Sealing plate for prismatic secondary battery, method for producing the same, and prismatic secondary battery using the same

Patent metadata

Field	Value
Publication number	US-9741985-B2
Application number	US-201514614821-A
Country	US
Kind code	B2
Filing date	Feb 5, 2015
Priority date	Jul 17, 2012
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A sealing plate for a prismatic secondary battery includes a pair of mouths for attaching a negative and positive electrode terminals, one mouth being formed near one end in a longitudinal direction of the sealing plate, and the other mouth being formed near the other end, coining areas used for positioning of an insulating member and formed around the pair of mouths on a front face of the sealing plate, a gas release valve and an electrolyte pour hole formed between the pair of mouths, and grooves formed between the respective coining areas and the long side edge of the sealing plate. The groove has a smaller depth near the gas release valve than the depth near the coining area. Even when the sealing plate is produced through forging, the front face has good flatness and the coining areas are unlikely to have a sink mark or a shear drop.

First claim

What is claimed is:

1. A prismatic secondary battery comprising:
a prismatic hollow outer body having a mouth and a bottom;
a flat electrode assembly including a positive electrode sheet and a negative electrode sheet;
a positive electrode collector electrically connected to the positive electrode sheet;
a negative electrode collector electrically connected to the negative electrode sheet;
an electrolyte;
a positive electrode terminal electrically connected to the positive electrode collector;
a negative electrode terminal electrically connected to the negative electrode collector;
a sealing plate sealing up the mouth of the prismatic outer body,
the sealing plate including
a front face;
a back face; and
a pair of mouths comprising:
a first mouth formed near one end in a longitudinal direction of the sealing plate, and
a second mouth formed near the other end in the longitudinal direction of the sealing plate;

a first coining area formed around the first mouth on the front face;
a gas release valve and an electrolyte pour hole formed between the pair of mouths;
a first long side edge;
a first groove formed on the front face from a position between the first coining area and the first long side edge to a position near the gas release valve along the first long side edge of the sealing plate;
a second groove formed on the front face,
the second groove is formed between the second long side edge and the first coining area;
a first insulating member attached to the first coining area,
wherein one of the positive electrode terminal and the negative terminal electrode terminal is inserted into the first mouth;
a region of the sealing plate where the first groove is formed has a thickness thinner than that of a region of the sealing plate which is located around the first groove,
a region of the sealing plate where the second groove is formed has a thickness thinner than that of a region of the sealing plate which is located around the second groove,
a length of the first groove in the longitudinal direction of the sealing plate is greater than a length of the first coining area in the longitudinal direction of the sealing plate;
an end of the first groove which is located near to the gas release valve is arranged between the gas release valve and the electrolyte pour hole in the longitudinal direction of the sealing plate; and
the first groove has a depth near the gas release valve smaller than a depth of a part of the first groove which is located between the first long side edge and the first coining area,
an end of the second groove which is located near to the gas release valve is arranged between the gas release valve and the electrolyte pour hole in the longitudinal direction of the sealing plate,
and the second groove has a depth near the gas release valve smaller than a depth of a part of the second groove which is located between the first long side edge and the first coining area.

2. The prismatic secondary battery according to claim 1 further comprising a second insulating member,
wherein:
the sealing plate further includes a second coining area formed around the second mouth on the front face,
the other of the positive electrode terminal and the negative electrode terminal is inserted into the second mouth,
the second insulating member is attached to the second coining area,
the first insulating member is disposed between the one of the positive electrode terminal and the negative electrode terminal and the sealing plate, and
the second insulating member is disposed between the other of the positive electrode terminal and the negative electrode terminal and the sealing plate.

3. The prismatic secondary battery according to claim 1 , wherein:
the gas release valve is formed at the center between the pair of mouths, and
a concaved flat face having a flat face with a height less than that of the surrounding portion is formed on a side opposite to a side having the electrolyte pour hole.

4. The prismatic secondary battery according to claim 1 , wherein:
the front face of sealing plate is positioned on an outer side of the prismatic secondary battery, and
the back face of the sealing plate is positioned on an inner side of the prismatic secondary battery.

5. The prismatic secondary battery according to claim 1 , wherein:
the first groove has a linear shape,
the sealing plate further includes
a second groove, and
a second long side edge;
the first long side edge and second long side edge are parallel;
the first groove and the second groove stand apart from each other in a perpendicular direction to the first long side edge;
the first groove is formed between the first long side edge and the first coining area; and
the second groove is formed between the second long side edge and the first coining area.

6. The prismatic secondary battery according to claim 5 , wherein the first groove and the second groove are formed in parallel.

7. The prismatic secondary battery according to claim 1 , wherein:
the electrolyte pour hole is circular when viewed from a perpendicular direction to the longitudinal direction of the sealing plate, and
a width of the first groove in a direction in which a short-side portion of the sealing plate extends is shorter than an inner diameter of the electrolyte pour hole.

8. The prismatic secondary battery according to claim 1 , wherein:
the sealing plate further includes
a second groove,
a third groove,
a fourth groove, and
a second long side edge;
the first long side edge and second long side edge are parallel;
the first groove and the second groove stand apart from each other in a perpendicular direction to the first long side edge;
the third groove and the fourth groove stand apart from each other in a perpendicular direction to the first long side edge;
the first groove and the third groove stand apart from each other in a parallel direction to the first long side edge;
the second groove and the fourth groove stand apart from each other in a parallel direction to the first long side edge;
the first groove is formed between the first long side edge and the first coining area;
the second groove is formed between the second long side edge and the first coining area;
the third groove is formed between the first long side edge and the second coining area;
the fourth groove is formed between the second long side edge and the second coining area;
wherein the third groove and the fourth groove are formed in parallel.

9. The prismatic secondary battery according to claim 1 , wherein:
the positive electrode terminal is insulated from the sealing plate, and
the negative electrode terminal is insulated from the sealing plate.

10. A prismatic secondary battery comprising:
a prismatic hollow outer body having a mouth and a bottom;
a flat electrode assembly including a positive electrode sheet and a negative electrode sheet;
a positive electrode collector electrically connected to the positive electrode sheet;
a negative electrode collector electrically connected to the negative electrode sheet:
an electrolyte;
a positive electrode terminal electrically connected to the positive electrode collector;
a negative electrode terminal electrically connected to the negative electrode collector;
a sealing plate sealing up the mouth of the prismatic outer body,
the sealing plate including
a front face;
a back face; and
a pair of mouths comprising:
a first mouth formed near one end in a longitudinal direction of the sealing plate, and
a second mouth formed near the other end in the longitudinal direction of the sealing plate;

a first coining area formed around the first mouth on th

Assignees

• Sanyo Electric Co

Inventors

• Okutani Eiji
• Yokoyama Yoshinori
• Hattori Takayuki
• Yamauchi Yasuhiro

Classifications

• H01M50/593

  Spacers; Insulating plates · CPC title

• H01M50/103

  prismatic or rectangular (H01M50/109, H01M50/11 take precedence) · CPC title

• H01M50/627

  Filling ports · CPC title

• H01M2/043

  Electricity · mapped topic

• H01M2/362

  Electricity · mapped topic