Superelastic Graphene Aerogel/Poly(3,4-Ethylenedioxythiophene)/MnO(2) Composite as Compression-Tolerant Electrode for Electrochemical Capacitors

Ultra-compressible electrodes with high electrochemical performance, reversible compressibility and extreme durability are in high demand in compression-tolerant energy storage devices. Herein, an ultra-compressible ternary composite was synthesized by successively electrodepositing poly(3,4-ethylenedioxythiophene) (PEDOT) and MnO(2) into the superelastic graphene aerogel (SEGA). In SEGA/PEDOT/MnO(2) ternary composite, SEGA provides the compressible backbone and conductive network; MnO(2) is mainly responsible for pseudo reactions; the middle PEDOT not only reduces the interface resistance between MnO(2) and graphene, but also further reinforces the strength of graphene cellar walls. The synergistic effect of the three components in the ternary composite electrode leads to high electrochemical performances and good compression-tolerant ability. The gravimetric capacitance of the compressible ternary composite electrodes reaches 343 F g(−1) and can retain 97% even at 95% compressive strain. And a volumetric capacitance of 147.4 F cm(−3) is achieved, which is much higher than that of other graphene-based compressible electrodes. This value of volumetric capacitance can be preserved by 80% after 3500 charge/discharge cycles under various compression strains, indicating an extreme durability.