琼脂包覆和NH_(4)F改性纳米硅用作锂离子电池负极材料的研究  

Agar-coated and NH_(4)F Modified Nanosilicon as Anode Material for Lithium-ion Battery

作　　者：李正伟 吴强 周建华 秦海青 苗蕾[1] 刘文平 雷晓旭 张振军 卢安军 莫祖学 LI Zhengwei;WU Qiang;ZHOU Jianhua;QIN Haiqing;MIAO Lei;LIU Wenping;LEI Xiaoxu;ZHANG Zhenjun;LU Anjun;MO Zuxue(Guangxi Key Laboratory of Conformational Relationships for Electronic Information Materials,School of Materials Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China;Guangxi Key Laboratory of Superhard Material,China Nonferrous Metal(Guilin)Geology and Mining Co.,Ltd.,Guilin 541004,Guangxi,China;Guangxi Technology Innovation Center for Special Mineral Material,China Nonferrous Metal(Guilin)Geology and Mining Co.,Ltd.,Guilin 541004,Guangxi,China)

机构地区：[1]桂林电子科技大学材料科学与工程学院,广西电子信息材料构效关系重点实验室,广西桂林541004 [2]中国有色桂林矿产地质研究院有限公司广西超硬材料重点实验室,广西桂林541004 [3]中国有色桂林矿产地质研究院有限公司广西特种矿物材料技术创新中心,广西桂林541004

出　　处：《陶瓷学报》2024年第3期501-507,共7页Journal of Ceramics

基　　金：桂林市重点研发计划项目(20220110-1);广西杰出青年基金(2019GXNSFFA245010);国家自然科学基金(52173094)。

摘　　要：硅负极材料由于具有成本低、比容量高和安全可靠的优势,成为高能量密度锂离子电池的理想材料之一。但是,在锂嵌入过程中会产生严重的体积膨胀,且材料导电性差及循环稳定性差等问题限制了硅负极材料的商业应用。为此,通过一锅水浴法采用琼脂和NH_(4)F对纳米硅实现碳包覆和掺杂改性,制备琼脂衍生碳/NH_(4)F@纳米硅复合材料(Si@FNC),对其结构、形貌和电化学性能进行研究。结果表明:经NH_(4)F掺杂改性处理后,Si@FNC复合材料的循环稳定性和导电性能显著提高。当掺杂的NH_(4)F与纳米硅粉质量比为1∶5时,在500 mA·g^(−1)的电流密度下,Si@FNC复合材料首次放电比容量为2001.0 mAh·g^(−1),循环充放电200次后仍保持在836.7 mAh·g^(−1),展示出优异的电化学性能,对推广高容量硅碳负极材料具有一定的参考价值。Silicon anode material becomes one of the ideal materials for high energy density lithium-ion battery,due to its low cost,high specific capacity and reliable safety.However,severe volume expansion during lithium embedding,poor material conductivity and poor cycling stability limit the commercial application of silicon anode material.Therefor,agar-derived carbon/NH_(4)F@nanosilicon composites(Si@FNC)were prepared by using a one-pot sol-gel method with agar and NH_(4)F to realize carbon coating and doping modification.Structure,morphology and electrochemical properties of the Si@FNC composites were studied.Cyclic stability and electrical conductivity of the Si@FNC composites were significantly improved after NH_(4)F modification.When the mass ratio of NH_(4)F to Si was 1:5,the first discharge specific capacity was 2001.0 mAh·g^(−1)at a current density of 500 mA·g^(−1),while the residual capacity was still maintained at 836.7 mAh·g^(−1)after 200 cycles.The results could be used as a reference for further exploration of high-capacity silicon-carbon anode materials.

关 键 词：锂离子电池 硅碳负极材料 纳米硅 NH_(4)F掺杂改性 

分 类 号：TQ174.75[化学工程—陶瓷工业]