A high-performance and flexible micro-supercapacitor was created using a self-generated nanoporous silver layer via a one-step laser-induced process. This method allows for adjustable porous structures on a polymer film, enhancing surface area and conductivity. The resulting device, with manganese and iron oxides as active materials, achieved a high volumetric energy density of 16.3 mW h cm−3 and power density of 3.54 W cm−3, outperforming traditional methods in cost and efficiency.