Surface-coating type lithium nickel manganese oxide material, lithium battery and preparation method thereof

Abstract

The invention discloses a surface-coating type lithium nickel manganese oxide material, a lithium battery and a preparation method thereof. The surface-coating type lithium nickel manganese oxide material is characterized in that the surface of LiNi0.5Mn1.5O4 is coated with LiM0.5Mn1.5O4 with spinel structure, wherein M is positive bivalent metal ion. The surface-coating type lithium nickel manganese oxide material is characterized in that the particle size is small and uniform, and the electro-chemical property of LiNi0.5Mn1.5O4 is favorably improved; the surface of the prepared material is coated with LiM0.5Mn1.5O4 with electro-chemical inactivity, so that the good lithium ion transfer rate and good structure stability of LiNi0.5Mn1.5O4 are guaranteed in the charging and discharging process, and the side reaction of LiNi0.5Mn1.5O4 and electrolyte is inhibited. The preparation method has the advantages that the operation is simple, the preparation is convenient, and the cost is low; the significance on promoting the application and development of LiNi0.5Mn1.5O4 positive electrode material is realized.

Description

technical field [0001] The invention relates to the field of electrochemistry, in particular to a surface-coated lithium nickel manganese oxide material, a lithium battery and a preparation method thereof. Background technique [0002] Compared with traditional batteries, such as lead-acid batteries, nickel-cadmium batteries and nickel-metal hydride batteries, lithium-ion batteries have outstanding advantages such as high energy density, long cycle life, low self-discharge rate, no memory effect, and environmental protection. After Sony developed it, lithium-ion batteries have been widely used in people's lives, such as portable electronic products, new energy vehicles, and energy storage. With the development of lithium-ion battery technology, lithium-ion batteries are required to have the characteristics of high energy density, high power, and low cost. The composition of lithium-ion batteries generally includes: positive electrode materials, negative electrode materials,...

AI Technical Summary

Problems solved by technology

[0003] (1) LiCoO 2 The positive electrode material has the disadvantages of high cost, serious environmental pollution, etc., and the cut-off voltage exceeds 4.4V, the material structure is unstable, and the cycle and safety performance are deteriorated;

[0004] (2) Li 2 MnO 4 Poor high-temperature cycle and storage performance of cathode materials;

[0005] (3) The compaction density of the positive electrode material of the ternary material is low, and its rate performance and safety performance are low;

[0006] (4) The discharge specific capacity of lithium iron phosphate cathode material is not high, the tap density is low, and the product has serious consistency

[0012] The above methods have a relatively complicated process, which makes it difficult to carry out industrial production. At the same time, there is no corresponding method to solve the dissolution of metal manganese. efficiency and structural stability, and a modification method that can inhibit the side reaction between lithium nickel manganese oxide and electrolyte