High Voltage LiNi0.5Mn1.5O4/Li4Ti5O12 Lithium Ion Cells at Elevated Temperatures: Carbonate- versus Ionic Liquid-Based Electrolytes

• DOI: 10.1021/acsami.6b07687
• Publication Date: 2016-09-12T15:50:20Z
• Authors: Xia Cao; Xin He; Jun Wang; Haidong Liu; Stephan Röser; Babak Rezaei Rad; Marco Evertz; Benjamin Streipert; Jie Li; Ralf Wagner; Martin Winter; Isidora Cekic-Las...
• Keywords: Thermal Stability; Linear sweep voltammetry

Thanks to its high operating voltage, the LiNi0.5Mn1.5O4 (LNMO) spinel represents a promising next-generation cathode material candidate for Lithium ion batteries. However, LNMO-based full-cells with organic carbonate solvent electrolytes suffer from severe capacity fading issues, associated electrolyte decomposition and concurrent degradative reactions at electrode/electrolyte interface, especially elevated temperatures. As alternatives, two selected LiTFSI/pyrrolidinium bis(trifluoromethane-sulfonyl)imide room temperature ionic liquid (RTIL) based inherent thermal stability were investigated in this work. Linear sweep voltammetry (LSV) profiles of LiTFSI/RTIL display much higher oxidative compared state-of-the-art LiPF6/organic Cycling performance LNMO/Li4Ti5O12 (LTO) reveals remarkable improvements respect retention Coulombic efficiency. Scanning electron microscopy (SEM) images X-ray diffraction (XRD) patterns indicate maintained pristine morphology structure LNMO particles after 50 cycles 0.5C. The outperform carbonate-based terms cycling LNMO/LTO