δ-MnO2 is a promissing electrode material of supercapacitors and Li ion batteries (LIBs) owing to its low cost, layer structure and composite valence of Mn. However, the unfavorable electronic conductivity of δ-MnO2 restricts its rate capability in both of the two devices. Herein, a vertically standing Ti nanowire array modified with δ-MnO2 nanoflakes is prepared by a electrodeposition method, and the electrochemical properties of Ti@δ-MnO2 nanowire arrays in supercapacitors and LIBs are investigated. The results show that, the arrays have a capacity of 195 F g-1 at 1.0 A g-1 and can cycle more than 10000 rounds at 10 A g-1 as electrodes of supercapacitors. On the other hand, the arrays behave good rate capability as LIB cathodes, which can release a capacity of 70 mAh g-1 at 10C rate charge/discharge. We suggest that, the good electronic conductivity owing to the core-shell structure and the facilitated mass transport supplied by the array architecture are responsible for the enhanced rate performances in the two devices.
Zhao, G., Zhang, D., Zhang, L., & Sun, K. (2016). Ti@δ-MnO2 core-shell nanowire arrays as self-supported electrodes of supercapacitors and Li ion batteries. Electrochimica Acta, 202, 8–13. https://doi.org/10.1016/j.electacta.2016.03.203