Yuanzheng Luo, Zhicheng Ye, Lianghao Mo, Buyin Li, Shufa Li
School of Electronic Information Engineering, Guangdong Ocean University China
School of Optical and Electronic Information, Huazhong University of Science and Technology China.
Nanoscale Adv. 2022 Apr 6;4(9):2189-2195. doi: 10.1039/d2na00072e. eCollection 2022 May 3.
Lithium-sulfur batteries (LSBs) take a leading stand in developing next-generation secondary batteries with an exceptionally high theoretical energy density. However, the insulating nature and undesirable shuttle effect still need to be solved to improve the electrochemical performance. Herein, a freestanding graphene supported N-doped TiCT MXene@S cathode is successfully synthesized a straightforward no-slurry method. Due to its unique hierarchical microstructure, the MXene-C/S ternary hybrids with high capacity can effectively adsorb polysulfides and accelerate their conversion. Cooperatively, conductive rGO can ameliorate N-MXene nanosheet' restacking, making the lamellar N-Mxene coated sulfur particles disperse uniformly. The assembled Li-S battery with a freestanding TiCT @S/graphene electrode provides an initial capacity of 1342.6 mA h g at 0.1C and only experiences a low capacity decay rate of 0.067% per cycle after. Even at a relatively high loading amount of 5 mg cm, the battery can still yield a high specific capacity of 684.9 mA h g at 0.2C, and a capacity retention of 89.3% after 200 cycles.
锂硫电池（LSB）在开发具有超高理论能量密度的下一代二次电池方面处于领先地位。然而，绝缘性和不良的穿梭效应仍需解决，以提高其电化学性能。在此，通过一种简单的无浆料方法成功合成了一种独立的石墨烯负载氮掺杂TiCT MXene@S阴极。由于其独特的分级微观结构，具有高容量的MXene-C/S三元杂化物能够有效吸附多硫化物并加速其转化。同时，导电的还原氧化石墨烯（rGO）可以改善氮掺杂MXene纳米片的重新堆叠，使层状氮掺杂MXene包覆的硫颗粒均匀分散。采用独立的TiCT @S/石墨烯电极组装的锂硫电池在0.1C时的初始容量为1342.6 mA h g，此后每循环的容量衰减率仅为0.067%。即使在5 mg cm的相对较高负载量下，该电池在0.2C时仍能产生684.9 mA h g的高比容量，并且在200次循环后容量保持率为89.3%。
