A Rapid, Scalable Laser-Scribing Process to Prepare Si/Graphene Composites for Lithium-Ion Batteries

Silicon has gained significant attention as a lithium-ion battery anode material due to its high theoretical capacity compared to conventional graphite. Unfortunately, silicon anodes suffer from poor cycling performance caused by their extreme volume change during lithiation and de-lithiation. Compositing silicon particles with 2D carbon materials, such as graphene, can help mitigate this problem. However, an unaddressed challenge remains: a simple, inexpensive synthesis of Si/graphene composites. Here, a one-step laser-scribing method is proposed as a straightforward, rapid (approximate to 3 min), scalable, and less-energy-consuming (approximate to 5 W for a few minutes under air) process to prepare Si/laser-scribed graphene (LSG) composites. In this research, two types of Si particles, Si nanoparticles (SiNPs) and Si microparticles (SiMPs), are used. The rate performance is improved after laser scribing: SiNP/LSG retains 827.6 mAh g-1 at 2.0 A gSi+C-1, while SiNP/GO (before laser scribing) retains only 463.8 mAh g-1. This can be attributed to the fast ion transport within the well-exfoliated 3D graphene network formed by laser scribing. The cyclability is also improved: SiNP/LSG retains 88.3% capacity after 100 cycles at 2.0 A gSi+C-1, while SiNP/GO retains only 57.0%. The same trend is found for SiMPs: the SiMP/LSG shows better rate and cycling performance than SiMP/GO composites. Silicon/graphene composites for lithium-ion battery anodes are successfully prepared by a rapid and scalable laser-scribing process. The well-exfoliated 3D graphene network formed by laser irradiation facilitates fast ion transport within the electrode, enabling fast charging and discharging. The laser process also improves the cycling performance of the cell by better dispersion of silicon particles after laser treatment. image