3D printing of CuO/Cu@Mullite electrodes with macroporous structures and their strong regulation on zinc ion storage

Zinc ion battery is a promising candidate as cost-efficient power source in astronautic electronics, industrial equipment, and integrated devices. However, it remains a great challenge to achieve electrodes with both high volumetric capacity and excellent mechanical strength. Herein, 3D macroporous electrodes for zinc ion storage are fabricated by 3D printing. Benefiting from unique lattice-like structures and nanosheet CuO, the structured electrodes achieve a high compressive strength of over 2.0 MPa and energy absorption of ∼40 kJ m⁻³. The assembled aqueous zinc ion battery with a body-centered electrode shows a high volumetric capacity of 31.95 mAh cm⁻³ at 14.0 mA cm⁻³. The resulting device provides an outstanding energy density of 25.47 Wh L⁻¹ at a power density of 10.2 W L⁻¹. More importantly, collective tests indicate that the regulation of electrochemical performance and compression strength of the electrodes significantly depend on the macro-porosity and specific surface area of lattice-like structures. The 3D-printed macroporous electrodes proposed here achieve a synergistic regulation of electrochemical and compression performance, providing an attractive way to enhance the designability and adjustability of customizable high-performance zinc ion storage devices.