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Electrocatalytic Iodine Reduction Reaction Enabled by Aqueous Zinc‐Iodine Battery with Improved Power and Energy Densities
Author(s) -
Ma Longtao,
Ying Yiran,
Chen Shengmei,
Huang Zhaodong,
Li Xinliang,
Huang Haitao,
Zhi Chunyi
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202014447
Subject(s) - tafel equation , prussian blue , battery (electricity) , power density , chemistry , aqueous solution , zinc , iodine , redox , capacity loss , kinetics , inorganic chemistry , electrochemistry , chemical engineering , electrode , materials science , power (physics) , organic chemistry , thermodynamics , physics , quantum mechanics , engineering
Proposed are Prussian blue analogue hosts with ordered and continuous channels, and electrocatalytic functionality with open Co and Fe species, which facilitate maximum I 2 utilization efficiency and direct I 2 to I − conversion kinetics of the I 2 reduction reaction, and free up 1/3 I − from I 3 − . Co[Co 1/4 Fe 3/4 (CN) 6 ] exhibits a low energy barrier (0.47 kJ mol −1 ) and low Tafel slope (76.74 mV dec −1 ). Accordingly, the Co[Co 1/4 Fe 3/4 (CN) 6 ]/I 2 //Zn battery delivers a capacity of 236.8 mAh g −1 at 0.1 A g −1 and a rate performance with 151.4 mAh g −1 achieved even at 20 A g −1 . The battery delivers both high energy density and high‐power density of 305.5 Wh kg −1 and 109.1 kW kg −1 , higher than I 2 //Zn batteries reported to date. Furthermore, solid‐state flexible batteries were constructed. A 100 mAh high capacity solid‐state I 2 //Zn battery is demonstrated with excellent cycling performance of 81.2 % capacity retained after 400 cycles.