【摘要】 通过冷冻干燥与镁热还原相结合的简单方法,设计制备了一种新型硅基/石墨烯复合材料（HD-P-Si/GS）.通过X射线衍射仪、扫描电镜和透射电镜研究了HD-P-Si/GS的物相组成、表面形貌及微观结构,并系统分析了HD-P-Si/GS的电化学性能.结果表明：多孔纳米硅高度分散在三维石墨烯导电网络中,这种石墨烯包覆多孔硅结构的设计能够有效缓解硅体积变化引起的过度应力,并为电子传输提供三维通道,提高复合材料的电导率.将HD-P-Si/GS复合材料用作锂离子电池负极获得了良好的循环稳定性及倍率性能.在1 000 m A/g的高电流密度下,HD-P-Si/GS负极经过200次循环后仍可提供约703 m Ah/g的高可逆比容量.更多还原

【Abstract】 A novel silicon-based/graphene composite(HD-P-Si/GS) was developed by a simple method combining with freeze-drying and magnesium-thermal reduction.The phase composition,surface morphology and micro structure of HD-P-Si/GS were studied by X-ray diffraction,Scanning electron microscope and Transmission electron microscope.The electrochemical performances of HD-P-Si/GS were analyzed by the NEWARE battery test system.The results show that porous nano silicon is highly dispersed in the 3D graphene conductive network.The design of graphene-wrapped porous silicon structure can effectively alleviate the excessive stress caused by silicon volume change,provide 3D channels for electrons transmission and improve the conductivity of composite.Based on this,the HD-P-Si/GS composite achieves good cycling stability as well as rate performance as anode for lithium-ion battery:HD-P-Si/GS anode delivers an excellent reversible capacity of 703 m Ah/g even at a high current density of 1 000 m A/g over 200 cycles.更多还原