Oxygen-Related Defect Engineering of Amorphous Vanadium Pentoxide Cathode for Achieving High-Performance Thin-Film Aqueous Zinc-Ion Batteries

Abstract

Thin-film aqueous zinc-ion batteries are expected to serve as next-generation energy storage devices that are both lowcost and safe. However, to realize practical energy storage devices based on zinc-ion batteries, it is necessary to develop reliable, highcapacity cathode materials. In this study, we prepared a V 2 O 5based thin-film electrode and investigated the effect of varying the Ar pressure during radio frequency magnetron sputtering of V 2 O 5 , a representative cathode material in thin-film zinc-ion batteries, to control the number of oxygen vacancies in the oxide lattice. The optimized V 2 O 5 thin-film electrode exhibited enhanced electrochemical activities, low degree of polarization, improved ion diffusion, and increased electrical conductivities. Specifically, an oxygen-deficient V 2 O 5−x thin-film prepared by sputtering under high pressure exhibited a high rate capability (57.2 mAh g −1 at 20 C) and superior electrochemical performance (105.2 mAh g −1 for up to 1000 cycles at a current density of 5 C). The mechanism for the performance enhancement was revealed by density functional theory calculations, which showed that the oxygen-deficient V 2 O 5−x had a lower Zn 2+ -ion diffusion energy barrier than that of pristine V 2 O 5 . This defect engineering strategy for tuning the oxidation state should aid in designing high-performance cathodes for advanced thin-film aqueous battery chemistry.

Strategies to alleviate distortive phase transformations in Li-ion intercalation reactions: an example with vanadium pentoxide

“…Despite the possible structural variations of quasi-crystalline or amorphous V 2 O 5 , certain trends are consistent with its crystalline counterparts, for example, oxygen defects in amorphous V 2 O 5 demonstrated enhanced performance in aqueous Zn-ion batteries and the same trend has been observed in crystalline V 2 O 5 as well. 119,120 3 Characterization by conventional molecular tools…”

Research Status and Optimization Methods of Zinc Ion Battery

“…PEDOT coating has good electrical conductivity and structural stability, which improves the diffusion kinetics of zinc ions and acts as a protective layer to inhibit structural collapse during the cycle. Su-Ho et al [31] optimized the diffusion kinetics of zinc ions in V 2 O 5 thin films by controlling the number of oxygen vacancies in the oxidation lattice. The prepared V 2 O 5 -x thin films were 57.2 mAh/g at 20C and 105.2 mAh/g at 5C (Figure 2b).…”

Evaluation of Low-Voltage-Driven Multi-Colored Electrochromic Device Based on Dry-Deposited V2o5

“…Exceptionally, vanadium oxide (V2O5) is a bifunctional electrochromic material that can function as both cathodic and anodic electrochromic materials [8,9]. Owing to its exceptional catalytic, electrical, optical, and magnetic properties, V2O5 is a promising candidate for applications in solar cells [10,11], energy storage devices [12][13][14][15], and ECDs [16,17]. V2O5 has a layered structure in which a series of (0 0 1) planes formed by connecting VO5 pyramids are stacked.…”