Laser technology continues to work its way into lithium-ion battery manufacturing, with processes such as electrode foil cutting on the front end and electrode welding for packaging and assembly most prominent. Other processes in research or early adoption include laser drying of coating films to reduce production costs as well as current collector foil texturing to increase battery lifetime. Over the years, significant research has been done on laser structuring of electrode coatings (i.e. graphite, NMC) to improve battery performance, specifically with respect to battery discharge capacity after accelerated charging. Laser-machined structures such as blind holes and patterned grooves have repeatedly been shown to enhance Li+ ion diffusion into the respective electrode material (“lithiation”), thus enabling high electrical currents to be applied. Unfortunately, low processing throughput—and therefore high costs—has proven to be a barrier to commercialization. Here we present experiment results for high-throughput Li-ion electrode structuring using tailored nanosecond (ns) pulse bursts. Optimized parameters include burst length (10’s to 100’s ns), burst pulse relative intensity, and intra-burst pulse frequency (up to 0.5 GHz). The results show that blind-hole structures are fully drilled with one shot from the laser at rates of 100’s of thousands per second. With the laser’s flexible pulse tailoring capability, highly efficient optimized processes are straightforward to achieve and implement in manufacturing systems.
Keywords
- Electrode Structuring
- Lithium-Ion Batteries
- Nanosecond Burst Processing
- Uv Laser Ablation