Positive electrode material as well as preparation method and application thereof

Abstract

The invention provides a positive electrode material as well as a preparation method and application thereof. The positive electrode material comprises a ternary positive electrode material, aluminumtriphosphate and a binder. The preparation method comprises the following steps: (1) carrying out mixing reaction on aluminum triphosphate and a ternary positive electrode material to form a positiveelectrode material pre-mixture; (2) mixing colloidal silica sol with the positive electrode material pre-mixture obtained in the step (1) to form a positive electrode material mixture; (3) drying thepositive electrode material mixture in the step (2) to obtain a positive electrode material matrix; and (4) sintering the positive electrode material matrix obtained in the step (3) to obtain the positive electrode material. The lithium ion battery prepared from the positive electrode material provided by the invention can effectively inhibit the decomposition of an electrolyte and the decline ofthe positive electrode material in an environment of 80-85 DEG C, and can be stored for more than two months.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a positive electrode material, its preparation method and application. Background technique [0002] Lithium-ion batteries have high energy density, high output power, are green and environmentally friendly, and do not contain toxic substances such as lead, cadmium and mercury, and have broad application prospects in the field of electrical equipment. Lithium-ion battery positive electrode material, negative electrode material and electrolyte are the three main components of lithium-ion batteries, and their performance basically determines the performance of lithium-ion batteries. With the rapid development of lithium-ion battery applications, people have higher and higher requirements for lithium-ion batteries. At present, common lithium-ion batteries cannot be used in a high temperature environment of 80°C. How to broaden the application temperature range of lithium-ion has...

AI Technical Summary

Problems solved by technology

Isolate the contact between the high-nickel ternary material and the electrolyte to improve the cycle stability of the battery, but the metal oxide used is an inert material with low ion conductivity, which reduces the capacity and rate performance of the positive electrode material, and its thermal conductivity Insufficient, the heat generated by the electrode material cannot be dissipated in time, so that the heat is continuously concentrated, and finally the temperature rises, causing a safety hazard

And this makes it difficult for the battery to be stored at high temperatures

[0006] CN107742711A discloses a surface coating method of a ternary positive electrode material, using hydroxypropyl guar gum and borax to react to generate a three-dimensional network-like gel system, borax as a crosslinking agent, boron crosslinking agent and guar gum crosslinking When , multilevel ionization occurs first, producing borate ion B(OH) 4 - , and then form a stable hydrogen bond with the cis-ortho hydroxyl group in the guar gum molecule, and generate a viscoelastic jelly through intermolecular cross-linking reaction, and then sinter to coat the boride on it, but this method has disadvantages , hydroxypropyl guar gum is an organic substance, high temperature sintering and carbonization will lead to the reduction of the positive electrode material, leading to the destruction of the corresponding structure

This document adopts the method of wet coating the sediment, using the method of polyacrylic acid or salt and insoluble salt, which has limitations, and the particle size of the insoluble salt seriously affects its coating effect

[0008] At present, ordinary lithium-ion batteries are generally not resistant to high-temperature storage. In an environment above 80°C, due to the decomposition of the electrolyte or the decline of the positive electrode material, they basically cannot be used.

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