Improving the performance of graphite/LiNi0.5Mn1.5O4 cells with added N,N-dimethylformamide sulfur trioxide complex
Date of Original Version
N,N-dimethylformamide sulfur trioxide complex (DMF-SO3) has been investigated as an electrolyte additive for LiNi0.5Mn1.5O4/graphite cells cycled to 4.8 V. Addition of 0.1% DMF-SO3 to 1.2 M LiPF6 in EC/EMC (3/7, v/v) standard electrolyte (STD) results in a significant improvement in the capacity retention and coulombic efficiency of LiNi0.5Mn1.5O4/graphite cells after 50 cycles at 45◦C. Ex-situ surface analysis of the electrodes after cycling has been conducted via scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy with attenuated total reflectance (IR-ATR). The surface analysis suggests that a uniform interfacial film is formed on the LiNi0.5Mn1.5O4 surface composed of the decomposition products of DMF-SO3. The novel cathode surface films passivates the surface at high potential leading to the improved electrochemical performance.
Journal of the Electrochemical Society
Dong, Yingnan, Julien Demeaux, Yuzi Zhang, and Brett L. Lucht. "Improving the performance of graphite/LiNi0.5Mn1.5O4 cells with added N,N-dimethylformamide sulfur trioxide complex." Journal of the Electrochemical Society 164, 13 (2017): A3182-A3190. doi:10.1149/2.1041713jes.