摘要
由于传统的正极材料LiCoO_2比容量相对较低,而LiMnO_2理论比容量可达285mAh/g,且锰资源储量丰富、价格低廉、不含毒性,可作为能源材料替代LiCoO2。但在制备LiMnO_2的过程中,由于姜泰勒效应,层状结构容易转变为尖晶石结构。此外,Mn在有机电解质溶液中易溶解,造成比容量大幅降低,制约着LiMnO_2的应用。本文主要通过掺杂改性,单元掺杂Cr相,进而研究掺杂对电化学性能的影响。研究结果表明,对LiMnO_2的Cr掺杂改性,提高了其放电比容量及循环寿命,电化学性能得到改善。
The specific capacity of traditional cathode material LiCoO_2 is relatively low,so the development of alternative high capacity cathode material is imminent. The theoretical specific capacity of LiMnO_2 is 285m Ah / g,furthermore,the manganese resource is abundant,and has the characteristics of low cost,without toxicity,so the manganese resource can be used as alternative energy materials for LiCoO_2. In the process of preparing LiMnO_2,the Mn^(3+) is liable to be oxidized due to Jahn-Teller effect,and the layer structure can be transformed into spinel structure easily. Moreover,Mn is easily dissolved in organic electrolyte solution,which significantly reduces specific capacity. Aiming at the shortcomings of the traditional high temperature solid-state method,researches mainly adopt doping and coating to produce cathode materials at present.Through the doping modification and mono-doped Cr which are contrasted with undoped pure phase,the effects of doping on the electrochemical performance are studied. The research results show that Cr-doped modification of LiMnO_2,can improve its discharge specific capacity and cycle life,then the electrochemical property is improved accordingly.
出处
《工程与试验》
2016年第3期49-53,共5页
Engineering and Test