Spatially restricted deposition of Zn metal in localized-activation 3D electrode enables long-term stable zinc ion batteries

3D structures with organized channels have attracted extensive interest in constructing weak-dendrite anode for Zinc ion batteries (ZIBs). However, the uncontrolled "top-growth" dendrites caused by the unrestricted zinc deposition at all locations of the 3D electrode may eventually trigger a separator failure. Herein, a novel design principle of localized-activation 3D electrodes for spatially restricted deposition of metals is proposed. Based on the principle, a 3D Zn@CuSnAg/SiOC anode with spatially restricted feature (P-G Zn@CuSnAg/SiOC-SR), whose top surface (near separator) is an insulating SiOC and other surfaces are highly reactive Zn@CuSnAg, is fabricated by coupling polymer-derived ceramics (PDCs) 3D printing and surface modified method. Uniquely, the insulated SiOC of the top surface bestows a spatially restricted Zn deposition within the anode and ultimately prevents the upper surface from Zn plating and stripping, eliminating "top-growth" Zn dendrites in the 3D electrode. As expected, the P-G Zn@CuSnAg/SiOC-SR symmetrical battery affords spatially restricted Zn plating/ stripping with a superior lifespan over 2100 h at 1.0 mA cm-2 for 0.82 mAh cm-2. Meanwhile, the VO2/C//P-G Zn@CuSnAg/SiOC-SR full battery demonstrates remarkable cyclic stability over 800 cycles (capacity retention: 80.5 %). This work sheds light on the 3D anode design and fabrication for the next-generation long-term stable ZIBs.