Demonstration of and future perspective on scaling ultrafast-laser-ablation microstructuring of Li-ion Battery electrodes to roll-to-roll production and large-format cells

Abstract

This work demonstrates integration of an ultrafast laser onto a roll-to-roll machine in order to create electrodes with a 3D architecture at scale. Both sides of a 700 m long double-sided graphite anode was microstructured and used to construct 27 Ah prismatic cells. The electrode was ablated with a novel hybrid-microstructure composed of both hexagonally arranged pores for enhanced rate performance and channels for fast electrolyte wetting. Subsequently, this anode and an unablated baseline anode are paired with an NMC111 cathode and manufactured into 27 Ah prismatic cells. The laser ablated cells were compared to their non-ablated counterparts, and demonstrated a reduction in soaking time of at least 60%, an improvement in fast charge capability with > 30% more capacity accepted during 6C charging, and an extension of cycle life of >20% during 0.5C cycling. Further, a perspective is provided on scaling ultrafast laser ablation of battery electrodes to industrial throughputs. Additionally, lessons learned from this pilot-scale demonstration are provided in regards to optical architecture, debris removal, and system control. A technoeconomic analysis is used to demonstrate that laser ablation can be integrated into existing electrode manufacturing facilities with only ≈$1.3/kWh increase (≈2%) in manufacturing cost. Preemptive electrode design for laser ablation is discussed as a further method for enhancing performance. Finally, an analysis of available laser systems and beam-scanning architectures is used to determine design requirements to scale process throughput to a state-of-the-art speed of 50 m min^-1 This analysis demonstrates that laser-ablating Li-ion battery electrodes has multiple benefits to manufacturing and battery performance, that the technology already exists to achieve high-laser ablation throughputs, and that integrating ultrafast laser ablation to electrode manufacturing will not create a processing bottleneck.