Layered manganese-based metal-organic framework as a high capacity electrode material for supercapacitors

Abstract

For the development of supercapacitors with higher energy densities, metal-organic frameworks (MOFs), as electrode materials for supercapacitors, have attracted much attention. Herein, layered manganese-based MOF ([Mn(tfbdc)(4,4′-bpy)(H2O)2], Mn-LMOF; H2tfbdc = 2,3,5,6-tetrafluoroterephthalic acid, 4,4′-bpy = 4,4′-bipyridine) was synthesized by a simple solution reaction and evaluated as an electrode material for supercapacitors for the first time. The Mn-LMOF electrode showed a high specific capacitance, a good cycling stability and a improved rate capability. Its maximum specific capacitances were 1098 F g-1 for 1 M KOH and 1178 F g-1 for 1 M LiOH solutions at a current density of 1 A g-1. The specific capacitance retention was maintained at 92.6% after 2000 cycles in 1 M KOH, slightly lower than that in 1 M LiOH. The excellent supercapacitive performance may be ascribed to the nature of Mn-LMOF, containing a layered structure and nano-sized particles.