Utilizing a graphene matrix to overcome the intrinsic limitations of red phosphorus as an anode material in lithium-ion batteries

Red phosphorus (P) shows enormous potential as a high-performance and cost-effective Lithium (Li)-ion anode material. It alloys with Li forming Li3P, which translates to a theoretical capacity of similar to 2595 mAh g(-1) (similar to 7 times better than graphite). Further, the cost of bulk P is comparable to battery-grade graphite. However, there are two intrinsic limitations that prevent deployment of P, viz., its low electrical conductivity and its high volume change on cycling that leads to pulverization and loss of electrical contact. Here, we present an approach to concurrently address both limitations. We employ electro-spraying and far-infrared reduction (FIR) to fabricate composites of P and reduced graphene oxide (rGO). The electro-spraying process enables ultra-small P particles (5-10 nm), which suppresses stress-induced pulverization and drastically reduces Li-ion diffusion distances. The low electrical conductivity of P is also not a limitation at such small particle sizes. FIR establishes carbon-phosphorous bonds that prevent surface migration and agglomeration of P, and enable efficient electron transfer between the rGO matrix and P nanoparticles. The P/rGO anode delivers outstanding specific capacity (similar to 1763 mAh g(-1) at current density of similar to 0.1 A g(-1)), extraordinary high-rate capability (up to similar to 40 A g(-1)) and long cycle-life (>1000 cycles with similar to 99% coulombic efficiency). (C) 2017 Elsevier Ltd. All rights reserved.