CO2 Ionized Poly(vinyl alcohol) Electrolyte for CO2‐Tolerant Zn‐Air Batteries. Issue 38 (1st September 2021) - Zhou, Yingjie
Abstract: CO2 poisoning of alkaline electrolytes is a critical issue that affects the energy efficiency and lifespan of Zn‐air batteries. However, few strategies have been explored to address this issue because it is challenging to block CO2 from the outer atmosphere. Herein, a CO2 ‐tolerant flexible quasi‐solid‐state electrolyte for Zn‐air batteries, which is achieved by the pre‐fixation of CO2 on poly(vinyl alcohol) (PVA) via its ionization in the form of side ‐OCO2 ‐ groups (PVA‐TMG), is reported. The pre‐fixation of CO2 enables excellent CO2 tolerance and alleviates the Zn dendrite and ZnO deposition, because the ‐OCO2 ‐ groups can strongly interact with the Zn 2+ . In addition, PVA‐TMG exhibits higher ionic conductivity and better water retention capability than the pristine PVA. Consequently, the fabricated Zn‐air batteries deliver excellent performance in both air and a CO2 ‐rich atmosphere. The optimized PVA‐TMG presents a cycling lifetime 12 times longer than that of the pristine PVA in the atmosphere with 22.7 vol% CO2 . The feasible study presented here presents a new milestone in CO2 utilization with energy storage technology. Abstract : Zn‐air batteries are susceptible to damage from environmental CO2 limiting their efficiency and durability. Herein, poly(vinyl alcohol) ionized by CO2 is applied as a quasi‐solid‐state electrolyte for Zn‐air batteries. The pre‐fixation of CO2 in the electrolyte enables the fabrication of a battery with high energy efficiency and CO2 tolerance.