Rational design of Sn4P3/Ti3C2Tx composite anode with enhanced performance for potassium-ion battery

The potential application of high-capacity Sn4P3 anode for potassium-ion batteries (PIBs) is hindered by the poor cycle stability mainly rooted from the huge volume changes upon cycling and low electronic conductivity. To address the above issues, sandwich-like structured Sn4P3/Ti3C2Tx was designed and synthesized as anode material for PIBs. As a result, Sn4P3/Ti3C2Tx presents superior cycle stability (retains a capacity of 103.2 mAh·g−1 even after 300 cycles at 1000 mA·g−1) and rate capability (delivers 60.7 mAh·g−1 at high current density of 2000 mA·g−1). The excellent electrochemical performance of sandwich-like structured Sn4P3/Ti3C2Tx is originated from the synergistic effect between Sn4P3 and Ti3C2Tx, where Ti3C2Tx acts as a conductive matrix to facilitate electron transfer and buffer the volume change of Sn4P3 particles upon cycling, while Sn4P3 serves as pillars to prevent the collapse and stacking of Ti3C2Tx sheets. Moreover, significant capacitive contribution is demonstrated as a major contributor to the excellent rate capability. Graphical abstract