Electrode of lithium ion battery, and lithium ion battery

Abstract

The invention relates to an electrode of a lithium ion battery and the lithium ion battery. The electrode comprises a current collector and an active substance layer laminated on the surface of the current collector, wherein the active material layer contains an electrode active material and a first lithium salt, the content of the first lithium salt in the active material layer does not exceed 10wt%, and the active material layer has a concentration gradient in which the concentration of the first lithium salt decreases in a direction away from the current collector. According to the electrode and the lithium ion battery, the active material layer is arranged on the electrode current collector, the concentration of the first lithium salt in the active material layer is gradiently reducedalong the direction far away from the current collector; the lithium ion battery containing the electrode, especially a lithium ion power battery, can supplement lost lithium salt in time in the using process, and the conductivity of lithium ions in electrolyte is kept constant, so that the power attenuation of the lithium ion battery in the whole battery life cycle is reduced.

Description

technical field [0001] The present disclosure relates to the technical field of lithium-ion batteries, in particular, to an electrode of a lithium-ion battery and a lithium-ion battery. Background technique [0002] Lithium-ion power battery is a new type of high-energy battery successfully developed in the 20th century. The negative electrode of this battery is usually graphite, and the positive electrode is usually lithium iron phosphate, lithium cobaltate and lithium titanate. Lithium-ion power batteries have the advantages of high energy, high battery voltage, wide operating temperature range, and long storage life, and have been widely used in military and civilian small electrical appliances. For lithium-ion power batteries, good power retention is required. The power retention of the power battery directly affects the acceleration performance and charging capacity of the electric vehicle throughout the life cycle, so the power retention performance requirements of t...

AI Technical Summary

Problems solved by technology

Its disadvantages are as follows: Cathode aspect: particle size reduction or surface coating will deteriorate the specific capacity of the particle itself, while surface coating or size reduction will reduce the compaction density and further deteriorate the energy density of the cell. On the other hand, size reduction will The increase in the specific surface area will deteriorate the long-term storage performance of the battery; in terms of the anode: particle size reduction or surface functional group modification will deteriorate the specific capacity of the particle itself, while surface coating or size reduction will reduce the compaction density, surface functional groups Modification will reduce the initial efficiency of the material, increase the consumption of active lithium, and further deteriorate the energy density of the cell. On the other hand, the reduction in size will increase the specific surface area, which will deteriorate the long-term storage performance of the cell; Membrane stabilizer stabilizes the surface structure of the electrode, but increases the thickness of the surface solid electrolyte membrane to a certain extent, increases the membrane impedance, and deteriorates the initial power performance; increases the concentration of lithium salts to ensure the electrolyte conductivity throughout the life. , but the initial electrolyte viscosity increases, resulting in deterioration of initial power performance, especially low temperature performance

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