A freestanding mesoporous CuCo₂O₄ nanograss electrode exhibits a superior pseudocapacitive performance and a high electrocatalytic activity towards methanol oxidation.

Well-aligned nickel oxide (NiO) nanosheets with the thickness of a few nanometers supported on a flexible substrate (Ni foam) have been fabricated by a hydrothermal approach together with a post-annealing treatment. The three-dimensional NiO nanosheets were further used as electrode materials to fabricate supercapacitors, with high specific capacitance of 943.5, 791.2, 613.5, 480, and 457.5 F g^-1 at current densities of 5, 10, 15, 20, and 25 A g^-1, respectively. The NiO nanosheets combined well with the substrate. When the electrode material was bended, it can still retain 91.1% of the initial capacitance after 1,200 charging/discharging cycles. Compared with Co₃O₄ and NiO nanostructures, the specific capacitance of NiO nanosheets is much better. These characteristics suggest that NiO nanosheet electrodes are promising for energy storage application with high power demands.

Flexible and easily reconfigurable supercapacitors show great promise for application in wearable electronics. In this study, multiwall C nanotubes (CNTs) decorated with hierarchical ultrathin zinc sulfide (ZnS) nanosheets (ZnS@CNT) are synthesized via a facile method. The resulting ZnS@CNT electrode, which delivers a high specific capacitance of 347.3 F·g^–1 and an excellent cycling stability, can function as a high-performance electrode for a flexible all-solid-state supercapacitor using a polymer gel electrolyte. Our device exhibits a remarkable specific capacitance of 159.6 F·g^–1, a high energy density of 22.3 W·h·kg^–1, and a power density of 5 kW·kg^–1. It also has high electrochemical performance even under bending or twisting. The all-solid-state supercapacitors can be easily integrated in series to power different commercial light-emitting diodes without an external bias voltage.

The flexible Fe₃O₄@MXene/CNFs electrode can efficiently enhance the adsorption of Li⁺, and improve the electronic conductance and ion transfer rate. The nanochains-like Fe₃O₄@MXene/CNFs electrodes constitute distinctive dual electronic pathways.