Ren Zongling, Wen Jie, Liu Wei, Jiang Xiaoping, Dong Yanheng, Guo Xiaolong, Zhao Qiannan, Ji Guipeng, Wang Ronghua, Hu Ning, Qu Baihua, Xu Chaohe
College of Aerospace Engineering, The State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing, 400044, People's Republic of China.
College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, People's Republic of China.
Nanomicro Lett. 2019 Aug 3;11(1):66. doi: 10.1007/s40820-019-0297-6.
Generally, the practical capacity of an electrode should include the weight of non-active components such as current collector, polymer binder, and conductive additives, which were as high as 70 wt% in current reported works, seriously limiting the practical capacity. This work pioneered the usage of ultralight reduced graphene fiber (rGF) fabrics as conductive scaffolds, aiming to reduce the weight of non-active components and enhance the practical capacity. Ultrathin SnS nanosheets/rGF hybrids were prepared and used as binder-free electrodes of sodium-ion batteries (SIBs). The interfused graphene fibers endow the electrode a porous, continuous, and conductive network. The in situ phase transformation from SnO to SnS could preserve the strong interfacial interactions between SnS and graphene. Benefitting from these, the designed binder-free electrode delivers a high specific capacity of 500 mAh g after 500 cycles at a current rate of 0.5 A g with almost 100% Coulombic efficiency. Furthermore, the weight percentage of SnS in the whole electrode could reach up to 67.2 wt%, much higher than that of common electrode configurations using Cu foil, Al foil, or carbon cloth, significantly highlighting the ultralight characters and advantages of the rGF fabrics for using as binder-free electrodes of SIBs.
一般来说，电极的实际容量应包括集流体、聚合物粘结剂和导电添加剂等非活性成分的重量，在目前已报道的工作中，这些成分高达70 wt%，严重限制了实际容量。本工作率先使用超轻还原氧化石墨烯纤维（rGF）织物作为导电支架，旨在减轻非活性成分的重量并提高实际容量。制备了超薄SnS纳米片/rGF复合材料，并将其用作钠离子电池（SIBs）的无粘结剂电极。相互融合的石墨烯纤维赋予电极多孔、连续且导电的网络结构。从SnO到SnS的原位相变能够保持SnS与石墨烯之间强烈的界面相互作用。受益于此，所设计的无粘结剂电极在0.5 A g的电流密度下循环500次后，具有500 mAh g的高比容量，库仑效率几乎达到100%。此外，整个电极中SnS的重量百分比可达67.2 wt%，远高于使用铜箔、铝箔或碳布的普通电极结构，显著突出了rGF织物用作SIBs无粘结剂电极的超轻特性和优势。
