The invention discloses a lithium difluoborate containing a sulfonate group and a battery employing a lithium salt. An electrolyte prepared from the lithium difluoborate containing the sulfonate group as an additive is novel lithium difluoborate containing the sulfonate group capable of effectively balancing the high and low temperature performance of a lithium-ion battery; the novel lithium difluoborate contains the sulfonate group; the lithium difluoborate containing the sulfonate group in the electrolyte has good high temperature characteristic; and meanwhile, the additive does not obviously increase the internal resistance of the battery, so that the lithium-ion battery also has relatively good performance at a low temperature.