Xu Jianguang, Jin Menglan, Shi Xinlu, Li Qiuyu, Gan Chengqiang, Yao Wei
School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
Nanomaterials (Basel). 2021 Sep 2;11(9):2279. doi: 10.3390/nano11092279.
Although silicon has highest specific capacity as anode for lithium-ion battery (LIB), its large volume change during the charge/discharge process becomes a great inevitable hindrance before commercialization. Metal silicides may be an alternative choice because they have the ability to accommodate the volume change by dispersing Si in the metal matrix as well as very good electrical conductivity. Herein we report on the suitability of lithium-ion uptake in C54 TiSi prepared by the "chemical oven" self-propagating high-temperature synthesis from the element reactants, which was known as an inactive metal silicide in lithium-ion storage previously. After being wrapped by graphene, the agglomeration of TiSi particles has been efficiently prevented, resulting in an enhanced lithium-ion storage performance when using as an anode for LIB. The as-received TiSi/RGO hybrid exhibits considerable activities in the reversible lithiation and delithiation process, showing a high reversible capacity of 358 mAh/g at a current density of 50 mA/g. Specially, both TiSi and TiSi/RGO electrodes show a remarkable enhanced electrochemical performance along with the cycle number, indicating the promising potential in lithium-ion storage of this silicide. Ex-situ XRD during charge/discharge process reveals alloying reaction may contribute to the capacity of TiSi. This work suggests that TiSi and other inactive transition metal silicides are potential promising anode materials for Li-ion battery and capacitor.
尽管硅作为锂离子电池（LIB）的负极具有最高的比容量，但其在充放电过程中的巨大体积变化成为商业化之前不可避免的重大阻碍。金属硅化物可能是一种替代选择，因为它们能够通过将硅分散在金属基体中来适应体积变化，并且具有非常好的导电性。在此，我们报道了通过“化学炉”自蔓延高温合成法由元素反应物制备的C54 TiSi对锂离子的摄取适用性，该物质先前在锂离子存储中被认为是一种惰性金属硅化物。被石墨烯包裹后，TiSi颗粒的团聚得到了有效防止，从而在用作LIB负极时提高了锂离子存储性能。所制备的TiSi/RGO复合材料在可逆锂化和脱锂过程中表现出相当的活性，在50 mA/g的电流密度下显示出358 mAh/g的高可逆容量。特别地，TiSi和TiSi/RGO电极的电化学性能都随着循环次数的增加而显著增强，表明这种硅化物在锂离子存储方面具有潜在的应用前景。充放电过程中的非原位XRD表明合金化反应可能对TiSi的容量有贡献。这项工作表明，TiSi和其他惰性过渡金属硅化物是锂离子电池和电容器潜在的有前景的负极材料。
