Regulating spatial distribution of silicon and graphite for high-performance anode materials via plasma-assisted ball milling

Silicon-graphite (Si/Gr) composite anode materials are essential for the advancement of high specific energy lithium-ion batteries (LIBs), yet their performances are often constrained by the interfacial interactions between Si and Gr. In this work, we used ball milling and plasma-assisted ball milling on Gr and nano-sized Si powders, followed by chitosan encapsulation and carbonization to synthesize SG@C and P-SG@C materials, respectively. Our findings indicated that plasma ball milling in an argon atmosphere promotes the exfoliation of Gr while facilitating the intercalation of Si particles within the Gr layers, thereby enhancing encapsulation by chitosan. Compared to SG@C, P-SG@C demonstrates superior initial specific capacity and Coulombic efficiency (CE), achieving a reversible specific capacity of 550.6 mAh/g with a capacity retention of 62.8% after 100 cycles at 0.5 A/g. Furthermore, we observed that the SG@C anodecharacterized by a random arrangement of Si and Gr resulting in degradation. In contrast, P-SG@C demonstrates a concurrent degradation pattern for both components. These observations underscore the advantages of plasma ball milling in optimizing the composite structure of Si and Gr, while highlighting how spatial distribution influences degradation mechanisms affecting anode performance.