Water-in-Salt Electrolyte optimisation for Zn-O2 batteries

• Grant number: 24/20108-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2025
• End date: March 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Vitor Leite Martins
• Grantee: Karoline de Freitas Ishida
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/26309-4 - Beyond Li-ion: development of reversible non-aqueous metal-air batteries, AP.JP

Abstract

The growing global energy consumption, driven by portable devices and electric vehicles, highlights the need for safe and sustainable energy storage technologies. Zinc-air (Zn-O¿) batteries emerge as a promising alternative to lithium-ion batteries, offering advantages in energy density potential (1353 Wh kg¿¹, excluding oxygen), lower cost, and reduced environmental impact. However, technical obstacles, such as low cycle stability, zinc dendrite formation, and side reactions between the electrolyte and the environment, still need to be overcome to enable large-scale application. To address these challenges, WiSE (Water-in-Salt Electrolyte) electrolytes emerge as an innovative solution due to their unique properties. The high salt concentration in WiSE minimizes side reactions and improves ionic conductivity, thermal stability, and battery durability. As a result, these electrolytes help mitigate issues such as dendrite formation and electrode degradation, enabling more durable and efficient Zn-O¿ batteries. Thus, this project proposes investigating different compositions of WiSE electrolytes applied to Zn-O¿ batteries, aiming to optimize their performance and durability. To this end, the electrolytes will be characterized through physicochemical techniques, such as conductivity, viscosity, and molecular structure analyses, to assess their fundamental properties. Subsequently, electrochemical tests will be conducted in symmetric zinc cells and three-electrode configurations to investigate electrolyte degradation and determine the electrochemical stability window. This approach aims to contribute to the advancement of more stable and sustainable Zn-O¿ batteries, addressing the growing global demand for efficient energy systems.