A kind of ternary lithium battery material, its preparation method and lithium ion battery

Abstract

The invention provides a preparation method of a ternary lithium battery material, comprising the following steps: A) ball milling and activating nickel source, cobalt source and manganese source to obtain a mixed material; B) mixing the mixed material, lithium source, flux, The compound of M is mixed with polyvinyl alcohol, spray-dried and pressed to obtain a block; C) the block is roasted and pulverized to obtain a single-crystal-like ternary material; D) the single-crystal-like ternary material is obtained Grinding and roasting the cladding source to obtain the ternary lithium battery material; the cladding source is LiCO 3 and LiOH·H 2 One of O and Al 2 o 3 , ZrO 2 and TiO 2 one or more of. The present application also provides the above-mentioned ternary lithium battery material and a lithium ion battery. The preparation method of the ternary lithium battery material provided by this application synthesizes a single-crystal ternary positive electrode material at one time through the self-fusion of raw materials. The particle size is large and uniformly distributed, and the high-temperature storage performance and high-temperature cycle performance of the positive electrode material are excellent.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery electrode materials, in particular to a ternary lithium battery material, a preparation method thereof and a lithium ion battery. Background technique [0002] In recent years, due to the advantages of high specific energy, small size, light weight and long cycle performance, lithium-ion batteries are not only widely used in portable electronic devices such as notebook computers, digital cameras, and mobile devices, but also gradually used in electric vehicles. , hybrid electric vehicles, energy storage power supplies and other high-power equipment. In order to meet the requirements of high-power equipment, the development of cathode materials with high energy density, low cost, and good high-voltage cycle stability has become a research hotspot for battery cathode materials. Nickel cobalt lithium manganate (NCM) ternary cathode material (LiNi x co y mn 1-x-y o 2 , 0<x, y<1)...

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Problems solved by technology

The study found that the particle-to-particle connection structure inside the secondary particle will cause the local current density to rise, thereby generating a large stress, thereby affecting the cycle performance of the material; at the same time, there is also a charge between the various parts inside the particle. The phenomenon of inconsistent state, which affects the electrochemical performance of the electrode

[0004] In addition, when the delithiation amount is large, the structure of the NCM ternary material becomes very fragile, the active metal and oxygen in the crystal lattice are displaced, reaching a certain high temperature and high pressure, the atomic rearrangement is gradually intensified, and the grain volume and material On the other hand, chemical and electrochemical interactions with the electrolyte cause the material to be easily deoxidized and the transition metal dissolves, especially under high voltage, the electrolyte will be oxidized to generate H + , the acidity of the electrolyte is increased, so that the surface film of the electrode material is damaged by HF, and the composition and structure of the interface are further changed, which seriously affects the electrochemical performance and cycle performance of the material.

[0005] At present, the method for preparing single-crystal ternary materials is generally as follows: first use nickel-cobalt-manganese sulfate to prepare nickel-cobalt-manganese hydroxide precursor or nickel-cobalt-manganese oxalate precursor by co-precipitation method, and then add lithium source to roast To obtain a ternary cathode material, this method is complex and costly, and the particle size of the single-crystal particles is small (3-7μm), which is easy to produce fine powder and affect the cycle stability and safety of the battery

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