Switchable and Strain-Releasable Mg-Ion Diffusion Nanohighway Enables High-Capacity and Long-Life Pyrovanadate Cathode.
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; 18(27): e2202250, 2022 07.
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| MEDLINE
| ID: mdl-35655327
ABSTRACT
Rechargeable magnesium batteries (RMBs) suffer from low capacity and poor cyclability of cathode materials, which is due to the sluggish Mg2+ diffusion kinetics and large lattice strain. Here, a layer-interweaving mechanism in lamellar cathode to simultaneously facilitate Mg2+ diffusion and release Mg2+ -insertion strain is reported. In the Cu3 V2 O7 (OH)2 ·2H2 O (CVOH) cathode, Mg2+ diffusion highways are generated by the vertical interweaving of CVOH layers and V6 O13 layers that nucleate in CVOH during discharging, which are switchable by Mg2+ insertion/extraction. These highways enhance the Mg2+ diffusion coefficient by three orders of magnitude and release 50% Mg2+ -insertion strain. This enables CVOH to exhibit a high capacity of 262 mAh g-1 at high current density of 250 mA g-1 in aqua, and extremely low capacity loss of 0.0004% per cycle in the activated carbon//CVOH cell. This work inspires designing the magnesiation phase transformation of electrodes to resolve both kinetic and strain issues for high-performance RMBs.
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MEDLINE
Asunto principal:
Suministros de Energía Eléctrica
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Magnesio
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En
Año:
2022
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Article