Robust and High-Performance Electrodes via Crumpled Au-CNT Forests for Stretchable Supercapacitors

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. Here, we demonstrate a robust and high-performance stretchable electrode based on crumpled Au-coated carbon nanotube forest (Au-CNT forest). 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. The biaxially crumpled Au-CNT forest electrode demonstrates nearly identical electrochemical performance at different measured charge/discharge rates under different strain conditions (i.e., from 0% to 800% area strain). The as-prepared symmetric supercapacitor demonstrates a maximum specific capacitance of ∼6 mF cm−2 at the current density of 40 mA cm−2 under large strains, exhibiting superior mechanical and electrochemical stability. This research presents a facile process to fabricate highly stretchable supercapacitors based on vertically aligned nanotubes or nanowires for achieving exceptional and robust electrochemical performance. [Display omitted] •Fabricating high-performance stretchable electrodes via crumpled Au-CNT forest•Inventing a simple method to reduce electronic resistance of CNT forest electrodes•Studying the reasons for reduced resistance and improved performance of Au-CNT forest electrodes•Developing supercapacitors with high power density and fast charge/discharge capability Emerging electronics such as wearable electronics and biointegrated electronics have evolved rapidly over the years. This bloom has generated great demands on high-performance stretchable energy devices such as batteries and supercapacitors. Although many nanomaterials and strategies are proposed to fabricate durable devices that can survive under large strains, they are suffering from the issues of robustness and low performance under large strains. Here, we successfully fabricated a robust and high-performance stretchable electrode and supercapacitor via the crumpled Au-CNT forest. Compared with the pure CNT forest, the Au-modified CNT forest electrode enabled a much smaller resistance. The all-solid-state supercapacitors demonstrated high power density and fast charge/discharge capability and represented a significant advancement toward the invention of highly stretchable, high-performance supercapacitors via vertically aligned CNT forests or oth