An electrode assembly, a battery cell, a battery, and an electrical device are provided. The electrode assembly includes: a plurality of electrode plates, each of the plurality of electrode plates having a first side and a second side which are oppositely arranged along a first direction, and at least one of the first side and the second side being provided with a tab; and a separator, arranged alternately with a plurality of electrode plates. The separator is configured to be thermally insulated on at least one of the first side and the second side; and/or the separator is configured to be thermally insulated on an outermost layer of the plurality of electrode plates.