The rise of electronic devices developed and utilized around the world requires having a diverse set of energy storage devices with different properties. Pseudocapacitors have the potential to be used in devices where traditional energy storage devices fall short by possessing both high energy and power. Pseudocapacitors accomplish this by storing energy via a redox process while having lithium ion insertion kinetics on par with capacitive like rates. By investigating structural and computational properties of pseudocapacitive T-Nb₂O₅, TT-Nb₂O₅, and H-Nb₂O₅ polymorphs, the key factors that assist in fast lithium ion kinetics can be elucidated and compared. The structural and computational comparison of the polymorphs results in similar factors assisting fast lithium ion transport; these factors being a large channel size, low energy barriers for lithium transport, and two dimensional transport pathways in the crystal. Although these polymorphs possess similar aspects leading to improved kinetics, the electrochemical performances of the polymorphs are significantly different. Taking a closer look at the computations and theorizing a reason for the difference in electrochemical properties may help in further understanding pseudocapacitive materials for fast energy storage.

Chen, D.; Wang, J.-H.; Chou, T.-F.; Zhao, B.; El-Sayed, M. A.; Liu, M. Unraveling the Nature of Anomalously Fast Energy Storage in T-Nb 2O 5. J. Am. Chem. Soc. 2017, 139 (20), 7071–7081. https://doi.org/10.1021/jacs.7b03141