Synthesis free‐template highly micro‐mesoporous carbon nanosheet as electrode materials for boosting supercapacitor performances

Abstract

Summary Porous carbon 2D nanosheets (CNSs) with micro‐mesopores interconnected are indispensable for energy conversion systems and storage applications. Herein, we synthesize free‐template highly micro‐mesoporous carbon nanosheet as electrode material for boosting supercapacitor performances. The activated carbon nanosheets derived from bio‐waste were prepared by chemical impregnation followed by high‐temperature pyrolysis without hard/soft/salt template‐assisted and free‐binder adhesives. Garlic skin wastes were selected as a precursor. Furthermore, activated carbon was designed in pellet/coin solids without the addition of binder materials. The porous carbon pellets exhibit a thin 2D nanosheet structure of 15 nm followed by unique wooden labyrinth‐like and rod‐like structures. The result showed that the impregnation of different chemical concentrations increases the surface area to 273% as high as 1002.920 m2 g−1 with a total volume of 1.3270 cm3 g−1. Moreover, the mesoporosity dominated 66.4%, followed by sub‐ultra‐micropores. In the symmetric supercapacitor, the carbon nanosheet boosted the specific capacitance almost 3‐fold to 320.95 F g−1 in the aqueous electrolyte of 1 M H2SO4. The supercapacitor cell has a high energy density of 43.12 Wh kg−1 and power density of 161.99 W kg−1 at a constant current density of 1.0 A g−1. This work proposes a more effective, green, efficient, and controlled approach to obtain bio‐waste‐based porous carbon 2D nanosheet with a controlled pore structure for energy conversion and storage systems. Novelty Statement The novelty of this study is a green synthesis has possessed highly micro‐mesopores nanosheet bio‐waste. 2D nanosheet was prepared free‐template and free‐binder. Sub‐ultra‐micropores were confirmed with dominated mesoporosity of 66.8%. Carbon nanosheet boosted specific capacitance almost 3‐fold to 320.95 F g−1.

A facile and scalable fabrication method of scrolled graphene/boron nitride-based van der Waals superlattice heterostructure materials for highly stable supercapacitor electrode application

“…The produced mesoporous structure in G/Fe/BN(NS) can provide fast and effective mass and ion transport channels into the interior surface by migration and diffusion, which can assist the rapid diffusion of electrolyte ions at the electrode-electrolyte interface. 59,60 As a result of the produced fast ion/mass transport channel, the G/Fe/BN(NS) electrode exhibited a higher specific capacitance than G/Fe/BN as shown in Fig. 7c.…”

Facile Preparation and Improved Electrochemical Performance of Oxygen‐Enriched Porous Carbon Materials Based on Diacetal‐Containing Polybenzoxazine

“…The porous carbon materials with macropores can be directly obtained by pyrolysis, and then a large number of microporous and mesoporous structures are formed by further activation. [15,16] It has been reported that the presence of O and N-containing structures in the precursors can effectively enhance the contents of the O and N elements in final carbon materials. On the one hand, these elements will affect the wettability of the electrolyte; on the other hand, they can react with the electrolyte rapidly, which will produce high pseudocapacitance and significantly improve the specific capacitance.…”