Coprecipitation-combustion synthesis method for lithium nickel cobalt manganate

Abstract

The invention discloses a process of coprecipitation-combustion synthesis of nickel cobalt manganese lithium carbonate. (1) Utilizing acetate or nitrate of nickel, cobalt, and manganese as transition metal source and ammonia as complexing agent and utilizing H2C2O4, (NH4)3C2O4, (NH4)2CO3 or NH4HCO3 as precipitator, compound carbonate contained Ni-Co-Mn or oxalate precursors is synthesized by coprecipitation method. (2) Directly drying the compound carbonate containing Ni-Co-Mn or the suspension liquid of the oxalate and adding lithium nitrate or lithium acetate or a small quantity of water or ethanol to adjust into rheological phase. (3) Laying the materials in rheological phase in an electric stove to perform burning synthesis reaction, wherein the electric stove heats the materials in rheological phase at temperature of 400-600DEG C and then keeps constant temperature. (4) Temper drawing the reaction product with temperature of 600-1200DEG C, and anode active materials of lithium ion battery LiNixCoyMn1-x-yO2 is obtained. The invention has the advantages of simple technique, easy operation, saving water and energy and environment-friendliness, further, the synthetic material is provided with the shape of sphere or near-sphere, high specific capacity and fine cycle performance.

Description

technical field [0001] The present invention relates to a kind of synthetic method of lithium ion battery cathode material, especially LiNi x co y mn 1-x-y o 2 Co-precipitation-combustion synthesis method. Background technique [0002] The vast majority of existing commercial lithium-ion batteries use lithium cobalt oxide as the positive electrode material. Although this material has the advantages of easy synthesis, stable performance, and high capacity, the cobalt required for its synthesis has serious disadvantages such as high price, high toxicity, and lack of resources. The development of cobalt-less or cobalt-free cathode materials has become a direction for the development of cathode materials for lithium-ion batteries. [0003] LiNi x co y mn 1-x-y o 2 It is one of the most promising new positive electrode materials developed in recent years to replace lithium cobalt oxide. Currently, synthetic LiNi x co y mn 1-x-y o 2 The methods mainly include co-prec...

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Problems solved by technology

Currently, synthetic LiNi x co y mn 1-x-y o 2 The methods mainly include co-precipitation method, sol-gel method, emulsion method, high-temperature solid-phase method and combustion method, among which the co-precipitation method is to synthesize homogeneous LiNi x co y mn 1-x-y o 2 The commonly used method, the synthesis temperature of this method is low, and spherical or quasi-spherical particles can be obtained, but because it is difficult to completely precipitate transition metal ions through a certain precipitant, it is easy to cause transition metal ions in the process of filtration and washing. loss, and the existing co-precipitation synthesis precursor needs to be carried out under the protection of the atmosphere. The stirring speed, pH value, solution concentration, etc. have a great influence on the electrochemical performance of the synthesized product, which requires high equipment and is difficult to industrialize.

The high-temperature solid-phase method has low equipment requirements, but because the mixing of raw materials cannot achieve uniformity at the molecular level, it generally needs to be calcined at a higher temperature for a long time at a constant temperature, which consumes a lot of energy in production, and the synthesized positive electrode material particles are irregular and prone to Heterogeneous phase, difficult to synthesize homogeneous LiNi x co y mn 1-x-y o 2 ; The combustion method has simple process, low equipment requirements, and short synthesis time, but the synthetic product particles are irregular, and impurities such as NiO are easily produced

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