A High‐Areal‐Capacity and Long‐Cycle‐Life Zinc‐Ion Battery with Robust V 2 O 3 @Graphene Microlattice Cathode and Interface‐Protected Zn Anode

The rapid failure of aqueous zinc‐ion batteries (ZIBs) under high electrode areal capacities greatly hinders their large‐scale application. The main reasons are the structural collapse of thick cathodes and the aggravated side reactions of Zn anode under high areal current densities. In this study, the issue is addressed from the dual perspectives of cathode structural engineering and anode interface protection. First, a customized V 2 O 3 @graphene (V 2 O 3 @G) microlattice cathode is manufactured by 3D printing. The intersecting printed filaments and the formed through‐hole structure endow the electrode with high structural robustness and unimpeded mass transport. Combined with the unique electrochemical activation behavior of low‐valent vanadium oxides, the electrode exhibits high Zn 2+ storage capacities. Second, a protective alginate‐polyacrylamide hydrogel layer is specifically introduced on the anode surface (Zn@AP), which can homogenize ion concentration and inhibit Zn corrosion. Consequently, the Zn@AP||3D‐V 2 O 3 @G full cell with a V 2 O 3 loading of 7.5 mg cm −2 demonstrated an excellent cycling stability of ∼2500 cycles at 1 A g −1 , with a capacity retention of 52.9%. When the areal loading reaches 20.4 mg cm −2 , the cell delivers an ultra‐high areal capacity of 7.9 mAh cm −1 at 1 A g −1 , and retains 4.3 mAh cm −2 after 980 cycles.