Decoupling Silicon and Graphite Contribution in High‐Silicon Content Composite Electrodes

Silicon–graphite (Si/Gr) composite electrodes are widely used in commercial Li‐ion batteries to enhance capacity while balancing mechanical stability. This study investigates the electrochemical behavior of high‐silicon‐content (30 wt%) Si/Gr blends using a decoupled blend cell setup. By analyzing the contributions of individual components, their effective C‐rates and charge distribution are assessed throughout the cycling process. The results confirm the nonadditive nature of Si/Gr electrochemistry, demonstrating significant variations in C‐rates between silicon and graphite, particularly during delithiation. The study also explores an alternative Si/Gr–Gr decoupled blend setup to better represent lower silicon content electrodes. The findings provide insights into lithium dynamics and the complexities of designing blended electrodes with materials of significantly different specific capacities. This work contributes to the understanding of silicon's role in composite anodes and offers valuable guidelines for designing high‐silicon‐content electrodes with improved electrochemical performance.