Secondary battery and electrode plate thereof having insulating layer

A secondary battery, comprising an electrode assembly, wherein the electrode assembly comprises an electrode plate (1), the electrode plate (1) comprising:

• a current collector (11);
• an active material layer (12);
• a conductive structure (13);
• and
• a first protective layer (14),
• wherein the current collector (11) comprises an insulating layer (111) and a conductive layer (112) disposed on the insulating layer (111), the conductive layer (112) includes a main body portion (1121) and a protrusion portion (1122) connected to the main body portion (1121), a surface of the main body portion (1121) facing away from the insulating layer (111) is covered by and in direct contact with the active material layer (12), and a surface of the protrusion portion (1122) facing away from the insulating layer (111) is uncovered by the active material layer (12),
• the conductive structure (13) is welded to the protrusion portion (1122) and thus a welded zone (W) is formed, and
• the first protective layer (14) has elasticity, and the first protective layer (14) is disposed on and in direct contact with a side of the protrusion portion (1122) facing away from the insulating layer (111) and is located between the welded zone (W) and the active material layer (12).