Effect of heptamethyldisilazane on the electrochemical performance of LiMn2O4/Li

The effect of heptamethyldisilazane as an electrolyte stabilizer on the cycling performance of a LiMn2O4/Li cell at different rates at 30 A degrees C and the storage performance at 60 A degrees C is investigated systematically based on conductivity test, linear sweep voltage, electrochemical impedance spectroscopy, scanning electron microscopy, X-ray diffraction, and charge-discharge measurements. The results show that heptamethyldisilazane added into the LiPF6-based electrolyte can increase the stability of the original electrolyte; coulomb efficiency, the initial discharge capacity, and cycling performance at different rates in a sense, meanwhile, improve the storage performance at elevated temperature, although the C-rate performance of the cell is a little worse than that without heptamethyldisilazane in the electrolyte. When the LiMn2O4/Li cell with heptamethyldisilazane in the LiPF6-based electrolyte stored at 60 A degrees C for a week cycles 300 times, the capacity retention is up to 91.18 %, which is much higher than that (87.18 %) without the additive in the electrolyte. This is mainly due to the lower solid electrolyte interface resistance (R (f)) in the cell, followed by the better morphology and structure of the cathode after storage at 60 A degrees C for a week compared with the LiMn2O4/Li cell without heptamethyldisilazane.