Rechargeable battery

A rechargeable battery, comprising:

• an electrode assembly including a first electrode and a second electrode;
• a case for accommodating the electrode assembly;
• a cap plate in an opening of the case to seal the case;
• and
• electrode terminals electrically coupled to the electrode assembly, each electrode terminal including:
• a rivet terminal extending through a terminal hole in the cap plate, a first end of the rivet terminal being electrically coupled to the electrode assembly, and a second end of the rivet terminal protruding out of the cap plate and including a protruding portion;
• a conductive terminal including an insertion hole, the protruding portion of the rivet terminal being inserted into the insertion hole and coupled to the conductive terminal, the conductive terminal and the protruding portion of the rivet terminal including different metals, and at least two different surfaces of the conductive terminal being perpendicular to each other and in direct contact with the rivet terminal;
• and
• a filler metal portion, the filler metal portion being in direct contact with each of the protruding portion of the rivet terminal and the conductive terminal,
• wherein an inner wall surface of the insertion hole includes inflow grooves that extend in a straight line in a height direction along an entire height of the inner wall surface of the insertion hole, the filler metal portion being in the inflow grooves, wherein:
• the inner wall surface of the insertion hole includes a thread so as to be screw-couplable with the protrusion portion, and
• the inflow grooves extend through the thread in the length direction.

A method of forming a rechargeable battery, the method comprising:

• forming an electrode assembly including a first electrode and a second electrode;
• forming a case for accommodating the electrode assembly;
• forming a cap plate in an opening of the case to seal the case;
• and
• forming electrode terminals electrically coupled to the electrode assembly, each electrode terminal including:
• a rivet terminal extending through a terminal hole in the cap plate, a first end of the rivet terminal being electrically coupled to the electrode assembly, and a second end of the rivet terminal protruding out of the cap plate and including a protruding portion,
• a conductive terminal including an insertion hole, the protruding portion of the rivet terminal being inserted into the insertion hole and coupled to the conductive terminal, the conductive terminal and the protruding portion of the rivet terminal including different metals, and at least two different surfaces of the conductive terminal being perpendicular to each other and in direct contact with the rivet terminal, and
• a filler metal portion in direct contact with each of the protruding portion of the rivet terminal and the conductive terminal,
• wherein either the protruding portion of the rivet terminal includes insertion grooves depressed inwardly of the protruding portion in a straight line in a length direction along an entire length of the protruding portion, the filler metal portion being in the insertion grooves, or an inner wall surface of the insertion hole includes inflow grooves in a straight line in a height direction along an entire height of the inner wall surface or the insertion hole, the filler metal portion being in the inflow grooves, wherein:
• an external surface of the protruding portion or the inner wall surface of the insertion hole includes a thread so that the protruding portion and the conductive terminal are screw-couplable, and
• the insertion grooves extend through the thread in the length direction of the protruding portion, or the inflow grooves extend through the thread in the height direction of the inner wall of the insertion hole.