Co-HKUST@CoMn-LDHs with synergistic effect as high performance electrode material for supercapacitors

Abstract

In this work, a new core-shell structure electrode material (Co-HKUST@CoMn-LDHs) was synthesized through a two-step hydrothermal and electrodeposition method. When used as the electrode material for supercapacitors (SCs), the specific capacitance is up to 1008.8 F g−1 at the current density of 1 A g−1 (Co-HKUST is 578.6 F g−1, CoMn-LDHs is 173.9 F g−1), and the capacitance retention rate is 79.6% after 1000 cycles at 5 A g−1. Meanwhile, the as-prepared Co-HKUST@CoMn-LDHs//AC asymmetric SC device shows a high specific capacitance of 313.8 F g−1 at 1 A g−1, and the energy density reaches 90.2 Wh Kg−1 at 719.0 W Kg−1 of the power density. Its good performance can be related to the synergistic effect between Co-HKUST and CoMn-LDHs. Studies have shown that Co-HKUST@CoMn-LDHs is a promising electrode material for SC applications.