Suppressed lithium plating in graphite anodes enabled by tailoring the interfacial lithium concentration

Lithium plating on graphite anodes stems from the inability of internal solid diffusion to keep pace with surface lithium supply, resulting in irreversible capacity loss and accelerated degradation. Here, we introduce an interfacial concentration-gradient-driven force that continuously relocates lithium from the graphite surface into the interior, eliminating the superficial lithium accumulation responsible for plating. By in situ forming a sulfurized polyacrylonitrile layer over graphite as a concentration modulator, a steeper concentration gradient is established across the interface, accelerating lithium transport inward. This strategy not only suppresses surface lithium plating but also unlocks additional reversible capacity of graphite itself. Free of scarce elements and compatible with existing electrode manufacturing, the approach delivers a scalable route to durable, high-performance graphite anodes. • The stability of graphite anode is limited by lithium plating at high current density • Li-rich coating layer steepens Li-concentration gradient at the graphite surface • The concentration gradient accelerates Li solid diffusion and suppresses Li plating The stability of graphite anode is limited by lithium plating at high current density Li-rich coating layer steepens Li-concentration gradient at the graphite surface The concentration gradient accelerates Li solid diffusion and suppresses Li plating Lithium plating in graphite anodes, caused by surface lithium congestion, hampers lithium-ion battery performance. Here, we introduce a concentration-gradient-driven force to improve lithium solid diffusion in graphite. Sulfurized polyacrylonitrile (SPAN) is selected as a modulator to tailor the interfacial lithium concentration via the in situ formation of SPAN over graphite (Gr@SPAN). SPAN induces a pronounced concentration gradient between the surface and the interior, initiating an accelerated solid diffusion process inside graphite. Such an accelerated solid diffusion process results in suppressed lithium plating and superior lithium storage of graphite itself with an ultrahigh capacity of ∼392 mAh g −1 of Gr@SPAN, exceeding the theoretical capacity of graphite (372 mAh g −1 ). Furthermore, the Gr@SPAN anode achieves a specific capacity of ∼357 mAh g −1 after 700 cycles, with a remarkable capacity retention of 91.3% at 1 C. This multifunctional interface based on the concentration-gradient-driven force paves a new way to fabricate advanced graphite anodes.