Lithium battery cathode material ultra-thin coating layer, lithium battery cathode material and preparation method thereof

Abstract

The invention discloses an ultrathin coating layer of a lithium battery cathode material. The ultrathin coating layer comprises Li-Ti-O titanate and is uniform and compact, and the thickness of the ultrathin coating layer is only 0.5-30 nm. A lithium battery cathode material with a core-shell type coating structure comprises an inner-core cathode active material and the ultrathin coating layer, wherein a mole ratio of Ti in the coating layer to a transition metal element in the inner-core cathode active material is 0.01%-3%. A preparation method of the lithium battery cathode material comprises steps as follows: lithium salt and a titanium contained compound are dissolved in an organic solvent, and the inner-core cathode active material is added to the organic solvent to be sufficiently infiltrated; the organic solvent is removed through heating, dry powder is obtained and is placed in dry air for standing to have in-situ hydrolysation with water molecules in air slowly and controllably, and intermediate powder is obtained and placed in an aerobic environment for calcination so as to obtain the lithium battery cathode material. The side reaction between the active materials of the lithium battery cathode material and electrolyte can be effectively inhibited, and the rate capability and the cycle performance of the lithium battery cathode material product are improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery positive electrode material modification, and in particular relates to a coating layer of lithium ion battery positive electrode material, lithium battery positive electrode material and a preparation method. Background technique [0002] In recent years, growing energy and environmental issues have intensified the desire for efficient energy storage and conversion devices. Lithium-ion batteries (LIBs) are currently the most widely used energy storage and conversion devices due to their many advantages such as high energy density and long cycle life. Relevant market analysis predicts that by 2020, the secondary battery market size is expected to reach US$119.3 billion, which is more than 10 times the corresponding market size in 2010. The next-generation LIB technology with the background of major applications such as electric vehicles requires that it not only has many traditional ad...

AI Technical Summary

Problems solved by technology

However, traditional cladding materials such as Al 2 o 3 , ZrO 2 , MgO, V 2 o 5 Other metal oxides, AlPO 4 、FePO 4 Such phosphates often do not have lithium ion conductivity, and the coating layer plays a certain role in hindering the extraction and insertion of lithium ions.

Moreover, in order to achieve full coverage of the surface of the material in the traditional coating method, the thickness is often greater than 30nm

A thick coating layer is not conducive to the deintercalation process of lithium ions on the surface of the material, resulting in a decrease in the rate performance of the material

Images