Synergistic Multi-Scale Confinement Engineering Stabilizes Organic Anode for High-Performance Potassium-Ion Batteries.

Organic small molecules are promising high-capacity anodes for potassium-ion batteries (PIBs), but their practical application is severely hampered by active material dissolution, persistent parasitic reactions at the solid-electrolyte interface, and sluggish reaction kinetics, resulting in rapid capacity decay. To holistically address these multifaceted drawbacks, this work demonstrates a synergistic multi-scale confinement engineering strategy through coordinated design at the molecule-ion-electron levels. Specifically, active molecules are physically confined within the ordered mesopores of conductive CMK3 carbon, ensuring structural stability and efficient electron transport. Concurrently, a high concentration electrolyte (3 m KFSI in EC/DEC) is employed to tailor the solvation environment, regulating anion activity, and stabilize the interface. At the molecular scale, an electron-withdrawing fluorine substituent is used to optimize electronic structure, enhancing potassium storage kinetics and capacity. The resulting 2FBA@CMK3 anode delivers an impressive reversible capacity of 152 mAh/g after 400 cycles at 500 mA/g, outperforming most reported organic PIB anodes. This work establishes a holistic and rational design paradigm for advancing organic electrode materials toward high-performance PIBs.