基于无金属石墨烯纳米片催化剂的锂-空气可充电电池。

Li-air rechargeable battery based on metal-free graphene nanosheet catalysts.

机构信息

Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology, Umezono 1-1-1, Central 2, Tsukuba, Ibaraki 305-8568, Japan.

出版信息

ACS Nano. 2011 Apr 26;5(4):3020-6. doi: 10.1021/nn200084u. Epub 2011 Mar 25.

DOI:10.1021/nn200084u

PMID:21438513

Abstract

Metal-free graphene nanosheets (GNSs) were examined for use as air electrodes in a Li-air battery with a hybrid electrolyte. At 0.5 mA cm(-1), the GNSs showed a high discharge voltage that was near that of the 20 wt % Pt/carbon black. This was ascribed to the presence of sp(3) bonding associated with edge and defect sites in GNSs. Moreover, heat-treated GNSs not only provided a similar catalytic activity in reducing oxygen in the air, but also showed a much more-stable cycling performance than GNSs when used in a rechargeable Li-air battery. This improvement resulted from removal of adsorbed functional groups and from crystallization of the GNS surface into a graphitic structure on heat treatment.

摘要

金属自由的石墨烯纳米片（GNSs）被用作带有混合电解质的锂-空气电池的空气电极进行了研究。在 0.5 mA cm(-1) 的电流密度下，GNSs 显示出接近 20 wt % Pt/炭黑的高放电电压。这归因于 GNSs 边缘和缺陷位置存在的 sp(3)键合。此外，经过热处理的 GNSs 不仅在还原空气中的氧气方面提供了类似的催化活性，而且与在可再充电的锂-空气电池中使用的 GNSs 相比，还显示出更稳定的循环性能。这种改善源于去除了吸附的官能团以及 GNS 表面在热处理时结晶成石墨结构。