Laser Direct Writing of Heteroatom-Doped Porous Carbon for High-Performance Micro-Supercapacitors

Simultaneously improving the specific surface area, pore size distribution, heteroatom doping, and electrode/electrolyte interface of carbon materials for high-performance supercapacitors or micro-supercapacitors (MSCs) is difficult, especially in one-step laser direct writing process. This study demonstrates a general and effective strategy for the first time to prepare heteroatom-doped porous carbon structures with high specific surface area, narrow pore size distribution, heteroatom doping, and improved electrode/electrolyte interface, through one-step laser direct writing on precursor-incorporated polyimide (PI) films, which endow the MSC with dramatically improved capacitive performance. The typical MSC prepared on the PI/H3BO3 film exhibits an ultrahigh specific capacitance of 65.7 mF/cm2 at 0.05 mA/cm2, which is more than 5400% of the 1.2 mF/cm2 and 250% of the 25.5 mF/cm2 for MSCs prepared on as-prepared H3BO3-free PI film and commercial PI film, respectively. Moreover, the MSC shows excellent cycling stability (>50000 cycles), outstanding flexibility (foldable), long-term stability (>6 months), and the capability of delivering high voltage and energy by connecting in series and parallel, which make it a promising energy storage component in next-generation portable electronics. What’s more, P-doped porous carbon MSCs and fluorinated porous carbon MSCs with high capacitive performances were also demonstrated by incorporating H3PO4 or NaBF4 into PI films followed by the same laser direct writing process, suggesting the generality of this approach. The strategy proposed in this work paves a new avenue for modulating structures and components and improving electrode/electrolyte interface of carbon materials for high-performance supercapacitors.