Motivated by properties such as environmental hazards and resource value, the recycling of used graphite has attracted increasing attention. Silicon / graphite composite is now considered a promising high-performance anode for lithium-ion batteries. The uniform dispersion and the above-average stability of the silicon (Si) particles in the graphite matrix remain a major challenge. Current solutions mainly focus on the design of Si nanostructures and the overall architecture of silicon / graphite composites, while little attention has been paid to the graphite matrix. Here, a Si / SG composite material (Si / SG) was produced on the basis of SG recycling. The SG was modified in situ during the battery cycle and developed unique physicochemical properties. By spontaneously setting the zeta potential, the electrostatic force integrated the Si nanoparticles into the SG matrix in order to reduce the volume load during lithiation / delithiation. In addition, defect-enriched and exfoliated SG can effectively improve the electrical conductivity and facilitate the electrochemical kinetics in the electrodes. In addition, the oxygen-containing functional groups on the SG could tune the solid electrolyte interphase component (SEI) by creating more organic components to improve the mechanical toughness of the SEI layer. As a result, the Si / SG composite electrode provides a high initial discharge capacity of 1321.8 mAh g & supmin; ¹ at 0.05 A g & supmin; ¹ and stable cycle life with 69% capacity retention at 1 A g & supmin; ¹ after 400 cycles. The proposed composite can provide some guidelines for improving the interfacial stability of the Si / graphite anode and at the same time the high quality application of spent graphite.


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