Integration of ionomer-based separator in high-performance quasi-solid-state zinc ion hybrid photo-supercapacitors

Abstract Renewable energy generation and storage on a single, compact device is a promising approach to addressing current energy problems. In this regard, recent advancements in zinc-ion hybrid photo-supercapacitors (Zn-HPSCs) have been noteworthy. However, their lower energy density compared to rechargeable batteries remains a major bottleneck that limits their widespread applications. We developed a quasi-solid-state Zn-HPSCs device using manganese-doped zinc oxide(Mn:ZnO) nanoparticles as the photoactive material and Zn ⁺² -treated Nafion ^TM 115(N115) ionomer as the separator, achieving a performance that is 3.9 times higher than that of a device made with filter paper (FP) under UV illumination. Moreover, both devices having FP and N115 separators showed a significant increase in specific capacitance ( C _p ) with UV illumination. More specifically, the C _p of the device was calculated from cyclic voltammetry at 1 mVs ⁻¹ scan rate, having the FP separator increase 212% compared to the dark condition and reach 1786 Fg ⁻¹ . On the other hand, the increase in the C _p of the N115 device (6952 Fg ⁻¹ ) under the same conditions was 1014%. It is believed that this high-performance, compact device will pave the way for next-generation energy storage devices, which can both absorb and store solar energy.