Tri(ethylene glycol)-substituted trimethylsilane/lithium bis(oxalate)borate electrolyte for LiMn2O4/graphite system

摘要

Silane-based electrolyte is a promising candidate for safer electrochemical energy storage devices because it is thermally and electrochemical stable, less flammable and environmental benign. In this paper, electrochemical properties of one of the silane-based electrolytes, tri(ethylene glycol)-substituted trimethylsilane (1NM3)-Iithium bis(oxalate)borate (LiBOB) was studied using LiMn2O4 as cathode and MAG graphite as anode. When combined with LiBOB as lithium salt, the lNM3-LiB0B electrolyte can provide solid electrolyte interface (SEI) formation due to the reductive decomposition of LiBOB at first charging cycle. Compared to the electrolyte used in the conventional lithium-ion batteries, 1 NM3-LiB0B electrolyte showed compatible battery performance in LiMn2O4/MAG chemistry. The AC impedance measurement indicates that the activation energy (Eo) obtained from the charge transfer impedance for 1 NM3-LiB0B was higher than that of the state-of-the-art electrolyte. Due to its low conductivity, the rate capability of 1NM3-LiB0B electrolyte needs to be improved.