研究具有高容量的负极材料是提高锂离子电池性能的重要方向。采用水热反应法制备环状Fe2O3晶体颗粒,环状Fe2O3晶体是由微米尺寸颗粒组成,环状晶体颗粒的内径约1μm,外径约1.5μm,平均高度为2.5μm。在0.01~3.0 V(Li+/Li)的电压区间内,采用动电流循环考察电极材料的储锂性能和循环性能。在100 m A/g的电流密度下稳定循环100次,环状Fe2O3晶体颗粒电极表现出高的可逆储锂容量480.8(m A·h)/g,和良好的循环稳定性能。Fe2O3晶体颗粒高的储锂性能和优异的循环性能是由于其特殊的环状结构形成了良好的导电网络,并有效地缓冲了锂离子嵌/脱反应过程中造成的电极材料巨大的体积变化。
Although metallic interconnects have many advantages,the formation of Cr2O3 scale and the evaporation of Cr(Ⅵ)species from alloys will greatly degrade the solid oxide fuel cell(SOFC)performance.In this paper,the electrochemical impedance spectroscopy(EIS)and the cathode polarization method of galvanostatic current interruption were employed to investigate the deposition mechanism of chromium with the electrochemical behavior of LSM cathode in the presence of chromia-forming alloys.The results show that the dissociative adsorption and the diffusion of oxygen on the LSM surface were inhibited by the gaseous chromium species and the migration processes of oxygen ions into YSZ electrolyte were inhibited by the solid chromium species deposited on the YSZ surface.