Ternary cathode active material of lithium ion battery, preparation method thereof, cathode material, lithium ion battery and product thereof

Abstract

The invention provides a ternary positive electrode active material of a lithium ion battery and a preparation method thereof, a positive electrode material, a lithium ion battery and a product thereof, which relate to the technical field of ternary materials. The ternary cathode active material of a lithium ion battery comprises a nickel-cobalt-manganese cathode material, a nanometer tin dioxideand graphene oxide, wherein the nanometer tin dioxide is coated on the surface of the nickel-cobalt-manganese cathode material, and the nickel-cobalt-manganese cathode material coated with the nanometer tin dioxide on the surface is embedded in the graphene oxide laminated structure; the ternary cathode active material of the lithium ion battery alleviates the technical problems of poor rate performance and poor cycle performance of a traditional cathode active material. The invention also provides a preparation method of the abovementioned cathode active material, a cathode material, a lithium ion battery and a product thereof.

Description

technical field [0001] The invention relates to the technical field of ternary materials, in particular to a ternary cathode active material for a lithium ion battery, a preparation method thereof, an anode material, a lithium ion battery and a product thereof. Background technique [0002] Lithium-ion batteries are widely used in a variety of electronic mobile products, electronic devices, power tools, electric vehicles or power storage systems. The cathode material of lithium-ion batteries is the key to determining the performance of lithium-ion batteries, accounting for 30% of the cost of lithium-ion battery materials about. Commonly used cathode materials are LiCoO 2 , LiNiO 2 , LiMn 2 o 4 、LiFePO 4 or LiNi 1-x-y co x mn y o 2 Wait. Among them, LiNi 1-x-y co x mn y o 2 Both LiCoO 2 , LiNiO 2 , LiMn 2 o 4 The common advantages of the three are that the overall performance is relatively better, and they are currently more widely used in the market. [00...

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Problems solved by technology

[0003] However, LiNi currently on the market 1-x-y co x mn y o 2 After repeated cycles, the rate performance and cycle performance of the material deteriorate more seriously, which affects the LiNi 1-x-y co x mn y o 2 There are many factors in the rate performance and cycle performance of material batteries, for example: there are often traces of moisture in the battery, LiPF in the electrolyte 6 It will react with water to generate HF, which can corrode the positive electrode active material, causing its structure to be damaged or collapsed by the electrolyte, which in turn affects the insertion and extraction rate of lithium ions in the next cycle, and some lithium ions cannot be inserted or extracted smoothly. The actual charge and discharge capacity becomes smaller, the irreversible capacity increases, and the cycle performance and rate performance become worse; or the prepared LiNi 1-x-y co x mn y o 2 Active material particle size is not uniform, Li + The transmission distance in the process of embedding and embedding and extraction is large, resulting in poor rate performance and cycle performance of the battery; in addition, the specific surface area of ​​the positive electrode material is also an important factor affecting the rate performance and cycle performance. The surface area is small, and the extraction of lithium ions per unit time is less, resulting in poor rate performance; the crystal structure changes too fast during the cycle, and the circulating material and electrolyte cannot form a dense and uniform SEI film, resulting in premature side effects between the active material and the electrolyte. The electrolyte is consumed too quickly due to the reaction, which affects the cycle and also leads to poor cycle performance

In addition, the poor conductivity of the cathode material will also lead to poor rate performance.

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