Photovoltaic Recycled Nano-Silicon–Silica-Based Anode to Enhance Lithium-Ion Battery Performance

Abstract

An economical, sustainable, and industry-acceptable process of utilizing low-value resources to produce highly competitive silicon-based anodes is attractive. In this study, a special anode architecture of PV nano-Si–SiO_x/graphite is developed by utilizing low-value photovoltaic (PV) recycled silicon, which is partially converted to new hybrid PV Si–SiO_x and nano-size simultaneously and wrapped by graphite fragments. An industry-grade ball milling techniques are exploited to assemble this special anode architecture under controlled environment conditions. The attained new PV nano-Si–SiO_x/graphite electrode-incorporated dual binders of carboxymethyl cellulose and poly (acrylic acid) demonstrates high charge capacity and stability (600 mAh g⁻¹ at 0.2 C after 500 cycles; 600 mAh g⁻¹ at 1 C after 100 cycles) as well as commendable Coulombic efficiencies (87% initial and ≥ 99.5% subsequent cycles), providing new opportunities for practical application. The structural analysis reveals that the partial conversion of Si to Si–SiO_x is critical to in situ generate the inert matrix of Li₂O–lithium silicate, which works as a buffer in diminishing the volume variation in the electrode during initial lithiation. Our silicon anode design and subsequent assembly by environmentally friendly processes can potentially be used to produce high-value practical silicon anodes for lithium-ion battery technology.