Metal-Organic Framework-Derived Bi2O3/C and NiCo2S4 Hollow Nanofibers for Asymmetric Supercapacitors

Asymmetric supercapacitors (ASCs) are regarded as promising energy storage devices due to their excellent electro-chemical properties, especially favorable power density. In this work, both the high-performance positive electrode and negative electrode materials are designed and prepared using the electro-spinning technique and a metal-organic framework (MOF)-derived strategy. The obtained Bi-MOF-derived Bi2O3/C hollow nanofibers have an outstanding specific capacity (1420 F g(-1) at 1 A g(-1)) and show an excellent cycling performance (92.21% retention after 4000 cycles) as negative electrodes, while the NiCo-MOF-derived NiCo2S4 hollow nanofibers as positive electrodes also have an excellent specific capacity (2656 F g(-1) at 1 A g(-1)), and their capacity retention is 92.11% after 4000 charge-discharge cycles. The assembled ASC device with these two electrodes displays a high energy density of 85.38 W h kg(-1) and excellent cycling performance with 80% retention after 10,000 cycles. Therefore, this work not only experimentally demonstrates MOF-derived Bi2O3/C and NiCo2S4 as fascinating candidate electrode materials for ASCs but also affords a method to rationally design and fabricate other electrode materials with unique hollow nanofiber structures for energy storage.

Automated summary

The Bi2O3/C and NiCo2S4 materials designed and prepared using electro-spinning and MOF-derived strategy exhibit excellent specific capacity and cycling performance as electrodes for ASCs, showing great potential for electrochemical energy storage applications.