Enhanced cyclability of LiNi0.5Mn1.5O4 cathode in carbonate based electrolyte with incorporation of tris(trimethylsilyl)phosphate (TMSP)

• Published in: Journal of power sources Vol. 261; pp. 148 - 155
• Main Authors: Rong, Haibo, Xu, Mengqing, Xing, Lidan, Li, Weishan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2014; Elsevier
• Subjects: Applied sciences; Cyclability; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrolyte additive; Exact sciences and technology; High voltage; LiNi0.5Mn1.5O4 cathode; Lithium ion battery; Materials; Tris(trimethylsilyl)phosphate; Lithium ion battery; Tris(trimethylsilyl)phosphate; LiNi0.5Mn1.5O4 cathode; Electrolyte additive; Cyclability; High voltage; Phosphates; Lithium ion batteries; Mn; Nickel Oxides; Lithium Oxides; Electrode material; O; Additive; Carbonates; LiNi; Electrical characteristic; Cycling; Cathode; Secondary cell; Phosphorus Compounds; Inorganic anion; Quaternary compound; Electrolyte; Manganese Oxides; Lithium oxide; Nickel oxide
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2014.03.032

In this work, tris (trimethylsilyl) phosphate (TMSP) is used as an electrolyte additive to improve the cycling performance of Li/LiNi0.5Mn1.5O4 cell upon cycling at high voltage, 4.9 V vs. Li/Li+ at room temperature and elevated temperature (55 °C). The effects of TMSP on the cathode interface and the cycling performance of Li/LiNi0.5Mn1.5O4 cell were investigated via the combination of electrochemical methods, including cycling test, cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). It is found that cells with electrolyte containing TMSP have better capacity retention than that of the cells without TMSP upon cycling at high voltage at room temperature and elevated temperature. The functional mechanism of incorporation of TMSP to the electrolyte to improve the cycling performance is conducted with ex-situ analysis approaches, including X-ray diffraction (XRD), scanning electron microscope (SEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM) and ICP-MS. The surface analysis results reveal that more stable and more conductive surface layer is formed on the LiNi0.5Mn1.5O4 electrode with TMSP containing electrolyte, which is a leading factor for the enhanced the cycling performance of Li/LiNi0.5Mn1.5O4 cells upon cycling at high voltage at room temperature and elevated temperature. •TMSP is used as an electrolyte additive for LiNi0.5Mn1.5O4 cathode battery at high voltage (4.9 V).•The cyclability of the Li-ion battery at RT and ET can be improved by the use of TMSP.•The rate capability of the Li-ion battery can be improved by the use of TMSP.•Incorporation of TMSP can form a more stable and more conductive surface film on the cathode.