Porous anhydrous CuF2 with a micro-nano-hierarchical structure as high-performance cathode material for Li-ion battery.

In this paper, anhydrous porous CuF2 with a micro-nano-hierarchical structure has been successfully fabricated via a precipitation method and a following solid-state reaction process. Scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption isotherms results confirm that the prepared porous CuF2 bulks are composed of loosely packed nanoparticles with a size range mainly between 30 and 50 nm, forming a micro-nano-hierarchical structure and possessing a large specific Brunauer–Emmett–Teller surface area of 24.93 m2 g−1. The porous CuF2 exhibits an outstanding initial discharge capability of 523 mAh g−1 at 0.1C and a superior rate capacity of 403 mAh g−1 at 5C with a cutoff voltage of 1.5 V versus Li/Li+. Moreover, electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic intermittent titration technique results verify porous structure can decrease the charge transfer resistance and boost the Li+ diffusion coefficient in CuF2. The method proposed in this work could be potentially used to synthesize other metal fluorides for high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]