Poly(Ionic Liquid)-Derived Graphitic Nanoporous Carbon Membrane Enables Superior Supercapacitive Energy Storage

• Published in: ACS nano 2019-09, Vol.13 (9), p.10261-10271
• Main Authors: Zhang, Weiyi, Wei, Shen, Wu, Yongneng, Wang, Yong-Lei, Zhang, Miao, Roy, Dipankar, Wang, Hong, Yuan, Jiayin, Zhao, Qiang
• Format: Article
• Language: English
• Subjects: carbon membranes; hierarchical nanoporosity; high energy density; poly(ionic liquid)s; superior areal capacitance
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.9b03514

High energy/power density, capacitance, and long-life cycles are urgently demanded for energy storage electrodes. Porous carbons as benchmark commercial electrode materials are underscored by their (electro)­chemical stability and wide accessibility, yet are often constrained by moderate performances associated with their powdery status. Here via controlled vacuum pyrolysis of a poly­(ionic liquid) membrane template, advantageous features including good conductivity (132 S cm–1 at 298 K), interconnected hierarchical pores, large specific surface area (1501 m2 g–1), and heteroatom doping are realized in a single carbon membrane electrode. The structure synergy at multiple length scales enables large areal capacitances both for a basic aqueous electrolyte (3.1 F cm–2) and for a symmetric all-solid-state supercapacitor (1.0 F cm–2), together with superior energy densities (1.72 and 0.14 mW h cm–2, respectively) without employing a current collector. In addition, theoretical calculations verify a synergistic heteroatom co-doping effect beneficial to the supercapacitive performance. This membrane electrode is scalable and compatible for device fabrication, highlighting the great promise of a poly­(ionic liquid) for designing graphitic nanoporous carbon membranes in advanced energy storage.