A kind of preparation method of lithium nickel manganese oxide cathode material

Abstract

The invention discloses a method for preparing a lithium nickel manganese oxide anode material. The method includes the steps that A, divalent nickel salt, divalent manganese salt and Li<+> compounds are evenly mixed and grinded, and a nickel, manganese and lithium mixture is obtained; B, persulfate with the molar weight larger than the sum of the molar weight of the divalent nickel salt and the molar weight of the divalent manganese salt and the mixture obtained in the step A are mixed and grinded, and a reaction mixture is obtained; C, the reaction mixture obtained in the step B is transferred into a polytetrafluoroethylene reaction kettle, water is added, a cover and a stainless steel reaction-kettle outer bush are arranged for sealing, the reaction temperature is controlled and kept, and reactants are obtained; D, the reactants obtained in the step C are taken out and washed with water till no sulfate radical is detected, suction filtration is carried out, and brown or black solid is obtained; E, the brown or black solid is transferred into a crucible, in the atmosphere environment, roasting is carried out, natural cooling is carried out, and the lithium nickel manganese oxide anode material is obtained. The raw materials are abundant, the price is low, environment pollution is avoided, and a brand new easy and convenient solid-liquid film phase reaction method with the easily-controlled conditions and the simple devices is adopted.

Description

technical field [0001] The invention relates to the technical field of battery materials, in particular to a preparation method of lithium nickel manganese oxide positive electrode material. Background technique [0002] LiCoO is the most widely used lithium-ion secondary battery, and its positive electrode active material is mostly LiCoO 2 , LiMn 2 o 4 , LiNiO 2 and other compounds, or compounds based on three compounds doped with each other, the so-called binary materials (such as LiNi x mn 2-x o 4 、LiCo x mn 2-x o 4 、LiNi x co 1-x o 2、 LiNi 0.5 mn 1.5 o 4 etc.) or ternary materials (such as LiNi x co y mn 2-x- y o 4 、LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 etc.) as the positive active material of lithium-ion batteries; or LiFePO 4 as the positive active material. Various compounds have their own advantages and disadvantages as cathode materials for lithium-ion batteries. The methods for synthesizing these materials mainly include liquid phase reaction method ...

AI Technical Summary

Problems solved by technology

[0007] First, solid state reaction synthesis of LiNi 0.5 mn 1.5 o 4 Lithium-ion battery positive electrode materials have poor uniformity, and the consistency of the synthesized materials is not good. Severe limitations (usually only oxides, hydroxides, nitrates, acetates, etc. that are easily decomposed and do not produce impurities), and the synthesis cost is relatively high. Although large-scale production can be achieved, it is difficult to achieve widespread Applications

[0008] Second, the synthesis of LiNi by microemulsion method 0.5 mn 1.5 o 4 Anode materials such as lithium-ion batteries use a large amount of organic solvents and a large amount of organic surfactants, which have a certain impact on the environment; the formation of microemulsions requires harsh conditions, the synthesis process steps are numerous, and the cost of material manufacturing is high. Limited by the method itself, it is difficult to achieve large-scale and efficient production

[0009] Third, hydrothermal or hydrothermal LiNi 0.5 mn 1.5 o 4 Although there are no shortcomings or defects such as uneven reaction, long reaction time, serious pollution, and high cost of solid-state reaction synthesis technology and microemulsion synthesis technology, etc., the positive electrode materials of lithium-ion batteries also have high energy consumption and strict control of process conditions. , high technical requirements for equipment, and the reaction is carried out in a solution state. Due to the limitation of the concentration, the amount of synthetic products is very limited. If the concentration of the solution is greatly increased or the volume of the reactor is increased, the technical difficulty of synthesis and the product quality will be greatly increased. Performance as LiNi 0.5 mn 1.5 o 4 Uncertainty in the structure, morphology, particle size and electrochemical performance of etc. is also greatly increased.

Synthesis of LiNi by hydrothermal method 0.5 mn 1.5 o 4 It is difficult to achieve high-efficiency industrial scale production of lithium-ion battery cathode materials

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