Journal of Power Sources, Vol.330, 175-185, 2016
The effectiveness of electrolyte additives in fluorinated electrolytes for high voltage Li[Ni0.4Mn0.4Co0.2]O-2/graphite pouch Li-ion cells
The effectiveness of electrolyte additives in fluorinated electrolytes containing 1 M LiPF6/fluoroethylene carbonate:bis (2,2,2-trifluoroethyl) carbonate (1:1 w:w) were studied in high voltage Li(Ni0.4Mn0.4Co0.2) O-2/graphite pouch cells tested to 4.5 V. The results showed that fluorinated electrolytes containing prop-1-ene-1,3-sultone alone or in combination with other additives exhibited significant improvements in terms of coulombic efficiency and charge endpoint capacity slippage during UHPC cycling, voltage drop during storage, as well as capacity retention during long-term cycling compared with state-of-the-art ethylene carbonate-based (ethylene carbonate: ethylmethyl carbonate 3:7) or sulfolane-based electrolytes (sulfolane: ethylmethyl carbonate 3:7) with some promising additive blends. These results indicate that fluorinated electrolytes offer an interesting alternative for high voltage Li-ion batteries. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:High voltage lithium-ion batteries;Fluorinated electrolytes;Limiting gas evolution;Electrolyte additives;Limiting impedance growth