47. Iodine-Adsorbing Aqueous PAA Binder for Shuttle-Free Zn-Iodine Batteries
- Journal
- Polymer (Korea)
- Date
- (2024.10), JCR: 94.68 %, IF: 0.4
- Year
- 2024
Aqueous zinc-iodine (Zn-I2) batteries have attracted significant research interest as an emerging alternative energy storage system because of its high capacity (mAh/g), safety, and low cost. However, the dissolution and shuttling effect of polyiodides at the cathode formed during the charge and discharge process causes severe capacity loss and low electrochemical reversibility, which limits their practical use. Here in, we demonstrate polyacrylic acid (PAA) polymer as a cathode binder with strong iodine-chemisorption ability for aqueous Zn-I2 batteries to suppress shuttle effect of the polyiodides. The results confirm that the carboxyl groups of the PAA binder can strongly adsorb polyiodides and effectively inhibit its dissolution from the cathode. Furthermore, the PAA binder exhibits much better electrolyte wettability (0°of contact angle) and adhesion performance (0.27 N/mm) than the PVDF(Poly vinylidene fluoride) binder. As a result, the cell with PAA electrode shows high efficiency (95.5%), long cycle life (570 cycles) and high cost (148.1 mAh/g) compared to PVDF binder. This strategy may open a new way to solve the shuttling problem of Zn-I2 batteries through functional binders.