Determination of Cyclability of Li/FeS2 Batteries Based on Measurement of Coulombic Efficiency

The electrochemical performance of negative electrodes based on different FeS2 samples was investigated. The study demonstrated a correlation between the coulombic efficiency obtained over 60 cycles and the capacity loss rate evaluated over 15 cycles. The accuracy of the coulombic efficiency and capacity loss rate measurements was advantageous for predicting the aging behavior of half-cells over a short-term test. A suggested classification of the coulombic efficiency and verification via a numerical analysis were proposed to determine the fading rate of batteries during the galvanostatic test

Improvement in the Electrochemical Properties of Lithium Metal by Heat Treatment: Changes in the Chemical Composition of Native and Solid Electrolyte Interphase Films

This study aims to improve the electrochemical properties of lithium metal for application as a negative electrode in high-energy-density batteries. Lithium metal was heat-treated at varying temperatures to modify the native and solid electrolyte interphase (SEI) films, which decreased the interfacial resistance between the lithium electrode and electrolyte, thereby improving the cycling performance. Moreover, the influence of the native and SEI films on lithium metals depended on the heat-treatment temperature. Accordingly, X-ray photoelectron spectroscopy (XPS) was performed to investigate the chemical composition of the native and SEI films on the heat-treated lithium metals before and after immersion in an organic electrolyte solution. The XPS results revealed the high dependence of the chemical composition of the outer layer of the native and SEI films on the heat-treatment temperature, implying that the native and SEI films can be effectively modified by heat treatment

Improvement in the Electrochemical Properties of Lithium Metal by Heat Treatment: Changes in the Chemical Composition of Native and Solid Electrolyte Interphase Films

This study aims to improve the electrochemical properties of lithium metal for application as a negative electrode in high-energy-density batteries. Lithium metal was heat-treated at varying temperatures to modify the native and solid electrolyte interphase (SEI) films, which decreased the interfacial resistance between the lithium electrode and electrolyte, thereby improving the cycling performance. Moreover, the influence of the native and SEI films on lithium metals depended on the heat-treatment temperature. Accordingly, X-ray photoelectron spectroscopy (XPS) was performed to investigate the chemical composition of the native and SEI films on the heat-treated lithium metals before and after immersion in an organic electrolyte solution. The XPS results revealed the high dependence of the chemical composition of the outer layer of the native and SEI films on the heat-treatment temperature, implying that the native and SEI films can be effectively modified by heat treatment

Electrochemical intercalation of Ca2+ ions into TiS2 in organic electrolytes at room temperature

This work investigates the electrochemical intercalation of Ca2+ ions into TiS2 in organic electrolytes at room temperature and demonstrates that successful intercalation/de-intercalation can be achieved using a 0.1 M solution of Ca(CF3SO3)2 in propylene carbonate (PC) as an electrolyte. Additionally, further performance (charge/discharge capacity, reversibility, and hysteresis) enhancement is observed when a 0.1 M solution of Ca(CF3SO3)2 in a 1:10 (mol/mol) mixture of PC and dimethyl carbonate (DMC) is employed, which is ascribed to the modulation of the solvation environment of Ca2+ ions by the use of the relatively low-polar DMC. Finally, the structural changes in TiS2 caused by Ca2+ intercalation/de-intercalation during charge/discharge are probed by in situ X-ray diffraction analysis. Keywords: Calcium-ion batteries, TiS2 electrode, Organic electrolyte, In situ X-ray diffraction analysi