二氧化锰纳米片作为锂离子电池负极材料研究

摘要

MnO2作为锂离子电池负极材料因具有高比容量已被广泛研究.在充放电过程中,其剧烈的体积膨胀变化导致电极粉化,从而比容量衰减严重.针对这一问题,本文采取水热及煅烧晶化法合成了薄层状MnO2纳米片.采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、高倍率透射电子显微镜(HR-TEM)和恒电流充放电测试,对充放电循环反应前后的电极片的物相结构、形貌结构和电化学性能进行了详细考察.结果表明,薄层片状结构有利于维持结构稳定性,在长时间充放电循环过程中展现出良好的循环稳定性,且在反应后依旧保持层状结构.%Manganese dioxide as a cathode material for lithium ion batteries has been given lots of attention due to the high specific capacity.But the large volume expansion during the process of charging and discharging make the electrode polarization and capacity fade.To solve this problem,nanoscale morphology of manganese dioxide is prepared by hydrothermal and calcining crystallization method.The phase structure,morphology and electrochemical properties of the electrodes were investigated by the XRD,FE-SEM,HR-TEM and charge techniques before and after the charge discharge cycle reaction.The results indicate that the nanoscale morphology is favour to maintain structural stability and shows well long-term cycle-stability,and keep the layered structure after the reaction