Lithium-ion power battery cathode material and lithium-ion power battery containing the material

Abstract

The invention belongs to the technical field of a lithium ion powder battery, and especially relates to an anode material of a lithium ion power battery. The anode material comprises a nuclear layer and a shell layer, wherein the material of the nuclear layer is LiNi1-x-yCoxMnyO2; the material of the shell layer is LiVFe(PO4)2 and / or LiFePO4; the material of the shell layer covers the outer surface of the material of the nuclear layer; the mass percent of the material of the shell layer is 5-30%; and the grain size of the material of the shell layer is 50-1000nm. Compared with the prior art, not only can the anode material of the lithium ion power battery provided by the invention be used for avoiding the potential safety hazards in the material of the shell layer, so as to improve the security property of the power battery, but also the nanoscale material of the shell layer can be filled in gaps of the material of the nuclear layer with large particles, so that the energy density of the power battery using the anode material can be ensured. Meanwhile, the influence of the material of the shell layer on the conductivity of the anode material can be greatly reduced due to non-uniform coating, so that the higher power can be ensured.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion power batteries, and more specifically, the invention relates to a lithium-ion power battery cathode material and a lithium-ion power battery containing the material. Background technique [0002] With the development of modern society and the enhancement of people's awareness of environmental protection, more and more devices choose to use batteries as power sources, such as laptops, smart phones, electric vehicles and energy storage power stations, etc. Both capacity and power have high requirements, and a large-capacity and high-power power battery is required. More importantly, electric vehicles and energy storage power stations also have stricter requirements on the safety performance of batteries. If the lithium-ion power battery is under abuse such as puncture or extrusion, the temperature inside the battery will rise. When the temperature rises to a certain degree, the battery may exp...

AI Technical Summary

Problems solved by technology

However, the mechanical method does not fundamentally solve the safety problem of lithium-ion power batteries

For this reason, some new solutions have been disclosed in some patent applications: for example, the Chinese patent application whose publication number is CN102117913 combines NCM ternary materials and LiFePO 4 When stirring and making slurry, they are mixed together as positive electrode materials to improve the safety performance of the battery, but the two materials cannot be mixed together well during the stirring and mixing process, and LiFePO with good safety 4 The material cannot be well coated on the outer surface of the NCM ternary material, so that the improvement of battery safety performance is very limited

The patent application with the application number US20120141873A uses a Li-rich NCM ternary material, and then coats it with (Fe) 3 (PO4) 2 , LiFePO is formed on the outer surface of the Li-rich NCM ternary material after high-temperature sintering 4 and (Fe) 3 (PO4) 2 The composite cladding layer, this process is complex, and the synthesis of Li-rich NCM ternary materials requires an oxidizing atmosphere, while LiFePO 4 The synthesis of NCM requires a reducing atmosphere, and it is difficult to satisfy the two conditions at the same time. In addition, if a layer of LiFePO is perfectly grown on the outer layer of the Li-rich NCM ternary material 4 and (Fe) 3 (PO4) 2 The composite cladding layer, then the conductivity of the whole material will be changed from LiFePO with poor conductivity 4 and (Fe) 3 (PO4) 2 to determine, thereby reducing the power performance of the material itself

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