Realization of a 594 Wh kg-1 Lithium-Metal Battery Using a Lithium-Free V2 O5 Cathode with Enhanced Performances by Nanoarchitecturing

To realize a high-energy lithium metal battery (LMB) using a high-capacity Li-free cathode, in this work, nanoplate-stacked V₂ O₅ with dominantly exposed (010) facets and a relatively short [010] length is proposed to be used as a cathode. The V₂ O₅ nanostructure can be fabricated via a modified hydrothermal method, including a Li⁺ crystallization inhibitor, followed by heat treatment. In particular, the enlargement of the favorable Li⁺ diffusion pathway in the [010] direction and the formation of a robust hierarchical nanoplate-stacked structure in the modified V₂ O₅ improves the electrochemical kinetics and stability; as a result, the nanoplate-stacked V₂ O₅ electrode exhibits a higher capacity and rate performance (258 mAh g^-1 at 50 mA g^-1 [0.17 C], 140 mAh g^-1 at 1 A g^-1 [3.4 C]) and cycling capability (79% capacity retention after 100 cycles at 0.5 C) compared to the previously reported V₂ O₅ nanobelt electrode. Notably, the LMB composed of Li//nanoplate-stacked V₂ O₅ full-cells shows high specific energy densities of 594.1 and 296.2 Wh kg^-1 at 0.1 and 1.0 C, respectively, and a high Coulombic efficiency of 99.6% during 50 cycles.

Modification of Graphene Oxide/V2O5·nH2O Nanocomposite Films via Direct Laser Irradiation

Herein, photothermal modification of nanocomposite films consisting of hydrated vanadium pentoxide (V₂O₅·nH₂O) nanoribbons wrapped with graphene oxide (GO) flakes was performed via 405 nm direct laser irradiation. The combination of X-ray diffraction, X-ray photoelectron spectroscopy, Raman scattering, transmission electron microscopy, and scanning electron microscopy allowed comprehensive characterization of physical and chemical changes of GO/V₂O₅·nH₂O nanocomposite films upon photothermal modification. The modified nanocomposite films exhibited porous surface morphology (17.27 m² g^-1) consisting of randomly distributed pillarlike protrusions. The photothermal modification process of GO/V₂O₅·nH₂O enhanced the electrical conductivity of nanocomposite from 1.6 to 6.8 S/m. It was also determined that the direct laser irradiation of GO/V₂O₅·nH₂O resulted in considerable decrease of C-O bounds as well as O-H functional groups with an increase of the laser power density.

Evolution analysis of V2O5·nH2O gels for preparation of xerogels having a high specific surface area and their replicas

V₂O₅·nH₂O gel skeletons comprised of nanofibers were formed through thin fibrils from ultrathin films.