Multi-objective optimization of stereolithography-pressureless sintering for fabrication of hierarchical porous current collector for lithium batteries

Abstract The growing demand for efficient energy storage systems in applications such as electric vehicles, smart grids, and portable electronics has intensified interest in high-performance lithium–metal batteries. Conventional fabrication routes for porous copper current collectors (CCs) face limitations in achieving complex architectures and reliable mechanical stability. In this work, stereolithography-based 3D printing combined with pressureless sintering is employed for the rapid fabrication of copper CCs. For the first time, porous copper CCs are fabricated using this approach, delivering controlled architectures with enhanced structural robustness and electrochemical functionality. Optimization of sintering parameters, including sintering temperature, heating rate, and holding time, was carried out using Response Surface Methodology based on a Box–Behnken design, followed by multi-objective genetic algorithm analysis in MATLAB. The optimized conditions significantly improved relative density, compressive yield strength, and volumetric shrinkage, while minimizing experimental effort. The fabricated porous copper CC exhibited superior mechanical strength under compression, withstanding ~ 35 MPa at 60% strain, ensuring integrity during coin cell assembly and cycling. Electrochemical testing demonstrated a stable and high Coulombic efficiency of approximately 95 percent over 100 cycles, significantly outperforming conventional copper foil. The porous structure effectively facilitated uniform lithium deposition, mitigated dendrite growth, and accommodated volume fluctuations. This research offers a scalable route to fabricate durable, high-performance CCs, advancing next-generation electrochemical systems with stable, high-surface-area electrodes. Graphical Abstract