A critical review on polyimide derived carbon materials for high-performance supercapacitor electrodes

Carbon-based materials are often utilized as active electrodes in energy storage devices, especially in supercapacitors. For production of electrodes with necessary architecture and performance, careful consideration of carbon precursors is essential. Polyimides (PI) have emerged as highly tuneable carbon precursors due to their flexible molecular structures (that allow controlled porosity and microstructure), tailorable architectures, heteroatom doping provisions, compositing capabilities, and retention of proper morphology after carbonization. This article emphasises the use of PIs as precursors for thermal carbonization and direct laser writing carbonization processes to produce high-performance supercapacitor (SC) electrodes. The research includes effects of various experimental and structural factors, such as carbonization temperatures, porogenic agents/templates, heteroatom doping, monomer structural characteristics, and degree of graphitization, on the electrochemical performance of various PI-derived carbon morphologies (porous bulk carbons, carbon nanofibers, carbon microspheres, and superstructures). Additionally, being discussed are hybrid supercapacitors made on PI-derived carbon nanocomposites. Comprehensive structural and SC performance data for carbon electrodes constructed from PI in various electrolytes is also provided. The structure-performance relationship of the electrodes can be predicted using the data from theoretical modelling and machine learning. We believe that this article offers the first in-depth, comprehensive analysis of PI-derived carbon materials for high-performance SC electrodes, which can offer valuable guidance and insight into future research and commercialization. • Polyimides as a carbon precursor for supercapacitor electrodes were thoroughly examined. • Monomers, synthesis, carbonization and activation conditions, and the resultant morphologies were investigated for SC. • Electrochemical data obtained for derived carbon materials e.g., nanostructures were explained and tabulated for comparison. • Presents up-to date progress in chronological order and provides future perspectives in this area.