서울대학교 · 공학
Youngmin Ko 교수의 연구실은 리튬-산소 배터리의 고에너지 밀도 구현을 위한 핵심 기술인 전기화학적 반응 메커니즘과 전자 이동 메커니즘을 중심으로 연구를 진행하고 있습니다. 특히, 산소 환원 반응을 효율적으로 촉진하는 레드옥스 매개체의 설계 및 고정화 기술, 전해질 시스템의 안정성 향상 전략을 통해 배터리의 사이클 수명과 전력 밀도를 동시에 향상시키는 데 초점을 맞추고 있습니다. 생체 전자 전달 체계를 모방한 촉매 설계와 고체-액체 이중상 전해질 시스템의 개발은 그 핵심 전략입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Abstract Governing the fundamental reaction in lithium–oxygen batteries is vital to realizing their potentially high energy density. Here, novel oxygen reduction reaction (ORR) catalysts capable of mediating the lithium and oxygen reaction within a solution‐driven discharge, which promotes the solution‐phase formation of lithium peroxide (Li 2 O 2 ), are reported, thus enhancing the discharge capacity. The new catalysts are derived from mimicking the biological redox mediation in the electron tr
Redox mediators (RMs) are considered an effective countermeasure to reduce the large polarization in lithium-oxygen batteries. Nevertheless, achieving sufficient enhancement of the cyclability is limited by the trade-offs of freely mobile RMs, which are beneficial for charge transport but also trigger the shuttling phenomenon. Here, we successfully decoupled the charge-carrying redox property of RMs and shuttling phenomenon by anchoring the RMs in polymer form, where physical RM migration was re
For the realization of high-power lithium–oxygen batteries, a comparative study was conducted to investigate the kinetic properties of redox mediators.
Unlike most anodes used in high energy density batteries, lithiated Si does not form long-lasting passivating solid-electrolyte interphases (SEI) during formation or on charge due to SEI delamination, reconstruction, or dissolution. As a result, electrolyte degradation is continuous and results in a permanent loss of the Li inventory, shortening the useful life of the battery. Here, we show that perfluoroether electrolyte additives featuring either sulfonyl fluorides or trifluorovinyl ethers, wh
Intrinsic properties of quinones such as steric hindrance and heterogeneous electron transfer kinetics that follows Marcus theory concurrently govern their performance as redox mediators for oxygen reduction reactions in lithium–oxygen batteries.
Abstract The discovery of a reliable electrolyte system remains one of the key challenges for the development of advanced lithium–oxygen batteries. To date, no single electrolyte is verified to be stable and compatible with both the cathode (e.g., oxygen radicals, lithium peroxide, etc.) and anode (lithium metal) for lithium–oxygen batteries. In this work, a novel liquid‐based Janus electrolyte system consisting of two different immiscible liquid phases is proposed and it is demonstrated that th
Abstract Redox mediators (RMs) are considered an effective countermeasure to reduce the large polarization in lithium‐oxygen batteries. Nevertheless, achieving sufficient enhancement of the cyclability is limited by the trade‐offs of freely mobile RMs, which are beneficial for charge transport but also trigger the shuttling phenomenon. Here, we successfully decoupled the charge‐carrying redox property of RMs and shuttling phenomenon by anchoring the RMs in polymer form, where physical RM migrati
