Battery cap assembly, secondary battery and battery module
The present disclosure provides a battery cap assembly, a secondary battery and a battery module. The battery cap assembly comprises: a cap plate, including a second terminal hole; a first electrode terminal, at least a part of which protruding above the cap plate; a second electrode terminal, including a second protruding portion protruding above the cap plate and a second base portion connected with the second protruding portion. The first electrode terminal is provided with a protrusion used for welding with a first connecting piece; the second protruding portion is used for welding with a second connecting piece to form a welding portion, and a projection of the welding portion in an up-down direction is positioned in a cross-section of the second base portion. The secondary battery comprises a case, an electrode assembly and the battery cap assembly. The battery module comprises the first connecting piece and the secondary batteries.
1. A battery module, comprising a first connecting piece, a second connecting piece and secondary batteries;
wherein
each secondary battery comprises a case, an electrode assembly and a battery cap assembly;
the case has an opening in a top thereof;
the battery cap assembly is fixed to the case and seals the opening of the case;
the electrode assembly is received in the case and comprises a first electrode plate and a second electrode plate;
the battery cap assembly comprises a cap plate, a first electrode terminal and a second electrode terminal;
the cap plate includes a first terminal hole and a second terminal hole;
at least a part of the first electrode terminal protrudes above the cap plate;
the second electrode terminal includes a second protruding portion protruding above the cap plate and a second base portion connected with the second protruding portion, the second base portion extends into the second terminal hole, a cross-sectional area of the second protruding portion is larger than a cross-sectional area of the second terminal hole;
a protrusion is provided on an upper surface of the first electrode terminal;
the first electrode terminal is electrically connected with the first electrode plate, the second electrode terminal is electrically connected with the second electrode plate;
the first connecting piece includes a first connecting portion and a second connecting portion; the first connecting portion is attached to the upper surface of the first electrode terminal of the battery cap assembly of one secondary battery and welded with the protrusion of the first electrode terminal of the battery cap assembly of the one secondary battery; the second connecting portion is welded with the second protruding portion of the second electrode terminal of the battery cap assembly of another secondary battery to form a welding portion, and a projection of the welding portion in an up-down direction is positioned in a cross-section of the second base portion of the battery cap assembly of the another secondary battery, and the welding portion extends into the second base portion,
an interface between the second connecting portion and the second electrode terminal is a plane and the entirety of the second electrode terminal is positioned below the second connecting portion.
2. The battery module according to claim 1 , wherein
the first connecting portion includes a through-hole fitted with the protrusion of the one secondary battery, the protrusion of the one secondary battery is fixed to the through-hole by laser welding.
3. The battery module according to claim 1 , wherein
a thickness of the first connecting piece is equal to a height of the protrusion of the one secondary battery in the up-down direction.
4. The battery module according to claim 1 , wherein the second base portion is connected with a bottom surface of the second protruding portion and extends downwardly.
5. The battery module according to claim 1 , wherein
the first electrode terminal includes a first protruding portion protruding above the cap plate and a first base portion connected with a bottom surface of the first protruding portion, the first base portion extends downwardly and extends into the first terminal hole.
6. The battery module according to claim 5 , wherein
the first electrode terminal is a negative electrode terminal and made of copper, the second electrode terminal is a positive electrode terminal and made of aluminum, and a cross-sectional area of the first base portion is smaller than a cross-sectional area of the second base portion.
7. The battery module according to claim 5 , wherein
a thickness of the first protruding portion is equal to a thickness of the second protruding portion in the up-down direction.
8. The battery module according to claim 1 , wherein
a cross-section of the protrusion is a rectangle and the protrusion extends along a transverse direction of the cap plate; or
the cross-section of the protrusion is a rectangle and the protrusion extends along a longitudinal direction of the cap plate.
9. The battery module according to claim 3 , wherein
the protrusion and the first connecting portion of the first connecting piece are arranged side by side, a side surface of the first connecting portion is directly attached to the protrusion.
10. The battery module according to claim 9 , wherein
in the up-down direction, an upper surface of the first connecting portion is flush with an upper surface of protrusion of the first electrode terminal.
11. The battery module according to claim 1 , wherein the cap plate is made of insulating material.
12. The battery module according to claim 1 , wherein
the first connecting piece further comprises a third connecting portion in the shape of arch, the third connecting portion connects the first connecting portion and the second connecting portion.