Lithium manganese oxide spinel of anode materials of lithium ion batteries and method for manufacturing lithium manganese oxide spinel

Abstract

The invention discloses lithium manganese oxide spinel of anode materials of lithium ion batteries. The specific surface area of the lithium manganese oxide spinel ranges from 0.2m<2> / g to 0.6m<2> / g, the content of K ions in the lithium manganese oxide spinel is lower than 800ppm, the content of other impurities in the lithium manganese oxide spinel is lower than 200ppm, the compaction density of the lithium manganese oxide spinel is higher than 3.35g / cm<3>, the initial discharge capacity of a 0.1C button battery is higher than 115mAh / g, and the 100-cycle capacity fading is lower than 8%. The method includes proportioning a lithium source, a manganese source and doping metal additives, and presintering the manganese source at the temperature ranging from 500 DEG C to 1000 DEG C; mixing the presintered manganese source, the lithium source and the doping metal additives to obtain a mixed raw material; performing multi-section sintering for the mixed raw material to obtain a sintered sample, washing the sintered sample by water, and centrifugally spinning and drying the sintered sample; and screening and grading to obtain a lithium manganese oxide product. The lithium manganese oxide product is regular in granule morphology, high in compaction density, low in impurity content and good in both processability and electric performance.

Description

technical field [0001] The invention relates to a battery cathode material and a preparation method thereof, in particular to a cathode material lithium manganate and a preparation method thereof. Background technique [0002] Lithium manganese oxide has many advantages such as good thermal stability, overcharge resistance, high-current charge and discharge performance, and good safety; in addition, abundant manganese ore resources and low price also give lithium manganate a great cost advantage. The dual advantages of performance and price make lithium manganese oxide the most promising cathode material in the production of lithium-ion batteries, and it is widely used in small digital products and lithium-ion secondary batteries for small electric tools. At the same time, the outstanding advantages of lithium manganate in terms of safety performance and price also make it one of the most promising cathode materials for power lithium-ion batteries. [0003] However, at pres...

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Problems solved by technology

[0003] However, at present, lithium manganese oxide still has disadvantages such as poor processability, low compaction density, large cycle attenuation, and poor high temperature performance.

Electrolytic manganese dioxide has become the main manganese source for industrial production of lithium manganate because of its low cost, easy preparation, and simple synthesis process of lithium manganate. However, electrolytic manganese dioxide itself has too small primary particles, too large pores, and large specific surface area. , the shape is irregular, resulting in many problems such as irregular particles, large specific surface area, poor processability, and low compaction density in the lithium manganate prepared from it.

At the same time, electrolytic manganese dioxide also contains a large amount of Na and K impurity ions, which directly affect the cycle performance and high temperature performance of the final product.

As a result, electrolytic manganese dioxide is used as a raw material, and the primary particle size of lithium manganate products prepared by traditional methods is small, the specific surface area is large, the particles are irregular, the compaction density is low, and the impurity content is high, which affects the processing performance and quality of lithium manganate products. Electrochemical properties

[0004] Through partial doping modification, although the cycle performance of lithium manganate has been improved to a certain extent, its primary particle morphology is still irregular, the compaction density is low, and the energy density of the battery is low.

At the same time, the high impurity content also restricts the development of lithium manganese oxide in the field of power batteries

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