3D Printing Manufacturing of Thick Electrodes With Hierarchical Porous Structures for High-Power Lithium Metal Batteries

Thick electrodes of Lithium Metal battery face significant challenges in balancing ionic transport kinetics with structural stability, particularly under high-rate conditions. This study develops a synergistic fabrication strategy integrating direct ink writing 3D printing with ice-templating and phase separation to construct LiFePO₄ thick electrodes with hierarchical porous architectures. Systematic rheological optimization identifies the P-30% ink with ideal shear-thinning behavior and shape retention capability (yield stress: 538.9 Pa, storage modulus: 21 480 Pa). The resulting electrode features macro-printed channels and interconnected phase-separated micropores, achieving high porosity (79.57%) and low tortuosity. This unique architecture delivers exceptional electrochemical performance: a specific capacity of 109.3 mAh g⁻¹ at 5C rate, 90.8% capacity retention after 2000 cycles, reduced charge transfer resistance (69.8 Ω), and enhanced Li-ion diffusion coefficient (1.65 × 10⁻¹⁰ cm² s⁻¹). COMSOL simulations confirm improved ion transport efficiency and mitigated concentration polarization. The assembled pouch cell maintains stable performance over 10 000 bending cycles, demonstrating superior mechanical flexibility and practical application potential for high-power energy storage systems.