【摘 要】
：
锂离子电池的性能在很大程度上取决于电池材料的可逆脱/嵌锂容量，其中阴极材料较低的容量是阻碍高容量锂离子电池发展的瓶颈。纳米材料因其具有离子扩散路径短、蠕动性强和塑性高等特点，将其应用于锂离子电池阴极材料可显著改善脱/嵌锂容量、电极的循环使用寿命和电极材料与电解质溶液的浸润性。本工作利用本课题组之前报道的专利技术，首先制备出物相纯净且平均晶粒尺寸＜15nm的纳米晶Li2C2合金。利用原位透射电镜技术
【机 构】
：
北京工业大学材料科学与工程学院/新型功能材料教育部重点实验室,北京100124
【出 处】
：
第十七届全国相图学术会议暨相图与材料设计国际研讨会
论文部分内容阅读
锂离子电池的性能在很大程度上取决于电池材料的可逆脱/嵌锂容量，其中阴极材料较低的容量是阻碍高容量锂离子电池发展的瓶颈。纳米材料因其具有离子扩散路径短、蠕动性强和塑性高等特点，将其应用于锂离子电池阴极材料可显著改善脱/嵌锂容量、电极的循环使用寿命和电极材料与电解质溶液的浸润性。本工作利用本课题组之前报道的专利技术，首先制备出物相纯净且平均晶粒尺寸＜15nm的纳米晶Li2C2合金。利用原位透射电镜技术直接动态观察纳米晶Li2C2合金电池材料的脱/嵌锂过程。发现在脱锂过程中发生较明显的体积减小，在嵌锂过程中纳米晶Li2C2电极发生显著的体积及形貌变化，而且在多次脱/嵌锂循环结束后纳米晶Li2C2发生了晶态向非晶态的相转变。原位脱/嵌锂实验所得结构和形貌数据对后续电化学测试参数的选取及其实际应用起到关键指导作用。纳米晶Li2C2在电化学测试中循环250次后放电容量仍保持较高水平(67 mAg-1)。本文研究结果证明，纳米晶Li2C2具有锂离子电池阴极材料的重要开发潜力。本工作为新型高容量纳米晶合金阴极材料的设计制备提供了新的研究思路和科学机理。
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