Owing to the overwhelming advantage in energy density, lithium–sulfur (Li–S) battery is a promising next-generation electrochemical energy storage system. Despite many efforts in pursuing long cycle life, relatively little emphasis has been placed on increasing the areal energy density. Herein, we have designed and developed a ‘pie’ structured electrode, which provides an excellent balance between gravimetric and areal energy densities. Combining lotus root-like multichannel carbon nanofibers ‘filling’ and amino-functionalized graphene ‘crust’, the free-standing paper electrode (S mass loading: 3.6 mg cm^-2) delivers high specific capacity of 1,314 mAh g^-1 (4.7 mAh cm^-2) at 0.1 C (0.6 mA cm^-2) accompanied with good cycling stability. Moreover, the areal capacity can be further boosted to more than 8 mAh cm^-2 by stacking three layers of paper electrodes with S mass loading of 10.8 mg cm^-2.

Nature Communications 6, Article number: 8850 doi:10.1038/ncomms9850
Received 02 July 2015 Accepted 09 October 2015 Published 26 November 2015

http://www.nature.com/ncomms/2015/151126/ncomms9850/full/ncomms9850.html

由于锂-硫（Li-S）电池具有很高的能量密度，因此有望成为下一代的电化学储能体系。尽管很多研究都集中在延长电池的寿命上，但极少有研究关注如何增加电池的区域能量密度。 Li 等人设计开发了一种圆盘状的电极，它可以在重量和区域能量密度间达到完美的平衡。这种电极具有莲藕状的多通道碳纳米纤维结构填充，外部由胺基修饰的石墨烯包围，因此可以获得很高的比容量（1314mAhg^-1/4.7mAhcm^-2）以及良好的循环稳定性。此外，通过叠加三层电极，电池的区域容量可以进一步提高至 8mAhcm^-2 。