Abstract
The surfaces of nanoporous metals are easy to be oxidized under normal ambient condition. This usual attribute permits the exploration of metal-core oxide-shell structure that would be used for supercapacitors (SCs). However, the large-scale application of such electrodes is still limited by the intrinsically low ion diffusion coefficient, poor electronic conductivity and frustrating structural stability. Here we design a defect decorated hierarchical nanoporous CuMn2O4/Cu0.2Ni0.8O/CuxOy @ alloy electrode (HNP-TMO) by dealloying-coarsening-dealloying a sandwich-like NiCuMn/Ni/NiCuMn alloy and followed by self-combusting (2.1 mm s?1). The sandwiched Ni can synergy with unoxidized alloy to provide excellent mechanical stability and electronic conductivity, while the hierarchically porous structure with robust defects can ensure rapid electron/ion transportation. Benefiting from these merits, the HNP-TMO electrode with high mass loading of 7.8 mg cm?2 delivers an ultrahigh area capacity of 6.78 mAh cm?2 at 10 mA cm?2, good rate capability (maintaining 3.33 mAh cm?2 at ultra-high current density of 100 mA cm?2) and outstanding cycling performance with capacity retention of 92.7% after 12000 cycles. Full symmetric supercapacitor also demonstrates high energy and power density of 0.17 mWh cm?2 and 40.15 mW cm?2, respectively, indicating the promise for practical energy storage applications.
NSTL
Elsevier