Achieving desirable charge transport by porous frame engineering for superior 3D printed rechargeable Ni-Zn alkaline batteries.

Rechargeable 3D printed batteries with extraordinary electrochemical potential are typical contenders as one of the promising energy storage systems. Low-cost, high-safety, and excellent rechargeable aqueous alkaline batteries have drawn extensive interest. But their practical applications are severely hampered by poor charge carrier transfer and limited electrochemical activity at high loading. Herein, we report a unique structure-based engineering strategy in 3D porous frames using a feasible 3D printing technique and achieve 3D printed full battery devices with outstanding electrochemical performance. By offering a 3D porous network to provide prominently stereoscopic support and optimize the pore structure of electrodes, the overall charge carrier transport of engineered 3D printed Ni-Zn alkaline batteries (E3DP-NZABs) is greatly enhanced, which is directly demonstrated through a single-wired characterization platform. The obtained E3DP-NZABs deliver a high areal capacity of 0.34 mA h cm at 1.2 mA cm, and an outstanding capacity retention of 96.2% after 1500 cycles is also exhibited with an optimal electrode design. Particularly, parameter changes such as a decrease in pore sizes and an increase in 3D network thickness are favorable to resultant electrochemical performance. This work may represent a vital step to promote the practical application progress of alkaline batteries.