A simple and low-cost strategy to prepare porous carbon nanosheets (PCNS).
PCNS with 2D structure shows a high specific surface area and pore volume.
The S/PCNS composites deliver an initial discharge capacity of about 1600 mAh/g.
It maintains a reversible capacity of 554 mAh/g after 50 cycles.
Highly porous 2D structure enables pathway for electron and ion transportation.