High Voltage LiNi0.5Mn1.5O4/Li4Ti5O12Lithium Ion Cells at Elevated Temperatures: Carbonate- versus Ionic Liquid-Based Electrolytes.
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 with electrolyte decomposition and concurrent degradative reactions at the electrode/electrolyte interface, especially at elevated temperatures. As promising alternatives, two selected LiTFSI/pyrrolidinium bis(trifluoromethane-sulfonyl)imide room temperature ionic liquid (RTIL) based electrolytes with inherent thermal stability were investigated in this work. Linear sweep voltammetry (LSV) profiles of the investigated LiTFSI/RTIL electrolytes display much higher oxidative stability compared to the state-of-the-art LiPF6/organic carbonate based electrolyte at elevated temperatures. Cycling performance of the LNMO/Li4Ti5O12(LTO) full-cells with LiTFSI/RTIL electrolytes reveals remarkable improvements with respect to capacity retention and Coulombic efficiency. Scanning electron microscopy (SEM) images and X-ray diffraction (XRD) patterns indicate maintained pristine morphology and structure of LNMO particles after 50 cycles at 0.5C. The investigated LiTFSI/RTIL based electrolytes outperform the LiPF6/organic carbonate-based electrolyte in terms of cycling performance in LNMO/LTO full-cells at elevated temperatures.
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Xia
X
Cao
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.|Helmholtz-Institute Münster, IEK-12, Forschungszentrum Jülich GmbH , Corrensstraße 46, 48149 Münster, Germany.
Xin
X
He
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Jun
J
Wang
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Haidong
H
Liu
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Stephan
S
Röser
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.|Helmholtz-Institute Münster, IEK-12, Forschungszentrum Jülich GmbH , Corrensstraße 46, 48149 Münster, Germany.
Babak Rezaei
BR
Rad
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Marco
M
Evertz
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Benjamin
B
Streipert
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Jie
J
Li
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Ralf
R
Wagner
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.|Helmholtz-Institute Münster, IEK-12, Forschungszentrum Jülich GmbH , Corrensstraße 46, 48149 Münster, Germany.
Martin
M
Winter
MEET Battery Research Center, Institute for Physical Chemistry, University of Münster , Corrensstraße 46, 48149 Münster, Germany.
Isidora
I
Cekic-Laskovic
Li4Ti5O12; LiNi0.5Mn1.5O4; high temperature; high voltage electrolyte; ionic liquids; lithium ion battery; safety