The integration of electronic devices has placed increasing demands on the low area occupancy, high areal capacity and safety of energy storage devices. Aqueous zinc ion batteries are expected to be used in highly integrated precision electronics due to their high safety, environmentally friendly and low cost advantages. However, the conventional coating method limits the structure and the areal capacity of electrodes. To address this issue, we design and fabricate a novel 3D printed reticular MnO2 self-supporting cathode. Ascribed to the high mass loading and reticular structure of the reticular MnO2 cathode, the AZIBs deliver a high areal capacity (3.43 mAh cm−2 at 2 mA cm−2). It is demonstrated that the reticular structure facilitates electrolyte storage and rapid diffusion of Zn2+ and reduces charge transfer impedance. Furthermore, the 3D printing technology can realize layer-by-layer printing of electrodes. The areal capacity of the two-layer 3D reticular MnO2 cathode is almost twice as high as that of 3D reticular MnO2. This work indicates the great potential of 3D printing technology in the design and fabrication of high-load electrodes with a high areal capacity and customized shapes.
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