Stability and Reliability of Dye‐Sensitized Solar‐Cell Mini‐Module for Photocharging Li‐Ion‐Battery‐Connected Internet of Things

Abstract

Dye‐sensitized solar cells (DSSCs) integrated Li‐ion batteries (LIBs) are considered a promising solution as a wireless power source for the increasing number of miniaturized portable devices and the Internet of Things (IoTs). DSSCs have high power conversion efficiency (PCE) under indoor light, are low cost, easy to manufacture, and environmentally friendly. However, DSSCs suffer from stability issues because they use volatile electrolyte solvents that leak through the seal. To solve this problem, we have used a polymer gel electrolyte (PGE) based on the high‐boiling solvent 3‐methoxypropionitrile (MPN, bp = 164‐165 °C), and the backside of the cells were sealed by hot press using surlyn and Al foil. A highly stable and efficient counter electrode, Pt/porous carbon (Pt/PC), was also used to fabricate the devices, which show a high PCE of 25.7‐29.4% under the illumination of 500‐2000 lux. The fabricated DSSC shows outstanding stability in the room condition. After 113.0 days, the cells did not show any efficiency deterioration. Moreover, only 18.2% of the efficiency of the cells decreased when the stability test was carried out under rigorous conditions. A mini‐module of 13.3 cm2 was fabricated with the same condition and showed a PCE of 22.9‐23.3% and Pmax of 166.4‐643.0 μW under the illumination of 500‐1000 lux. The mini‐module was then wire‐connected with a commercially available Li‐ion battery (LIB, Maxell ML2032) and an IoT device (ZigBee temperature and humidity sensor). The mini‐module generates a higher power output than the power consumed by the IoT device and can recharge the LIB while operating the IoT device, indicating the reliability of the DSSC mini‐module for photocharging LIB as a wireless power source for the IoT devices.This article is protected by copyright. All rights reserved.

Quasi-Solid-State Dye-Sensitized Solar Cells by Mechanically Stable Semi-Interpenetrating Network Polymer Gel Electrolytes for Indoor Applications

“…Among various PV technologies, the dye-sensitized solar cell (DSSC) is the most promising to power IoT, and low-power consumed electronic devices because of its easy fabrication, cheap materials, and outstanding power output in an entire range of light; ambient, cloudy, rainy, and sunny light atmospheres. ,− DSSC-integrated photorechargeable supercapacitor and battery are also appealing to store energy and provide continuous power to IoT and portable electronic devices. − Recently, dye-sensitized PV fiber, which can be woven into textiles to power wearables, has been made with outstanding power conversion efficiency (PCE). , This promises the application of DSSCs by harvesting ambient light in wearables. However, these dye-sensitized PV fibers contain volatile iodine liquid electrolytes (LEs) inside.…”