Investigation of the influence of different metals on high-entropy layered oxides for cathodes for sodium-ion batteries

• Grant number: 24/14118-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2024
• End date: October 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Gustavo Doubek
• Grantee: Maria Gabriella Detone Guaita
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country, AP.PCPE

Abstract

Lithium-ion batteries are the most advanced and currently used rechargeable batteries, however, their widespread use may limit the available lithium and cobalt resources in the future, significantly influencing the cost and survival of this technology. Therefore, new technologies have been investigated to replace lithium, the raw material for the active material in the cathode of lithium-ion batteries. Among the emerging technologies, sodium-ion batteries stand out, replacing lithium with sodium, which is more abundant and cheaper. Among the materials used as cathodes in sodium-ion batteries, O3-type layered oxides have the most suitable properties for commercial applications, however, these oxides suffer from numerous phase transitions during battery operation, reducing their lifetime. Recent studies have reported that the use of high-entropy oxides, containing five or more elements in equal or approximately equal amounts, improves the electrochemical properties of layered oxides, however, a systematic study of the role of each element in these high-entropy materials is still lacking. In this project, we propose a meticulous investigation of the impact of different transition metals on the structural and electrochemical properties of O3-type layered oxides through the standardized synthesis of compounds with high entropy fixed. The influence of the elements Mg, Al, Zr, and Mo will be evaluated through solid-state synthesis, keeping their concentrations fixed, allowing the evaluation of the impact of the oxidation state, ionic radii, and interaction with oxygen on the properties of the high-entropy oxide. Through ex situ and operando characterizations of the synthesized materials, especially operando XRD and XANES, it will be possible to correlate the impact of each metal evaluated on the acceleration, retardation, or even inhibition of phase transitions and determine the variation of oxidation states during electrode operation. All data collected will be used to understand the impact of each metal on the intrinsic properties of the high-entropy oxide, which will be related to the electrochemical performances obtained. Thus, it will be possible to rationally design, based on the properties and trends observed for each metal, a high-entropy O3 oxide composition with the best properties that will be tested as a cathode in complete sodium-ion batteries.