Activating and stabilizing a reversible four electron redox reactions of I-/I+ for aqueous Zn-iodine battery

Angew Chem Int Ed Engl. 2024 Mar 19:e202403187. doi: 10.1002/anie.202403187. Online ahead of print.ABSTRACTLow capacity and poor cycle stability greatly inhibit the development of zinc-iodine batteries. Herein, a high-performance Zn-Iodine battery has been reached by designing and optimizing both electrode and electrolyte. The Br- is introduced as the activator to trigger I+, and coupled with I+ forming interhalogen to stabilize I+ to achieve a four-electron reaction, which greatly promotes the capacity. And the Ni-Fe-I LDH nanoflowers served as the confinement host to enable the reactions of I-/I+ occurring in the layer due to the spacious and stable interlayer spacing of Ni-Fe-I LDH, which effectively suppresses the iodine-species shuttle ensuring high cycling stability. As a result, the electrochemical performance is greatly enhanced, especially in specific capacity (as high as 350 mAh g-1 at 1 A g-1 far higher than two-electron transfer Zn-Iodine batteries) and cycling performance (94.6% capacity retention after 10000 cycles). This strategy provides a new way to realize high capacity and long-term stability of Zn-Iodine batteries.PMID:38501218 | DOI:10.1002/anie.202403187
Source: Angewandte Chemie - Category: Chemistry Authors: Source Type: research