Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries

Abstract

SiOx is an encouraging anode material for high-energy lithium-ion batteries owing to the following unique characteristics: a relatively high theoretical capacity, low operating potential, ample resource availability, and, most importantly, lower volume changes compared to Si. However, its utilization has been hindered by a significant ~200% volume change during lithiation and low conductivity, leading to the breakdown of anode materials and accelerated capacity degradation. This study presents a novel SiOx/G/C composite comprising SiOx nanoparticles, graphite, and carbon nanotubes fabricated through a simple ball milling and annealing process. This composite features a dual-carbon framework interconnected with SiOx via C–O–Si bonds, enhancing reaction kinetics and accommodating volume fluctuations. These enhancements translate into remarkable advancements in cycling stability and rate performance. Specifically, as-prepared SiOx/G/C exhibits a high capacity retention of ~700 mAh·g-1 over 500 charging/discharging times at 1.0 A·g-1. Furthermore, when incorporated into a full-cell configuration (SiOx/G/C//LiNi1/3Co1/3Mn1/3O2), this system demonstrates a reversible capacity of 113 mAh·g-1 over 100 cycles at 1.0 mA·cm-2, underscoring its practical viability.