Controllable Synthesis of a Hybrid Carbon Nanofiber/NiCo ₂ O ₄ Composite for Supercapacitors

Carbon nanofiber (CNF)/transition metal oxide (TMO) composites have obtained much attention in the applications of electrodes, catalysts, and sensors with benefits from the superior electrical conductivity of carbon materials and high activity of TMOs. However, nanosized TMOs are prone to agglomeration and hard to grow efficiently and uniformly on CNFs because the surface of CNFs lacks effective targets, thus limiting its performance. In this paper, different hybrid carbon nanofibers/NiCo 2 O 4 composites were prepared by solvent treatment. The morphology characterizations demonstrated that CNF-NiCo 2 O 4 prepared by the treatment of potassium permanganate (CNF-NCO4) showed uniform growth of NiCo 2 O 4 on CNFs. The electrochemical measurements of the prepared electrodes showed that CNF-NCO4 exhibited a high capacity of 588 C g –1 at a current density of 1 A g –1 and long-term cycling stability with 93% capacitance retention after 3000 cycles. This approach provides a strategy for controllable design and synthesis of hybrid CNF/TMO composites.