Lithium-rich manganese-based oxides(LRMOs)have been considered as one of the most promising cath-ode materials owing to their superior specific capacity and high operating voltage.However,their large-scale commercial applications are limited due to problems such as structural instability,voltage decay,and poor cycle stability.Herein,pre-generated oxygen vacancies and oxygen-deficient phase were intro-duced to Li1.2Mn0.6Ni0.2O2(LMNO)using a facile urea-assisted mixed gas treatment(UMGT)method for facilitating electronic and ionic conductivity,reducing the surface oxygen partial pressure,and suppress-ing the release of lattice oxygen.Compared with the pristine LMNO material,the UMGT sample modified at 200℃exhibited enhanced discharge capacity,capacity retention,and rate capability.In addition,the Li+diffusion coefficient significantly improved by 50％than that of the reference LMNO.More impor-tantly,the voltage decay was effectively suppressed,with average potential decreasing from 0.53 V(LMNO)to 0.39 V(UMGT-200)after 200 cycles at 1 C.The proposed UMGT method provides an effective strategy to alleviate the phase transition and improve the electrochemical performance for lithium-rich materials,and identifies a promising research direction to inhibit the voltage decay of layered anion redox cathode materials.

Liying Bao;Lei Wei;Nuoting Fu;Jinyang Dong;Lai Chen;Yuefeng Su;Ning Li;Yun Lu;Yongjian Li;Shi Chen;Feng Wu

School of Materials Science and Engineering,Beijing Institute of Technology,Beijing Key Laboratory of Environmental Science and Engineering,Beijing 100081,China;Beijing Institute of Technology Chongqing Innovation Center,Chongqing 401120,China;School of Automation,Beijing Institute of Technology,Beijing 100081,China

能源化学

[1]Liying Bao;Lei Wei;Nuoting Fu;Jinyang Dong;Lai Chen;Yuefeng Su;Ning Li;Yun Lu;Yongjian Li;Shi Chen;Feng Wu-.Urea-assisted mixed gas treatment on Li-Rich layered oxide with enhanced electrochemical performance)[J].能源化学,2022(03):123-132

LRMOs,LMNO,UMGT

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