Ultrathin TiO2 coating layer of lithium battery cathode material, lithium battery cathode material and preparation method of lithium battery cathode material

Abstract

The invention discloses an ultrathin TiO2 coating layer of a lithium battery cathode material. The coating layer is uniform and compact, and the thickness is only 0.5-20 nm. The lithium battery cathode material with a core-shell type coating structure comprises an inner-core cathode active material and the externally coated ultrathin TiO2 coating layer, wherein a mole ratio of Ti in the coating layer to a transition metal element in the inner-core cathode active material is 0.01%-3%. A preparation method of the lithium battery cathode material comprises steps as follows: a titanium contained compound is dissolved in an organic solvent; the inner-core cathode active material is added to the solution and stirred rapidly, the organic solvent is removed through heating, dry powder is obtained and is placed in dry air for standing to have in-situ hydrolysation with water molecules in air slowly and controllably, and intermediate powder is obtained and placed in an aerobic environment for calcination so as to obtain the lithium battery cathode material. The side reaction between the active material and electrolyte can be effectively inhibited, and the rate capability and the cycle performance of the lithium battery cathode material are improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery positive electrode material modification, and in particular relates to a lithium ion battery positive electrode material coating layer, a lithium battery positive electrode material and a preparation method thereof. Background technique [0002] Lithium-ion batteries have unique advantages such as high specific capacity, high working voltage, wide application temperature range, low self-discharge rate, long cycle life, no pollution, and good safety performance. In recent years, the use of lithium-ion batteries has gradually expanded from small electronic devices, including hybrid electric vehicles (HEV), electric vehicles (EV), smart grid energy storage, new energy (wind, solar, etc.) applications in fields such as energy. While the applications in these fields have expanded the scope of the lithium-ion battery market, they have also put forward higher requirements for the performance...

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Problems solved by technology

However, the existing coating methods also have certain shortcomings. For example, Chen et al. realized the hydrolysis of titanium salt by adding water to the ethanol solution of titanium salt, and then coated the positive electrode material. The reaction process is not easy to control, which is not conducive to Form a uniform and dense ultra-thin coating layer, which is difficult to apply to industrial production

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