A supercapacitor electrode with ultrahigh areal capacity by using loofah-inspired bimetallic selenide-incorporated hierarchical nanowires

• Published in: Journal of alloys and compounds 2023-05, Vol.943, p.169045, Article 169045
• Main Authors: Chen, Gang, Zhang, Lunqiang, Zhu, Yatong, Wan, Zuteng, Huang, Xiaodong, Yin, Jiang, Liu, Zhiguo, Zhou, Yue, Xia, Yidong
• Format: Article
• Language: English
• Subjects: Bimetallic selenide; Bio-inspired engineering; Core-shell structure; Energy density; Supercapacitor
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.169045

Nanostructure engineering on the electrodes remains challenging for high-performance supercapacitors to meet the ever-increasing demands. Inspired by the function and structure of the loofah which possesses an inner firm skeleton coupled with the outer crisscrossed fibers, herein, a novel loofah-like core-shell nanostructure is synthesized with well-designed Co0.6Mn0.4Se nanowires dominated as the core, and MnO2 nanoflakes decorated as the shell. The bimetallic selenide exhibits high conductivity and rich electrochemical activity owing to the coexisting metals component. It also serves as a robust support to hinder the agglomeration of MnO2 nanoflakes, forming a unique porous structure with great ability of self-adapting to volumetric changes. The optimized Co0.6Mn0.4Se/MnO2 electrode exhibits an ultrahigh areal capacity (3.91 F cm−2/0.60 mAh cm−2 at 2 mA cm−2) and an exceptional retention of 95.47 % after 8000 cycles. Both performances are superior to the MnCo2O4/MnO2 electrode without the loofah-like networks in our work. Moreover, the assembled Co0.6Mn0.4Se/MnO2//AC (active carbon) hybrid supercapacitor delivers a high energy density of ∼89.67 Wh kg−1 at a power density of 399.98 W kg−1, and a remarkable life span with ∼97.30 % retention after 12,000 charge/discharge cycles. The eye-catching results indicate that the integrated Co0.6Mn0.4Se nanowires show great potential to engineering advanced electrodes. Further demonstration of the all-solid-state flexible cell based on the bio-inspired Co0.6Mn0.4Se/MnO2 structure also proves its practical application in wearable electronics. •The loofah-like Co0.6Mn0.4Se/MnO2 core-shell structure is synthesized.•The innovative bimetallic selenide serves as the outstanding core material.•The advanced cathode exhibits an extremely high areal capacity.•Asymmetric supercapacitor delivers high energy density and remarkable life span.