富锂锰基材料(LRM)由于电压平台高、比容量高,在锂电池材料研究中受到广泛关注。针对富锂锰基材料首次充放电库仑效率较低的问题,采用Li2S对富锂锰基材料(LRM)进行掺杂改性制备得到LRM-S材料。结果表明:LRM和LRM-S的晶体结构相近,具有层状晶体结构。扫描电镜分析表明,LRM-S材料由10～20nm的一次颗粒团聚而成。元素分析表明LRM-S材料中含有均匀分散的S元素。电化学分析表明,LRM的首次充电比容量为291.80mAh/g,首次放电比容量为188.63mAh/g,首次库仑效率为64.64%。Li2S掺杂改性材料LRM-S的首次充电比容量为387.04mAh/g,首次放电比容量为272.64mAh/g,首次库仑效率为70.44%,在首次充放电比容量和效率方面均有显著提升。
Lithium-rich manganese-based materials (LRM) have received extensive attention in the research of lithium battery materials due to their high voltage platform and high specific capacity.In this paper,in order to solve the problem of low first coulombic efficiency of LRM,Li2S was used to dope and modify LRM to prepare LRM-S materials.The results showed that the crystal structures of LRM and LRM-S were similar and had a monoclinic crystal structure.Scanning electron microscopy analysis revealed that the LRM-S material was formed by agglomeration of primary particles of about 10～20nm.Elemental analysis exhibited that the LRM-S material contained evenly dispersed S element.Electrochemical analysis displayed that the first charge specific capacity of LRM was 291.80mAh/g,the first discharge specific capacity was 188.63mAh/g,and the first charge-discharge efficiency was 64.64%.The first charge specific capacity of the Li2S-doped modified material LRM-S was 387.04mAh/g,the first discharge specific capacity was 272.64mAh/g,and the coulombic efficiency was 70.44%,indicating the first charge and discharge specific capacity and efficiency were significantly improved.
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基金资助
2021年度河南省重点研发与推广专项(科技攻关)(212102210215);2021年度河南工程学院科研培育基金项目(PYXM202101)
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