A groovy laser processing route to achieving high power and energy lithium-ion batteries

Abstract

3D-structured NMC622 with precisely controlled electrolyte channels were manufactured by incorporating femtosecond laser processing with conventional slurry casting. Demonstrated in a full cell for the first time, the 3D electrode structures mitigate plating and dendrite growth at the graphite electrode and lead to improved cycling performance, 75 % capacity retention vs 58 % after 500 cycles. 3D-structured NMC622 with a high areal capacity, 5.5 mAh cm−2, exhibits an areal capacity retention of ∼70 % and volumetric capacity exceeding 250 mAh cm−3 at ∼1.15C, three times and twice that of a conventional slurry-casted NMC622, respectively. The improved rate performance is attributed to the enhanced ionic transport and reduced charge transfer resistance facilitated by the 3D electrode structure, as shown through galvanostatic titration measurements. A finite element method-based 3D model illustrated the improved uniform distribution of Li-ion concentration and state of charge within the 3D-structured electrode. Additionally, the 3D electrode structure proved beneficial for wettability and accelerated electrolyte absorption, leading to improved manufacturing efficiency.