Work

Metal Ions versus Protons: Tracking of Charge‐Carrier Insertion into a Cathode Oxide in Aqueous Rechargeable Batteries

Year: 2023

Type: article

Abstract: Protons in aqueous electrolytes can perform as an additional type of charge carrier for insertion/extraction in addition to the primary carrier cations in aqueous rechargeable batteries. Despite many diverse claims regarding the effect of protons, mutually conflicting experimental results and their interpretations without direct evidence have been reported over the last decade. Systematic examinations and analyses are thus imperative to clarify the conditions of proton insertion in aqueous rechargeable batteries. Utilizing V 2 O 5 as a model cathode and beaker‐type cells with a sufficient amount of ZnSO 4 aqueous electrolytes in this work, it is demonstrated that protons are inserted into the cathode prior to Zn‐ions in low‐pH conditions (pH ≤ 3.0). In stark contrast, the influence of protons on the discharge voltage and capacity is insignificant, when either the pH becomes higher (pH ≥ 4.0) or the electrolyte volume is considerably low in coin‐type cells. Similar behavior of pH‐dependent proton insertion is also verified in Na–, Mg–, and Al‐ion electrolytes. Providing a resolution to the controversy regarding proton insertion, the present study emphasizes that the influence of protons substantially varies depending on the pH and relative volume of electrolytes in aqueous batteries.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202303763

Authors: Changmin Lee, Youngjae Hong, Dongho Kim, Younghwan Lim, Jang Wook Choi, Sung‐Yoon Chung

Institutions: Korea Advanced Institute of Science and Technology, Seoul National University

Language: English

Topic: Advanced battery technologies research

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: bronze

Funders: National Research Foundation, National Research Foundation of Korea, Samsung