Fibrous phosphorus: A promising candidate as anode for lithium-ion batteries

Phosphorus-based LIBs anode have attracted much attention for its high theoretical capacity. Much work so far has focused on the anode such as commercial red phosphorus and black phosphorus. However, little is known about the other phases of phosphorus. Here, we proposed a promising LIBs anode based on fibrous phosphorus and Hittorf's phosphorus. An Iodine-assisted CVD method was used to synthesize urchin-like fibrous phosphorus crystals and flower-like Hittorf's phosphorus crystals and the morphology of the twin phases was investigated systematically. Hittorf's Phosphorus exhibited an initial capacity of 2113.8 mA h g−1 and a capacity of 558.0 mA h g−1 after 40 cycles, whereas the fibrous phosphorus delivered a slightly lower initial discharge capacity of 1783.0 mA h g−1 but a higher capacity of 817.0 mA h g−1 after 40 cycles. It is concluded that fibrous phosphorus exhibited a best performance comparing with other single phases such as commercial red phosphorus (irreversible) and black phosphorus (the capacity fades from 1800.0 mA h g−1 to 200.0 mA h g−1 after 30 cycles). The Li-ion storage mechanism of fibrous phosphorus was investigated deeply. The uniform rod-like morphology and high conductivity of fibrous phosphorus improved the performance. Besides, the presence of Li3P and LiP phases contributed to the cyclability.