Co3O4 nanoneedle@electroactive nickel boride membrane core/shell arrays: A novel hybrid for enhanced capacity

- Active nickel boride membrane anchored Co3O4 nanoneedle arrays core-shell hybrid architectures was fabricated via rapid interface reaction.
- Specific capacity was improved by synergy between highly active components and optimized electron transfer microstructure.
- The assembled asymmetric supercapacitor device exhibited excellent electrochemical performance.

Exploring novel hybrid materials with efficient microstructure using facile approaches is highly urgent in designing supercapacitor electrodes. Here, the Ni-B membrane was used for coating the porous Co3O4 nanoneedle arrays which supported on the nickel foam (NF) frameworks through a rapid chemical reduction process (denoted as NF/Co3O4@NiB). The Ni-B membrane both provided sufficient active sites for redox reactions and inhibited the aggregation of formed hybrid architectures. Benefiting from the unique structural design and strongly coupled effects between porous Co3O4 arrays and Ni-B membrane, the resulted NF/Co3O4@NiB electrode exhibited high areal capacitance of 3.47 F cm−2 (0.48 mAh cm−2) at a current density of 2.5 mA cm−2, an excellent rate capability while maintaining 95.5% capacity retention after 2000 cycles. The asymmetric supercapacitor constructed with the NF/Co3O4@NiB as positive electrode and hierarchical porous carbon (HPC) as negative electrode also showed ideal capacitive behavior, and simultaneously delivered high energy and power densities. The easily decoration of Ni-B membrane on various active nanoarrays may arouse more novel design about hybrid architectures for large-scale applications.

Active nickel boride membrane anchored Co3O4 nanoneedle arrays hybrid is synthesized via rapid interface reaction. The optimized core/shell nanostructure demonstrates greatly enhanced electrochemical properties.131