In Operando Synchrotron Studies of NH4+ Preintercalated V2O5· n H2O Nanobelts as the Cathode Material for Aqueous Rechargeable Zinc Batteries

Hainan Zhao; Qiang Fu; Di Yang; Angelina Sarapulova; Qiang Pang; Yuan Meng; Luyao Wei; Helmut Ehrenberg; Yingjin Wei; Chunzhong Wang; Gang Chen

doi:10.1021/acsnano.0c04669

In Operando Synchrotron Studies of NH₄⁺ Preintercalated V₂O₅· n H₂O Nanobelts as the Cathode Material for Aqueous Rechargeable Zinc Batteries

ACS Nano. 2020 Sep 22;14(9):11809-11820. doi: 10.1021/acsnano.0c04669. Epub 2020 Sep 3.

Authors

Hainan Zhao¹, Qiang Fu², Di Yang¹, Angelina Sarapulova², Qiang Pang^{1

3

4}, Yuan Meng⁵, Luyao Wei¹, Helmut Ehrenberg², Yingjin Wei¹, Chunzhong Wang¹, Gang Chen¹

Affiliations

¹ Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Qianjin Street 2699, Changchun 130012, China.
² Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
³ School of Science, Dalian Maritime University, Linghai Road 1, Dalian 116026, China.
⁴ State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, China.
⁵ School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China.

PMID: 32865959
DOI: 10.1021/acsnano.0c04669

Abstract

NH₄⁺ preintercalated V₂O₅·nH₂O nanobelts with a large interlayer distance of 10.9 Å were prepared by the hydrothermal method. The material showed a large specific capacity of 391 mA·h·g^-1 at the 500 mA·g^-1 current density in aqueous rechargeable zinc batteries. In operando synchrotron X-ray diffraction demonstrated that the material experienced reversible solid-solution reaction and two-phase transition during charge-discharge cycling, accompanied by the reversible formation/decomposition of a ZnSO₄Zn₃(OH)₆·5H₂O byproduct. In operando X-ray absorption spectroscopy confirmed the reversible reduction/oxidation of V, together with small changes in the VO₆ local structure. The formation of byproduct was attributed to the dehydration of [Zn(H₂O)₆]²⁺, which concurrently improved the desolvation of [Zn(H₂O)₆]²⁺ into Zn²⁺. Bond valence sum map analysis and electrochemical impedance spectroscopy demonstrated that the byproduct improved the charge transfer kinetics of the electrode. Cyclic voltammetry and galvanostatic intermittent titration technique showed that the electrode reaction was dominated by ionic intercalation where the discharge capacity in the voltage window of 1.4-0.85 V was attributed to the intercalation of [Zn(H₂O)₆]²⁺, followed by the intercalation of Zn²⁺ at 0.85-0.4 V.

Keywords: X-ray absorption spectroscopy; aqueous rechargeable zinc batteries; electrochemical properties; in operando X-ray diffraction; vanadium oxide.