A secondary battery , comprising: a top cover plate , having an outer surface and an inner surface disposed opposite each other in a thickness direction of the top cover plate and an electrode lead-out hole extending along the thickness direction; a pole , disposed in the electrode lead-out hole , wherein the pole comprises a first metal layer and a second metal layer , and the first metal layer and the second metal layer are stacked along a direction from the inner surface to the outer surface ; an insulation member , disposed between the top cover plate and the pole ; and a first bonding layer , disposed between the insulation member and the first metal layer , wherein the first metal layer and the first bonding layer are bonded by a chemical bond, the insulation member and the first bonding layer are bonded by a chemical bond, and the insulation member is hermetically connected to the first metal layer through the first bonding layer ; wherein the first metal layer has a first concave portion facing away from the second metal layer , part of the insulation member extends into the first concave portion , and the first bonding layer extends to between the first concave portion and the insulation member ; wherein the secondary battery further comprises a second bonding layer , the second bonding layer is disposed between the insulation member and the second metal layer , the second metal layer and the second bonding layer are bonded by a chemical bond, the insulation member and the second bonding layer are bonded by a chemical bond, and the insulation member is hermetically connected to the second metal layer through the second bonding layer ; the second metal layer has a second concave portion facing away from the first metal layer , part of the insulation member extends into the second concave portion , and the second bonding layer extends to between the second concave portion and the insulation member . a top cover plate , having an outer surface and an inner surface disposed opposite each other in a thickness direction of the top cover plate and an electrode lead-out hole extending along the thickness direction; a pole , disposed in the electrode lead-out hole , wherein the pole comprises a first metal layer and a second metal layer , and the first metal layer and the second metal layer are stacked along a direction from the inner surface to the outer surface ; an insulation member , disposed between the top cover plate and the pole ; and a first bonding layer , disposed between the insulation member and the first metal layer , wherein the first metal layer and the first bonding layer are bonded by a chemical bond, the insulation member and the first bonding layer are bonded by a chemical bond, and the insulation member is hermetically connected to the first metal layer through the first bonding layer ; wherein the first metal layer has a first concave portion facing away from the second metal layer , part of the insulation member extends into the first concave portion , and the first bonding layer extends to between the first concave portion and the insulation member ; wherein the secondary battery further comprises a second bonding layer , the second bonding layer is disposed between the insulation member and the second metal layer , the second metal layer and the second bonding layer are bonded by a chemical bond, the insulation member and the second bonding layer are bonded by a chemical bond, and the insulation member is hermetically connected to the second metal layer through the second bonding layer ; the second metal layer has a second concave portion facing away from the first metal layer , part of the insulation member extends into the second concave portion , and the second bonding layer extends to between the second concave portion and the insulation member . <EOS>