Volume 63, Issue 6 e202318444
Research Article

Revealing the Dominance of the Dissolution-Deposition Mechanism in Aqueous Zn−MnO2 Batteries

Yadong Li

Yadong Li

College of Physics, Qingdao University, Qingdao, 266071 China

These authors contributed equally to this work.

Search for more papers by this author
Yuhao Li

Yuhao Li

College of Physics, Qingdao University, Qingdao, 266071 China

These authors contributed equally to this work.

Search for more papers by this author
Qingshan Liu

Qingshan Liu

College of Physics, Qingdao University, Qingdao, 266071 China

Search for more papers by this author
Yongshuai Liu

Yongshuai Liu

College of Physics, Qingdao University, Qingdao, 266071 China

Search for more papers by this author
Tiansheng Wang

Tiansheng Wang

College of Physics, Qingdao University, Qingdao, 266071 China

Search for more papers by this author
Mingjin Cui

Mingjin Cui

Center of Energy Storage Materials & Technology, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093 P. R. China

Search for more papers by this author
Prof. Yu Ding

Corresponding Author

Prof. Yu Ding

Center of Energy Storage Materials & Technology, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093 P. R. China

Search for more papers by this author
Prof. Hongsen Li

Corresponding Author

Prof. Hongsen Li

College of Physics, Qingdao University, Qingdao, 266071 China

Search for more papers by this author
Prof. Guihua Yu

Corresponding Author

Prof. Guihua Yu

Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 USA

Search for more papers by this author
First published: 20 December 2023
Citations: 26

Graphical Abstract

This work pinpointed the cause of the capacity degradation of Zn−MnO2 batteries and established the dominance of the MnO2/Mn2+ dissolution-deposition mechanism. Such a methodology circumvents the complicated characterization methods used in previous studies and provides a universal approach to accurately identify the reaction mechanism of other aqueous batteries.

Abstract

Zn−MnO2 batteries have attracted extensive attention for grid-scale energy storage applications, however, the energy storage chemistry of MnO2 in mild acidic aqueous electrolytes remains elusive and controversial. Using α-MnO2 as a case study, we developed a methodology by coupling conventional coin batteries with customized beaker batteries to pinpoint the operating mechanism of Zn−MnO2 batteries. This approach visually simulates the operating state of batteries in different scenarios and allows for a comprehensive study of the operating mechanism of aqueous Zn−MnO2 batteries under mild acidic conditions. It is validated that the electrochemical performance can be modulated by controlling the addition of Mn2+ to the electrolyte. The method is utilized to systematically eliminate the possibility of Zn2+ and/or H+ intercalation/de-intercalation reactions, thereby confirming the dominance of the MnO2/Mn2+ dissolution-deposition mechanism. By combining a series of phase and spectroscopic characterizations, the compositional, morphological and structural evolution of electrodes and electrolytes during battery cycling is probed, elucidating the intrinsic battery chemistry of MnO2 in mild acid electrolytes. Such a methodology developed can be extended to other energy storage systems, providing a universal approach to accurately identify the reaction mechanism of aqueous aluminum-ion batteries as well.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the supplementary material of this article.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.