High-nickel ternary positive electrode material and preparation method thereof

Abstract

The invention relates to a high-nickel ternary positive electrode material and a preparation method thereof. The high-nickel ternary positive electrode material comprises a positive electrode active material and a coating layer, and the positive electrode active material comprises a nano oxide; the nano oxide comprises any one or more of zirconium oxide, titanium oxide, tungsten oxide, molybdenum oxide, aluminum oxide and yttrium oxide; the coating layer comprises lithium zirconate, lithium titanate and lithium cobalt oxide. According to the ternary positive electrode material and the preparation method thereof provided by the invention, residual alkali on the surface of the high-nickel positive electrode material is reduced, the electronic conductivity of the material is increased, and gas production and cycle stability in the cycle process of the positive electrode material are improved.

Description

technical field [0001] This article relates to but not limited to the technical field of lithium batteries, in particular to but not limited to a low surface residual alkali and high nickel positive electrode material and a preparation method thereof. Background technique [0002] Low-cost, high-energy-density and low-toxicity high-nickel ternary nickel-cobalt lithium manganate (NCM) cathode materials or nickel-cobalt-aluminate (NCA) cathode materials are widely used in the field of new energy vehicles. However, pure high-nickel ternary positive electrode materials have serious lithium-nickel mixing phenomenon during battery charging and discharging, and the structure will collapse during the cycle; at the same time, the residual alkali content on the surface of high-nickel ternary positive electrode materials is relatively high, generally in the form of carbonic acid Lithium, lithium hydroxide and lithium oxide exist in the form of lithium, which leads to high alkalinity an...

AI Technical Summary

Problems solved by technology

However, pure high-nickel ternary positive electrode materials have serious lithium-nickel mixing phenomenon during battery charging and discharging, and the structure will collapse during the cycle; at the same time, the residual alkali content on the surface of high-nickel ternary positive electrode materials is relatively high, generally in the form of carbonic acid Exist in the form of lithium, lithium hydroxide and lithium oxide, resulting in high alkalinity and high water absorption of positive electrode materials

On the one hand, it causes difficulties for the subsequent coating of the positive electrode material, and at the same time puts forward higher requirements for the electrolyte in terms of alkali resistance. High alkalinity will cause the battery to swell during the cycle, which will affect the cycle performance of the battery; on the other hand On the one hand, in the charging state, because Ni4+ exists on the surface of the positive electrode material particles, Ni4+ has high activity and is prone to side reactions with the electrolyte, thus increasing the battery life. Impedance and loss of irreversible capacity

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