A battery includes a case and a battery core assembly disposed in the case, the battery core assembly includes a plurality of battery core groups and an receiving space holding the plurality of battery core groups, the battery core groups are connected in series, and the battery core group includes at least one battery core; a separator plate is disposed between at least two adjacent battery core groups, the separator plate divides the receiving space into a plurality of receiving cavities, each of the receiving cavities holds one or more battery core groups, and a cavity wall of the receiving cavity comprised by a connection of the separator plate and a separation membrane; and the battery further includes a liquid injection channel and the liquid injection channel in a sealed state, the liquid injection channel is disposed on at least one of the separation membranes and the separator plates.