Boosting Potassium Storage Performance of Red Phosphorous via Modifying the Nickel Foam Substrate

A strategy is developed to fabricate NiO-reduced graphene oxide (rGO) layer-modified nickel foam (M-NF) as a current collector. Red phosphorous (RP) nanoparticles embedded in rGO nanosheets (P-rGO) are loaded on the M-NF (P-rGO@M-NF) as a superior anode for high-performance potassium-ion batteries. The binder-free P-rGO@M-NF anode exhibits a remarkable electrochemical performance with outstanding cycling stability and high rate capability, delivering a specific capacity of 361.2 mA h g–1 at a current density of 100 mA g–1 after 125 cycles. Theoretical calculations reveal that RP loaded on NiO can absorb K atoms easily and exhibit a semiconductor-to-metal transition after the incorporation of K atoms, exhibiting the significantly enhanced conductivity. In addition, a NiO layer can efficiently anchor RP nanoparticles by a strong Ni–O–P bond, which can endow P-rGO@M-NF a long-term lifespan. Thus, the excellent potassium storage performance of P-rGO@M-NF can be attributed to synergistic effects between modified nickel foam and P-rGO network. This present strategy to modify the current collector for anchoring alloy-type RP can be extended to other novel electrodes for high-performance energy-storage devices.