Rational design of Sn 4 P 3 /Ti 3 C 2 T x composite anode with enhanced performance for potassium‐ion battery

Abstract The potential application of high‐capacity Sn 4 P 3 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 Sn 4 P 3 /Ti 3 C 2 T x was designed and synthesized as anode material for PIBs. As a result, Sn 4 P 3 /Ti 3 C 2 T x 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 Sn 4 P 3 /Ti 3 C 2 T x is originated from the synergistic effect between Sn 4 P 3 and Ti 3 C 2 T x , where Ti 3 C 2 T x acts as a conductive matrix to facilitate electron transfer and buffer the volume change of Sn 4 P 3 particles upon cycling, while Sn 4 P 3 serves as pillars to prevent the collapse and stacking of Ti 3 C 2 T x sheets. Moreover, significant capacitive contribution is demonstrated as a major contributor to the excellent rate capability.