One-step process to obtain manganese-assisted laser-induced multi-layer graphene-like carbon supercapacitor.

• Combination of unilateral solution impregnation with laser induction in one-step process to get manganese-assisted graphene electrodes. • The modifier under the laser is cleverly used to achieve the enhancement of the electric double layer capacitance and the incorporation of pseudocapacitance. • Nitrogen, oxygen and manganese in superhydrophilic graphene with high yield, large surface area and low impedance. • The capacitance of as-prepared device is performing ∼25 times of the control. • Balancing cycling performance and capacity improvement of supercapacitors. Laser-induced graphene (LIG) technology has made it possible to prepare graphene-based supercapacitors on a large scale and at low cost. However, the performance of graphene-based supercapacitors fabricated solely by laser still has a great potential for improvement. In this work, we obtained high-performance supercapacitors based on manganese-assisted laser-induced multi-layer graphene-like carbon (MLIGC) by a simple process. Poly-(m-phenylene isophthalamide) (PMIA) papers treated with modifier (KMnO 4) were used as substrates. Modifier not only deepened the cross-sectional carbonization and achieveed uniform dispersing of manganese oxide nanoparticles, but also changeed the surface properties of MLIGC. Benefit from the hybrid structure of manganese oxide nanoparticles uniformly dispersed inside multi-layer graphene-like carbon (LIGC) prepared by one-step laser process, the combination of electric double-layer capacitance and pseudocapacitance allows for a further breakthrough in capacity while maintaining excellent cycling stability. Specifically, the supercapacitors achieve an area capacity of 72.4 mF cm−2 at 0.2 mA cm−2, which is 25 times higher than the control. In addition to the significant capacity increase, the addition of the modifier also achieveed a significant impedance reduction (almost one ninth of the control) and demonstrateed excellent cycling stability (nearly 100 % capacity retention after 7500 cycles at 10 mA cm−2). More importantly, the method is simple, fast, low-cost and high-efficiency, which provides a new path for the large-scale preparation of planar carbon-based supercapacitors. [Display omitted] [ABSTRACT FROM AUTHOR]