Ti@delta-MnO2 core-shell nanowire arrays as self-supported electrodes of supercapacitors and Li ion batteries

摘要

delta-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 delta-MnO2 restricts its rate capability in both of the two devices. Herein, a vertically standing Ti nanowire array modified with delta-MnO2 nanoflakes is prepared by a electrodeposition method, and the electrochemical properties of Ti@delta-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. (C) 2016 Elsevier Ltd. All rights reserved.