Assembly of flexible CoMoO(4)@NiMoO(4)·xH(2)O and Fe(2)O(3) electrodes for solid-state asymmetric supercapacitors

In this work, CoMoO(4)@NiMoO(4)·xH(2)O core-shell heterostructure electrode is directly grown on carbon fabric (CF) via a feasible hydrothermal procedure with CoMoO(4) nanowires (NWs) as the core and NiMoO(4) nanosheets (NSs) as the shell. This core-shell heterostructure could provide fast ion and electron transfer, a large number of active sites, and good strain accommodation. As a result, the CoMoO(4)@NiMoO(4)·xH(2)O electrode yields high-capacitance performance with a high specific capacitance of 1582 F g(−1), good cycling stability with the capacitance retention of 97.1% after 3000 cycles and good rate capability. The electrode also shows excellent mechanical flexibility. Also, a flexible Fe(2)O(3) nanorods/CF electrode with enhanced electrochemical performance was prepared. A solid-state asymmetric supercapacitor device is successfully fabricated by using flexible CoMoO(4)@NiMoO(4)·xH(2)O as the positive electrode and Fe(2)O(3) as the negative electrode. The asymmetric supercapacitor with a maximum voltage of 1.6 V demonstrates high specific energy (41.8 Wh kg(−1) at 700 W kg(−1)), high power density (12000 W kg(−1) at 26.7 Wh kg(−1)), and excellent cycle ability with the capacitance retention of 89.3% after 5000 cycles (at the current density of 3A g(−1)).