高温驱动氧化锰刻蚀制备纳米氧化锰-多孔石墨烯及其锂空气电池性能研究

Preparations of Nanostructural Mn O-Porous Graphene Hybrid Material by Thermally-Driven Etching of MnO for Lithium-Air Batteries

本文通过简单的电荷吸附制备了高分散的氧化石墨烯含锰化合物(Mn-GO),利用高温驱动下氧化锰的生长以及热运动同时实现了GO的还原、刻蚀和纳米氧化锰的负载,即成功构筑了纳米氧化锰-多孔石墨烯复合材料(MnO-PGNSs).对影响GO分散性的Mn2+的添加量、影响GO层数的分散液浓度以及影响MnO热运动的烧结条件进行了详细的考察.研究发现,当Mn-GO同时满足优异的分散性、适合的片层厚度和烧结条件(>800oC,>2h),才能在GNSs表面刻蚀成孔制备得到MnO-PGNSs.本文进一步将MnO-PGNSs作为锂空气电池正极材料,结果表明在50 mA·g-1的电流密度下深度放电后容量达到5100 mA h·g-1,相比于GNSs和PGNSs,MnO-PGNSs具有更高的比容量.锂空气电池性能的提高得益于GNSs表面的多孔结构和MnO优异的催化活性.

In order to emphasize improving the surface morphology of graphene(GNSs)as a designed concept,the magnesium oxide-porous-graphene(MnO-PGNSs)hybride material was synthesized with a simple site-localized Mn2+on graphene oxide(Mn-GO)by charge adsorption,and then driving by high-temperature calcination,growing MnO nanoparticles and etching GNSs.The key factors that influenced the etch hole formation are analyzed with the focuses on the dispersion of Mn-GO,layer number of GO and calcination temperature.It was shown that the Mn O-PGNSs,when used as a lithium-air battery cathode,exhibited high reversible capacity as compared with GNSs and PGNs,and delivered the storage capacity as high as 5100 m Ah·g-1 at 50 m A·g-1.