Abstract
The studies aim at exploring the correlation of electrolyte volume with electrochemical performance and solid electrolyte interphase in pouch cells having 1.2 M LiPF6 in ethylene carbonate:ethylmethyl carbonate with 10% fluoroethylene carbonate as the electrolyte and 15wt% Si-graphite / LiNi0.5Mn0.3CO0.2O2 as the electrodes. It is found that a minimum electrolyte volume factor of 3.1 times to the total pore volume of cell components (cathode, anode, and separator) is needed for better cyclability tests. Less electrolyte causes increases in ohmic and charge transfer resistances. Lithium dendrites are observed at electrolyte volume factor 1.6. The resistances from 15wt% Si-graphite anodes become significant as the cells were discharged. The thickness of SEI increases as increasing the electrolyte volume factor. Si presents under non-uniform solid electrolyte interphase after cycles.
