Electrolyte Volume Effects on Electrochemical Performance and Solid Electrolyte Interphase in Si-Graphite/NMC Lithium-Ion Pouch Cells

This study aims to explore the correlations between electrolyte volume, electrochemical performance, land properties of the solid electrolyte interphase in Ouch cells with Si-graphite composite anodes. The electrolyte is 1.2 M LiPF6 in ethylebe carbonate:ethylmethyl carbonate with 10 wt % fluoroethylene carbonate. Single layer pouch cells (100 mA h) constructed with 15 wt % Si-graphite/LiNi05Mn0.3CO0.2O2 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 cycling Stability. Less electrolyte causes increases in ohmic and change transfer resistances. Lithium dendrites are observed when the electrolyte volume factor is low. The resistances from the anodes become significant as the cells are discharged. Solid electrolyte interphase thickness grows as the electrolyte volume factor increases and is nonuniform after cycling.