Jian Zhixu, Zhang Shichao, Guan Xianggang, Li Jiajie, Li Honglei, Wang Wenxu, Xing Yalan, Xu Huaizhe
School of Materials Science and Engineering, Beihang University Beijing 100191 PR China
School of Physics, Beihang University Beijing 100191 PR China.
RSC Adv. 2020 Sep 4;10(54):32966-32975. doi: 10.1039/d0ra04986g. eCollection 2020 Sep 1.
Lithium-sulfur batteries are considered the most promising next-generation energy storage devices. However, problems like sluggish reaction kinetics and severe shuttle effect need to be solved before the commercialization of Li-S batteries. Here, we successfully prepared ZnO quantum dot-modified reduced graphene oxide (rGO@ZnO QDs), and first introduced it into Li-S cathodes (rGO@ZnO QDs/S). Due to its merits of a catalysis effect and enhancing the reaction kinetics, low surface impedance, and efficient adsorption of polysulfide, rGO@ZnO QDs/S presented excellent rate capacity with clear discharge plateaus even at a high rate of 4C, and superb cycle performance. An initial discharge capacity of 998.8 mA h g was delivered, of which 73.3% was retained after 400 cycles at a high rate of 1C. This work provides a new concept to introduce quantum dots into lithium-sulfur cathodes to realize better electrochemical performance.
锂硫电池被认为是最有前途的下一代储能设备。然而，在锂硫电池商业化之前，诸如反应动力学迟缓以及严重的穿梭效应等问题需要解决。在此，我们成功制备了氧化锌量子点修饰的还原氧化石墨烯（rGO@ZnO QDs），并首次将其引入锂硫电池正极（rGO@ZnO QDs/S）。由于其具有催化作用、增强反应动力学、低表面阻抗以及高效吸附多硫化物的优点，rGO@ZnO QDs/S即使在4C的高倍率下也呈现出优异的倍率性能，具有清晰的放电平台，并且循环性能卓越。其首次放电容量为998.8 mA h g，在1C的高倍率下循环400次后仍保留73.3%。这项工作为将量子点引入锂硫电池正极以实现更好的电化学性能提供了一个新概念。
