Delithiation-accelerating and self-healing strategies realizes high-capacity and high-rate black phosphorus anode in wide temperature range

Abstract

Black phosphorus (BP) anode with high capacity (2596 mAh g⁻¹) and suitable lithiation potential (0.7 ​V vs. Li⁺/Li) is an ideal candidate for high-energy-density and high-safety lithium-ion batteries, however, the practical implementation is greatly limited by its slow reaction kinetics and huge volume expansion. Here, inspired by nature, liquid metal (LM) is explored as a self-heal agent, which can well stabilize the BP anode through buffering the volumetric expansion and re-activating “dead P and Li_xP”. Moreover, LM also acts as a good catalyst, which can adjust Li ion concentration and reduce the activation energy of delithiation reaction, thus prolonging the cycling life. Therefore, the LM modified BP/graphite (G) composite delivers an excellent high-rate performance of 1123 mAh g⁻¹ ​at 4 ​C with 80.0 ​% capacity retention after 200 cycles, a superior wide-temperature performance of 1547.5 mAh g⁻¹ and 569.0 mAh g⁻¹ ​at 50 ​°C and −20 ​°C, respectively.