Low-temperature burning preparation method and positive electrode material of spinel lithium nickel manganese oxide

Abstract

The invention provides a low-temperature burning preparation method of spinel lithium nickel manganese oxide. The preparation method comprises the steps of preparing a uniform mixed solution of lithium nitrate, nickel nitrate, manganese nitrate, organic fuel and ammonium nitrate by using deionized water, adding aqueous ammonia, and regulating to be neutral; heating to evaporate the mixed solution,so as to obtain a brown resinous matter; raising heating temperature to cause the resinous matter to burn, after completely burning, obtaining a black brown fluffy precursor; and smashing the precursor and calcining the precursor in an air atmosphere, and cooling to obtain a positive electrode material of spinel lithium nickel manganese oxide. The invention further provides a positive electrode material of spinel lithium nickel manganese oxide prepared by the above method.

Description

technical field [0001] The invention belongs to the technical field of preparation of electrochemical power source materials, and in particular relates to a low-temperature combustion preparation method of a spinel lithium nickel manganese oxide cathode material for a lithium-ion secondary battery and the cathode material prepared by the method. Background technique [0002] Lithium-ion secondary batteries have been widely used in various portable battery products. In recent years, the demand for energy storage devices for electric vehicles and hybrid vehicles has put forward higher requirements for lithium-ion secondary batteries and their electrode materials. The cathode material is the key It is a research hotspot in the field of lithium-ion secondary batteries to seek cheap, safe, environmentally friendly and high-potential, high-specific-energy lithium-ion secondary battery cathode materials. [0003] The spinel lithium nickel manganese oxide cathode material has a 4.7V...

AI Technical Summary

Problems solved by technology

The solid-phase synthesis method cannot achieve uniformity at the molecular level due to the mixing of raw materials, and requires long-term constant temperature calcination at a relatively high temperature. The synthesis time is long, the calcination temperature is high, and the production energy consumption is large.

In addition, the materials synthesized by solid phase synthesis are prone to impurities such as NiO, and there is a large 4V discharge platform during the discharge process.

Although the co-precipitation method can realize the uniform mixing of raw materials at the molecular level, the synthesis temperature is low, and the product purity is high, but the process is complicated, the operation is cumbersome, the variables in the process are difficult to control, the output is low, and it is difficult to mass-produce

[0004] In view of the shortcomings of the above high-temperature solid-phase method and co-precipitation method, the low-temperature combustion synthesis method is simple to operate, the reaction temperature is low, the crystal growth is sufficient, the product phase is pure, and it is easy to prepare nano-scale powders. It has been used in other ceramic powder materials. , but there are few reports on the synthesis of spinel lithium nickel manganese oxide

[0005] In the existing technology for preparing spinel lithium nickel manganese oxide, such as the preparation method published by the Chinese invention patent with the application number 200910166745.4, its deficiency is that methanol and ethanol are used as dispersants, and the self-chelation between carboxylate and metal ions The cooperation effect is not sufficient, and it is difficult to obtain a gel state; and ethylene glycol, as a dispersant, increases the viscosity of the system, is difficult to volatilize, and requires a long heating process to obtain a gel state

[0006] Another example is the preparation method published by the Chinese invention patents with application numbers 201611042691.7 and 201710330440.7. The disadvantage is that the combustion reaction needs to be initiated at a higher temperature (400 ° C). In addition, the preparation method only uses the flash point of the metal nitrate in the raw material The intense heat release, but the heat is not enough to fully burn the gel system, resulting in a low yield of combustion products

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