Sodium-ion batteries(SIBs),as the low-cost and large-scale energy storage devices,have attracted wide attention,but their capacity and cycle performance are limited by cathode materials.Here,P2-Na0.7MnO2.05microflakes...Sodium-ion batteries(SIBs),as the low-cost and large-scale energy storage devices,have attracted wide attention,but their capacity and cycle performance are limited by cathode materials.Here,P2-Na0.7MnO2.05microflakes with the diameter 500 nm to 1μm are synthesized by an improved solid-state reaction.The as-prepared P2-Na0.7MnO2.05microflakes exhibit excellent electrochemical performance when tested as a cathode material of SIBs.It delivers a considerably reversible capacity of 142.7 mA h g-1at a current density of 0.3C(1C=180 mA g-1)with a slow capacity decay to121.5 mA h g-1after 50 cycles.Even at a high current density of 2C,the P2-Na0.7MnO2.05microflakes still show a specific capacity of 88.9 mA h g-1with a capacity retention of 75%after 100 cycles.The above performance of Na0.7MnO2.05microflakes are better than Na0.7MnO2.05with large block morphology,which is mainly attributed to the lamellar morphology of P2-Na0.7MnO2.05alleviating structural deformation and accelerating reaction kinetics.This strategy will provide new opportunities to develop stable oxide cathodes for SIBs.展开更多
Single phase polycrystalline samples Na0.7Co1-xAlxO2 （x = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 030） were prepared by solid state reaction. The magnetic properties from 5 K to 300 K have been studied by dc and ac magneti...Single phase polycrystalline samples Na0.7Co1-xAlxO2 （x = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 030） were prepared by solid state reaction. The magnetic properties from 5 K to 300 K have been studied by dc and ac magnetic susceptibility measurements. Samples with lower doping quantity （x = 0, 0.05, 0.10） showed paramagnetic behaviors, but those with higher doping quantity （x=0.20, 0.25, 0.30）showed spin-glass behaviors with a freezing temperature （Tf） of about 13 K.展开更多
文摘Sodium-ion batteries(SIBs),as the low-cost and large-scale energy storage devices,have attracted wide attention,but their capacity and cycle performance are limited by cathode materials.Here,P2-Na0.7MnO2.05microflakes with the diameter 500 nm to 1μm are synthesized by an improved solid-state reaction.The as-prepared P2-Na0.7MnO2.05microflakes exhibit excellent electrochemical performance when tested as a cathode material of SIBs.It delivers a considerably reversible capacity of 142.7 mA h g-1at a current density of 0.3C(1C=180 mA g-1)with a slow capacity decay to121.5 mA h g-1after 50 cycles.Even at a high current density of 2C,the P2-Na0.7MnO2.05microflakes still show a specific capacity of 88.9 mA h g-1with a capacity retention of 75%after 100 cycles.The above performance of Na0.7MnO2.05microflakes are better than Na0.7MnO2.05with large block morphology,which is mainly attributed to the lamellar morphology of P2-Na0.7MnO2.05alleviating structural deformation and accelerating reaction kinetics.This strategy will provide new opportunities to develop stable oxide cathodes for SIBs.
基金This work was supported by the National Science Foundation of China under Grant No. 50372052, 50430137, 50588201 the National Basic Research Program of China (973 program), under Grant No. 2007CB616906)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in UniversityAustralian Research Council under Grant No. DP0559872, DP0881739.
文摘Single phase polycrystalline samples Na0.7Co1-xAlxO2 （x = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 030） were prepared by solid state reaction. The magnetic properties from 5 K to 300 K have been studied by dc and ac magnetic susceptibility measurements. Samples with lower doping quantity （x = 0, 0.05, 0.10） showed paramagnetic behaviors, but those with higher doping quantity （x=0.20, 0.25, 0.30）showed spin-glass behaviors with a freezing temperature （Tf） of about 13 K.
