3D interconnected macrostructure based on nano-scale pyroprotein units for energy storage

• Published in: Electrochimica acta 2016-12, Vol.222, p.1887-1894
• Main Authors: Kim, Na Rae, Cho, Se Youn, Yoon, Hyeon Ji, Jin, Hyoung-Joon, Yun, Young Soo
• Format: Article
• Language: English
• Subjects: Electrode; Hybrid capacitor; Nanocarbon; Porous carbon; Pyroprotein
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2016.12.002

[Display omitted] 3D interconnected pyroprotein macrostructures (3D-IPMs) were fabricated from silk proteins using a simple templated sol-gel method followed by heating with potassium hydroxide. The resulting materials exhibit outstanding electrochemical performance. •3D interconnected pyroprotein macrostructures (3D-IPMs) are fabricated.•3D-IPMs have well-developed pore structures and numerous redox-active nitrogen atoms.•3D-IPMs exhibit high capacities of ∼680mAhg−1 and great rate/cycling performances.•High energy (142.7Whkg−1) and high power (23,850Wkg−1) are achieved. A porous carbon monolith with a well-defined internal nanostructure consisting of highly redox-active materials has potential as an electrode in energy storage applications. In this study, 3D interconnected pyroprotein macrostructures (3D-IPMs) were fabricated from silk proteins using a simple templated sol-gel method and subsequently heated with potassium hydroxide. The resulting 3D-IPMs, which were further optimized, had high nitrogen concentrations (C/N ratio: 11.4), good electrical conductivities of ∼2.8Scm−1, and well-developed pore structures. The 3D-IPMs showed reversible storage capacities of ∼680mAhg−1 at 0.1Ag−1 via a pseudocapacitive Li ion storage mechanism in the anodic potential range. Even when a 300-fold larger current rate was used, a reversible capacity of ∼230mAhg−1 was maintained. In addition, the 3D-IPMs exhibited remarkable stability over the course of 1,000 cycles. The practicability of 3D-IPM-based energy storage devices was demonstrated by assembling full cells with a well-known cathode material. The full cell devices delivered a specific energy of 142.7Whkg−1 at 190Wkg−1 and specific power of 23,850Wkg−1 at 48.1Whkg−1. In addition, their performance remained stable across many cycles.