A kind of positive electrode material of lithium ion battery and preparation method thereof

Abstract

The invention discloses a preparation method of a lithium ion battery anode material. The method is characterized in that the outer surface of the existing lithium ion battery anode material is sequentially coated with an aluminum oxide layer and a carbon layer, wherein the coating condition is liquid-phase coating, in the coating process of the aluminum oxide, the addition sequence of the existing lithium ion battery anode material and aluminum salt is adjusted, and the coating substance organic aluminum salt is added under the continuously stirring condition, so that a hydrolytic product is uniformly adsorbed onto the surface of an active substance. The carbon coating is carried out through a spray drying and rapid sintering way in the inert gas atmosphere, so that the problems that the metal is reduced due to the high-temperature carbon coating and the organic carbon source is difficultly carbonized in low temperature can be avoided. The invention also discloses a lithium ion battery anode material prepared through the method. The energy density and power density of the battery can be remarkably improved, and the cycling performance, the capacity retention rate and the safety performance of the battery can be improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a novel lithium ion battery cathode material and a preparation method thereof. Background technique [0002] In the 1980s, American scholar J.B.Goodenough and others first discovered lithium cobalt oxide (LiCoO 2 ), lithium nickelate (LiNiO 2 ) and lithium manganate (LiMn 2 o 4 ) can be used as a material for deintercalating lithium ions. In the 1990s, Sony successfully applied lithium cobalt oxide to commercial small electronic products for the first time. Since then, lithium-ion batteries have been widely used in various electronic devices due to their high cycle performance, high operating voltage and low pollution. In recent years, with the continuous development of science and technology, the functions of electronic equipment have been continuously upgraded, so higher requirements have been placed on the energy and rate performance of lithium batteries. At present, c...

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Problems solved by technology

At present, the method of carbon doping is mainly the mechanical mixing method, and the mechanical mixing method has disadvantages such as long operation time and uneven mixing; carbon coating can effectively improve the conductivity of the material, improve the surface chemistry of the active material, and prevent the electrode from directly contacting the electrolyte. Contact can improve the rapid charge-discharge performance and cycle performance of the electrode; while the commonly used lithium-ion battery cathode materials (lithium cobaltate, lithium manganate or three-element materials, etc.) are synthesized under air or oxygen atmosphere, and the synthesis temperature is 900 Above ℃, under such conditions, carbon is oxidized and it is difficult to achieve carbon coating. Therefore, an inert atmosphere is required to achieve carbon coating; in addition, the temperature of carbon decomposition and graphitization is as high as 600-900 °C, and it is easy to convert nickel and cobalt , manganese and other metal ions are reduced to simple substances, so it is difficult to achieve carbon coating by traditional organic carbon decomposition

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