Nat Mater. 2012 Apr 29;11(6):512-7. doi: 10.1038/nmat3309.
Rechargeable lithium batteries have risen to prominence as key devices for green and sustainable energy development. Electric vehicles, which are not equipped with an internal combustion engine, have been launched in the market. Manganese- and iron-based positive-electrode materials, such as LiMn(2)O(4) and LiFePO(4), are used in large-scale batteries for electric vehicles. Manganese and iron are abundant elements in the Earth's crust, but lithium is not. In contrast to lithium, sodium is an attractive charge carrier on the basis of elemental abundance. Recently, some layered materials, where sodium can be electrochemically and reversibly extracted/inserted, have been reported. However, their reversible capacity is typically limited to 100 mAh g(-1). Herein, we report a new electrode material, P2-Na(2/3)[Fe(1/2)Mn(1/2)]O(2), that delivers 190 mAh g(-1) of reversible capacity in the sodium cells with the electrochemically active Fe(3+)/Fe(4+) redox. These results will contribute to the development of rechargeable batteries from the earth-abundant elements operable at room temperature.
可充电锂电池作为绿色和可持续能源发展的关键设备而备受关注。市场上已经推出了不带内燃机的电动汽车。锰和铁基正极材料，如 LiMn(2)O(4) 和 LiFePO(4)，用于大型电动汽车电池。锰和铁在地壳中含量丰富，但锂却不是。相比之下，钠在元素丰度的基础上是一种有吸引力的电荷载体。最近，一些层状材料被报道可以电化学和可逆地提取/插入钠。然而，它们的可逆容量通常限于 100 mAh g(-1)。在此，我们报告了一种新的电极材料 P2-Na(2/3)[Fe(1/2)Mn(1/2)]O(2)，在钠离子电池中具有 190 mAh g(-1)的可逆容量，其中 Fe(3+)/Fe(4+)氧化还原反应是电化学活性的。这些结果将有助于开发可在室温下使用丰富的地球元素运行的可充电电池。
