Unveiling the heterogeneity of cellulose separators and lignin-derived electrodes fabricated from different bamboo tissues in supercapacitors application

Bamboo, as a natural and sustainable biomass materials has garnered significant attention due to its wide distribution, rapid growth, and considerable economic value. However, bamboo is composed of fibers (F) and parenchyma (P) cells with different anatomical structures and chemical compositions, which present challenges for efficient deconstruction and high-value conversion. Herein, we used microwave-assisted maleic acid (MA) treatment to effectively deconstruct the main components of different bamboo tissues (bamboo powder, F and P), further achieved the preparation of lignin-containing cellulose nanofibrils (LCNFs)-based separators and lignin-based electrode materials. Then, their differences in physicochemical properties and application performance were comprehensively analyzed and compared. The results showed that the prepared LCNFs separators exhibited excellent mechanical strength and stable thermal properties. Specially, the LCNFs separator prepared from bamboo powder (B-LCNF-S) had the highest diameter size (15.7 ± 1.8 nm), porosity (69 %), and electrolyte absorption rate (296 %), which effectively promoted the ion transport. In addition, the lignin-based carbon materials derived from F exhibited the highest specific surface area (1373.31 m 2  g −1 ) and total pore volume (0.99 cm 3  g −1 ), and specific capacity. Finally, LCNFs separators and the corresponding lignin-based electrodes were further assembled into symmetrical supercapacitors, which showed significant differences in electrochemical performance. This study provides valuable insights into the efficient deconstruction and targeted conversion of different bamboo tissues, offering a pathway to harness bamboo's unique structural and chemical properties for advanced energy storage applications.