All-Fibrous Pyroprotein-Based Monolithic Electrodes Containing Heteroatoms for Sodium-Ion Hybrid Capacitors

초록

In this study, pyroprotein-incorporated freestanding papers (PFPs) were fabricated using silk proteins and carbon nanotubes through a facile filtration and heat treatment, and hierarchically nanoporous pyroproteins (HNPs) were fabricated using silk protein fibers via thermal treatment with activation using an alkali agent. The PFPs formed a monolith without any binder and exhibited a surface area of approximate to 97 m(2) g(-1) with a microporous structure, whereas the HNPs maintained a fibrous structure with a high surface area of approximate to 2,880 m(2) g(-1). The pyroproteins presented in PFP and HNP led to the charge storage capacity originating from heteroatoms such as oxygen and nitrogen. The reversible capacities of the PFP and HNP as the anode and cathode, respectively, were approximate to 228 and approximate to 205 mA h g(-1), respectively, at current density of 0.1 A g(-1). In particular, the PFPs exhibit a high cycling stability over 1,000 cycles at a current density of 0.5 A g(-1). Furthermore, energy storage devices based on all-fibrous pyroprotein electrodes achieved a high specific power of approximate to 12,100 W kg(-1), a high specific energy of approximate to 150 Wh kg(-1), and an excellent cycling performance with approximate to 83% capacitance retention after over 2,000 cycles.

키워드