Unveiling the Mechanism of V 6 O 13 /MnO 2 Heterojunction for High‐Performance Aqueous Zinc‐Ion Batteries via Combined Experiments, DFT, and Deep Learning

ABSTRACT Aqueous zinc‐ion batteries (AZIBs) suffer from sluggish diffusion kinetics and poor structural stability. Single‐phase V 6 O 13 exhibits a high Zn 2+ diffusion barrier (~0.55 eV), while MnO 2 suffers from rapid capacity fading due to Mn dissolution and phase transformation. Here, we construct a tightly coupled V 6 O 13 /MnO 2 heterostructure with a well‐defined interface to overcome these limitations. This heterostructure generates a built‐in electric field, which reduces the charge‐transfer resistance ( R ct ) from 773.3 Ω (V 6 O 13 ) to 218.8 Ω (V 6 O 13 /MnO 2 ) and enhances electronic conductivity. Electrochemical tests show that the heterojunction cathode delivers an initial capacity of 258.3 mAh g −1 at 10 A g −1 and maintains 97.8% capacity retention after 10,000 cycles at 20 A g −1 . Density functional theory calculations reveal that the heterointerface induces pronounced electronic reconstruction and orbital hybridization. This leads to a higher density of states near the Fermi level, a stronger Zn 2+ adsorption energy (−1.85 eV), and a significantly reduced diffusion barrier (0.38 eV). Therefore, the V 6 O 13 /MnO 2 heterojunction shows great potential as a cathode material for AZIBs.