CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China , Hefei 230026, Anhui, P. R. China.
Nano Lett. 2014;14(4):2175-80. doi: 10.1021/nl500548a. Epub 2014 Mar 31.
Sodium ion batteries are one of the realistic promising alternatives to the lithium analogues. However, neither theoretical energy/power density nor the practical values reach the values of Li cathodes. Poorer performance is expected owing to larger size, larger mass, and lower cell voltage. Nonetheless, sodium ion batteries are considered to be practically relevant in view of the abundance of the element Na. The arguments in favor of Li and to the disadvantage of Na would be completely obsolete if the specific performance data of the latter would match the first. Here we present a cathode consisting of carbon-coated nanosized Na3V2(PO4)3 embedded in a porous carbon matrix, which not only matches but even outshines lithium cathodes under high rate conditions. It can be (dis)charged in 6 s with a current density as high as 22 A/g (200 C), still delivering a specific capacity of 44 mAh/g, while up to 20 C, the polarization is completely negligible.
钠离子电池是最有前途的锂离子电池替代品之一。然而，无论是理论上的能量/功率密度，还是实际价值都无法与锂离子电池相媲美。由于钠离子尺寸更大、质量更大、电池电压更低，因此性能预计会更差。尽管如此，鉴于钠元素的丰富性，钠离子电池仍被认为具有实际意义。如果后者的比性能数据能够与前者相匹配，那么支持锂离子电池而不利于钠离子电池的论点将完全过时。在这里，我们提出了一种阴极，由纳米尺寸的碳涂层 Na3V2(PO4)3 嵌入多孔碳基质中组成，在高倍率条件下，它不仅与锂离子电池相匹配，甚至超过了锂离子电池。它可以在 6 秒内以高达 22 A/g（200 C）的电流密度充电，仍然可以提供 44 mAh/g 的比容量，而在 20 C 时，极化可以完全忽略不计。
