Sodium-ion
batteries offer an attractive option for grid-level
energy storage due to the high natural abundance of sodium and low
material cost of sodium compounds. Phosphorus (P) is a promising anode
material for sodium-ion batteries, with a theoretical capacity of
2596 mAh/g. The red phosphorus (RP) form has worse electronic conductivity
and lower initial Coulombic efficiency than black phosphorus (BP),
but high material cost and limited production capacity have slowed
the development of BP anodes. To address these challenges, we have
developed a simple and scalable method to synthesize layered BP/graphene
composite (BP/rGO) by pressurization at room temperature. A carbon-black-free
and binder-free BP/rGO anode prepared with this method achieved specific
charge capacities of 1460.1, 1401.2, 1377.6, 1339.7, 1277.8, 1123.78,
and 720.8 mAh/g in a rate capability test at charge and discharge
current densities of 0.1, 0.5, 1, 5, 10, 20, and 40 A/g, respectively.
In a cycling performance test, after 500 deep cycles, the capacity
of BP/rGO anodes stabilized at 1250 and 640 mAh/g at 1 and 40 A/g,
respectively, which marks a significant performance improvement for
sodium-ion battery anodes
