High-Power Battery Electrodes Fabricated by Acupuncture-Inspired Microneedle Processing.

Advancing battery electrode performance is essential for high-power applications. Traditional fabrication methods for porous electrodes, while effective, often face challenges of complexity, cost, and environmental impact. Inspired by acupuncture, here we introduce an eco-friendly and cost-effective microneedle process for fabricating lithium iron phosphate electrodes. This technique employs commercial cosmetic microneedle molds to create low-curvature holes on electrode surfaces, significantly enhancing electrolyte infiltration and ion transport kinetics. The punctured electrodes were prepared and characterized, with comparisons to pristine electrodes conducted using scanning electron microscopy, 3D metallurgical microscopy, and detailed electrochemical evaluations. Our results show that the microneedle-processed electrodes exhibit superior rate performance and diffusion properties. Simulations and experimental data reveal that the low-curvature holes reduce Li-ion concentration polarization and improve Li-ion transport within the electrode. This enhancement leads to higher specific capacities and better rate capabilities in the punctured electrodes. The findings highlight the potential of this innovative microneedle technique for large-scale production of high-performance electrodes, offering a promising avenue for the development of high-power-density batteries.