摘要
为改善LiFePO4低电子导电性和缓慢的锂离子扩散,采用十二烷基苯磺酸钠(SDBS)辅助水热法合成了LiFePO4/rGO复合正极材料。利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)和电化学测试等手段对复合物进行了表征。结果表明:SDBS最优浓度为0.225mol/L,此时合成的LiFePO4为高纯度的橄榄石型物相,其形貌为棒状,沿b轴尺寸为60~80nm,并且紧密地负载在褶皱的rGO的表面。在0.1C放电倍率下,LiFePO4/rGO复合物的首次容量为145.0mAh/g,且在1C倍率下循环200次没有明显的容量衰减,表现出良好的循环性能。电化学性能的改善归因于LiFePO4/rGO复合物极化和电荷转移电阻更小,电化学反应动力学更好。廉价易得的SDBS作为形貌诱导模板的同时实现了石墨烯的原位复合,该方法简单高效,可为其他电极材料改性提供借鉴。
In order to improve the inherent low electronic conductivity and sluggish Li+ diffusion of LiFePO4, LiFePO4/rGO composite cathode material was prepared by the hydrothermal approach assisted with sodium dodecylbenzene sulfonate(SDBS).LiFePO4/rGO composite was characterized by X-ray diffraction(XRD),field emission scanning electron microscopy (FE-SEM)and electrochemical techniques.Under the optimal concentration of SDBS with 0.225mol/L,the morphology of LiFePO4with pure olivine phase is rod-like with the dimension of 60~80nm in b-axis direction,anchoring well to the surface of rGO.At the discharge rate of 0.1C,the initial capacity of LiFePO4/rGO composite is 145.0mAh/g and no obvious capacity fading is observed after cycled 200times at the rate of 1C,manifesting a good cycle lifespan.The improvement of electrochemical performance is attributed to smaller polarization and charge transfer resistance,and better electrochemical reaction kinetics.The cheap and available SDBS can be used as morphology induced template and in-situ composite graphene is realized simultaneously.The method is simple and efficient,and it could be regarded as a reference for other electrode materials modification.
作者
胡志海
江国栋
熊剑
朱星
袁颂东
HU Zhi-hai;JIANG Guo-dong;XIONG Jian;ZHU Xing;YUAN Song-dong(Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy,Hubei University of Technology,Wuhan 430068,China;The Synergistic Innovation Center ofCatalysis Materials of Hubei Province,Wuhan 430068,China)
出处
《武汉理工大学学报》
CAS
北大核心
2018年第2期21-27,共7页
Journal of Wuhan University of Technology
基金
太阳能高效利用湖北省协同创新中心开放基金(HBSKFZD2015001,HBSKFQN2016005)
太阳能高效利用湖北省协同创新中心大学生科技创新基金(HBSDY201614)
中英研究与创新桥计划合作项目(2016YFE0124300)
创客创业资助科技创新项目(CKCY2017042814264604)
