Pore Structure Regulation of RF-Derived Porous Carbons Using a Mixed-Level Design of Experiments for Lithium-Ion...

Resorcinol-formaldehyde (RF)-derived porous carbons have attracted considerable attention as anode materials for lithium-ion batteries because of their tunable pore structures and continuous carbon frameworks. However, conventional one-factor-at-a-time experiments do not readily allow the relative effects of multiple preparation factors to be systematically compared within a unified experimental framework. In this study, a mixed-level Design of Experiments (DOE) was employed to systematically investigate the effects of solid content, gelation temperature, R/C ratio, combined gelation and acid-washing/aging times, and drying method on the BET specific surface area, total pore volume, and dominant pore size of RF-derived porous carbons. Representative preparation conditions were subsequently selected to prepare PC-1 and PC-2. Both samples exhibited predominantly amorphous mesoporous carbon structures and similar electrochemical response profiles. PC-1 exhibited a higher reversible specific capacity and slightly more favorable electrochemical kinetics. These concurrent observations suggest an association between the pore-structure characteristics and electrochemical behavior of the selected samples. PC-1 delivered an initial charge capacity of 416.67 mAh g^-1 with an initial Coulombic efficiency of 79.31%. After 200 cycles at 0.1 A g^-1, it retained a reversible capacity of 307.86 mAh g^-1, corresponding to a capacity retention of 88.64% relative to the second-cycle charge capacity. These results indicate that, within the investigated design space, the DOE approach provides an exploratory basis for jointly comparing the statistical evidence and practical effect magnitudes of the preparation factors and for selecting representative candidates with favorable pore-structure characteristics. The integration of DOE-based factor screening with subsequent structural and electrochemical validation provides an experimentally grounded framework for relating preparation parameters to pore-structure responses and lithium-storage behavior, thereby supporting the rational development of RF-derived porous carbon anodes for lithium-ion batteries.