Investigation of lithium-sulfur batteries containing polymer-derived ceramic-based cathodes by in-situ synchrotron-based X-ray techniques.

• Grant number: 23/11416-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: September 30, 2024
• End date: March 28, 2025
• Field of knowledge: Engineering - Electrical Engineering - Electrical Materials
• Principal Investigator: Hudson Giovani Zanin
• Grantee: Murilo Machado Amaral
• Supervisor: Johanna Nelson Weker
• Host Institution: Faculdade de Engenharia Elétrica e de Computação (FEEC). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: SLAC National Accelerator Laboratory, United States
• Associated to the scholarship: 21/09387-1 - In-situ FTIR and Raman spectroscopy of lithium-ion batteries and lithium-sulfur batteries, BP.DR

Abstract

Lithium-sulfur batteries have presented promising results, such as high capacity and energy density. However, the shuttle effect is a significant drawback of this category of battery, which provides an irreversible sulfur loss, culminating in battery fade after a low number of cycles compared to lithium-ion batteries. Therefore, several carbonaceous materials have been investigated as sulfur hosts to inhibit the sulfur volume expansion and the shuttle effect. Recently, polymer-derived ceramics (PDCs) have been investigated as sulfur hosts, showing significant adsorption of lithium-polysulfides (LiPS), providing higher capacity retention for Li-S batteries. Thus, to investigate novel súlfur host materials for Li-S batteries, in-situ techniques should be conducted to understand the stability of these materials and the formation of new species under operating conditions. Among in-situ techniques used to characterize batteries, there are surface-sensitive techniques, such as Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopies, while others are bulk-sensitive. Therefore, it is important to investigate novel electrode materials using complementary in-situ techniques to observe different phenomena under electrochemical reactions. Among bulk-sensitive techniques, X-ray absorption near-edge spectroscopy (XANES) is efficient in investigating chemical states. X-ray diffraction (XRD) analysis can provide information about the crystallographic structure of the material. Both XANES and XRD techniques are appropriate for identifying the formation of lithium sulfate (Li2S) and sulfur (S8). Furthermore, imaging X-ray techniques are also important, which can evidence the morphological changes in the electrode under operating conditions, such as transmission X-ray microscopy (TXM). Therefore, complementary techniques, particularly bulk-sensitive techniques, are essential to conducting an advanced analysis of porous materials investigated as sulfur hosts, such as PDCs. Thus, the use of these techniques will provide a better understanding of the efficiency of sulfur hosts in the adsorption of lithium polysulfides, which can contribute to the design of novel materials that can provide higher performance to Li-S batteries.