Low-Resistance Porous Nanocellular MnSe Electrodes for High-Performance All-Solid-State Battery-Supercapacitor Hybrid Devices

Searching for materials with improved electrochemical behaviors is an important topic in portable energy storage devices. In this work a simple one-step solvothermal process is developed to rationally synthesize nanocellular alpha-MnSe and its applications in energy storage devices are studied. The MnSe faradic electrode shows a low internal resistance (0.37 Omega), high capacity (84.7 mAh g(-1) at 10 mV s(-1)), good rate capability, and long cycle life. All-solid-state battery-supercapacitor hybrid (BSH) devices are assembled using binder-free nanocellular MnSe as the positive electrode and active carbon (AC) as the negative electrode. The MnSe//AC all-solid-state devices exhibit large energy and power densities (39.6 mu Wh cm(-2) at 0.96 mW cm(-2)), extremely low internal resistance (only 1.34 Omega), fast charge process, outstanding cycle stability (119.79% retention after 8000 cycles), and flexibility with rather low bending loss. The wrist strap product by connecting three MnSe//AC all-solid-state devices in series can readily drive a green light-emitting diode for 3 min after 5 s of charging process. This work demonstrates that MnSe is an ideal low-resistance candidate of electrode materials for all-solid-state BSH devices, which is expected to facilitate the development in the portable and wearable energy storage.