Lim, Gukhyun Shin, Dongki Chae, Keun Hwa Cho, Min Kyung Kim, Chan Sohn, Seok Su Lee, Minah Hong, Jihyun 2024-01-19T10:33:30Z 2024-01-19T10:33:30Z 2022-10-20 2022-12 1614-6832 https://pubs.kist.re.kr/handle/201004/114258 The exploding electric-vehicle market requires cost-effective high-energy materials for rechargeable lithium batteries. The manganese-rich spinel oxide LiNi0.5Mn1.5O4 (LNMO) can store a capacity greater than 200 mAh g(-1) based on the multi-cation (Ni2+/Ni4+ and Mn3+/Mn4+) redox centers. However, its practical capacity is limited to Ni2+/Ni4+ redox (135 mAh g(-1)) due to the poor reversibility of Mn3+/Mn4+ redox. This instability is generally attributed to the Jahn-Teller distortion of Mn3+ and its disproportionation, which leads to severe Mn dissolution. Herein, for the first time, the excellent reversibility of Mn3+/Mn4+ redox within 2.3-4.3 V is demonstrated, requiring revisiting the previous theory. LNMO loses capacity only within a wide voltage range of 2.3-4.9 V. It is revealed that a dynamic evolution of the electrochemical interface, for example, potential-driven rocksalt phase formation and decomposition, repeatedly occurs during cycling. The interfacial evolution induces electrolyte degradation and surface passivation, impeding the charge-transfer reactions. It is further demonstrated that stabilizing the interface by electrolyte modification extends the cycle life of LNMO while using the multi-cation redox, enabling 71.5% capacity retention of LNMO after 500 cycles. The unveiled dynamic oxide interface will propose a new guideline for developing Mn-rich cathodes by realizing the reversible Mn redox. English Wiley-VCH Verlag Regulating Dynamic Electrochemical Interface of LiNi0.5Mn1.5O4 Spinel Cathode for Realizing Simultaneous Mn and Ni Redox in Rechargeable Lithium Batteries Article 10.1002/aenm.202202049 1 Advanced Energy Materials, v.12, no.46 Advanced Energy Materials 12 46 Y scie scopus 000863025900001 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Energy & Fuels Materials Science Physics Article HIGH-VOLTAGE SPINEL LIMN1.5NI0.5O4 SPINEL CYCLING STABILITY HIGH-CAPACITY LI PERFORMANCE RICH ELECTRODES EVOLUTION BEHAVIOR EC-free electrolytes Mn-rich cathodes multi-cation redox rechargeable Li batteries spinel oxides surface reconstruction cathode-electrolyte interfaces