Preparation and performance of beta-MnO2 nanorod @ nanoflake (Ni, Co, Mn) oxides with hierarchical mesoporous structure

作者：Wang, Hao; Zhao, Qinglan; Wang, Xianyou^*; Zhang, Youwei; Gao, Jiao; Fu, Yanqing; Yang, Xiukang; Shu, Hongbo

来源：RSC Advances, 2014, 4(81): 42910-42916.

DOI：10.1039/c4ra08444f

The rational design and facile synthesis of transition metal oxides are necessary to improve their application in supercapacitors. Herein three kinds of hierarchical mesoporous structured transition metal oxides, which are composed of a beta-MnO2 nanorod core and one of three different nanosheet hybrid (Ni, Co, Mn) oxide shells, are facilely synthesized via a novel in situ nucleation and growth of transition metal oxides on the surface of the beta-MnO2 nanorods. The crystallo-graphic analyses demonstrated that the three kinds of hybrid oxide shells consisted of cobalt manganese oxide (CMO), nickel manganese oxide (NMO), and nickel cobalt manganese oxide (NCMO). These transition metal oxides are evaluated as electrodes for high performance supercapacitors (SCs). The results reveal that beta-MnO2@CMO exhibits a good rate capability of 35% capacity retention even at 20 A g(-1), while beta-MnO2@NMO displays a high pseudocapacitance of 560 F g(-1) at 1 A g(-1). However, beta-MnO2@NCMO combined the advantages of both beta-MnO2@CMO and beta-MnO2@NMO, and exhibits a high specific capacitance of 675 F g(-1) at 1 A g(-1) with excellent rate performance (about 30% capacity retention at 20 A g(-1)) and cycling stability (83% capacity retention after 3000 cycles). The improved electrochemical performance can be attributed to the unique hierarchical architecture and the synergistic effect of different components.

• 出版日期2014
• 单位湘潭大学