Preparation of Prussian Blue Submicron Particles with a Pore Structure by Two-Step Optimization for Na-Ion Battery Cathodes.
Traditional Prussian blue (Fe4[Fe(CN)6]3) synthesized by simple rapid precipitation shows poor electrochemical performance because of the presence of vacancies occupied by coordinated water. When the precipitation rate is reduced and polyvinylpyrrolidone K-30 is added as a surface active agent, the as-prepared Prussian blue has fewer vacancies in the crystal structure than in that of traditional Prussian blue. It has a well-defined face-centered-cubic structure, which can provide large channels for Na(+) insertion/extraction. The material, synthesized by slow precipitation, has an initial discharge capacity of 113 mA h g(-1) and maintains 93 mA h g(-1) under a current density of 50 mA g(-1) after 150 charge-discharge cycles. After further optimization by a chemical etching method, the complex nanoporous structure of Prussian blue has a high Brunauer-Emmett-Teller surface area and a stable structure to achieve high specific capacity and long cycle life. Surprisingly, the electrode shows an initial discharge capacity of 115 mA h g(-1) and a Coulombic efficiency of approximately 100% with capacity retention of 96% after 150 cycles. Experimental results show that Prussian blue can also be used as a cathode for Na-ion batteries.
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.|Collaborative Innovation Center of Electric Vehicles in Beijing , Beijing 100081, P.R. China.
Renjie
R
Chen
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.
Yongxin
Y
Huang
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.
Man
M
Xie
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.
Qianyun
Q
Zhang
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.
XiaoXiao
X
Zhang
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.|Collaborative Innovation Center of Electric Vehicles in Beijing , Beijing 100081, P.R. China.
Li
L
Li
School of Materials Science & Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology , Beijing 100081, P.R. China.|Collaborative Innovation Center of Electric Vehicles in Beijing , Beijing 100081, P.R. China.
Feng
F
Wu
Prussian blue; cathode materials; porous submicron cubes; sodium-ion batteries; structural optimization