The Effect of 1-Pentylamine as Solid Electrolyte Interphase Precursor on Lithium Metal Anodes

•Manufacturing of a well-controlled artificial SEI on lithium metal electrodes.•Native SEI-free lithium electrodes.•Lithium electrodes with decreased impedance and overpotential due to artificial SEI.•Process development to remove influence of native SEI.•1-pentylamine in n-pentane as artificial SEI precursor for lithium metal.

In this study, the formation of an artificial primary solid electrolyte interphase on a fresh Li surface, via reaction with 1-pentylamine (PA), is reported, allowing removing the influence of the metal electrode's prior history. Electrochemical impedance spectroscopy, galvanostatic cycling, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) are used in order to investigate the effect of PA as solid electrolyte interphase precursor on Li metal. It is shown that pretreating native SEI-free Li metal surfaces with 1 M PA in n-pentane sharply decreases the electrode impedance and overpotential with respect to the treatment with only n-pentane. The treatment with 1 M PA in n-pentane results in surface roughening, but no increase of dendrite formation upon cycling. However, the use of higher PA concentration (5 M) increases impedance and overpotential and leads to dendrite growth.

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