Modelling and experimental investigation of Nb2O5 as a high-rate battery anode material

Modelling and understanding the battery electrochemical performance at high rates is a great challenge. Known for its fast rate good cyclability, niobium pentoxide (Nb2O5) promising anode material lithium-ion batteries specifically modelled investigated in this work. Commercially sourced Nb2O5 was characterised using scanning electron microscopy, X-ray diffraction, micro-computed tomography. The found to contain large rod- ball-like polycrystalline particles of tens microns size have mixed T-Nb2O5 H-Nb2O5 phases. after ball milling tested via cyclic voltammetry constant-current cycling different C-rates up 50C (10,000 mA g−1). achieved similar charge capacity (143 mAh g−1) 0.5C could be retained by more than 55% when C-rate increased 10C. experimental results were used support development Doyle-Fuller-Newman model Nb2O5. By parameterization, reference exchange-current density solid-state diffusivity present estimated 9.6 × 10−4 A m−2 6.2 10−14 m2 s−1, respectively. accurate prediction currents 5C with obtained constant properties. However, properties rate-dependent higher agreements between experiment maintained. decrease two 10−50C revealed that there change dominant storage mechanism from diffusion-controlled lithium insertion capacitive effects, which experimentally observed voltammetry.