Enhancing low-temperature lithium-ion battery performance under high-rate conditions with niobium oxides

Low-temperature operation (-20 degrees C and below) under high-rate conditions is a critical deficiency for lithium-ion batteries. To achieve size, weight, and power requirements tailored for demanding applications, novel materials are needed to sustain high performance. In the present study, we synthesize a series of niobate anode materials (Nb2O5, Nb2O5-x, and Nb12O29) and tailor their particle size, defect nature, and electrical/ionic conductivity to enable high-performance operation at -20 degrees C under high-rate conditions (1.2C-2C). When paired with lithium manganese oxide (LMO) in a full-cell configuration, the Nb2O5-x-based full-cells achieve high-rate capability (similar to 90 mAh/g up to 2C cycling rate at -20 degrees C) and great long-term stability (>98% retention up to 50 cycles at -20 degrees C). During a simulated 30 min duty cycling test synthesized from measured data from an actual drone flight (continuous range of 1.2C-2C cycling rates), the Nb2O5-x||LMO cell enables full discharge at -20 degrees C, with only a 0.3 V voltage drop when compared to duty cycling at room temperature. The work presented herein demonstrates the future possibilities of expanding the operational capabilities of lithium-ion batteries.