Electrolyte and electrochemical device comprising same

Abstract

The present application relates to an electrolyte and an electrochemical device comprising the same, the electrolyte comprising lithium bis (fluorosulfonyl) imide and lithium hexafluorophosphate, the weight percentage content of the lithium bis (fluorosulfonyl) imide being a% and the weight percentage content of the lithium hexafluorophosphate being b% based on the total weight of the electrolyte, with 12 < a + b < 20, and 0.2 < a / b < 1.5. The electrochemical device adopting the electrolyte provided by the invention can realize high energy density, and also can consider rate capability at normal temperature and low temperature and cycling stability at normal temperature and high temperature.

Description

technical field [0001] The present application relates to the technical field of energy storage, in particular to an electrolyte and an electrochemical device containing the electrolyte. Background technique [0002] With the popularization and application of smart products, people's demand for electronic products such as mobile phones, laptops, and cameras is increasing year by year, and electrochemical devices, as power sources for electronic products, play an increasingly important role in our daily life. Among them, lithium-ion batteries are widely used in the field of consumer electronics due to their advantages such as large specific energy, high working voltage, low self-discharge rate, small size, light weight, long life, and no memory effect. [0003] However, with the wide application of electrochemical devices in the above fields, people have higher and higher requirements for the energy density of electrochemical devices, which forces the design and development o...

AI Technical Summary

Problems solved by technology

For example, regarding the positive electrode material of electrochemical devices, increasing the content of Ni element in the transition metal oxide positive electrode material of lithium to form a high-nickel material can well improve the gram capacity of the positive electrode material; however, after the high nickelization of the positive electrode material , the kinetic properties of the material will decrease, and the residual alkali on the surface of the material will increase, which will easily produce gas (especially in high temperature environment)

For another example, increasing the compaction density of the active material layer in the positive and negative electrodes can improve the volumetric energy density of the electrochemical device; however, this will lead to smaller pores in the electrode and lower electrolyte retention. , resulting in the deterioration of the kinetic performance of the electrochemical device

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