High power nano-Nb2O5 negative electrodes for lithium-ion batteries

Nano-sized, semi-crystalline niobium pentoxide (Nb2O5) was synthesized in a single step via a continuous hydrothermal process. The nanomaterial was characterized using a range of analytical techniques including powder X-ray diffraction and transmission electron microscopy. The “as-prepared” Nb2O5 nanomaterial was investigated as negative electrode for a lithium-ion battery and was shown to be stable during electrochemical cycling (98.6 % capacity retention after 800 cycles) and showed promising high rate performance, with a specific capacity of 43 mAh g−1 at an applied current of 10,000 mA g−1 (in the wide potential range of 0.05 to 3 V vs Li/Li+). Scan rate tests were used to investigate the proportion of stored charge from diffusion-limited processes and that from surface effects, which showed that at higher currents, charge storage from the latter was dominant.