Hyper-Thick Electrodes for Lithium-Ion Batteries Enabled by Micro-Electric-Field Process.

Abstract

Increasing electrode thickness is a key strategy to boost energy density in lithium-ion batteries (LIBs), which is essential for electric vehicles and energy storage applications. However, thick electrodes face significant challenges, including poor ion transport, long diffusion paths, and mechanical instability, all of which degrade battery performance. To overcome these barriers, a novel micro-electric-field (μ-EF) process is introduced that enhances particle alignment during fabrication with reduced distance between anode and cathode. This process produces hyper-thick (≈700 µm) electrodes with low tortuosity and improved ion diffusion. The μ-EF electrodes achieve high areal capacities (≈8 mAh cm^-2), while maintaining power density and long cycle life. The electrodes show stable performance under high C-rate cycling and retain structural integrity after 1000 cycles at 2 C. By offering a scalable solution to the challenges of thick electrode fabrication, the μ-EF process represents a significant advancement for high-capacity LIBs in electric vehicles and energy storage systems.