Experimental Validation of Density Functional Theory Predictions on Structural Water Impact in Vanadium Oxide Cathodes for Zinc-Ion Batteries.

This study combines experimental methods with density flooding theory (DFT) calculations to investigate the enhancement of the electrochemical performance of vanadium oxide cathodes for aqueous zinc ion batteries (AZIBs) through strategic water content management. DFT predictions indicated that a moderate presence of structural water optimizes electrical conductivity and facilitates zinc ion diffusion. These theoretical insights are empirically validated by synthesizing AlVO-1.6 H2O using a hydrothermal method, which exhibited superior electrochemical properties. This material demonstrated an impressive initial capacity of 316 mAh g-1 at 0.2 A g-1, with robust capacity retention after extended cycling. Remarkably, even at an elevated current density of 10 A g-1, it sustains a capacity of 161.6 mAh g-1, while maintaining a capacity retention of 97.6% over 2000 cycles. The results confirm that adjusting the structural water content in vanadium oxides significantly boosts their electrochemical capabilities, aligning experimental outcomes with computational forecasts and showcasing a novel approach for developing high-performance cathodes in energy storage technologies.

Amorphous Structure Benefits in MgV2O4/V2O3 Composites for Zinc-Ion Storage: An Integration of Computational and Experimental Studies.

This study investigates the electrochemical properties of MgV2O4/V2O3 composites for Aqueous Zinc-Ion Batteries (AZIBs) using both Density Functional Theory (DFT) calculations and experimental validation. DFT analysis reveals significant electron mobility and reactivity at the MgV2O4/V2O3 interface, enhancing Zn2+ storage capabilities. This theoretical prediction is confirmed experimentally by synthesizing a novel MgV2O4/V2O3 composite that demonstrates superior electrochemical performance compared to pristine phases. Notably, the transition of the MgV2O4/V2O3 composite into an amorphous structure during electrochemical cycling is pivotal, providing enhanced diffusion pathways and increased conductivity. The composite delivers a consistent specific capacity of 330.2 mAh g-1 over 50 cycles at 0.1 A g-1 and maintains 152.7 mAh g-1 at an elevated current density of 20 A g-1 after 2000 cycles, validating the synergy between DFT insights and experimental outcomes, and underscoring the potential of amorphous structures in enhancing battery performance.

Empirical Confirmation of Theoretical Predictions for Amorphous H/VO4 Cathodes: Advancing Durability and Efficiency in Zinc-Ion Batteries.

Advancing cathode materials is crucial for the broader application of aqueous zinc-ion batteries (ZIBs) in energy storage systems. This study presents amorphous H/VO4 (HVO), a novel cathode material engineered by substituting H+ for Mg2+ in Mg2VO4 (MgVO), designed to enhance performance of ZIBs. Initial exploration of MgVO through ab initio molecular dynamics (AIMD) simulations and density functional theory (DFT) calculations revealed a favorable Mg2+ and Zn2+ exchange mechanism. This mechanism notably reduces electrostatic interactions and facilitates ion diffusion within the host lattice. Building upon these findings, in this work, theoretical calculations analysis indicated that amorphous HVO offers a higher diffusion coefficient for Zn2+ ions and fewer electrostatic interactions compared to its crystalline MgVO precursor. Subsequent empirical validation is achieved by synthesizing amorphous HVO using a rapid ion-exchange process, effectively replacing Mg2+ with H+ ions. The synthesized amorphous HVO demonstrated 100% capacity retention after 18000 cycles at a current density of 2 A g-1 and exhibited exceptional rate performance. These findings underscore the significant potential of HVO cathodes to enhance the durability and efficiency of aqueous ZIBs, positioning them as promising candidates for future energy storage technologies.