Artificial Graphite-Based Silicon Composite Anodes for Lithium-Ion Batteries

Abstract

To develop an advanced anode for lithium-ion batteries, the electrochemical performance of a novel material comprising a porous artificial carbon (PAC)–Si composite was investigated. To increase the pore size and surface area of the composite, ammonium bicarbonate (ABC) was introduced during high-energy ball-milling, ensuring a uniform distribution of silicon within the PAC matrix. The physical and structural properties of the developed material were evaluated using several advanced techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and galvanostatic intermittent titration (GITT). Artificial graphite contains several macropores that can accommodate volume hysteresis and provide effective sites for anchoring Si nanoparticles, enabling efficient electrochemical reactions. GITT analysis revealed that the PAC-Si-CB-ABC composite exhibited superior lithium-ion diffusion compared to conventional graphite. The developed PAC(55%)-Si(45%)-CB-ABC electrode with PAA as the binder demonstrated a reversible capacity of 850 mAh g−1 at 100 mA g−1 and a high-rate capability of 600 mAh g−1 at 2000 mA g−1. A full cell employing the NCM622 cathode exhibited reversible cyclability of 128.9 mAh g−1 with a reasonable energy density of 323.3 Wh kg−1. These findings suggest that the developed composite is a useful anode system for advanced lithium-ion batteries.