Porous Co3O4 nanorods as superior electrode material for supercapacitors and rechargeable Li-ion batteries

Porous aggregated nanorods of Co₃O₄ with a surface area of ~100 m² g^?1 synthesized without using any templates or surfactants give very high specific capacitance of ~780 F g^?1 when used as electrode in a faradaic supercapacitor, with a cycle life of more than 1,000 cycles. Further, in Li-ion batteries when used as an anode, the Co₃O₄ nanorods achieved a capacity of 1155 mA h g^?1 in the first cycle and upon further cycling it is stabilized at 820 mA h g^?1 for more than 25 cycles. Detailed characterization indicated the stability of the material and the improved performance is attributed to the shorter Li-insertion/desertion pathways offered by the highly porous nanostructures. The environmentally benign and easily scalable method of synthesis of the porous Co₃O₄ nanorods coupled with the superior electrode characteristics in supercapacitors and Li-ion batteries provide efficient energy storage capabilities with promising applications.