Highly conductive MXene binder enabling Ge anode for stable sodium storage

Traditional binders and conductive agents are important electrode additives that contribute to the mechanical integrity and conductivity of sodium ion batteries (SIBs), but they affect the energy density of the batteries. In this study, Ti3C2Tx MXene was used as a conductive binder for a Ge anode owing to its high conductivity and clay-like property, which not only combined the functionality of the binders and additives but also provided additional sodium ion storage capacity. Ultra-long lifetime (high-capacity retention of 88% after 20 000 cycles) and enhanced rate performance (124.5 at 1500 mA g-1) were observed for the as-designed Ge-Ti3C2Tx anode. The Ge-Ti3C2Tx anode exhibited a specific capacity of 125.7 mA h g-1 at a current density of 100 mA g-1 after 100 cycles even at -20 °C. This Ti3C2Tx MXene conductive binder may enhance the electrode performance of the SIBs and other energy storage devices.