A High-Temperature β-Phase NaMnO2 Stabilized by Cu Doping and Its Na Storage Properties

Li-Wei Jiang, Ya-Xiang Lu, Yue-Sheng Wang, Li-Lu Liu, Xing-Guo Qi, Cheng-Long Zhao, Li-Quan Chen, Yong-Sheng Hu
2018 Chinese Physics Letters  
The high-temperature -phase NaMnO2 is a promising material for Na-ion batteries (NIBs) due to its high capacity and abundant resources. However, the synthesis of phase-pure -NaMnO2 is burdensome and costineffective because it needs to be sintered under oxygen atmosphere at high temperature and followed by a quenching procedure. Here we first report that the pure phase can be stabilized by Cu-doping and easily synthesized by replacing a proportion of Mn with Cu via a simplified process including
more » ... sintering in air and cooling to room temperature naturally. Based on the first-principle calculations, the band gap decreases from 0.7 eV to 0.3 eV, which indicates that the electronic conductivity can be improved by Cu-doping. The designed -NaCu0.1Mn0.9O2 is applied as cathode in NIBs, exhibiting an energy density of 419 Wh/kg and better performance in terms of rate capability and cycling stability than those in the undoped case.
doi:10.1088/0256-307x/35/4/048801 fatcat:r2dmz2mdu5gijjawxomnrzdohu