US 12,244,039 B2
Secondary battery and assembled battery
Ryoichi Wakimoto, Kobe (JP)
Assigned to PRIME PLANET ENERGY & SOLUTIONS, INC., Tokyo (JP)
Filed by PRIME PLANET ENERGY & SOLUTIONS, INC., Tokyo (JP)
Filed on Nov. 29, 2021, as Appl. No. 17/536,456.
Claims priority of application No. 2020-200852 (JP), filed on Dec. 3, 2020.
Prior Publication US 2022/0181755 A1, Jun. 9, 2022
Int. Cl. H01M 50/566 (2021.01); H01M 10/0587 (2010.01); H01M 50/103 (2021.01); H01M 50/502 (2021.01); H01M 50/528 (2021.01); H01M 50/553 (2021.01)
CPC H01M 50/566 (2021.01) [H01M 10/0587 (2013.01); H01M 50/103 (2021.01); H01M 50/502 (2021.01); H01M 50/528 (2021.01); H01M 50/553 (2021.01); H01M 2220/20 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A secondary battery, comprising:
an electrode body comprising a positive electrode and a negative electrode;
a battery case which houses the electrode body and which has a terminal extracting hole;
a terminal which is electrically connected to the positive electrode or the negative electrode inside the battery case and which is extracted to outside of the battery case from the terminal extracting hole; and
an external conductive member which is joined to the terminal outside of the battery case, wherein the external conductive member comprises:
a first recessed portion extending into the external conductive member from an upper surface of the external conductive member,
a second recessed portion extending into the external conductive member from a lower surface of the external conductive member,
a through-hole having a central axis and extending through the external conductive member, the through-hole extending from a radially inner edge of the first recessed portion to a radially inner edge of the second recessed portion and into which a part of the terminal is inserted, and
an annular protruded portion disposed between the first recessed portion and the second recessed portion and extending radially outwardly from an inner diameter wall surface of the through-hole, wherein
the second recessed portion of the external conductive member forms an inner chamfered edge of the through-hole facing the part of the terminal,
a weld joining portion between the external conductive member and the terminal is formed by welding between a radially inner peripheral edge of the annular protruded portion and a radially outer peripheral edge of an end of the part of the terminal inserted into the through-hole, wherein the weld joining portion is located closer to the central axis of the through-hole in a radial direction than an outer peripheral edge of the second recessed portion,
the annular protruded portion is configured to melt when a current of 1000 A or more flows through the secondary battery, and
a thinnest portion of the annular protruded portion as measured in a direction parallel to the central axis of the through-hole is provided at a position separated from the through-hole in a radial direction.