Li-rich layered oxide(LLO),e.g.,Li_(1.12)[Mn_(0.56)Ni_(0.16)Co_(0.08)]O_(2)(LRMO),is considered as a promising cathode material due to its superior Li-storage capability.However,the poor cycling stability and large vo...Li-rich layered oxide(LLO),e.g.,Li_(1.12)[Mn_(0.56)Ni_(0.16)Co_(0.08)]O_(2)(LRMO),is considered as a promising cathode material due to its superior Li-storage capability.However,the poor cycling stability and large voltage decay,which are related to the phase transition,limit its industrialization process.Herein,a Mo-doped LRMO(Li_(1.12)[Mn_(0.56)Ni_(0.16)Co_(0.08)]_(0.98)Mo_(0.02)O_(2),LRMO-Mo2.0%)was successfully synthesized via a simple combination of co-precipitation with high-temperature calcination for solving the mentioned above-disadvantages.Compared with the pristine counterpart,the as-prepared LRMO-Mo2.0%shows more excellent electrochemical performance in terms of rate capability(reversible capacity of 118 mA·h·g^(−1) at 5 C),cyclic ability(94.3%capacity retention after 100 cycles at 0.2 C)and discharge midpoint voltage decay(0.11 V after 100 cycles).Systematic investigation of structural evolution and electrochemical kinetics elucidate that the synergic effect of robust oxygen framework and layered/spinel heterostructure is the key to its performance improvement.Such synergy helps to stabilize the layered structure by curbing the structural transformation and oxygen escaping during the electrochemical cycling.This work paved the way for the simple and efficient preparation of highly stable LLO cathode materials.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.51964017,Grant No.51874151)the Jiangxi Provincial Natural Science Foundation(Grant No.20212BAB214004)+1 种基金the Jiangxi Provincial Education Office Natural Science Fund Project(Grant No.GJJ201413)the Jiangxi University of Science and Technology College Student Innovation and Entrepreneurship Training Program Support Project(Grant No.DC2019-042).
文摘Li-rich layered oxide(LLO),e.g.,Li_(1.12)[Mn_(0.56)Ni_(0.16)Co_(0.08)]O_(2)(LRMO),is considered as a promising cathode material due to its superior Li-storage capability.However,the poor cycling stability and large voltage decay,which are related to the phase transition,limit its industrialization process.Herein,a Mo-doped LRMO(Li_(1.12)[Mn_(0.56)Ni_(0.16)Co_(0.08)]_(0.98)Mo_(0.02)O_(2),LRMO-Mo2.0%)was successfully synthesized via a simple combination of co-precipitation with high-temperature calcination for solving the mentioned above-disadvantages.Compared with the pristine counterpart,the as-prepared LRMO-Mo2.0%shows more excellent electrochemical performance in terms of rate capability(reversible capacity of 118 mA·h·g^(−1) at 5 C),cyclic ability(94.3%capacity retention after 100 cycles at 0.2 C)and discharge midpoint voltage decay(0.11 V after 100 cycles).Systematic investigation of structural evolution and electrochemical kinetics elucidate that the synergic effect of robust oxygen framework and layered/spinel heterostructure is the key to its performance improvement.Such synergy helps to stabilize the layered structure by curbing the structural transformation and oxygen escaping during the electrochemical cycling.This work paved the way for the simple and efficient preparation of highly stable LLO cathode materials.
