title: Janus Solid-Liquid Interface Enabling Ultrahigh Charging and Discharging Rate for Advanced Lithium-Ion Batteries.
abstract: LiFePO4 has long been held as one of the most promising battery cathode for its high energy storage capacity. Meanwhile, although extensive studies have been conducted on the interfacial chemistries in Li-ion batteries,1-3 little is known on the atomic level about the solid-liquid interface of LiFePO4/electrolyte. Here, we report battery cathode consisted with nanosized LiFePO4 particles in aqueous electrolyte with an high charging and discharging rate of 600 C (3600/600 = 6 s charge time, 1 C = 170 mAh g(-1)) reaching 72 mAh g(-1) energy storage (42% of the theoretical capacity). By contrast, the accessible capacity sharply decreases to 20 mAh g(-1) at 200 C in organic electrolyte. After a comprehensive electrochemistry tests and ab initio calculations of the LiFePO4-H2O and LiFePO4-EC (ethylene carbonate) systems, we identified the transient formation of a Janus hydrated interface in the LiFePO4-H2O system, where the truncated symmetry of solid LiFePO4 surface is compensated by the chemisorbed H2O molecules, forming a half-solid (LiFePO4) and half-liquid (H2O) amphiphilic coordination environment that eases the Li desolvation process near the surface, which makes a fast Li-ion transport across the solid/liquid interfaces possible.
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Jiaxin
authors: J
authors: Zheng
authors: College of Energy, Nanjing Tech University , Nanjing 211816, Jiangsu Province, People's Republic of China.|New Energy and Materials Laboratory (NEML), Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors: Yuyang
authors: Y
authors: Hou
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Yandong
authors: Y
authors: Duan
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Xiaohe
authors: X
authors: Song
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Yi
authors: Y
authors: Wei
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Tongchao
authors: T
authors: Liu
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Jiangtao
authors: J
authors: Hu
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Hua
authors: H
authors: Guo
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Zengqing
authors: Z
authors: Zhuo
authors: New Energy and Materials Laboratory (NEML), Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors: Lili
authors: L
authors: Liu
authors: New Energy and Materials Laboratory (NEML), Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors: Zheng
authors: Z
authors: Chang
authors: New Energy and Materials Laboratory (NEML), Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors: Xiaowei
authors: X
authors: Wang
authors: Materials Science Division, Lawrence Berkeley National Laboratory , Berkely, California 94720, United States.
authors: Danylo
authors: D
authors: Zherebetskyy
authors: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors: Yanyan
authors: Y
authors: Fang
authors: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors: Yuan
authors: Y
authors: Lin
authors: Electrochemistry Branch, U.S. Army Research Laboratory, Adelphi, Maryland 20783, United States.
authors: Kang
authors: K
authors: Xu
authors: Materials Science Division, Lawrence Berkeley National Laboratory , Berkely, California 94720, United States.
authors: Lin-Wang
authors: LW
authors: Wang
authors: College of Energy, Nanjing Tech University , Nanjing 211816, Jiangsu Province, People's Republic of China.|New Energy and Materials Laboratory (NEML), Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors: Yuping
authors: Y
authors: Wu
authors: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors: Feng
authors: F
authors: Pan
keywords: LiFePO4; ab initio calculations; aqueous electrolyte; organic electrolyte; rate performance; solid−liquid interface