Using Side Reactions for Extra Capacitive Energy Storage Based on Spin Regulated MnO2

Export Citation

Wan, Y, Xu, Y, Wang, B, Cao, T, Zhang, D, Li, Q, Fielding, AJ orcid iconORCID: 0000-0002-4437-9791, Wu, M and Hu, H (2026) Using Side Reactions for Extra Capacitive Energy Storage Based on Spin Regulated MnO2. Advanced Functional Materials. ISSN 1616-301X

[thumbnail of Using Side Reactions for Extra Capacitive Energy Storage Based on Spin Regulated MnO2.pdf]
Preview
 Text
Using Side Reactions for Extra Capacitive Energy Storage Based on Spin Regulated MnO2.pdf - Published Version
Available under License Creative Commons Attribution.
Download (390kB) | Preview

Abstract

Pseudocapacitive materials in neutral aqueous electrolytes are promising for large-scale energy storage but are hindered by parasitic reactions like the oxygen evolution reaction (OER). This work demonstrates that spin-regulated MnO2 can redirect such side reactions toward capacitive storage by modulating the rate-determining step. Theoretical analysis indicates that MnO2 with unpaired eg electrons facilitates water dissociation, the initial OER step, while stabilizing intermediates *OH on active sites to prevent the subsequent gas evolution. This channels the charges associated with water dissociation into additional capacitive charge storage. By engineering Mn and O vacancies in MnO2 to delocalize eg electrons, a 53% capacitance increase and markedly enhanced rate capability are achieved. In situ characterizations, especially electron paramagnetic resonance, confirm that water dissociation is driven by a double exchange interaction along Mn3+ (eg1)─O2−─Mn4+ (t2g3), consistent with theoretical simulations. This work offers a practical approach to enhance MnO2-based pseudocapacitors and deepens the understanding of their charge storage mechanisms.

Item Type: Article
Uncontrolled Keywords: 34 Chemical Sciences; 3406 Physical Chemistry; 40 Engineering; 51 Physical Sciences; 4016 Materials Engineering; 7 Affordable and Clean Energy; 02 Physical Sciences; 03 Chemical Sciences; 09 Engineering; Materials; 34 Chemical sciences; 40 Engineering; 51 Physical sciences
Subjects: R Medicine > RS Pharmacy and materia medica
Divisions: Pharmacy and Biomolecular Sciences
Publisher: Wiley
Date of acceptance: 20 July 2026
Date of first compliant Open Access: 28 August 2026
Date Deposited: 28 Aug 2026 14:45
Last Modified: 28 Aug 2026 14:45
DOI or ID number: 10.1002/adfm.77480
URI: https://researchonline.ljmu.ac.uk/id/eprint/29223
View Item View Item
CORE (COnnecting REpositories)