【摘要】 研究了富锂锂锰氧化物中氧缺陷对材料电化学性能的影响 .X射线衍射谱表明有氧缺陷的锂锰氧化物仍可保持尖晶石结构 ,当氧缺陷浓度达到一定程度时 ,高角度区的衍射峰出现分裂 ,说明其微观结构发生了变化 .充放电实验结果表明氧缺陷使 4V区的锂离子嵌脱变成了多步 ,模拟电池的容量微分曲线有 3对清晰的氧化还原峰 ,低电位的氧化还原峰被一分为二 .氧缺陷降低了材料的放电容量 ,同时引起低电位区的放电容量向更低电位区转移 ,使电化学性能恶化 .锂锰氧化物中氧缺陷对电化学性能的影响对此类材料的合成提供了理论和实践依据 .更多还原

【Abstract】 Three lithium-rich manganese oxides with oxygen deficiency, Li 1.07Mn 1.93O 4-δ, were obtained. Their structure and electrochemical characterizations were carried out. They have the spinel structure based on XRD analysis. It was observed that their specific capacities of charge/discharge reaction at 4V plateau decreased with increasing the population of oxygen vacancy. Their relationships of dQ/dV vs V all show three-step for lithium ion extraction and insertion instead of the two-step reaction. That is due to the peak splitting into two in low potential district. The effect of oxygen vacancies in lithium-rich manganese oxides on the electrochemical performance was discussed.更多还原