Orchestrated interfacial reprogramming via Al-F-C synergy for dynamic CEI structuring in advanced cathodes

초록

Achieving robust interfacial stability under high-rate operation remains a grand challenge for commercial lithium-ion batteries, particularly in cathodes subjected to extreme cycling conditions. Herein, we propose an orchestrated interfacial reprogramming strategy that integrates Al3+/F-co-doping and conformal carbon coating to direct the formation of a self-aligned, LiF-rich cathode-electrolyte interphase (CEI). Unlike conventional CEI regulation strategies based on single-element doping or inert surface coatings, this multi-component approach enables an actively constructed, crystallographically aligned CEI through the synergistic interplay of dopants and carbon. This approach enables dynamic CEI structuring that minimizes interfacial resistance and enhances lithium-ion transport kinetics. As a proof of concept, LiFePO4 (LFP) was employed as a model system, delivering an ultrafast discharge capacity of 146.6 mAh g-1 at 10C and exceptional longevity with 2931 cycles at 1C and 100 % Coulombic efficiency. XPS and in situ XRD analyses confirmed the preferential orientation of the LiF-rich CEI, linked to the improved electrochemical performance. To validate the platform independence of this approach, the same interfacial framework was extended to layered NCM613 cathodes, which exhibited significant performance enhancement despite the absence of detectable crystalline LiF signals-likely due to the formation of a thinner, more uniform CEI layer. This work establishes a universal and actively tunable CEI engineering paradigm that transcends traditional passive approaches, offering a transformative pathway toward high-power, long-life lithium-ion batteries.

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