Enhancing Structural Integrity With Stress‐Resilient Carbon for Stable Potassium‐Ion Storage

Abstract While graphite anodes hold promise for potassium‐ion batteries (PIBs), their practical implementation faces critical challenges stemming from mechanical degradation and interfacial compatibility in carbonate ester electrolytes. Herein, a hierarchical porous carbon architecture derived from renewable biomass precursors with stress‐resilient characteristics are developed to enhance structural integrity and cyclability in PIBs. The synergistic combination of homogeneous shell and structural frameworks enables the anode to form an integrated solid electrolyte interphase with uniform stress distribution in carbonate ester‐based electrolyte. The optimized anode delivers a high reversible capacity of 170.3 mAh g −1 at 200 mA g −1 , with a capacity retention of 84.0% after 600 cycles. Remarkably, full cells integrating Mn‐based layered oxides and Prussian blue analogue cathodes demonstrate 70.1% and 70.8% capacity retention after 200 cycles. This work establishes a biomass‐to‐device engineering paradigm for sustainable energy storage systems, offering fundamental insights into interface‐structure‐property relationships for alkali‐metal ion batteries.