Recent progress in the all‐solid‐state flexible supercapacitors

Abstract

In the past few years, supercapacitors (SCs) have attracted great attention in both academic and industrial sectors due to their high energy storage efficiency, reliable stability, and eco‐friendly process. Flexible solid‐state SCs as one of the ongoing focuses for the development of wearable and portable electronics have become the most promising energy storage devices for the smart power system due to their high power density, fast electrochemical response, high efficiency on the charge‐discharge process, and excellent electrochemical stability. In this study, the recent progress in the electrodes and electrolytes used for approaching high‐performance of the all‐solid‐state flexible SCs is reviewed. We first introduce basic operational principles of various SCs. And then we overview the electrode materials including carbon materials, conducting polymers, transition metal oxides/chalcogenides/nitrides, MXenes, metal‐organic frameworks, covalent‐organic frameworks, and the polymer‐based solid‐state electrolytes in different systems. Afterward, we summarize recent progress in the development of the all‐solid‐state flexible SCs and outlook for future research directions.

Integration of supercapacitor with solar cell based on NiO 2 and CdS nanopillars embedded in porous anodic alumina templates

“…Several review papers on various PVSC, 12‐29 EES devices, 29‐48 and integrated systems 1‐12 have been published recently. As much as 90% of the worldwide PV market is currently dominated by the first‐generation Si‐based PVSCs, which have a high power conversion efficiency (PCE) as high as 27%, 12,21 as well as good stability and fixed industrial production standards.…”

“…In contrast to EDLC, pseudocapacitors use a quick and reversible faradaic redox process to store electrical energy by transferring charges from electrode to electrolyte. They have a greater ED value than EDLC, but chemical processes reduce their power density and shorten their lifespan 39‐43 …”

“…Over the past 20 years, these solar cells have been improved even more, and to this day, their PCE reaches 22.1%. 17 Electrochemical Li-ion batteries (ECB), 29 capacitors, and electrochemical supercapacitors (SC) [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] are the primary electrochemical EES components at the moment. The primary distinction between SCs and ECBs is how they operate their charge storage systems.…”

“…They have a greater ED value than EDLC, but chemical processes reduce their power density and shorten their lifespan. [39][40][41][42][43] An important family of pseudocapacitive electrode materials for supercapacitors in which transition metals (group IV to VII B elements) are linked to oxygen atoms includes transition metal oxides (TMO) like RuO 2 , MnO 2 , V 2 O 5 , ZnO, Fe 2 O 3 , Co 3 O 4 , and NiO 2. [42][43][44] In terms of energy density, specific capacitance (1000-2000 F/g), and chemical stability, TMOs perform better than carbon-based materials.…”

“…Electrochemical Li‐ion batteries (ECB), 29 capacitors, and electrochemical supercapacitors (SC) 30‐45 are the primary electrochemical EES components at the moment. The primary distinction between SCs and ECBs is how they operate their charge storage systems.…”