Understanding microstructure formation in lignocellulosic-biomass-derived hard carbon anode via CRISPR–Cas9 engineering

The composition of lignocellulosic precursors, encompassing cellulose, hemicellulose, and lignin, plays a pivotal role in shaping the microstructural features of biomass-derived hard carbons (HCs), including crystalline regions, defects, heteroatoms, and open/closed pores, which are critical determinants of electrochemical alkali-metal ion (AMI) storage performance. However, understanding the correlation between the variations in the composition of lignocellulosic raw materials and electrochemical performance is challenging due to the complexity of designing experimental models that demand fundamental control over the compositional factors. In this study, we address this challenge by introducing a gene-edited hybrid poplar wood engineered using CRISPR–Cas9 technology as a precursor for HC models. The experimental models elucidated the effects of cellulose-hemicellulose-lignin composition and carbonization temperature on the chemical and microstructural characteristics of HCs and their consequent influence. Our findings with three AMIs: Li⁺, Na⁺, and K⁺ revealed that reducing the lignin content in the precursors plays a pivotal role in forming active sites within HC anodes, thereby enhancing both sloping and plateau capacities for AMIs storage. These insights into the compositional effects of lignocellulosic-precursors provide a rational framework for designing high-performance HCs optimized for AMIs storage.