Assessment of Laser-Ablated Silicon Wafers as Lithium-Ion Battery Anodes

Silicon materials have been widely investigated as anode materials for lithium-ion batteries. However, they are typically processed as fine powders into composite electrodes. Towards potentially repurposing silicon wafers as battery anodes, in this work, the impacts of the laser ablation of silicon wafers on electrochemical cycling outcomes were investigated. Both pristine wafers and laser-ablated wafers were assessed, where the silicon anodes were paired with all-active material LiCoO2 cathodes to assess the system as lithium-ion full cells. The laser ablation process modified the surface morphology of the silicon wafers, creating a polycrystalline silicon layer with increased surface area. Electrochemical cycling revealed that the laser-treated wafers demonstrated higher capacity retention and improved rate capability compared to untreated wafers, especially when discharged at the highest current density of 7 mA cm−2. This work demonstrated the improvements in electrochemical outcomes with the direct use of silicon wafers as lithium-ion anodes when laser ablation surface treatment is applied.