The effect of the nitrile electrolyte additives, succinonitrile (SN), adiponitrile (AN) and pimelonitrile (PN) was studied using High Precision Charger at Dalhousie University, automated cell storage and AC impedance. Li[Ni1/3Mn1/3Co1/3]O-2/graphite (NMC111/graphite) cells containing the nitrile electrolyte additives showed no significant effect on the cycling between 2.8 V and 4.2V and storage at 4.2Vat 60 .+/- 0.1 degrees C. However, when the high cutoff voltage increased to 4.5 V in Li[Ni0.4Mn0.4Co0.2]O-2/graphite (NMC442/graphite) cells, the addition of 2 wt% SN and 2 wt% vinylene carbonate (VC) reduced the reversible capacity loss and gas generation during storage experiments at 60. +/- 0.1 degrees C compared to 2 wt% VC alone. The addition of 2 wt% SN also caused a large impedance growth during the 4.5 V storage period, but that could be suppressed by the addition of 1 wt% ethylene sulfite (ES) + 1 wt% tris(trimethlysilyl) phosphite (TTSPi) or 2 wt% trimethylene sulfate (TMS) + 2 wt% TTSPi. This work shows that SN leads to meaningful improvements in storage properties at voltages higher than 4.4 V. This also suggests that SN can enhance the long-term cycle life of the high voltage NMC/graphite cells by suppressing electrolyte oxidation at the positive electrode. (C) The Author(s) 2015. Published by ECS. All rights reserved.