One-step laser fabrication of phosphorus-doped porous graphene electrodes for high-performance flexible microsupercapacitor

• Published in: Carbon (New York) Vol. 180; pp. 56 - 66
• Main Authors: Rao, Yifan, Yuan, Min, Luo, Feng, Wang, Zeping, Li, Hui, Yu, Jiabing, Chen, Xianping
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 15.08.2021; Elsevier BV
• Subjects: Capacitance; Carbon; Density functional theory; DFT calculations; Direct laser writing; Dopants; Doping; Electrochemical analysis; Electrodes; Graphene; Laser direct writing; Micro-supercapacitors; Phosphorus; Phosphorus doping; Polyvinyl alcohol; Porous graphene; Laser direct writing; Porous graphene; Phosphorus doping; Micro-supercapacitors; DFT calculations
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2021.05.001

Heteroatoms modification of carbon electrodes is an effective strategy to boost its electrochemical performance. In this work, we demonstrate a one-step and scalable method to manufacture phosphorus-doped (P-doped) 3D porous graphene electrodes from a flexible H3PO4-incorporated polyimide (PI)/Polyvinyl alcohol (PVA) composite film via laser direct writing. Benefiting from the synchronous P-doping and activation caused by H3PO4, the optimal P-doped porous graphene-based micro-supercapacitors (MSCs) present an impressive areal capacitance of 55.5 mF cm−2, good long-term cyclability (with ∼85% capacitance retention after 10000 cycles), superior mechanism flexibility, and outstanding capability of modular integration in series and parallel. Furthermore, density functional theory (DFT) calculations were also carried out to prove that P-doping could enhance the affinity towards electrolyte ions on the carbon surface to improve the electrochemical performance. In particular, due to the highly hydrophilic nature and good film-forming properties of PVA, other dopants can be also well dissolved in the PI/PVA slurry to synthesize a dopants-incorporated PI/PVA composite membrane. Hence, this method offers a convenient and potential route to prepare free-standing heteroatom-doped porous graphene electrodes, which has promising applications for various flexible/wearable electronics. [Display omitted] •A flexible H3PO4-incorporated PI/PVA composite film is first synthesized by a drop-casting and low-temperature drying process.•Synchronous in-situ P-doping and H3PO4 activation are realized during the laser direct writing process.•The fabricated P-doped porous graphene presents higher porosity and better hydrophilia.•The optimized P-doped MSC provides an enhanced areal capacitance of 55.5 mF cm-2.