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

ABSTRACT

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.