Bifunctional Photo-Supercapacitor with a New Architecture Converts and Stores Solar Energy as Charge

Abstract

Photo-supercapacitors (PSCs) combine functions of energy harvesting and storage in a single device, and in this study, a new architecture for a PSC is designed and implemented. Cadmium sulfide (CdS) quantum dots/hibiscus (hb) dye co-sensitized TiO2 is used as the solar cell. Poly­(3,4-ethylenedioxypyrrole) (PEDOP)@manganese dioxide (MnO2) is employed as the counter electrode (CE) for the solar cell and also as the electrodes for the symmetric supercapacitor. The two ends of a long flat current collector support two spatially separated PEDOP@MnO2 coatings, which serve as the CEs for the TiO2/hb/CdS photoanode and yet another PEDOP@MnO2 electrode in sandwich configurations. In this cell, under 1 sun (100 mW cm–2) illumination, the TiO2/hb/CdS photoanode undergoes charge separation and by channeling the photocurrent to the PEDOP@MnO2 electrodes, the symmetric cell part is charged to a voltage of 0.72 V. The PSC delivers a specific capacitance of 183 F g–1, an energy density of 13.2 Wh kg–1, and a power density of 360 W kg–1 at a discharge current density of 1 A g–1. During the self-discharge process, PEDOP@MnO2-based PSC retains a voltage of 0.72 V up to 500 s and maintains a stable voltage of 0.5 V thereafter. The TiO2/hb/CdS photoanode with the PEDOP@MnO2 CE in an aqueous polysulfide–silica gel electrolyte delivers a power conversion efficiency of 6.11%. This demonstration of a novel PSC opens up opportunities to develop new architectures for efficiently combining energy conversion and storage.

Photo‐Supercapacitors Based on Third‐Generation Solar Cells

“…Recently, Das et al. employed CdS QDs/hibiscus (hb) dye cosensitized TiO 2 as a photoanode . Electropolymerized PEDOP@MnO 2 was used as both the CE for the solar cell and electrodes for the symmetric pseudocapacitor, while a PIC ([BuMeIm][CF 3 SO 3 ]; BuMeIm=1‐butyl‐3‐methylimidazolium) was employed as the non‐redox electrolyte.…”

“…Recently,D as et al employed CdS QDs/hibiscus( hb) dye cosensitized TiO 2 as ap hotoanode. [40] Electropolymerized PE-DOP@MnO 2 was used as both the CE for the solar cell and BuMeIm = 1-butyl-3-methylimidazolium) was employed as the non-redox electrolyte. These two parallel modulesa re linked by FTO modified glass.…”

High Energy Capacitors Based on All Metal‐Organic Frameworks Derivatives and Solar‐Charging Station Application

“…Solar energy is readily available and the most abundant renewable resources on the earth, however, given the intermittent nature of solar energy, designing efficient solar charge–discharge system is one of the main trends for green energy development in the future . Recently, some research have investigated solar charging system, which is composed by solar cell and energy storage device. One of the critical issues needs to be addressed for efficient solar charging system is the power matching principle.…”

“…High power solar cell should the device exhibited a high energy density of 42.5 Wh kg −1 at 21.1 kW kg −1 due to the unique hollow structure with defined mesoporosity that allow efficient electrolyte diffusion/penetration and enlarge the electrolyte/electrode interface. [28] In our previous work, Co 3 6 ] 2 ·10H 2 O were prepared and used for symmetric supercapacitors, the structure and compositional advantages made the device presented an energy density of 35.15 Wh kg −1 at 1125 W kg −1 . [38] Therefore, all evidences demonstrated that PB/PBAs derivatives had promising prospect for ECs and batteries application with high energy density.…”

“…[Fe(CN)6 ] and K3 [Co(CN)6 ] were purchased from Sigma-Aldrich Co., Ltd. Ni(NO 3 ) 2 ·6H 2 O, C 4 H 6 N 2 , CH 3 CH 2 OH, Na 3 C 6 H 5 O 7 ·2H 2 O, and KOH were purchased from Aladdin Biological Technology. The monocrystalline silicon plates were purchased from Solar Tech Co., Ltd., China.…”