Ultrathick LiCoO2 cathodes with low tortuosity and accelerated kinetics enable high areal capacity and long-life customable batteries

3D-printed ultrathick electrodes with high active material loading enable exceptionally high areal capacity and energy density in batteries, but face challenge in ion transport and cycle life. Herein we report a 3D-printed ordered-channel electrode structure design strategy for building high-voltage LiCoO₂ (LCO) ultrathick cathode. These electrodes feature long-range ordered, three-dimensional porous conductive networks that facilitate rapid ion-transport pathways, enabling both high areal capacity and extended cycle life toward customizable 3D-printed batteries. Due to ultralow tortuosity, the lithium-ion diffusion coefficient of 3D-printed LCO thick electrodes is 3.8 times higher than the traditional coated LCO thick electrodes. This enhanced lithium-ion transport mitigates the lattice stress from frequent lithiation and de-lithiation cycles, preventing irreversible H2-H1/H2 phase transition, and maintaining the structural stability of LCO. The 3D-printed LCO||Li cell, with a mass loading of 29 mg cm⁻², delivers a high areal capacity of 5.16 mAh cm⁻² and capacity retention of 89 % after 200 cycles at 3 mA cm⁻². Our 3D-printed LCO ultrathick electrodes achieve outstanding mass loading of 190 mg cm⁻² (2686 µm thick), extremely high areal capacity of 29.15 mAh cm⁻² and stable cyclability, outperforming the reported LCO thick electrodes up to date. This work will offer valuable insights for developing high energy density lithium-ion batteries.