Electrolyte Interphases in Aqueous Batteries

Abstract

The narrow electrochemical stability window of water poses a challenge to the development of aqueous electrolytes. In contrast to non‐aqueous electrolytes, the products of water electrolysis do not contribute to the formation of a passivation layer on electrodes. As a result, aqueous electrolytes require the reactions of additional components, such as additives and co‐solvents, to facilitate the formation of the desired solid electrolyte interphase (SEI) on the anode and cathode electrolyte interphase (CEI) on the cathode. This review highlights the fundamental principles and recent advancements in generating electrolyte interphases in aqueous batteries.

An Energetic Aqueous Mn Metal Anode

“…Low-redox-potential metal anodes commonly encounter electrochemical HER in aqueous electrolytes, , with the aqueous Mn metal anode being more severely affected. Due to the deposition/​dissolution potential of aqueous Mn metal as low as −1.19 V vs SHE, the HER phenomenon is highly pronounced during the Mn metal deposition process, which we call competing Mn, being the primary reason for the relatively low CE of the aqueous Mn metal anode.…”

Polymers for Aqueous Zinc‐Ion Batteries: From Fundamental to Applications Across Core Components

“…These merits endow them with great prospects in future large‐scale electric energy storage. [ 4 ] Specifically, aqueous zinc‐ion batteries (AZIBs) employing a zinc metal anode stand out of all aqueous batteries due to their non‐toxicity, high theoretical capacity (820 mAh g −1 ), high safety, excellent stability and compatibility in aqueous solutions, low raw material cost, and easy‐to‐handle assembly process in air. [ 5 ] However, dendrite growth and surface passivation from the heterogeneous deposition/dissolution of Zn 2+ , hydrogen evolution reaction (HER), and surface by‐product formation resulting in low Coulomb efficiency (CE) have hindered further advances of AZIBs.…”

Constructing a Topologically Adaptable Solid Electrolyte Interphase for a Highly Reversible Zinc Anode

“…However, unlike organic solvents, reduction and oxidation products of H 2 O cannot directly contribute to SEI formation. 12 Therefore, additional additives need to be introduced into the aqueous electrolyte to promote SEI formation. 12 Furthermore, the formation of the SEI is intricately linked to the electrical double layer (EDL) structure at AEI since various electrochemical or chemical reactions occur there, including zinc deposition/dissolution and undesired side reactions.…”

“…Currently, the focus is on promoting the formation of a solid electrolyte interface (SEI) phase on the zinc anode to inhibit related side reactions. ,, This approach is inspired by the successful formation of the SEI on lithium-ion battery anodes. However, unlike organic solvents, reduction and oxidation products of H 2 O cannot directly contribute to SEI formation . Therefore, additional additives need to be introduced into the aqueous electrolyte to promote SEI formation .…”

“…However, unlike organic solvents, reduction and oxidation products of H 2 O cannot directly contribute to SEI formation . Therefore, additional additives need to be introduced into the aqueous electrolyte to promote SEI formation . Furthermore, the formation of the SEI is intricately linked to the electrical double layer (EDL) structure at AEI since various electrochemical or chemical reactions occur there, including zinc deposition/dissolution and undesired side reactions. ,, Therefore, the introduction of additives to regulate the structure of the EDL is a crucial factor in achieving an ideal SEI.…”