Lithium-rich manganese-based layered lithium battery cathode material and preparation method thereof

Abstract

The invention relates to a lithium rich manganese based layered lithium battery cathode material, the formula is Li[Li<1-x-y-z>NixCoyMn2]O2, wherein x is more than zero and less than 0.5, y is more than zero and less than 0.5, z is more than 0.1 and less than 0.7, (1-x-y-z) is more than zero and less than 0.5, D50 is 10 to 20 micrometers, the specific surface area is 1-4 square meters per gram, and the discharging capacity reaches 200 to 300mAh per gram at charging / discharging current density of 12.5mA per gram. The preparation method comprises the following steps of: firstly, preparing a lithium source, a nickel source, a cobalt source and a manganese source; secondly, mixing original materials according to proportion to prepare a mixed salt solution; thirdly, adding polyacrylic acid and citric acid and uniformly mixing; fourthly, heating to form a stable sol, evaporating water to form gel, and drying the gel to form xerogel; and finally, sintering to obtain the lithium rich manganese based layered lithium battery cathode material. The cathode material disclosed by the invention has the advantages of high specific discharging capacity, good safety, low production cost and high performance cost rate.

Description

Technical field [0001] The invention relates to a lithium ion battery cathode material and a preparation method thereof, in particular to a lithium-rich manganese-based cathode material Li[Li 1-x-y-z Ni x Co y Mn z ]O 2 And its preparation method. Background technique [0002] Since its successful development in the 1990s, lithium-ion batteries have become an ideal power source for portable electronic products due to their large specific energy, low self-discharge, light weight, and environmental friendliness. They are also the preferred power source for future electric vehicles and hybrid electric vehicles. . Therefore, lithium-ion batteries and related materials have become one of the research hotspots of researchers from all over the world (see XuB, QianD, WangZY, MengYS. / sulfurbatteries[J].JournalofPowerSources,2012,200:77-82.). [0003] At present, the specific capacity of the carbon negative electrode of lithium-ion batteries is usually above 350mAh / g, while the specific c...

AI Technical Summary

Problems solved by technology

Although ternary materials reduce material cost and toxicity, and obviously improve the safety of materials, the actual specific capacity of these layered structure materials has not made a big breakthrough, generally less than 200mAh / g

Although the co-precipitation method has the advantages of uniform multicomponent components and controllable particle size distribution, in order to remove impurity ions such as Na in the reaction system + and SO 4 2- etc., the co-precipitated substance needs to be washed repeatedly, which causes the loss of the material, which leads to the inability to accurately control the stoichiometry of the material, and at the same time produces a large amount of waste water during the production process, which limits the large-scale production and popularization of the material.

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