Cobalt oxysulphide/hydroxide nanosheets with dual properties based on electrochromism and a charge storage mechanism.

The charge storage mechanism of mixed cobalt oxysulphide/hydroxide materials having electrochromic properties was investigated. The cobalt oxysulphide/hydroxide materials exhibit a dual reversible redox reaction and electrochromic properties in 1 M KOH during charging and discharging.

Novel Hybrid Energy Conversion and Storage Cell with Photovoltaic and Supercapacitor Effects in Ionic Liquid Electrolyte.

A single hybrid energy conversion and storage (HECS) cell of alpha-cobalt hydroxide (α-Co(OH)) in ionic liquid was fabricated and operated under light illumination. The α-Co(OH), which is unstable in an aqueous electrolyte (i.e.

A new concept of charging supercapacitors based on the photovoltaic effect.

A significant enhancement in the areal capacitance of a Co(OH) supercapacitor charged and discharged under light illumination is clearly observed, with the capacitance about two-fold higher than that operated under dark conditions. This is because Co(OH) has an energy band gap of 2.85 eV and can absorb blue light and generate photoelectrons via the photovoltaic effect, leading to high current density.

Turning conductive carbon nanospheres into nanosheets for high-performance supercapacitors of MnO2 nanorods.

Oxidized carbon nanosheets (OCNs), produced from black carbon nanospheres and used as a conductive additive in the supercapacitor electrodes of MnO2 nanorods, can significantly improve the charge-storage performance of the symmetric MnO2-nanorod supercapacitors with a maximum specific energy of 64 W h kg(-1) and power of 3870 W kg(-1). An optimum material composition of the supercapacitor electrode finely tuned is 60 : 30 : 10 wt% of MnO2 : OCN : PVDF, respectively. Interestingly, after 5000 charge/discharge cycles, the oxidation numbers of Mn at the positive and negative electrodes of the as-fabricated supercapacitor are +3.