The invention relates to the field of
lithium ion batteries, and discloses an
electrolyte which comprises a high-temperature
organic solvent, a positive and negative
electrode protection additive andan
electrolyte lithium salt, wherein the high-temperature
organic solvent comprises the following components in parts by weight of 5-30 parts of
ethylene carbonate, 5-30 parts of
propylene carbonate,5-30 parts of
diethyl carbonate, 5-50 parts of propyl
propionate and 1-10 parts of
fluorobenzene; the positive and negative
electrode protection additive comprises the following components in parts byweight of 0.2 to 5 parts of
ethylene sulfate, 0.2 to 5 parts of fluoroethylene
carbonate, 0.2 to 5 parts of difluoroethylene
carbonate, 0.2 to 5 parts of a dinitrile
organic matter, 0.2 to 3 parts oflithium
difluorophosphate, 0.2 to 5 parts of
diethylene glycol dipropionitrile
ether, 0.2 to 3 parts of
lithium fluorosulfonyl
imide, 0.1 to 2 parts of 1-propyl
phosphoric anhydride, 0.5 to 20 partsof 1, 1, 2, 2-tetrafluoroethyl-2, 2, 3, 3-tetrafluoropropyl
ether, 0.1 to 2 parts of lithium oxalyldifluoroborate and 0.1 to 1 part of
methylene methanedisulfonate. The
electrolyte is excellent in high-
temperature resistance, enables the
lithium ion battery with
high energy density to normally work at the temperature of 70 DEG C or above, and can keep the relatively better endurance.