Details

Autor(en) / Beteiligte

• Chen, Shuai
• Xu, Qiucheng
• Chen, Ling
• Hu, Yanjie
• Jiang, Hao
• Li, Chunzhong

Titel

Engineering VO nanoarrays with abundant localized defects towards high-voltage aqueous supercapacitors

Ist Teil von

• Journal of materials chemistry. A, Materials for energy and sustainability, 2022-03, Vol.1 (9), p.4825-4832

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Exploiting high-capacitance and more negative potential anode materials is pivotal to the breakthrough of energy density for aqueous supercapacitors. In this work, we demonstrated the localized defect engineering of Mo-doped V 2 O 3 nanoarrays with abundant V 4+ around Mo-ions. The localized defect engineering remarkably reduces the energy barrier of V-ion redox reactions and broadens the work potential window, thereby greatly increasing the energy density. The target sample delivers a specific capacitance of 333.9 F g −1 at 1.0 A g −1 within −1.2-0.2 V ( vs. Ag/AgCl) in a LiTFSI aqueous electrolyte, about 3 times higher than that of the corresponding V 2 O 3 nanoarrays. Electrochemical quartz crystal microbalance (EQCM) directly exhibits a triple increase in the adsorption capacity of cations under a 100% charging state. When assembled into aqueous supercapacitors with a MnO 2 nanosheet cathode, it can be operated at a very large potential window up to 2.7 V with an energy density as high as 149.9 W h kg −1 at 1.35 kW kg −1 , which is among the best report for aqueous supercapacitors. Defect engineering on V 2 O 3 exhibits great potential to decrease the energy barrier of ion diffusion; meantime, it expedites the electron transfer rate.