Redox-Mediated Polymer Catalyst for Lithium-Air Batteries with High Round-Trip Efficiency

• Main Authors: Min-Cheol Kim, Jung Hyun Song, Young-Woo Lee, Jung Inn Sohn
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Catalysts
• Subjects: PVDF-HFP; LiI; redox-mediated polymer catalyst; lithium-air batteries
• Online Access: https://www.mdpi.com/2073-4344/10/12/1479

Lithium-air batteries (LABs) continue to receive attention as a promising power source because they possess a high theoretical energy density of 3436 Wh L⁻¹. However, the remaining Li₂O₂ resulting from the irreversible decomposition of Li₂O₂ during the charge process is one of the key challenges so as to address the deterioration of the cycling performance of LABs. In this study, we propose and report a redox-mediated polymer catalyst (RPC) as a cathode catalyst being composed of LiI and poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) with multi-wall carbon nanotubes (MWCNTs) as the cathode material. In the RPC, iodine molecules are chemically combined with the PVDF-HFP chain. The as-prepared RPC exhibits increased cycling performance by 194% and decreased overpotential by 21.1% at 0.1 mA cm⁻² compared to the sample without LiI molecules. Furthermore, these results suggest that the RPC consisting of a polymer chain and redox mediators will be extensively utilized as highly efficient catalysts of LABs.