| 학회 | 한국재료학회 |
| 학술대회 | 2021년 가을 (11/24 ~ 11/26, 경주 라한호텔) |
| 권호 | 27권 2호 |
| 발표분야 | C. 에너지 재료 분과 |
| 제목 | Iron Phthalocyanine as Electrolyte Catalyst Alternative for Sustainable and Efficient Lithium-Oxygen and Air-Breathing Batteries |
| 초록 | Lithium-air (Li-air) batteries employing a lightweight and gaseous oxygen cathode have recently received great attentions because of their exceptionally high energy density. However, Li-air batteries often suffer from high overpotential and the formation of lithium oxide products resulting in poor cyclability and efficiency. To deal with these problems, catalysts have been investigated to facilitate the reversible formation and decomposition reaction of lithium oxide products. Although various solid catalysts such as noble metal or transition metal oxide-based catalysts have been introduced, the surface deactivation issues originated from lithium oxide or lithium carbonate-based surface products still remain. Therefore, soluble catalysts called redox mediators (RMs) have been considered as alternative. Redox mediators(RMs) as electrolyte catalysts are the compounds that facilitate the charge transfer reaction by shuttling electrons between electrode and lithium oxide products, thereby improving performance of Li-air batteries. Using a redox mediator transforms the charge reactions from electrochemical pathways to chemical pathways, which unexpectedly bypasses the formation of highly reactive intermediates upon electro-oxidation of lithium oxide product. Although various RM candidates have improved electrochemical properties of Li-air cells, there are intrinsic limitations regarding (i) non-binding property of RMs with oxygen, (ii) improper economical benign, (iii) abundancy issue of raw materials, and so on. As a potential alternative, phthalocyanine (Pc), which is easily found in natural sources, are tetrapyrrolic conjugated aromatic macrocycles with transition metal at their core. They enable to bind with oxygen on the axial coordination site of porphyrin structure, further enhancing catalytic activities and increasing oxygen solubility even under ambient air atmosphere. In this work, we introduce the iron phthalocyanine (FePc) as a electrolyte catalyst alternative for sustainable and efficient Li-O2 and Li-air batteries. We compare the catalytic behavior of FePc catalyst in the cells under different O2 and ambient air atmosphere. We investigate the electrolyte stabilization properties and catalytic characteristics of the FePc catalysts via diverse electrochemical characterizations and in-situ characterizations. The reversibility of Li-O2 and Li-Air cells is elucidated by ex-situ characterizations of electrodes collected at different electrochemical states. |
| 저자 | Bo-Ran Kim, Hyun-Soo Kim, Jun-Seo Lee, Won-Hee Ryu |
| 소속 | Sookmyung Women's Univ. |
| 키워드 | Lithium-oxygen battery; Lithium-air battery; Redox mediator; Phthalocyanine; Catalyst |
