摘要
巴尔沙木是一种典型的速生木,并可以通过高温碳化制备为硬碳材料。该硬碳材料作为钠离子电池负极使用时,虽然表现出较高的比容量,但首次库伦效率(ICE)较低,为70%左右,从而限制了其作为钠离子电池负极材料的进一步应用。为提高其ICE,本工作将巴尔沙木在氧化石墨水溶胶中真空浸渍处理后,再经高温热处理得到改性材料。该材料在氧化石墨的孔道覆盖和共碳化作用下,相比未改性的材料,比表面积降低,碳层间距变小,碳层堆叠结构更加有序,最终实现了首次库伦效率的大幅度提升(电流密度20 mA·g^(-1)下为86.9%,电流密度1 A·g^(-1)下为96.6%)。同时,改性后的巴尔沙木基硬碳在容量上也表现出了更优的性能:0.1 A·g^(-1)电流密度下,容量达到约314 mAh·g^(-1);1 A·g^(-1)电流密度下充放电循环500次后,容量高于240 mAh·g^(-1),具有很好的应用前景。
As a kind of typical fast growing wood,balsa wood can be used to prepare hard carbon by high temperature carbonization.Although the obtained hard carbon has high specific capacities when using as sodium ion battery anodes,its initial coulombic efficiency(ICE)is just about 70%,which limits it’s further application.In order to increase ICE,the raw balsa wood was impregnated with graphite oxide hydrosol under vacuum and then treated with high temperature.Owing to pores’covering and co-carbonization with graphite oxide,the specific surface area of balsa wood based hard carbon decreases,the carbon layers in hard carbon shows less interlayer distance and better stacking structure,which increases the ICE of balsa wood based hard carbon to be 86.9%at a current density of 20 mA·g^(-1)and 96.6%at a current density of 1 A·g^(-1).Additionally,the hard carbon modified by graphite oxide shows higher specific capacities(about 314 mAh·g^(-1)at a current density of 0.1 A·g^(-1),more than 240 mAh·g^(-1)at 1 A·g^(-1)after 500 times charge/discharge cycles)than original hard carbon,which has a very good application prospect.
作者
王蕾
刘少冕
范凤兰
韩伟
WANG Lei;LIU Shaomian;FAN Fenglan;HAN Wei(Department of Chemistry and Chemical Engineering,Hebei Minzu Normal University,Chengde 067000,Hebei,China;School of Physics and Electronic Engineering,Hebei Minzu Normal University,Chengde 067000,Hebei,China)
出处
《材料导报》
北大核心
2025年第23期219-224,共6页
Materials Reports
基金
河北省教育厅科学研究项目(ZC2024162)
河北民族师范学院科研项目(PT2023002)
河北民族师范学院博士科研启动基金项目(DR2022008)。
关键词
速生木
氧化石墨水溶胶
硬碳
钠离子电池
电化学性能
fast growing wood
graphite oxide hydrosol
hard carbon
sodium ion batteries
electrochemical performances
