Nanofibers-NiCo₂O₄: Fabrication and Li-storage properties

Nano-size particles and composites as anode materials have been explored in recent years in order to reduce the cost, improve the capacity as well as cycle-life of the Lithium ion batteries (LIBs). In view of same, the nanofibers of spinel-NiCo₂O₄ are prepared by easy, viable and cost effective electrospinning technique. The as spunned nanofibers composed of polymer solution and metal precursors are sintered at various temperature, and 500⁰C. 2h is found to be the appropriate to get best crystalline nanofibers of spinel-NiCo₂O₄. The structural, morphological and thermal characterizations are carried out by XRD, FESEM, TGA, respectively. The Li-storage and cycling properties of optimized nano-fibers of NiCo₂O₄ are examined by means of galvanostatic cycling and cyclic voltammetry. The spinel-NiCo₂O₄ delivers the first discharge and charge capacities of 1220(±10) mAhg⁻¹ and 910(±10) mAhg⁻¹ that corresponds the consumption of 11.0 and 8.2 mole of Li, respectively. The cyclic voltammetry studies reveal the average charge and discharge potentials of ∼2.2 and ∼0.9 V, respectively. Based on galvanostatic cycling, cyclic voltammetry and ex-situ studies like XRD, TEM and SAED, a plausible reaction mechanism is proposed.