Work

3D WO3 nanostructuration for high power energy storage micro-devices

Year: 2026

Type: article

Abstract: The key technical challenge in developing high-performance micro-energy storage systems based on thin films that offer enhanced rate performance and cycling stability is to find low-energy, time-consuming methodologies for depositing thick, conformal films on complex 3D architectures. This work addresses this challenge by presenting a chemical solution deposition approach based on spin coating, which can deposit WO₃ thin films with a thickness ranging from 100 to 500 nm on high-aspect-ratio 3D silicon substrates. Combining an optimized 3D substrate with a high AEF and an optimized film thickness results in the electrodes exhibiting a 30-fold increase in capacity compared to 2D planar counterparts, in line with the area enlargement factor. Electrochemical evaluations demonstrate stable capacity of 320 µAh cm⁻², even when the potential is limited to prevent conversion reactions. Furthermore, a capacity of 82 µAh cm⁻² is retained at a high charge density of 500 µA cm⁻². The improved rate capability is attributed to reversible Li+ intercalation mechanisms and the nanoscale WO3 structure with 8 nm particles, as confirmed by XRD, which minimizes lithium-ion diffusion pathways.

Source: Journal of Power Sources

DOI: 10.1016/j.jpowsour.2026.241592