High Rate Lithium Ion Battery With Niobium Tungsten Oxide Anode

Highly stable lithium-ion battery cycling of niobium tungsten oxide (Nb16W5O55, NWO) is demonstrated in full cells with cathode materials LiNi0.6Mn0.2Co0.2O2 (NMC-622) and LiFePO4 (LFP). The cells show high rate performance and long-term stability under 5 C and 10 C cycling rates with a conventional carbonate electrolyte without any additives. The degradation of the cell performance is mainly attributed to the increased charge transfer resistance at the NMC side, consistent with the ex situ XRD and XPS analysis demonstrating the structural stability of NWO during cycling together with minimal electrolyte decomposition. Finally, we demonstrate the temperature-dependent performance of this full cell at 10, 25 and 60 degrees C and confirm, using operando XRD, that the structural change of the NWO material during lithiation/de-lithiation at 60 degrees C is very similar to its behaviour at 25 degrees C, reversible and with a low volume change. With the merits of high rate performance and long cycle life, the combination of NWO and a commercial cathode represents a promising, safe battery for fast charge/discharge applications.