Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Phys Chem Chem Phys. 2013 Sep 28;15(36):15098-105. doi: 10.1039/c3cp52808a.
Porous activated graphene sheets have been for the first time exploited herein as encapsulating substrates for lithium ion battery (LIB) anodes. The as-fabricated SnO2 nanocrystals-porous activated graphene sheet (AGS) composite electrode exhibits improved electrochemical performance as an anode material for LIBs, such as better cycle performance and higher rate capability in comparison with graphene sheets, activated graphene sheets, bare SnO2 and SnO2-graphene sheet composites. The superior electrochemical performances of the designed anode can be ascribed to the porous AGS substrate, which improves the electrical conductivity of the electrode, inhibits agglomeration between particles and effectively buffers the strain from the volume variation during Li(+)-intercalation-de-intercalation and provides more cross-plane diffusion channels for Li(+) ions. As a result, the designed anode exhibits an outstanding capacity of up to 610 mA h g(-1) at a current density of 100 mA g(-1) after 50 cycles and a good rate performance of 889, 747, 607, 482 and 372 mA h g(-1) at a current density of 100, 200, 500, 1000, and 2000 mA g(-1), respectively. This work is of importance for energy storage as it provides a new substrate for the design and implementation of next-generation LIBs exhibiting exceptional electrochemical performances.
多孔活性石墨烯片首次被用作锂离子电池 (LIB) 阳极的封装衬底。所制备的 SnO2 纳米晶-多孔活性石墨烯片 (AGS) 复合电极作为 LIB 阳极材料表现出改善的电化学性能，例如与石墨烯片、活性石墨烯片、裸 SnO2 和 SnO2-石墨烯片复合材料相比，具有更好的循环性能和更高的倍率性能。设计的阳极的优异电化学性能可归因于多孔 AGS 基底，其提高了电极的导电性，抑制了颗粒之间的团聚，并有效缓冲了在 Li(+)嵌入-脱嵌过程中体积变化引起的应变，为 Li(+)离子提供了更多的面内扩散通道。结果，设计的阳极在 50 次循环后在 100 mA g(-1)的电流密度下表现出高达 610 mA h g(-1)的出色容量，并且在 100、200、500、1000 和 2000 mA g(-1)的电流密度下分别表现出良好的倍率性能，为 889、747、607、482 和 372 mA h g(-1)。这项工作对于储能很重要，因为它为设计和实施具有出色电化学性能的下一代 LIB 提供了一种新的衬底。
