用于锂氧电池阴极的铁基金属聚合物纳米壁基复合材料。

Fe-based metallopolymer nanowall-based composites for Li-O2 battery cathode.

作者信息

Zhang Wenyu, Zhu Jixin, Ang Huixiang, Wang Haibo, Tan Hui Teng, Yang Dan, Xu Chen, Xiao Ni, Li Bing, Liu Weiling, Wang Xin, Hng Huey Hoon, Yan Qingyu

机构信息

School of Materials Science and Engineering, Nanyang Technological University , Singapore, 639798, Singapore.

出版信息

ACS Appl Mater Interfaces. 2014 May 28;6(10):7164-70. doi: 10.1021/am500158s. Epub 2014 May 6.

DOI:10.1021/am500158s

PMID:24761777

Abstract

Metallopolymer nanowalls were prepared through a simple wet-chemical process using reduced graphene oxides as heterogeneous nucleation aids, which also help to form conductive electron paths. The nanowalls grow vertically on graphene surface with 100-200 nm in widths and ∼20 nm in thickness. The Fe-based metallopolymer nanowall-based electrode shows best performance as O2 cathode exhibiting high round-trip efficiencies and stable cycling performance among other transition metal containing metallopolymer counterparts. The electrode delivers discharge-charge capacities of 1000 mAh/g for 40 cycles and maintains round-trip efficiencies >78% at 50 mA/g. The 1(st)-cycle round-trip efficiencies are 79%, 72%, and 65% at current densities of 50, 200, and 400 mA/g, respectively. The NMR analysis of the Fe-based metallopolymer based electrode after 40 cycles reveals slow formation of the side products, CH3CO2Li and HCO2Li.

摘要

通过简单的湿化学工艺，以还原氧化石墨烯作为异质形核助剂制备了金属聚合物纳米壁，还原氧化石墨烯还有助于形成导电电子路径。纳米壁在石墨烯表面垂直生长，宽度为100 - 200 nm，厚度约为20 nm。基于铁基金属聚合物纳米壁的电极作为氧气阴极表现出最佳性能，在其他含过渡金属的金属聚合物对应物中具有高往返效率和稳定的循环性能。该电极在40个循环中提供1000 mAh/g的充放电容量，并在50 mA/g下保持往返效率>78%。在电流密度为50、200和400 mA/g时，第1循环的往返效率分别为79%、72%和65%。对经过40个循环的铁基金属聚合物基电极的核磁共振分析表明，副产物CH3CO2Li和HCO2Li的形成缓慢。