Fundamentals and Scientific Challenges in Structural Design of Cathode Materials for Zinc‐Ion Hybrid Supercapacitors

Abstract

One of the most exciting new developments in energy storage technology is Zn‐ion hybrid supercapacitors (ZHSCs). ZHSCs combine Zn‐ion batteries with supercapacitors (SCs) to address the energy and power needs of portable devices and electric automobiles. Low energy density and the development of cathode material are significant issues for ZHSCs. This review provides an in‐depth investigation of charge storage mechanisms from SCs to ZHSCs. The advantages/disadvantages of ZHSCs, the recent development of cathode materials, and the new design for device fabrications are critically summarized. New cathode materials should be developed to achieve high energy density while preserving the inherent power capability and stability. People increasingly engage with smart electronic and hybrid gadgets, demanding flexible, resilient, and highly safe energy storage devices. ZHSC has emerged as a complete alternative to risky sodium‐ion/lithium‐ion technologies. An overview of all reported carbon‐based, biomass‐derived carbons, metal oxides, MOFs, COFs, MXenes, graphene, and composite materials employed for ZHSCs is comprehensively provided. Furthermore, cathode materials for flexible, micro, wire‐shaped, printed, and photo‐rechargeable ZHSCs are also examined with their practical challenges. This review is anticipated to offer valuable recommendations for designing and manipulating cathode materials for high‐performance ZHSCs to achieve real‐world applications.

All-Round Enhancement in Zn-Ion Storage Enabled by Solvent-Guided Lewis Acid–Base Self-Assembly of Heterodiatomic Carbon Nanotubes

“…It originates from the reversible precipitation–dissolution transition of flaky Zn­(CF 3 SO 3 ) 2 [Zn­(OH) 2 ] 3 · x H 2 O salt (ZHTS) on C FDA/DCE cathode (Figure S12). , Considering the weak acidity of Zn­(CF 3 SO 3 ) 2 /H 2 O electrolyte and the very small size of protons, , a control electrochemical experiment was performed to unravel whether protons participate in the energy storage of C FDA/DCE cathode. Zn//C FDA/DCE device in HCF 3 SO 3 /H 2 O electrolyte (with the same pH of Zn­(CF 3 SO 3 ) 2 /H 2 O electrolyte, pH = 3.26) achieves a low capacity of 32 mA h g –1 (Figure S13), indicating that H + ions take part in the cathodic electrochemistry.…”

Enhancing supercapacitor performance of Ni–Co–Mn metal–organic frameworks by compositing it with polyaniline and reduced graphene oxide

“…To accomplish this, a dual-structured architecture is employed, wherein one component of the hybrid device operates via EDLC behaviour, leveraging its inherent strengths, while the other component functions as a pseudocapacitor, harnessing its distinctive properties. 26 This integration of EDLC and pseudocapacitor functionalities within the hybrid device enables the realization of improved energy storage performance without compromising other critical parameters. 27,28 The development of nanocomposites emerges as a captivating trajectory for augmenting the synergistic amalgamation of electric double layer capacitance (EDLC) and pseudocapacitive behaviour within hybrid supercapacitors.…”

Atomic Layer Deposition—A Versatile Toolbox for Designing/Engineering Electrodes for Advanced Supercapacitors

“…By employing various strategies such as developing nanostructured active materials, optimizing constituents, and creating novel cell configurations, the challenges faced by SCs have been addressed. [46,47,64,[90][91][92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108] One significant challenge in fabricating nanostructured materials is manipulating materials with both structural and chemical differences at the nanometer scale. Combining a single material with ideal support characteristics, such as a large specific surface area and superior physicochemical properties, with another material offering unique properties, poses a frequent difficulty.…”