通过共沉淀法与高温固相法相结合的方法合成锂离子电池用富锂层状正极材料Li[Li0.17Ni0.17Co0.10Mn0.56]O2,利用液相沉淀法对材料进行Li Co PO4包覆,通过X射线衍射(XRD)、扫描电子显微镜(SEM)对材料物性进行表征,利用恒电流充放电仪对材料电化学性能进行研究,结果表明包覆后材料电化学性能有较大改善,0.05 C首次放电比容量为245m Ah/g,经过50次循环后放电比容量为232 m Ah/g,且经过Li Co PO4包覆后材料首次效率明显提高,同时循环及倍率性能也得到改善,包覆层Li Co PO4不仅允许更多锂离子嵌入材料,而且隔绝富锂材料与电解液接触,有效阻止材料与电解液发生反应。
A novel composite of monoclinic manganite/multi-walled carbon nanotubes(c-MnOOH/MWCNTs)composite as a cathode material of lithium-air batteries was successfully synthesized by a simple one-step hydrothermal method.Owing to the unique three-dimensional network of c-MnOOH embedded in the porous structure of MWCNTs,the c-MnOOH/MWCNTs composite could have an advantage of high electrocatalytic activities over those of two other kinds of cathode materials(MWCNTs and c-MnOOH/MWCNTs mixture).The results of chargedischarge tests showed that the c-MnOOH/MWCNTs composite as a cathode material of lithium-air batteries could effectively enhance the catalytic activity for the oxygen evolution reduction(OER)process.The lithium-air battery based on c-MnOOH/MWCNTs composite exhibits low charge potential and high discharge capacity.
