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Updated: Jun 11, 2025

Zinc-Sponge Battery Electrodes that Suppress Dendrites
Published on: September 29, 2020
Toward High-Energy-Density Aqueous Zinc-Iodine Batteries: Multielectron Pathways
Shao-Jian Zhang1, Junnan Hao1, Han Wu1
1School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
Abstract:
Aqueous zinc-iodine batteries (ZIBs) based on the reversible conversion between various iodine species have garnered global attention due to their advantages of fast redox kinetics, good reversibility, and multielectron conversion feasibility. Although significant progress has been achieved in ZIBs with the two-electron I-/I2 pathway (2eZIBs), their relatively low energy density has hindered practical application. Recently, ZIBs with four-electron I-/I2/I+ electrochemistry (4eZIBs) have shown a significant improvement in energy density. Nonetheless, the practical use of 4eZIBs is challenged by poor redox reversibility due to polyiodide shuttling during I-/I2 conversion and I+ hydrolysis during I2/I+ conversion. In this Review, we thoroughly summarize the fundamental understanding of two ZIBs, including reaction mechanisms, limitations, and improvement strategies. Importantly, we provide an intuitive evaluation on the energy density of ZIBs to assess their practical potential and highlight the critical impacts of the Zn utilization rate. Finally, we emphasize the cost issues associated with iodine electrodes and propose potential closed-loop recycling routes for sustainable energy storage with ZIBs. These findings aim to motivate the practical application of advanced ZIBs and promote sustainable global energy storage.
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