Development of high power density electrode system on the basis ofconstruction of ionic conduction channel of hierarchic structure

首次用电化学方法测定了锂在磁赤铁矿（γ-Fe_2 O_3）中的扩散系数。将磁赤铁矿纳米粒子与结构导电介质科琴黑复合，制备出具有纳米尺度和介观尺度离子导电通道的分级结构材料。将其作为锂空气电池的正极进行了研究，发现其具有良好的可逆性和循环性能，并通过转化反应得到了铁基层状化合物CaFeO 2和SrFeO 2作为锂离子电池的负极。特别地，CaFeO 2显示出比基于转化反应预期的高的比容量，这可能归因于钙和锂的合金化反应。

Lithium diffusion coefficient in maghemite(γ-Fe2O3) was first and electrochemically determined. A composite material of the maghemite nanoparticles and ketjenblack, which was a structural and electrically conducting medium, was fabricated as hierarchically structural material possessing nano-and meso-scale ionic conduction channel. It was examined as cathode of lithium-air battery and exhibited good performance in terms of both reversibility and cyclability.Iron-based layer compounds CaFeO2 and SrFeO2 were found to serve as anodes of lithium ion battery through conversion reactions. In particular, CaFeO2 showed higher specific capacity than expected on the basis on the conversion reaction, which was probably attributed to alloying reaction of calcium and lithium.