3D nanocubes NiCo-PBA sulfide for high-performance supercapacitors

In this work, 3D nanocubes NiCo-PBA sulfide (NiCoS-PBA) has been prepared by ammonia solution etching and vulcanizing for NiCo-Prussian blue analogue (NiCo-PBA) homemade. The SEM and TEM show that the obtained NiCoS-PBA has the 3D nanocubes structure with rough surface and inward depressions. Electrochemical analysis indicates that an ultrahigh specific capacitance of NiCoS-PBA is 965 C g−1 at 1 A g−1, which is better than that of NiCo-PBA# (256 C g−1), only sulfurized NiCoS-PBA# (369 C g−1) and only etched NiCo-PBA (281 C g−1) at the same condition. This is thanks to the 3D nanocubes structure, which has large accessible areas and rich active sites for redox reactions to enhance the electrochemical performance of supercapacitors. Meanwhile, this also illustrates that the etching and vulcanizing treatments can significantly boost the specific capacitance of NiCoS-PBA. Additionally, the NiCoS-PBA-based asymmetric supercapacitor (ACS) device offers an energy density of 61.7 Wh kg−1 at a power density of 800.1 W kg−1. It is believed that NiCoS-PBA will be a strong contender as an electrode material in supercapacitors.