Impact of Selected LiPF6 Hydrolysis Products on the High Voltage Stability of Lithium-Ion Battery Cells

• DOI: 10.1021/acsami.6b09164
• Publication Date: 2016-10-28T18:40:09Z
• Authors: Ralf Wagner; Martin Korth; Benjamin Streipert; Johannes Kasnatsc...; Dennis R. Gallus; Sebastian Brox; Marius Amereller; Isidora Cekic-Las...; Martin Winter
• Keywords: Electrochemical window

Diverse LiPF6 hydrolysis products evolve during lithium-ion battery cell operation at elevated temperatures and high voltages. However, their impact on the formation stability of electrode/electrolyte interfaces is not yet investigated understood. In this work, literature-known dimethyl fluorophosphate (DMFP) diethyl (DEFP) were synthesized characterized. The use DMFP DEFP as electrolyte additive in 1 M EC:EMC (1:1, by wt) was LiNi1/3Mn1/3Co1/3O2/Li half cells. When charged to a cutoff potential 4.6 V vs Li/Li+, containing cells showed improved cycling stability, increased Coulombic efficiencies, prolonged shelf life. Furthermore, low amounts (1 wt % study) aforementioned additives did show any negative effect graphite/Li are susceptible oxidation contribute an effective cathode/electrolyte interphase confirmed means electrochemical window determination, X-ray photoelectron spectroscopy characterization pristine cycled electrodes, they supported computational calculations.