Two-Dimensional F-Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>@Ag Composite for an Extraordinary Long Cycle Lifetime with High Specific Capacity in an Aluminum Battery
Xiaogeng Huo, Bao Zhang, Jianling Li, Xiao‐Xu Wang, Te Qin, Yu Zhang, Feiyu Kang
Abstract
According to the current research, the graphene-like two-dimensional materials present excellent electrochemical performance in aluminum batteries. However, there is less research on emerging two-dimensional materials in aluminum batteries, and the energy storage mechanism is ambiguous. Herein, we modified the two-dimensional few layered Ti3C2Tx (F-Ti3C2Tx) with Ag+ and prepared a composite material F-Ti3C2Tx@Ag. The results of physical characterization show that Ag+ is reduced to Ag by Ti ions and is in situ grown on the surface and interlayer of F-Ti3C2Tx. More importantly, the electrochemical performance of the two-dimensional material F-Ti3C2Tx@Ag is studied in an aluminum battery and shows extraordinary long cycle lifetime with high specific capacity. The discharge specific capacity is about 150 mA h g–1 after 2000 cycles at a current density of 0.5 A g–1. Furthermore, the energy storage mechanism of F-Ti3C2Tx@Ag in aluminum batteries is studied, which shows that it is mainly the intercalation/de-intercalation of [AlCl4]−, accompanied by a small amount of Al3+ intercalating/de-intercalating. In addition, density functional theory (DFT) calculations are carried out to study the interaction between MXene@Ag and [AlCl4]− and between MXene and [AlCl4]−. The results show that [AlCl4]− anions are easier to intercalate/de-intercalate between the layers of Ti3C2O2–Ag.