<p>Aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates for next-generation energy storage systems due to their inherent safety, cost-effectiveness, and high theoretical capacity. However, their practical application remains constrained by limited cycling stability and sluggish ion diffusion kinetics, particularly under high mass loading conditions. These limitations are primarily attributed to the restricted ion transport pathways within the electrode structure and structural degradation caused by repeated zinc-ion insertion and extraction in highly loaded electrodes. To address these challenges, formamide (FA)-inserted VOPO₄ (FA-VOPO₄) nanosheet cathodes were designed with expanded interlayer spacing (9.3 Å), where FA molecules partially replace interlayer water, thereby enhancing both structural stability and ion transport pathways. This unique structural modification, supported by synergistic hydrogen bonding between FA and residual water, significantly improves Zn²⁺ diffusion kinetics and charge transfer properties, as confirmed by electrochemical tests and theoretical analysis. Consequently, FA-VOPO₄ electrodes delivered a remarkable volumetric capacity of 733 mAh/cm³ at 40 mA/g, approximately 8 times higher than that of the VOPO₄·2H₂O electrode, and retained 82.1% of their capacity after 1000 cycles at 1 A/g with a mass loading of 10 mg/cm². Even at a high mass loading of 20 mg/cm² (4.4 mAh/cm²), the FA-VOPO₄ cathode maintained a volumetric capacity of 535 mAh/cm³. These findings provide valuable insights into electrode design strategies for high-performance AZIBs, contributing to the development of safer, more efficient energy storage technologies with potential applications in grid storage and portable electronics.</p>