Ultra-pressure-resistant SiOC@Cu2Se 3D printed cathode for aqueous zinc-ion batteries

Abstract Zinc-ion batteries have attracted significant attention for practical energy storage because of their uniqueness in terms of high capacity, safety and low cost. However, due to the instability of electrodes, large-scale practical applications are challenging. 3D electrodes with high porosity and specific surface area provide an opportunity to solve these problems, increasing their stability, energy density and mechanical properties. Herein, an ultrapressure-resistant self-supporting SiOC@Cu2Se 3D cathode was fabricated and applied in aqueous zinc-ion batteries. The battery with the as-obtained cathode delivers a maximum compressive strength of 89.23 MPa and a toughness up to 16453 kJ m−3. In addition, the structural electrodes possess a specific capacity of 2.9 mWh cm−3 at a current density of 4.88 mA cm−3, demonstrating excellent deformation resistance and high specific capacity. Ex situ XRD and EDS show an interesting Cu2Se to Cu2O transformation during the first charge and discharge cycle. As expected, the electrode prepared in this paper provides a novel idea to manufacture 3D structured zinc-ion batteries with high specific capacity and excellent deformation resistance, fulfilling the demand for energy storage in astronautic industries and space exploration facing shock and high-pressure environments.