Newtonian Pendulum-Inspired Fast Kinetics via Potassium Coordinated Molecules for Potassium-Ion Batteries

Ions desolvation and diffusion at solid electrolyte interphase (SEI) represent the dominant kinetic limitations that hinder the storage performance of ester electrolytes-based potassium-ion batteries (PIBs). Herein, potassium coordinated 3, 4-dihydroxycinnamic acid (CAK) is reported on the hard carbon (HC) surface, as Newtonian pendulum-like mediators to regulate desolvation barriers and diffusion capability. The CAK molecules dynamically capture solvated K⁺ via coordination interaction with energetically favorable desolvation paths and shorten the diffusion distance analogous to the pendulum-like transport. Simultaneously, the CAK also induces a desirable SEI with more inorganic species, further reducing polarization and accelerating the desolvation process. Benefiting from these advantages, such HC anode delivers a remarkable capacity after 1000 cycles without capacity fading as well as impressive rate performance with 142.2 mAh g^-1 under a high current density of 2000 mA g^-1. Moreover, the as-fabricated full battery achieves an energy density of 60.7 Wh kg^-1 at a high rate of 2000 mA g^-1. This work visually demonstrates the significance of interface design and its association with fast interfacial kinetics for high-performance PIBs.