Unexpected Li displacement and suppressed phase transition enabling highly stabilized oxygen redox in P3-type Na layered oxide cathode

作     者：Myungeun Choi Hobin Ahn Hyunyoung Park Yongseok Lee Jinho Ahn Bonyoung Ku Junseong Kim Wonseok Ko Jungmin Kang Jung-Keun Yoo Duho Kim Jongsoon Kim Myungeun Choi;Hobin Ahn;Hyunyoung Park;Yongseok Lee;Jinho Ahn;Bonyoung Ku;Junseong Kim;Wonseok Ko;Jungmin Kang;Jung-Keun Yoo;Duho Kim;Jongsoon Kim

作者机构：Department of Energy ScienceSungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST)Sungkyunkwan UniversitySuwon 16419Republic of Korea Carbon Composites DepartmentKorea Institute of Materials Science(KIMS)Changwon 51508Republic of Korea Department of Mechanical Engineering(Integrated Engineering Program)Kyung Hee University1732Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 17104Republic of Korea Department of KHU-KIST Convergence Science and TechnologyKyung Hee University23Kyunghee-daero Dongdaemun-guSeoul 02447Republic of Korea 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2023年第85卷第10期

页      面：144-153,I0006页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Research Foundation of Korea grant funded by the Korea government (NRF2021R1A2C1014280) the Fundamental Research Program of the Korea Institute of Material Science (PNK9370) 

主　　题：Layered oxide cathode Oxygen redox reaction Structural stability Li displacement No phase transition 

摘      要：Oxygen redox is considered a new paradigm for increasing the practical capacity and energy density of the layered oxide cathodes for Na-ion batteries. However, severe local structural changes and phase transitions during anionic redox reactions lead to poor electrochemical performance with sluggish ***, we propose a synergy of Li-Cu cations in harnessing the full potential of oxygen redox, through Li displacement and suppressed phase transition in P3-type layered oxide cathode. P3-type Na_(0.7)[Li_(0.1)Cu_(0.2)Mn_(0.7)]O_(2) cathode delivers a large specific capacity of ~212 mA h g^(-1)at 15 mA g^(-1). The discharge capacity is maintained up to ~90% of the initial capacity after 100 cycles, with stable occurrence of the oxygen redox in the high-voltage region. Through advanced experimental analyses and first-principles calculations, it is confirmed that a stepwise redox reaction based on Cu and O ions occurs for the charge-compensation mechanism upon charging. Based on a concrete understanding of the reaction mechanism, the Li displacement by the synergy of Li-Cu cations plays a crucial role in suppressing the structural change of the P3-type layered material under the oxygen redox reaction, and it is expected to be an effective strategy for stabilizing the oxygen redox in the layered oxides of Na-ion batteries.