Electrolyte solution and electrochemical energy storage device

Abstract

The application provides an electrolyte solution and an electrochemical energy storage device. The electrolyte solution is prepared from an electrolyte salt and an additive, wherein the additive is prepared from a sulfonate cyclic quaternary ammonium salt and an isocyanate compound; in the isocyanate compound, the quantity of -N=C-O is larger than or equal to 2. Dense, uniform and stable passivation membranes can be formed on the surfaces of thea positive pole and thea negative pole of the electrochemical energy storage device under the coaction of the electrolyte salt and the additive. In particular, a low-impedance and dense solid electrolyte interfacial membrane can be formed on the surface of the negative pole, so that the electrolyte solution can be prevented from undergoing an oxidization-reduction reaction continously with the positive pole and the negative pole, the interface impedance of the positive pole and the negative pole is reduced, and the electrochemical energy storagedevice has higher high-temperature storage performance.

Description

technical field [0001] The present application relates to the field of energy storage devices, in particular to an electrolyte and an electrochemical energy storage device. Background technique [0002] With the depletion of fossil energy and the increasing pressure of environmental pollution, the automotive industry urgently needs a new type of energy to drive it. Lithium-ion batteries stand out due to their high energy density, no memory effect, and high operating voltage. It is currently becoming the preferred solution for the power supply of new energy vehicles. However, with the expansion of market demand for electronic products and the development of power and energy storage equipment, people's requirements for lithium-ion batteries continue to increase, and the development of lithium-ion batteries with high energy density and fast charging and discharging has become a top priority. At present, the effective methods are to increase the voltage and compaction density o...

AI Technical Summary

Problems solved by technology

[0003] At present, the electrolyte widely used in lithium-ion batteries usually uses lithium hexafluorophosphate as the electrolyte salt and a mixture of cyclic carbonate and chain carbonate as the organic solvent. However, there are many shortcomings in the above electrolyte, especially At high voltage, the high-temperature storage performance of lithium-ion batteries is poor, and lithium-ion batteries face the problem of rapid capacity decay after long-term cycling

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