NON-AQUEOUS ELECTROLYTE AND ELECTROCHEMICAL DEVICE WITH AN IMPROVED SAFETY

摘要

A non-aqueous electrolytic solution is provided to prevent battery ignition caused by external shocks(thermal shocks) and/or ignition/explosion caused by an internal short circuit of a battery at high temperature by using both an ethylene carbonate compound and a nitrile compound. The non-aqueous electrolytic solution including a lithium salt and a solvent contains 10-40wt% of a compound of a formula 1 or a decomposed product thereof and 1-40wt% of an aliphatic nitrile compound based on the electrolytic solution. In the formula 1, X and Y each are independently hydrogen, chlorine, or fluorine, with the proviso that both X and Y are not hydrogen. The electrochemical device comprises a positive electrode having a complex formed between a positive electrode active material surface and an aliphatic nitrile compound, and a negative electrode having coatings containing the decomposed product of the compound of the formula 1.