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 pratical 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 LixP”. 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 oC and −20 oC, respectively.