Novel GaNb49O124 microspheres with intercalation pseudocapacitance for ultrastable lithium-ion storage.

To meet the demand of high power and energy densities of Li-ion batteries, M-Nb-O compounds are of significance due to not only the intercalation pseudocapacitance but also the high theoretical capacities and excellent cycling stability. However, the exploration of M-Nb-O is very limited. Herein, we firstly report GaNb 49 O 124 as a novel intercalation-type M-Nb-O anode material. GaNb 49 O 124 microspheres (GaNbO-S) with an average diameter of ∼2 μm are fabricated through a hydrothermal method. Benefiting from the nanosized architecture, GaNbO-S delivers superior electrochemical performance in Li-ion batteries. A large reversible specific capacity of 294 mAh g−1 is obtained at 50 mA g−1, while 205 mAh g−1 is reached at 4000 mA g−1. Furthermore, GaNbO-S delivers long-term cycling life with a 72.0% capacity retention over 1800 cycles at 2000 mA g−1. Thus, GaNb 49 O 124 microspheres could be developed as an efficient anode material for Li-ion batteries. [ABSTRACT FROM AUTHOR]