3D Micro-Architected Materials for Batteries

Citation

Sun, Yuchun (2024) 3D Micro-Architected Materials for Batteries. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/y6bt-xb40. https://resolver.caltech.edu/CaltechTHESIS:04162024-184348195

Abstract

Additive manufacturing (AM) enables three-dimensional micro-patterning of battery electrode materials, permitting complex structural designs beyond those of traditional slurry electrodes. We demonstrate two novel AM approaches for architecting electrode materials in lithium-ion batteries. First, we introduce a process for fabricating 3D micro-architected cathodes utilizing gel infusion additive manufacturing, and demonstrate this technique with lithium cobalt oxide (LCO). This method combines VP-based 3D printing with subsequent ion infusion and calcination processes. It starts with the printing of a blank organogel structure using a customized acrylate-based photoresin. This organogel is then converted into a hydrogel, infused with lithium and cobalt precursors, and finally subjected to calcination to form the LCO structure. This technique achieves 3D micro-architected LCO lattices with beam diameters of 45 μm, and maintains the designed architecture with tunable microstructures. By fabricating 3D micro-architected LiNi_0.33Mn_0.33Co_0.33O₂ (NMC111) through a very similar process, we demonstrate the potential for this gel infusion additive manufacturing method to engineer a variety of cathode materials for lithium-ion batteries in 3D.

We also develop a fabrication method to create 3D lithium anodes supported by micro-architected carbon scaffold. By pyrolyzing 3D printed polymer microlattices, mechanically robust carbon electrodes are produced. Their micro-scale features and flexible structural control make them suitable as scaffolds for lithium-metal anodes. Surface functionalization and lithium electrodeposition are explored for dense lithium nucleation and uniform epitaxial growth on the carbon framework, resulting in micro-architected lithium/carbon anodes. With the rapid development of high-resolution AM techniques in recent decades, these approaches to additively manufacture cathode and anode materials provide promising pathways to build batteries with customizable 3D designs, and pursue higher energy and power densities for different applications.

Thesis Files