Study Progress On Cathode Material LiMnO₂ Of Lithium-ion Battery

With the development of electronic information technology,demands for portable electronic devices increase.Li-ion battery becomes main choice for Battery charging power source of the carriable electronic product.LiCoO2 has become the main cathode material in commercial lithium-ion batteries.Because of the high cost and toxicity of LiCoO2,researchers have been searching for alternative materials.They wish that the manganese can alternate the cobalt because of Abound in natural resources and innoxious,so LiMnO2 as Li-ion battery cathode material is paied close attention by much more researchers,there are great quantities spend for improving further problems.It is focus of attention to manufacture LiMnO2 with high specific capacity and steady cyclicity.I summarize the structure,principle of work,electrochemistry performance,preparation method and the multi-substitution at the beginning of development of battery .I put forward a developing direction of study and application of cathode material in future.LiMnO2 is a kinds of homogeneous polycrystal compound,it contains orthogonality system,monoclinic system and hexagonal system,with space group Pmnm,C2/m and R3 m.The theory study shows that the LiMnO2 with space group R3 m is very difficult to be synthesized . Under thethermodynamics balance condition ,orthogonality system LiMnO2 is more steady than monoclinic system LiMnO2 because of counter-ferromagnetic coactions among Mn3+,but they all become spinel structure easily in electrochemical reaction. o-LiMnO2 and m-LiMnO2 have the same theory capacity 285 mA·h/g ,compare with m-LiMnO2, o-LiMnO2 is synthesized easily and has better electrochemical stability.People have done lots of study on Preparation method and electrochemistry function about LiMnO2,the commonsense method is high temperature solid reaction process,ion exchange technique andhydrothermal synthesis method.The study indicates that multi-substitution is propitious to improve electrochemical stability of LiMnO2 and to keep down turning to spinel structure.It is important reference value to further study on LiMnO2 material ,we give some useful advice on preparation of Li-ion battery cathode material stratified.