Disclosed is an adhesive tape for an electrode tab, which includes a base-material layer and an adhesive layer. The adhesive layer includes a thick region and a thin region which extend from a side edge of the adhesive tape in a width direction of the adhesive layer, the thick region is distributed along the side edge of the adhesive tape, and an adhesive layer thickness of the thick region is greater than an adhesive layer thickness of the thin region. A ratio of an area of the thin region to an area of the thick region is 1:0.02-0.25, optionally 1:0.025-0.18, and further optionally 1:0.0275-0.125. The adhesive tape covers an edge of the tab to fundamentally prevent contact between the tab and a battery cell body.