Co-activation Pore Engineering of Polyphthalocyanine-Derived Carbon Nanosheets for Supercapacitors in Organic Electrolytes

As the primary electrode active materials for supercapacitors, porous carbons are widely prepared by carbonization-activation methods. Nevertheless, a simple activation procedure by using a single activator is hard to satisfy requirements of electrode materials in organic electrolytes, which can provide a larger voltage window but also demand larger-size micropores to accumulate/release charges than aqueous electrolytes. Herein, a rational co-activation method toward porous carbon nanosheets is developed for high-performance organic electrolyte-based supercapacitors by directly pyrolyzing zinc polyphthalocyanines-graft-potassium hydroxide (ZnPPc-g-KOH). The Zn2+ and K+ participate in pore formation, which facilitates the fabricating of porous carbon nanosheets with a large surface area of 2701 m2 g–1 and a narrow micropore-size distribution at around 1.50 nm. The resulting polyphthalocyanines-derived carbons deliver a high specific capacitance of 200 F g–1 at 10 A g–1 and a long cycling lifetime (over 98% of the initial capacitance after 10000 cycles) in 1.0 M TEABF4/AN, along with high energy and power properties (44.5/35.0 Wh kg–1 at 3.1/28.6 kW kg–1, respectively) in the symmetric supercapacitor. This polyphthalocyanines-derived carbon opens up a route to develop carbon-based active materials with well-built porous structures for electrochemical energy storage and conversion.