Robust and High-Performance Electrodes Via Crumpled Au-CNT Forests for Stretchable Supercapacitors
37 Pages Posted: 15 Jan 2020 Sneak Peek Status: Review CompleteMore...
Stretchable supercapacitors based on vertically aligned nanotubes or nanowires have attracted considerable attention because of their improved robustness and electrochemical performance under large and repeated deformations. However, it is still challenging to maintain the low electric resistance of stretchable electrodes of such a stretchable supercapacitor under extremely large strains due to the variation of the contacts between individual nanotubes/wires. Here, we develop and demonstrate a robust and high-performance stretchable electrode based on crumpled Au coated CNT forest (Au-CNT-forest), which significantly increases the conductivity of the original CNT-forest electrode while maintaining its unique crumpled hierarchical structures. Experimental measurements show that the resistance of the Au-CNT- forest electrode is around one order magnitude lower than that of a pure CNT-forest electrode and is comparable to that of a conventional thin film electrode. The biaxially crumpled Au-CNT-forest electrode demonstrates nearly identical electrochemical performance at all the measured charge/discharge rates (i.e., from 0.5 to 80 mA cm-2) under different strain conditions (i.e., from 0% to 800%), which can not be achieved by a pure CNT-forest electrode. The as-prepared symmetric supercapacitor with crumpled Au-CNT forest electrodes demonstrates a maximum specific capacitance of ~ 6 mF cm-2 at the scan rate of 40 mA cm-2 under different strains, exhibiting superior mechanical and electrochemical stability. This research demonstrates a facile process to fabricate highly stretchable supercapacitors based on vertically aligned nanotubes or nanowires for achieving exceptional and robust electrochemical performance.
Keywords: stretchable supercapacitors, carbon nanotube forest (CNT-forest), crumpled Au-CNT forests, energy storage devices, all-solid-state supercapacitors
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