amorphous carbon, hard carbon, lithium metal, sodium metal, and lithium alloy.
  11. 11. The battery cell of any one of claims 1-10, wherein the battery cell comprises a positive electrode sheet comprising a positive electrode active material comprising one or more of lithium cobaltate, lithium manganate, lithium nickel cobalt aluminate, lithium iron phosphate, lithium iron manganese phosphate, sodium iron phosphate, and sodium iron pyrophosphate.
  12. 12. An electrolyte for a battery cell, characterized in that the electrolyte comprises an electrolyte salt, an organic solvent, and a thioester additive comprising a structure represented by any one or more of formulas (1) to (6): Wherein R1 and R2 each independently comprise a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which is unsubstituted or substituted with a hetero atom, n, m are each integers, n is 1 to 4, and m is 0 to 4.
  13. 13. A battery device comprising the battery cell according to any one of claims 1 to 11 or a battery cell produced by the electrolyte according to claim 12.
  14. 14. An electrical device comprising the battery device of claim 13.

Description

Battery cell, electrolyte, battery device and electricity utilization device Technical Field The application belongs to the technical field of battery monomers, and particularly relates to a battery monomer, electrolyte, a battery device and an electricity utilization device. Background In recent years, battery cells have been widely used in energy storage power systems such as hydraulic power, thermal power, wind power and solar power stations, and in various fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, and the like. With the application and popularization of the battery cells, the comprehensive performance of the battery cells is paid more attention to, for example, the battery cells need to meet the requirements of high reliability, strong charging performance and the like. The electrolyte in the battery cell may act to transfer active ions, which is one of the key factors affecting the performance of the battery cell. Therefore, it is desirable to provide a battery cell with good overall performance. Disclosure of Invention The application provides a battery monomer which has better dynamic performance, the electrolyte can participate in the formation of a solid electrolyte membrane, the dynamic performance of the battery monomer is improved, and a battery device and an electricity utilization device comprising the battery monomer have at least the beneficial effects. In a first aspect, embodiments of the present application provide a battery cell comprising an electrolyte, the electrolyte comprising an electrolyte salt, an organic solvent, and a thioester additive, the thioester additive comprising a structure represented by any one or more of formulas (1) to (6): Wherein R1 and R2 each independently comprise a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which is unsubstituted or substituted with a hetero atom, n, m are each integers, n is 1 to 4, and m is 0 to 4. In the embodiment of the application, the thioester additive is dispersed in the electrolyte containing electrolyte salt and organic solvent, and can participate in the formation of a solid electrolyte membrane (SEI film), namely, the thioester additive is reduced into a sulfur-containing electrolyte salt component to be introduced into SEI, so that the dynamic performance of the battery monomer is improved. The analysis is that the binding energy delta E (for example S-Li) of the sulfur element and the active ion is lower than the binding energy delta E of the active ion and the oxygen element, so that the binding energy of the element and the active ion in SEI is reduced, the transmission energy barrier of the active ion in SEI film is also reduced, the active ion is transmitted in SEI more easily, and the charging impedance Rct is reduced. In some alternative embodiments, the mass content of the thioester additive in the electrolyte is 0.001% to 10%, alternatively 0.5% to 2%. The mass content of the thioester additive in the electrolyte is in the range, so that the transmission energy barrier of active ions in the SEI film is further reduced, and the dynamic performance of the battery monomer is improved. In some alternative embodiments, R1 and R2 each independently comprise a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Compared with other groups substituted by hetero atoms, the R1 and R2 adopt the groups, so that side reactions such as corrosion to the battery monomer are reduced, the probability that the thioester additive releases toxic gas under extreme conditions such as overheat or overcharge of the battery monomer is reduced, and the reliability and the cycle life of the battery monomer are improved. In addition, R1 and R2 adopt the groups of the types, are easier to degrade in natural environment and have lower damage to the environment. In some alternative embodiments, the thioester additive comprises a structure represented by any one or more of formulas (I-1) to (I-26): in the embodiment of the application, the thioester additive of the type can participate in the formation of an SEI film, and the dynamic performance of a battery monomer is improved. The analysis is because the transmission energy barrier of the active ions in the SEI film is lowered, so that the active ions are more easily transmitted in the SEI. In some alternative embodiments, the concentration of electrolyte salt in the electrolyte is 0.5mol/L to 3mol/L, alternatively 0.8mol/L to 1.2mol/L. The mass content of the electrolyte salt in the range can optimize the interface characteristic of the electrode and the electrolyte, enhance the interface stability of the battery and prolong the service life of the battery monomer. In some alternative embodiments, the mass content of the organic solvent in the electrolyte is 60% to 95%, alternatively 80% to 88%. Therefore, the viscosity of the electrolyte and the ionic conductivity can be further controlled, thereby