Method for preparnig spherical spinel Li-Mn-oxide lithium ion cell anode material

Abstract

First, using special electrolytic technology in low temperature, the method prepares spherical MnO2 fine grain of pure or composite M metallic oxide. Then, through diffusion process of dissolution (melt), lithium ion is led in; and through thermal reaction, anode material of spinel LiMxMn2-xO4 is obtained. Spherical Li-Mn-Oxide anode material of lithium ion cell prepared by the invention is different from material of polyhedral columnar material prepared by traditional solid phase method, combustion method, coprecipitation method, sol-gel method, and hydrothermal method etc. Spherical form possesses minimal external surface per unit volume. Thus, Spherical form can reduce surface area exposed in electrolyte solution so as to avoid point active effect and restrain Mn2+ from dissolution and running out as well as decomposition of electrolyte. The invention raises performance of anode material LiMn2O4 and improves allover properties of pole pieces.

Description

technical field [0001] The invention relates to a preparation method of spherical spinel lithium manganese oxide lithium ion battery cathode material. Background technique [0002] Energy, materials and information are the three pillars for the survival and development of human society. To achieve a sustainable development strategy for human society, it is necessary to develop new materials and new energy technologies and protect the natural environment and natural resources. At the same time, with the rapid development of modern electronic technology, electronic appliances continue to develop rapidly in the direction of miniaturization, light weight and high performance, coupled with the continuous enhancement of people's environmental awareness, there is an urgent need to develop green power supplies that are environmentally friendly and have excellent performance. Lithium-ion batteries, which have become a worldwide boom in the past ten years, are undoubtedly one of the m...

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Problems solved by technology

[0004] Lithium-ion secondary battery cathode material is mainly lithium intercalation transition metal oxide LiCoO 2 , LiNiO 2 , LiMn 2 o 4 And its modified compounds, the current commercial cathode material is mainly LiCoO 2 , but LiCoO 2 The fatal disadvantage is that the reserves of cobalt resources are limited, the price is expensive, and the manufacturing cost is too high to be used in large batteries (such as EV, HEV), and Co is a toxic element that will cause environmental pollution. Therefore, it is necessary to look for alternatives to lithium cobaltate has become inevitable

LiNiO 2 Although compared with LiCoO 2 With the advantages of low cost and high energy, it has become a very attractive cathode material, but its disadvantages are: firstly, its reversible capacity is affected by the irreversible stage change during the first lithium deintercalation, and the capacity loss is large; secondly, in LiNiO during cycling 2 The structure of NiO is easy to change, and NiO 2 more stable than CoO 2 It is also poor, it is prone to thermal decomposition and produces oxygen, so its safety problem is the focus of general attention, and it is also difficult to prepare

[0005] But the spinel phase LiMn 2 o 4 Cathode materials are not yet fully accepted by the lithium-ion battery industry, which affects LiMn 2 o 4 There are four key factors of performance, namely, the crystal structure phase transition caused by Jahn-Teller effect, Mn 2+ Dissolution loss, decomposition of electrolyte and formation of passivation film, even at high temperature (>55°C), LiMn 2 o 4 The reason for the rapid decay of the positive electrode material capacity is also due to the Jahn-Telle: effect, Mn 2+ Dissolution and surface passivation are more severe as a result

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