Exploring a Li-ion battery using surface modified titania nanotubes versus high voltage cathode nanowires

•Nanofabricated HV cathodes and titania anodes are suitable for 3D microbatteries.•Lithium phosphate-coated electrodes stabilize the electrode/electrolyte interface.•TiO2, Li3PO4/EC:DEC LiPF6/LiNi0.5Mn1.5O4 safe battery with high energy and power densities.

Novel battery architectures with improved safety, power and energy density are currently being demanded for battery miniaturization. We present a rechargeable full cell fabricated with self-organized titania nanotubes (nt-TiO2) and self-organized LiNi0.5Mn1.5O4 nanowires (LNMO). The effects of the Li3PO4-coated nt-TiO2 on the electrochemical performance of the full cell are studied. A complete (de)-intercalation of lithium into both electrodes is observed, and cells avoid the use of metallic lithium while displaying improved safety and restrained lowering of the overall cell voltage. The surface modified electrodes exhibit better rate capability and cycling performance compared to non-treated electrodes. The nt-TiO2, Li3PO4/EC:DEC LiPF6/LiNi0.5Mn1.5O4 cell could be cycled at 5C rate, with associated capacity of 125 mA h g−1, energy density of 325 W h kg−1 and power density of 637 μW cm−2 μm−1. These results give evidence to the compatibility between both nanostructured electrodes particularly when lithium phosphate exerts a stabilization effect at the electrode/electrolyte interface, facilitating improved mass transfer and Li-diffusion at high rates.

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