快速充电速率和大储能是电动汽车锂离子电池(LIB)的关键要求。开发具有可在高速率下操作的高体积和重量容量的电极材料是最具挑战性的问题。在这项工作中,提出了一种用于Li/Na离子电池的具有增强的综合电化学性能的致密碳材料的通用多界面策略。将氧化石墨烯和蔗糖溶液的混合物喷雾到水/油系统中并进一步碳化以获得石墨烯/硬碳球(GHS)。在这种材料中,结晶石墨烯和碳基质之间丰富的巧妙的内部界面是在硬碳球内部创建的。构造的界面不仅可以作为蔗糖热解过程中产生的挥发性气体逸出的途径,以防止形成丰富的孔隙,导致0.910gcm-3的高包装密度和13.3m2g-1的低表面积,但也可以为离子和电子提供导电的“高速公路”。当用作LIB和钠离子电池(SIB)的阳极材料时,GHS显示出高重量/体积可逆容量,高速率性能,同时具有低温特性,暗示着在实际LIB和SIB中的巨大潜在应用。
Fast charging rate and large energy storage are key requirements for lithium-ion batteries (LIBs) in electric vehicles. Developing electrode materials with high volumetric and gravimetric capacity that could be operated at a high rate is the most challenging problem. In this work, a general multi-interface strategy toward densified carbon materials with enhanced comprehensive electrochemical performance for Li/Na-ion batteries is proposed. The mixture of graphene oxide and sucrose solution is sprayed into a water/oil system and furtherly carbonized to get graphene/hard carbon spheres (GHSs). In this material, abundant ingenious internal interfaces between the crystalline graphene and the carbon matrix are created inside the hard carbon spheres. The constructed interfaces can not only work as a pathway for the escape of volatile gas generated during sucrose pyrolysis to prevent the formation of abundant pores, which leads high packing density of 0.910 g cm-3 and low surface area of 13.3 m2 g-1 , but can also provide a conductive \"highway\" for ions and electrons. When used as the anode material for both LIBs and sodium-ion batteries (SIBs), the GHS shows the high gravimetric/volumetric reversible capacities, high-rate performance, and low temperature properties simultaneously, implying the great potential application in practical LIBs and SIBs.