Solar-powered electrochemical cells (SPECs) have been perceived as a potential strategy for coping with the intermittent nature of solar power. Most of the SPECs reported so far use corrosive/toxic liquid electrolyte and/or need very careful packaging, which is restricted by the scenario of implementation and arises the fabrication cost. Here, we demonstrate an all-in-one, solid-state SPEC with solar-to-output energy conversion efficiency of ca. 2.8% under AM 1.5 G irradiation. In this SPEC, a LiBr/polyacrylamide (PAM) hydrogel serves both as electrolyte, cathode-active mediator, and separator, which is sandwiched between an FTO/BiVO4 photoanode and an FTO/Prussian blue (PB) anode. The use of solid-state PAM hydrogel promotes the charge-transfer dynamics at the interface of the photoanode and suppressed the undesired side reactions of electrolyte decomposition, representing an effective strategy by interfacial engineering toward the development of high-performance SPECs.
Keywords: charge-transfer dynamics; electrochemical cell; energy storage and conversion; hydrogel; interface engineering.