Co-free Li-rich layered oxide cathodes have drawn much attention owing to their low cost and high energy density.Nevertheless,anion oxidation of oxygen leads to oxygen peroxidation during the first charging process,which leads to co-migration of transition metal ions and oxygen vacancies,causing structural instability.In this work,we propose a pre-activation strategy driven by chemical impregnation to modulate the chemical state of surface lattice oxygen,thus regulating the structural and electrochem-ical properties of the cathodes.In-situ X-ray diffraction confirms that materials based on activated oxy-gen configuration have higher structural stability.More importantly,this novel efficient strategy endows the cathodes having a lower surface charge transfer barrier and higher Li+transfer kinetics characteristic and ameliorates its inherent issues.The optimized cathode exhibits excellent electrochemical perfor-mance:after 300 cycles,high capacity(from 238 mAh g-1 to 193 mAh g-1 at 1 C)and low voltage atten-uation(168 mV)are obtained.Overall,this modulated surface lattice oxygen strategy improves the electrochemical activity and structural stability,providing an innovative idea to obtain high-capacity Co-free Li-rich cathodes for next-generation Li-ion batteries.

Gui-Jing Xu;Wang Ke;Fu-Da Yu;Jie Feng;Yun-Shan Jiang;Lan-Fang Que;Lei Zhao;Zhen-Bo Wang

MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage,School of Chemistry and Chemical Engineering,State Key Lab of Urban Water Resource and Environment,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China;Engineering Research Center of Environment-Friendly Functional Materials,Ministry of Education,Institute of Materials Physical Chemistry,Huaqiao University,Xiamen 361021,Fujian,China;College of Materials Science and Engineering,Shenzhen University,Shenzhen 518071,Guangdong,China

能源化学

[1]Gui-Jing Xu;Wang Ke;Fu-Da Yu;Jie Feng;Yun-Shan Jiang;Lan-Fang Que;Lei Zhao;Zhen-Bo Wang-.Modulation of lattice oxygen boosts the electrochemical activity and stability of Co-free Li-rich cathodes)[J].能源化学,2022(12):117-126

Li+transfer

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