Rapid Microwave-Assisted Solvothermal Synthesis of Non-Olivine <i>Cmcm</i> Polymorphs of LiMPO<sub>4</sub> (M = Mn, Fe, Co, and Ni) at Low Temperature and Pressure
作者:Gaurav Assat、Arumugam Manthiram
DOI:10.1021/acs.inorgchem.5b01787
日期:2015.10.19
phosphates, LiMPO4 (M = Mn, Fe, Co, and Ni), have attracted significant research interest over the past two decades as an important class of lithium ion battery cathode materials. However, almost all of the investigations thus far have focused on the olivine polymorph that exists in the orthorhombic Pnma space group. In this study, a distinct orthorhombic but non-olivine polymorph of LiMPO4, described
锂过渡金属磷酸盐LiMPO 4(M = Mn,Fe,Co和Ni)作为锂离子电池正极材料的重要一类,在过去的二十年中引起了广泛的研究兴趣。但是,到目前为止,几乎所有的研究都集中在正交晶体Pnma空间群中存在的橄榄石多晶型物上。在这项研究中,已合成出一种由Mcm,Mn,Fe,Co和Ni组成的,由Cmcm空间群对称性描述的LiMPO 4的正交晶但非橄榄石的多晶型物。其中,的LiMnPO 4在CMCM空间组是首次报告。快速微波辅助溶剂热(MW-ST)加热工艺,以四甘醇(TEG)为溶剂,草酸过渡金属盐为前体,有助于这些材料的合成。峰值反应温度和压力分别低于300°C和30 bar,比以前报道的高压方法(千兆帕斯卡)要低几个数量级。X射线衍射(XRD)证实了Cmcm的晶体结构空间群,扫描电子显微照片表明亚微米级的薄片状形态。通过XRD和电感耦合等离子体发射光谱(ICP-OES)对合成工艺条件进行了优化