Enhancing Capacity and Rate Performance of Lamellar V_{2}O_{5} Cathode Materials by Modulating Vanadium 3d Orbital Splitting
Magnesium-ion batteries (MIBs) are promising next-generation energy storage devices. Vanadium oxides are promising cathode materials for MIBs due to their rich chemical valences and versatile structures. However, vanadium oxide cathodes face challenges such as low structural stability, slow Mg^{2+}...
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| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2025-08-01
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| Series: | PRX Energy |
| Online Access: | http://doi.org/10.1103/9wnj-xv2w |
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| Summary: | Magnesium-ion batteries (MIBs) are promising next-generation energy storage devices. Vanadium oxides are promising cathode materials for MIBs due to their rich chemical valences and versatile structures. However, vanadium oxide cathodes face challenges such as low structural stability, slow Mg^{2+} diffusion kinetics, and low electrical conductivity. The work reported herein used hydrothermal synthesis to pre-intercalate H_{2}O molecules and Mg^{2+} into V_{2}O_{5} interlayers to stabilize the lamellar structure and modulate V 3d orbital splitting, leading to a Mg_{0.2}V_{2}O_{5}⋅1.5H_{2}O cathode (MVOH1). The V 3d orbital splitting facilitates electron hopping between V^{4+} and V^{5+} cations, leading to the enhanced conductivity of MVOH1; it also makes it easier for V atoms to acquire and lose electrons during discharging and charging, leading to high capacity and high rate capability of MVOH1. Consequently, the MVOH1 cathode exhibited a high specific capacity of 300 mA h g^{−1} at a current density of 0.05 A g^{−1} and retained a specific capacity of 85 mA h g^{−1} at 10 A g^{−1}; the capacity and rate capability surpass those of previously reported V_{2}O_{5} cathode materials. The aqueous MIB based on MVOH1 demonstrated an ultralong lifespan of 11 000 cycles, which is significantly longer than that of previously reported aqueous MIBs. This study highlights the synergistic effect of regulating interlayer spacing and V 3d orbital splitting on electrochemical performance, which is crucial for developing more efficient and more durable energy storage systems. |
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| ISSN: | 2768-5608 |