3, 3′-sulfonyldipropionitrile: A novel electrolyte additive that can augment the high-voltage performance of LiNi1/3Co1/3Mn1/3O2/graphite batteries

•SDPN firstly used as an additive in the high-voltage electrolyte system.•SDPN participated in the formation of CEI on the surface of cathode.•The addition of SDPN enhanced cycling performance of cells.

Our study shows that 3, 3′-sulfonyldipropionitrile (SDPN), as an electrolyte additive, can dramatically enhance the performance of LiNi1/3Co1/3Mn1/3O2/graphite lithium-ion batteries (LIBs) at high voltages (3.0–4.6 V vs. Li/Li+). After adding 0.2 wt% SDPN to the electrolytes; i.-e., 1.0 M LiPF6-EC/DMC/EMC, the capacity for the LiNi1/3Co1/3Mn1/3O2/graphite cell to retain power was significantly increased from 59.5% to 77.3% after only 100 cycles, which shows the promising application of SDPN at higher voltages. Density functional theory calculation results indicate that SDPN had reduced oxidative constancy compared to ethylene carbonate (EC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC). The effects of SDPN on cell performance are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The testing results indicate that the improvement in cycling activity could be ascribed to the thinner cathode electrolyte interface film originated from SDPN on the LIB using LiNi1/3Co1/3Mn1/3O2, which reduced the interfacial resistance at a high voltage, but also protected the decomposition of electrolytes and suppressed transition metal dissolution.

Graphical abstract3, 3′-sulfonyldipropionitrile presented a lower oxidative stability than EC, DMC and EMC, which participated in the formation of cathode electrolyte interface film and then helped to improve the cycling performance of cells at the high voltage.Figure optionsDownload full-size imageDownload as PowerPoint slide