Wire-Shaped 3D-Hybrid Supercapacitors as Substitutes for Batteries

Highlights The flexible 3D porous structure with a large surface area provides pathways for rapid ion/electron transport and ion diffusion as well as numerous electroactive sites.The wire-shaped supercapacitor exhibits a high energy density of 153.3 Wh kg−1 and a power density of 8810 W kg−1.The hybrid device demonstrates excellent durability under various mechanical deformations. Electronic supplementary material The online version of this article (10.1007/s40820-019-0356-z) contains supplementary material, which is available to authorized users.
We report a wire-shaped three-dimensional (3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of electrochemical active sites, easy access of electrolyte ions, and facile charge transport for flexible wearable applications. The interconnected and compact electrode delivers a high volumetric capacitance (gravimetric capacitance) of 73 F cm−3 (2446 F g−1), excellent rate capability, and cycle stability. The 3D-nickel cobalt-layered double hydroxide onto 3D-nickel wire (NiCo LDH/3D-Ni)//the 3D-manganese oxide onto 3D-nickel wire (Mn3O4/3D-Ni) hybrid supercapacitor exhibits energy density of 153.3 Wh kg−1 and power density of 8810 W kg−1. The red light-emitting diode powered by the as-prepared hybrid supercapacitor can operate for 80 min after being charged for tens of seconds and exhibit excellent electrochemical stability under various deformation conditions. The results verify that such wire-shaped 3D-hybrid supercapacitors are promising alternatives for batteries with long charge–discharge times, for smart wearable and implantable devices. Electronic supplementary material The online version of this article (10.1007/s40820-019-0356-z) contains supplementary material, which is available to authorized users.