Biotemplated fabrication of hierarchically porous NiO/C composite from lotus pollen grains for lithium-ion batteries

In this work, hierarchically porous NiO/C microspheres were successfully synthesized via a facile biotemplating method using natural porous lotus pollen grains as both the carbon source and the template. The as-prepared hierarchically porous NiO/C microspheres exhibited a large specific surface area and multiple pore size distribution, which could effectively increase the electrochemical reaction area and allow better penetration of the electrolyte. The Raman results also confirmed that the pollen grains have been well carbonized, which could provide good electronic conductivity. The specific capacities of the porous NiO/C microspheres after every 10 cycles at 0.1, 0.5, 1, and 3 A g−1 are about 698, 608, 454 and 352 mAh g−1. As an anode material in a Li ion half-cell, these unique hybrid hierarchically porous NiO/C microspheres exhibited fascinating electrochemical performance.