Hierarchical pore engineering of lignocellulose-based carbon materials for electric double-layer capacitors

Lignocellulose is an ideal precursor for supercapacitor electrodes due to its diverse structures and abundant availability. For supercapacitors, particularly electric double-layer capacitors (EDLCs), pore structure is critical. This review summarizes advances in lignocellulose-derived hierarchical porous carbon (LHPC) for supercapacitors, focusing on pore structure and future research directions. We discuss how pore structure influences supercapacitor performance, the activation methods for creating pores in LHPC, and review studies on optimizing pore structure for high-performance supercapacitors. Hierarchical porous carbon should feature a sufficient micropore surface area along with suitable mesoporous and macroporous surfaces to enhance rate performance while maintaining capacitance. This review is expected to actively advance the selection of lignocellulosic precursors and the development of optimized pore structure models, with the ultimate goal of enabling efficient production of lignocellulose-derived hierarchical porous carbon electrodes with superior properties.