LAUSR

Abstract 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.