RGO/Polydopamine Co-Coating to Construct Rigid-Flexible Structure to Enhance the Stability of SiOx Lithium Anode Materials

Silicon oxide (SiO x ) anode materials have emerged as a leading candidate for next-generation high-energy-density lithium-ion batteries, primarily due to their high specific capacity. Nonetheless, inherent challenges-namely, poor electrical conductivity and significant volume expansion-severely impede their commercial viability. To address these issues, we have developed a coating material that exploits a “rigid-flexible” synergistic effect via electrostatic self-assembly, in situ cladding, and thermal reduction. This engineered architecture effectively mitigates the volumetric expansion of SiO x while markedly enhancing the lithium-ion diffusion coefficient. Electrochemical testing reveals that the composite exhibits excellent rate performance, showing high capacity retention of 96% from the 2nd to the 160th cycle at a current density of 0.2 A g −1 , with a substantial reversible capacity of 791 mAh g −1 , and only a 2.2% electrode expansion after 200 cycles. These results underscore a promising strategy for the advancement of silicon-based anodes in lithium-ion batteries.