Positive electrode slurry and preparation method thereof and lithium-ion battery

Abstract

The invention provides positive electrode slurry, which comprises the following raw materials in parts by weight: 93-97.5 parts of lithium cobalt oxide materials, 1.5-2.5 parts of conductive agents, 1.5-3 parts of binders and 0.1-0.5 part of a nano-aluminum oxide and a solvent. In a plurality of influence factors of the lithium-ion battery, first of all, nano Al2O3 is added to the positive electrode slurry from components and proportion of the positive electrode slurry, so that the positive electrode slurry can effectively play roles in heat insulation and insulation and the safety performance of the battery is improved. Furthermore, a lithium cobalt oxide and the nano Al2O3 form a solid solution and can stabilize lattices and the rate capability and the cycle performance of the battery are improved. Meanwhile, the nano Al2O3 coats the lithium cobalt oxide, so that the heat stability can be improved, the cycle ability and the overcharge resistance are improved, generation of oxygen and decomposition of LiPF6 are inhibited, contact of the lithium cobalt oxide and an electrolyte can be reduced and the capacity loss is reduced, so that the capacity is improved.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery materials, and relates to a positive electrode slurry, a preparation method thereof, and a lithium ion battery, and in particular to a lithium cobaltate positive electrode slurry, a preparation method thereof, and a lithium ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high specific energy, long cycle life, light weight, less white discharge, no memory effect and high cost performance, and have become rechargeable batteries in high-power electric vehicles, artificial satellites, aerospace and other fields. The main selection object of the power supply. Therefore, lithium-ion batteries and related materials have become a research hotspot for researchers. Cathode material is one of the key materials of lithium-ion batteries, which determines the performance of lithium-ion batteries. At present, the biggest bottleneck that ...

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Problems solved by technology

[0005] However, in practical applications, lithium cobalt oxide materials also have two problems: (1) due to the structure of deep deintercalation lithium materials is easily damaged

High voltage can extract more lithium ions from the crystal structure, increasing the capacity of the battery, but a large amount of lithium extraction will affect the cycle performance and safety performance of the battery due to structural damage

Especially under high-voltage charge-discharge conditions, the cycle performance of lithium cobalt oxide deteriorates, and the main reason for the rapid capacity decay is the phase transition of the material in the high delithiation state and the loss of oxygen in the lattice, resulting in structural instability; the reaction between the material and the electrolyte causes Caused by factors such as the dissolution of cobalt

[0006] At present, the cycle performance and stability of lithium cobalt oxide batteries are deteriorating and other defects have increasingly restricted lithium cobalt oxide materials. Overcoming the defects has become one of the focuses of many R&D manufacturers in the industry.

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