An electrode plate, comprising a current collector , an electrode active material layer disposed on at least one surface of the current collector , and an electrical connection member electrically connected to the current collector , wherein the electrode active material layer is disposed on a main body portion of the current collector at a zone referred to as a film zone (A), the electrical connection member and the current collector are welded and connected at an edge of the current collector at a welding zone referred to as an transfer welding zone (C), and a transition zone of the current collector between the film zone (A) and the transfer welding zone (C), coated with no electrode active material layer , is referred to as an extension zone (B); the current collector comprises a support layer and a conductive layer disposed on at least one surface of the support layer , a single-sided thickness D2 of the conductive layer satisfies: 30 nm ≤ D2 ≤ 3 μm, and the support layer is a polymer material layer or a polymer composite material layer; and the electrode active material layer comprises an electrode active material, a binder, and a conductive agent, viewed in a width direction of a coated surface of the electrode plate, the electrode active material layer comprises 2n + 1 zones based on compacted density, compacted density of a middle zone is greater than compacted density of zones on both sides, wherein n = 1, 2, or 3, and preferably, n = 1, and a support protection layer is disposed on a surface of the extension zone (B) of the current collector , wherein a conductive primer coating layer comprising a binder and a conductive material is provided between the current collector in the film zone (A) and the electrode active material layer and on a surface of the current collector in the extension zone (B). the electrode active material layer is disposed on a main body portion of the current collector at a zone referred to as a film zone (A), the electrical connection member and the current collector are welded and connected at an edge of the current collector at a welding zone referred to as an transfer welding zone (C), and a transition zone of the current collector between the film zone (A) and the transfer welding zone (C), coated with no electrode active material layer , is referred to as an extension zone (B); the current collector comprises a support layer and a conductive layer disposed on at least one surface of the support layer , a single-sided thickness D2 of the conductive layer satisfies: 30 nm ≤ D2 ≤ 3 μm, and the support layer is a polymer material layer or a polymer composite material layer; and the electrode active material layer comprises an electrode active material, a binder, and a conductive agent, viewed in a width direction of a coated surface of the electrode plate, the electrode active material layer comprises 2n + 1 zones based on compacted density, compacted density of a middle zone is greater than compacted density of zones on both sides, wherein n = 1, 2, or 3, and preferably, n = 1, and a support protection layer is disposed on a surface of the extension zone (B) of the current collector , wherein a conductive primer coating layer comprising a binder and a conductive material is provided between the current collector in the film zone (A) and the electrode active material layer and on a surface of the current collector in the extension zone (B). <EOS>