A simple and efficient sol−gel/electrospinning technique is employed for the preparation of high aspect ratio CuO nanofibers. Characterizations studies including X-ray diffraction, scanning electron microscopy, High-resolution-transmission electron microscopy are employed to analyze the crystal structure, and morphology of electrospun CuO nanofibers. Electrochemical lithium storage properties are evaluated in half-cell configurations at room temperature between 0.005 and 3 V vs Li. Cyclic voltammetry is used to study the reaction mechanism during charge− discharge process. Electrospun CuO nanofibers delivered stable reversible capacity of 452 mAh g −1 at current density of 100 mA g −1 in half-cell configuration (Li/CuO nanofibers). The cell displayed the very stable cycling behavior up to 100 cycles at current density of 100 mA g −1 . Rate capability studies of CuO nanofibers are conducted and presented. Our studies have shown that the enhanced cycleability of CuO electrospun nanofibers are due to the fibrous morphology formed by nanoscopic CuO particles which could not only increase the electrode/electrolyte contact area but also enables the facile partial reduction of Cu 2 O into metallic particles (Cu 0 ).

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We report the extraordinary performance of an Li-ion battery (full-cell) constructed from one-dimensional nanostructured materials, i.e. nanofibers as cathode, anode, and separator-cum-electrolyte, by scalable electrospinning. Before constructing such a one-dimensional Li-ion battery, electrospun materials are individually characterized to ensure its performance and balancing the mass loading as well. The insertion type anode TiNb2O7 exhibits the reversible capacity of ∼271 mAh g(-1) at current density of 150 mA g(-1) with capacity retention of ∼82% after 100 cycles. Under the same current density, electrospun LiMn2O4 cathode delivered the discharge capacity of ∼118 mAh g(-1). Gelled electrospun polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) nanofibers membrane is used as the separator-cum-electrolyte in both half-cell and full-cell assembly which exhibit the liquid like conductivity of ∼2.9 mS cm(-1) at ambient conditions. Full-cell, LiMn2O4|gelled PVdF-HFP|TiNb2O7 is constructed by optimized mass loading of cathode with respect to anode and tested between 1.95 and 2.75 V at room temperature. The full-cell delivered the reversible capacity of ∼116 mAh g(-1) at current density of 150 mA g(-1) with operating potential and energy density of ∼2.4 V and ∼278 Wh kg(-1), respectively. Further, excellent cyclability is noted for such configuration irrespective of the applied current densities.

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We successfully demonstrated the performance of novel, one-dimensional electrospun nanofibers as cathode, anode and separator-cum-electrolyte in full-cell Li-ion configuration. The cathode, LiMn2O4 delivered excellent cycle life over 800 cycles at current density of 150 mA g(-1) with capacity retention of ~93% in half-cell assembly (Li/LiMn2O4). Under the same current rate, the anode, anatase phase TiO2, rendered ~77% initial reversible capacity after 500 cycles in half-cell configuration (Li/TiO2). Gelled electrospun PVdF-HFP exhibits liquid-like conductivity of ~3.2 mS cm(-1) at ambient temperature conditions (30 °C). For the first time, a full-cell is fabricated with enitrely electrospun one-dimensional materials by adjusting the mass loading of cathode with respect to anode in the presence of gelled PVdF-HFP membrane as a separator-cum-electrolyte. Full-cell LiMn2O4|gelled PVdF-HFP|TiO2 delivered good capacity characteristics and excellent cyclability with an operating potential of ∼2.2 V at a current density of 150 mA g(-1). Under harsh conditions (16 C rate), the full-cell showed a very stable capacity behavior with good calendar life. This clearly showed that electrospinning is an efficient technique for producing high performance electro-active materials to fabricate a high performance Li-ion assembly for commercialization without compromising the eco-friendliness and raw material cost.