Method for preparing lithium-enriched lithium manganese oxide solid solution cathode material

Abstract

The invention relates to a method for preparing a lithium-enriched lithium manganese oxide solid solution cathode material. The method comprises the following steps of: adding a mixed aqueous solution of nickel salt, cobalt salt and manganese salt into an oxalic acid or oxalate aqueous solution by an oxalate coprecipitation high-temperature solid state method, and stirring and reacting to generate nickel, cobalt and manganese oxalate coprecipitation; performing solid and liquid separation, washing and drying to obtain a nickel, cobalt and manganese oxalate precursor; and mixing and grinding the precursor and lithium salt, drying, baking at high temperature in an air atmosphere, and thus obtaining the lithium-enriched lithium manganese oxide solid solution cathode material. During preparation of the precursor, the proportion of the nickel salt, the cobalt salt and the manganese salt is adjusted, so that the constituents of the lithium-enriched lithium manganese oxide solid solution cathode material can be adjusted flexibly. The preparation method is suitable for large-scale, economic, stable and reliable production of the lithium-enriched lithium manganese oxide solid solution cathode material, has obvious advantages, and is high in practical value.

Description

technical field [0001] The invention belongs to the technical field of energy material preparation, and relates to a lithium-rich lithium manganate solid solution positive electrode material (Li 2 MnO 3 -LiMO 2 , M is at least one of Ni, Co, and Mn), the material is a new type of high-voltage, high-capacity lithium-ion battery positive electrode material. Background technique [0002] Lithium-ion batteries have been widely used in electronic products such as mobile phones, notebook computers, and digital cameras, and are developing into large-scale power batteries (such as for electric vehicles) and energy storage batteries (such as for solar and wind power generation systems). The pursuit of high energy density is an important goal in the development of lithium-ion batteries. [0003] The core of lithium-ion batteries is materials, including positive electrode materials, negative electrode materials, separators, electrolytes, etc. At present, the practical cathode mate...

AI Technical Summary

Problems solved by technology

[0012] 1. In order to ensure the uniform co-precipitation of the three ions of nickel, cobalt and manganese, a certain complexing agent must be used, and even multiple complexing agents must be used at the same time, which significantly increases the cost;

[0013] 2. Divalent manganese ions are easily oxidized when forming hydroxide precipitates. Inert gas protection is required during preparation, and oxidation should also be prevented during drying. Otherwise, the ratio of raw materials will be deviated during subsequent batching, which will affect product performance and consistency. ;

[0014] 3. Due to the different complexing abilities of complexing agents to nickel, cobalt, and manganese, and the different solubility products of hydroxides, it is difficult to flexibly adjust the composition of products in a wide range by the hydroxide co-precipitation method, resulting in the preparation of The composition of lithium-rich lithium manganese oxide solid solution cathode material is greatly restricted;

[0016] At present, there is no report on the preparation of lithium-rich lithium manganese oxide solid solution positive electrode materials by oxalate co-precipitation-high temperature solid phase method