V₂CT_x MXene-Encapsulated Liquid Metal Composite as an Anode for Wide-Temperature Li-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) suffered from severe performance fading when operated at lower temperatures due to the increase of Li desolvation energy and the formation of Li dendrites on the anode surface. It is critically important to develop a suitable anode with higher capacity retention at lower temperatures for advanced LIBs. Herein, we report the fabrication of a composite anode by confining room-temperature liquid GaInSn alloys within a porous 2D-layered V 2 CT x MXene. This configuration combines the high capacity of liquid metal (LM) and high ionic conductivity of 2D V 2 CT x by confining self-healing LM within the V 2 CT x framework, resulting in enhanced long-term cycle performance (1174.6 mA h g −1 after 200 cycles at 200 mA g −1 ) and low-temperature performance (529.6 mA h g −1 after 100 cycles at −20 °C). Theoretical calculations disclose that the strong adsorption of V 2 CT x to LM ensures the stability of the composites. It also reveals that LM with a lower adsorption energy promotes the transportation of Li + . The LM nanodroplets buffer the volume change of V 2 CT x during charging/discharging and avoid electrode crushing. The expanded layers of V 2 CT x and the porous structure facilitate the Li-ion desolvation and transportation at lower temperatures, thus suppressing the performance fading. This work paves the way for the development of composite anodes for LIBs with high specific capacity toward low-temperature applications.