Nanofibers of spinel-CdMn₂O₄: A new and high performance material for supercapacitor and Li-ion batteries

Porous nanofibric network of spinel-CdMn₂O₄(CDMO) nanoparticles is prepared by facile, cost effective and potentially scalable electrospinning technique. The morphological, structural and thermal characterizations are figured out by FE-SEM, TEM, XRD, BET, XPS, FTIR and TGA techniques. One dimensional (1D) and high aspect ratio nanofibers of CDMO are employed as electrode material for aqueous supercapacitor. Further, the nanofibers of CDMO are also tested as anode material for Li-ion batteries. Remarkable energy storage performance in terms of high specific capacitance (C_s) of 210 (±5) F g⁻¹at 1 A g⁻¹, cyclability (till 2000 cycles) and high energy density (∼25 W h kg⁻¹at power density of 1.5 kW kg⁻¹) is obtained. Furthermore, CDMO nanofibers as LIB anode exhibit high reversible capacity ∼500 (±10) mAhg⁻¹at 30 mAg⁻¹up to 50^thcycles (almost 1.5 times of experimentally observed capacity in commercialized anode (graphite)). The reasonable storage property of nanofibers of CDMO as supercapacitor is mainly ascribed to unique morphology where nanoparticles are interconnected to form the fibric morphology. The voids/gaps in between the particles works as spacer to buffer the stress/strain developed during reversible reactions and thereby the stable storage in both the devices is obtained. Further, Cd and Mn works as mutually beneficial matrices and aids each other to enable high and stable capacity as a consequence of alloying-de-alloying and conversion reactions particularly as LIB anode.