Sn-Decorated red P entangled in CNTs as anodes for advanced lithium ion batteries.

Abstract

Phosphorus (P) is an appealing electrode material for lithium ion batteries owing to its high theoretical capacity. In particular, red P has attracted considerable research attention due to its commercial availability, low cost and easy handling. In this study, red P was combined with Sn particles and then interwoven into a carbon nanotube network (P@Sn@CNT). The electronic conductivity can be enhanced by the dual effect of the conductive CNT framework and decorated Sn particles. The Li storage capability of red P and Sn can be boosted with the synergistic effect, both contributing to the overall capacity of the composite. The P@Sn@CNT composite exhibits excellent lithium storage performance, delivering a capacity of 1197 mA h g-1 after 200 cycles at 0.2 A g-1. Outstanding cyclic stability and high rate capability are also exhibited, with a capacity retention of 79% in 200 cycles and a capacity of 911 mA h g-1 at 10 A g-1. The ex situ X-ray diffraction and X-ray photoelectron spectroscopic study also reveals the reversible lithiation mechanism of the P@Sn@CNT composite, forming Li3P and Li22Sn5. The systematic investigation on the low-cost P@Sn@CNT sheds light on the development of high-performance red P-based lithium-ion batteries for real applications.