Search

CN-122025795-A - Electrolyte and lithium ion battery containing same

CN122025795ACN 122025795 ACN122025795 ACN 122025795ACN-122025795-A

Abstract

The invention discloses an electrolyte and a lithium ion battery containing the same. The electrolyte comprises electrolyte lithium salt, an organic solvent, an auxiliary additive and a p-sulfonylmethyl isocyanide compound, wherein the structural formula of the p-sulfonylmethyl isocyanide compound is shown as a formula I, and R is at least one selected from hydrogen atoms, halogen, C 1‑20 alkyl, halogen substituted C 1‑20 alkyl, C 3‑20 cycloalkyl, C 2‑10 epoxy alkyl, C 2‑20 alkenyl, C 2‑20 alkynyl, C 3‑20 cycloalkenyl, C 6‑26 aryl and C 6‑26 heteroaryl. The electrolyte can form a stable SEI film on the surface of the electrode, and improves the cycling stability of the battery, so that the battery has excellent cycling performance.

Inventors

  • MA YUNXIANG
  • Bao Fujie
  • HU XIAOBING

Assignees

  • 合肥国轩高科动力能源有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. An electrolyte is characterized by comprising electrolyte lithium salt, an organic solvent, an auxiliary additive and a p-sulfonyl methyl isocyanide compound; The structural formula of the p-sulfonyl methyl isocyanide compound is shown as formula I: In the formula I, R is at least one selected from a hydrogen atom, halogen, C 1-20 alkyl, halogen substituted C 1-20 alkyl, C 3-20 cycloalkyl, C 2-10 epoxy alkyl, C 2-20 alkenyl, C 2-20 alkynyl, C 3-20 cycloalkenyl, C 6-26 aryl and C 6-26 heteroaryl.
  2. 2. The electrolyte according to claim 1, characterized in that it is made of components comprising the following mass percentages: 10-14% of electrolyte lithium salt; 1-5% of an auxiliary additive; 1-5% of p-sulfonyl methyl isocyanide compound; The balance being the organic solvent.
  3. 3. Electrolyte according to claim 1 or 2, characterized in that it is made of components comprising the following mass percentages: 10-14% of electrolyte lithium salt; 1-5% of an auxiliary additive; 3% of the p-sulfonyl methyl isocyanide compound; The balance being the organic solvent.
  4. 4. The electrolyte according to claim 1 or 2, wherein in formula I, R is selected from at least one of a hydrogen atom, a halogen, a C 1-10 alkyl group, a halogen substituted C 1-10 alkyl group, a C 3-20 cycloalkyl group, a C 3-5 alkylene oxide group, a C 2-10 alkenyl group, a C 2-10 alkynyl group, a C 3-10 cycloalkenyl group, a C 6-16 aryl group, and a C 6-16 heteroaryl group.
  5. 5. The electrolyte according to claim 1 or 2, wherein the p-sulfonylmethyl isocyanate compound is selected from at least one of the structural formulas shown below: 。
  6. 6. The electrolyte according to claim 1 or 2, wherein the electrolyte lithium salt is selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (oxalato) borate, lithium difluoro (oxalato) borate, lithium bis (fluorosulfonyl) imide, and lithium bis (trifluoromethanesulfonyl) imide.
  7. 7. The electrolyte according to claim 1 or 2, wherein the organic solvent is at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, methylethyl carbonate, propylmethyl carbonate, ethylene carbonate and propylene carbonate.
  8. 8. The electrolyte according to claim 1 or 2, wherein the auxiliary additive is at least one selected from the group consisting of vinylene carbonate, fluoroethylene carbonate, fluoropropylene carbonate, ethylene sulfite, 1, 3-propane sultone, 1, 4-butane sultone, propylene sulfate, ethylene carbonate.
  9. 9. A lithium ion battery comprising a positive plate, a negative plate, a separator and the electrolyte of any one of claims 1-8.
  10. 10. The lithium ion battery of claim 9, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer composited on the positive electrode current collector, the positive electrode active material layer comprising a positive electrode active material selected from at least one of lithium manganate, lithium cobaltate, lithium nickel cobalt manganate, and lithium iron phosphate; The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer compounded on the negative electrode current collector, wherein the negative electrode active material layer comprises a negative electrode active material, and the negative electrode active material is at least one of carbon-containing materials, titanium oxides, silicon, lithium and lithium alloys; the diaphragm is made of at least one of polyethylene, polypropylene and polyvinylidene fluoride.

