Sustainably transforming biomass into advanced carbon materials for solid-state supercapacitors: a review

Biomass-derived carbon materials (BDCMs) are widely considered as promising and practical candidates for electrode materials of solid-state supercapacitors (SSCs), due to their low cost, good chemical and mechanical stabilities, excellent electrical conductivity, and high deployment feasibility. Numerous investigations have recently been conducted for sustainably transforming biomass into electrode materials with high electrochemical performance in SSCs, even guided by data-driven approaches. Therefore, this review addresses conventional and emerging synthesis routes for BDCM-based electrode materials and discusses recent advances in energy storage mechanisms and electrochemical performance enhancement of BDCMs for SSCs, improving electrode preparation and performance optimization of BDCMs in a practical and efficient manner. As two of the most powerful tools for novel material discovery and design, machine learning (ML) and 3D printing technologies are introduced to provide closed-loop guidelines for accurately and efficiently producing BDCMs with excellent electrochemical performance; main challenges for successfully applying ML and 3D printing methodologies are also addressed, providing critical guidelines for potential innovation and future development of BDCM-based SSCs. In this review, from life-cycle perspective, environmental benefits are assessed for BDCM-based SSCs, being highlighted as a promising and practical alternative to solidify energy security and achieve sustainable biomass management. The concluding remarks and future prospects are finally discussed to provide valuable insights for academic researchers and governmental policymakers. With concerted efforts, sustainably transforming biomass into high-performance electrode materials for SSCs is beneficial to achieving UN Sustainable Development Goals 7, 11-13.