Preparation method of lithium-rich manganese-based positive electrode material for lithium ion battery

Abstract

The invention relates to a preparation method of a lithium-rich manganese-based positive electrode material for a lithium ion battery, belonging to the field of energy materials. The preparation method comprises the steps of dropwise adding the prepared lithium, nickel, cobalt and manganese metal salt solution into acrylic acid solution, heating, stirring, adding a small amount of ammonium persulfate to polymerize to form a gum forming compound, then drying, grinding, carrying out presintering and sintering to obtain the lithium-rich positive electrode material, namely Li1+alphaMnxNiyCozO2, with high specific capacity, wherein alpha is more than 0.02 and less then 0.5, x is more than 0.4 and less than 0.75, y is more than 0.02 and less than 0.3, and z is more than 0.02 and less than 0.25; the acrylic acid is used as a metal ion complexing agent and the ammonium persulfate is used as a polymerization initiator of the acrylate. PH value adjustment is not required in the whole preparation process, the metal ions are distributed regularly, and the reaction time is short. The preparation method has simple process, is convenient for operation, can easily realize industrial production, and can be used for the lithium ion battery.

Description

technical field [0001] The invention relates to a preparation method of a lithium-rich manganese-based cathode material for a lithium ion battery, belonging to the field of energy materials. Background technique [0002] Lithium-ion batteries are widely used in many fields such as portable electronic devices and electric vehicles because of their high energy, long service life, and low pollution. Cathode materials occupy the most important position in the structure of lithium-ion batteries, and their performance directly affects the performance and price of lithium-ion batteries. [0003] Lithium-rich cathode materials, especially lithium-rich manganese-based cathode materials, have attracted widespread attention due to their ultra-high specific capacity and relatively low price. Lithium-rich manganese-based cathode materials are essentially a class of layered compounds xLi[Li 1 / 3 mn 2 / 3 ](1-x)LiMO 2 , has a higher specific capacity (250mAh / g), and the transition metal e...

AI Technical Summary

Problems solved by technology

Chinese patent 102339997 A proposes to mix nickel oxide, cobalt oxide, manganese oxide and lithium salt ball mill and roast to obtain the final product Li 1+z Ni x co y mn 1-x-y o 2 , where 0≤z≤0.2, 0.5≤x≤0.8, 0.1≤y≤0.2, it is difficult to make Li + It is uniformly mixed with Ni, Co and Mn, so the calcination temperature is required to be greater than 800°C, and the high temperature makes Ni 2+ Occupy Li + The 3a position produces cation mixing, which reduces the electrochemical performance of the material

The main disadvantage of the sol-gel method is that the pH value of the reaction system needs to be precisely controlled during the formation of the sol. Once the pH value changes, the sol may not be obtained; in order to eliminate the influence of impurity ions, ammonia water is generally used to adjust the pH value, which is harmful to the environment. harm to people

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