Description

Electrolyte and lithium ion battery containing same Technical Field The invention belongs to the technical field of lithium ion batteries, and particularly relates to an electrolyte and a lithium ion battery containing the same. Background The lithium ion battery has the advantages of high voltage, no memory effect, high capacity, long service life and the like, is an ideal chemical power supply, and is widely applied to the fields of consumer electronic products, power batteries and energy storage. Along with the fire explosion of the new energy automobile market, the power battery market also receives attention from the highlight moment, and the cycle performance which is one of the key performances of the battery cell is certainly focused. The factors influencing the cycle life of the lithium ion battery are various, positive and negative electrode main materials, a conductive agent, a binder and the like can influence the cycle performance of the battery to a certain extent, and the lithium ion battery electrolyte is taken as one of important components of the lithium ion battery, besides playing an ion transmission role in the battery, different electrolyte additives have decisive influence on the composition and the performance of an SEI film, and further influence the cycle stability of the battery, namely influence the cycle performance of an electric core, so that the cycle performance of the battery is also influenced by the proper lithium ion battery electrolyte. Disclosure of Invention The invention aims to provide an electrolyte and a lithium ion battery containing the same. The electrolyte can form a stable SEI film on the surface of the electrode, and improves the cycling stability of the battery, so that the battery has excellent cycling performance. The invention provides an electrolyte, which comprises electrolyte lithium salt, an organic solvent, an auxiliary additive and a p-sulfonyl methyl isocyanide compound; The structural formula of the p-sulfonyl methyl isocyanide compound is shown as formula I: In the formula I, R is at least one selected from a hydrogen atom, halogen, C 1-20 alkyl, halogen substituted C 1-20 alkyl, C 3-20 cycloalkyl, C 3-10 epoxy alkyl, C 2-20 alkenyl, C 2-20 alkynyl, C 3-20 cycloalkenyl, C 6-26 aryl and C 6-26 heteroaryl. In the electrolyte, the electrolyte is prepared from the following components in percentage by mass: 10-14% of electrolyte lithium salt; 1-5% of an auxiliary additive; 1-5% of p-sulfonyl methyl isocyanide compound; The balance being the organic solvent. In the electrolyte, the electrolyte is prepared from the following components in percentage by mass: 10-14% of electrolyte lithium salt; 1-5% of an auxiliary additive; 3% of the p-sulfonyl methyl isocyanide compound; The balance being the organic solvent. In the invention, the electrolyte is prepared from the following components in percentage by mass: 14% of electrolyte lithium salt; Auxiliary additive 1%; 3% of the p-sulfonyl methyl isocyanide compound; The balance being the organic solvent. In the above electrolyte, in the formula I, R is at least one selected from a hydrogen atom, halogen, C 1-10 alkyl, halogen substituted C 1-10 alkyl, C 3-20 cycloalkyl, C 3-5 alkylene oxide, C 2-10 alkenyl, C 2-10 alkynyl, C 3-10 cycloalkenyl, C 6-16 aryl and C 6-16 heteroaryl. In the above electrolyte, the p-sulfonylmethyl isocyanate compound is at least one selected from the following structural formulas: 。 in the above electrolyte, the electrolyte lithium salt is at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bisoxalato borate, lithium difluorooxalato borate, lithium bisfluorosulfonyl imide and lithium bistrifluoromethane sulfonyl imide. In the above electrolyte, the organic solvent is at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, methylethyl carbonate, propylmethyl carbonate, ethylene carbonate and propylene carbonate. In the above electrolyte, the auxiliary additive is at least one selected from vinylene carbonate, fluoroethylene carbonate, fluoropropylene carbonate, vinylene sulfite, 1, 3-propane sultone, 1, 4-butane sultone, propylene sulfate and ethylene carbonate. The invention also provides a lithium ion battery, which comprises a positive plate, a negative plate, a diaphragm and the electrolyte as claimed in any one of claims 1 to 8. In the lithium ion battery, the positive plate comprises a positive current collector and a positive active material layer compounded on the positive current collector, wherein the positive active material layer comprises a positive active material, and the positive active material is at least one of lithium manganate, lithium cobaltate, lithium nickel cobalt manganate and lithium iron phosphate; The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer compounded on the negative electrode c