Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
ACS Nano. 2012 Jan 24;6(1):530-8. doi: 10.1021/nn203869a. Epub 2011 Dec 23.
Tailoring nanoarchitecture of materials offers unprecedented opportunities in utilization of their functional properties. Nanostructures of vanadium oxide, synthesized by electrochemical deposition, are studied as a cathode material for rechargeable Na-ion batteries. Ex situ and in situ synchrotron characterizations revealed the presence of an electrochemically responsive bilayered structure with adjustable intralayer spacing that accommodates intercalation of Na(+) ions. Sodium intake induces organization of overall structure with appearance of both long- and short-range order, while deintercalation is accompanied with the loss of long-range order, whereas short-range order is preserved. Nanostructured electrodes achieve theoretical reversible capacity for Na(2)V(2)O(5) stochiometry of 250 mAh/g. The stability evaluation during charge-discharge cycles at room temperature revealed an efficient 3 V cathode material with superb performance: energy density of ~760 Wh/kg and power density of 1200 W/kg. These results demonstrate feasibility of development of the ambient temperature Na-ion rechargeable batteries by employment of electrodes with tailored nanoarchitectures.
对材料的纳米结构进行剪裁，为利用其功能特性提供了前所未有的机会。通过电化学沉积合成的氧化钒纳米结构被研究为可充电钠离子电池的阴极材料。原位和非原位同步辐射研究揭示了存在电化学响应的双层结构，具有可调的层内间距，可容纳 Na(+)离子的嵌入。钠离子的摄入诱导整体结构的组织化，出现长程和短程有序，而脱插伴随长程有序的丧失，而短程有序则得以保留。纳米结构电极实现了理论上的可逆容量，对于 Na(2)V(2)O(5)的化学计量比为 250 mAh/g。在室温下的充放电循环稳定性评估中，发现了一种高效的 3 V 阴极材料，具有出色的性能：能量密度约为 760 Wh/kg，功率密度为 1200 W/kg。这些结果表明，通过采用具有定制纳米结构的电极，开发在环境温度下工作的钠离子可充电电池是可行的。
