Provided is a battery pack. The battery pack includes a first battery cell, a second battery cell, and a third battery cell. A positive electrode active substance of each battery cell is composed of lithium iron phosphate and a low-temperature additive. The low-temperature additive is selected from compounds containing at least two carbonyl groups, which are conjugated with an unsaturated structure or an atom having lone-pair electrons connected with the carbonyl groups. At a temperature lower than or equal to 10° C., a ratio of a discharging capacity of a single cell of the second battery cell to a discharging capacity of a single cell of the first battery cell ranges from 1.003 to 1.12, and a ratio of a discharging capacity of a single cell of the third battery cell to a discharging capacity of a single cell of the second battery cell ranges from 1.005 to 1.15.