Prismatic secondary battery

Abstract

A highly reliable prismatic secondary battery with a current interruption mechanism that is unlikely to be damaged even if the battery is subjected to shock due to vibration, falling, etc. A second insulating member that has a through-hole is disposed between an inversion plate and the first region of a positive electrode collector, and through the through-hole the first region of the positive electrode collector is electrically connected to the inversion plat. First to third projections to formed around the through-hole formed in the second insulating member fit respectively into first to third openings formed in the first region of the positive electrode collector, and the diameters of their apexes are widened, thus forming first to third fixing portions. Thereby, the second insulating member is robustly joined to the first region of the positive electrode collector.

What is claimed is: 
     
         1 . A prismatic secondary battery comprising:
 a bottomed, hollow, prismatic outer casing that has a mouth;   an electrode assembly that is housed inside the prismatic outer casing and has positive electrode plate and negative electrode plate;   a positive electrode collector that is electrically connected to the positive electrode plate;   a negative electrode collector that is electrically connected to the negative electrode plate;   a sealing body that seals the mouth of the outer casing;   at least one external terminal that is inserted into a through-hole provided in the sealing body while being electrically insulated from the sealing body with first insulating member interposed therebetween;   a conductive member that has a tubular portion;   an inversion plate containing conductive material, that is deformed when the battery interior pressure exceeds a particular value, the inversion plate having a periphery edge with a periphery rib standing in a direction toward the battery interior; and   a second insulating member that is interposed between the inversion plate and at least one of the positive electrode collector and the negative electrode collector, and in which a through-hole is formed,   at least one of the positive electrode collector and the negative electrode collector being connected to the inversion plate through the through-hole formed in the second insulating member,   one end of the tubular portion of the conductive member being electrically connected to the external terminal, and the other end being sealed by the inversion plate,   the tubular portion of the conductive member and the periphery rib of the inversion plate being connected,   at least one of the positive electrode collector and the negative electrode collector having a first region that is parallel to the sealing body and a second region that extends from the first region in the direction of the electrode assembly and is connected to the positive electrode plate or negative electrode plate,   the first region having; a connecting portion with the inversion plate; a first opening; and a second opening,   the second insulating member having projections formed at positions corresponding to each of the first opening and the second opening,   the first opening and the second opening, each engaging with the projections formed in the second insulating member to form a first fixing portion and a second fixing portion, respectively.   
     
     
         2 . The prismatic secondary battery according to  claim 1 , wherein an inner surface of the tubular portion of the conductive member and an outer surface of the periphery rib of the inversion plate are in contact physically. 
     
     
         3 . The prismatic secondary battery according to  claim 1 , wherein the tubular portion of the conductive member and the periphery rib of the inversion plate are welded. 
     
     
         4 . The prismatic secondary battery according to  claim 1 , wherein
 the tubular portion of the conductive member has a fitting portion having an inner diameter larger than that of the other part of the tubular portion,   the periphery edge of the inversion plate fits into the fitting portion.   
     
     
         5 . The prismatic secondary battery according to  claim 1 , wherein
 the inversion plate has a slant portion formed at an interval from the sealing plate, the interval increases gradually from the periphery edge toward the center of the inversion plate.   
     
     
         6 . The prismatic secondary battery according to  claim 1 , wherein
 the inversion plate has   a protruding portion having a circular shape, formed on the center of the inversion plate, and   a slant portion formed at an interval from the sealing plate, the interval increases gradually from the periphery edge toward the center of the inversion plate.   
     
     
         7 . The prismatic secondary battery according to  claim 1 , wherein
 the connecting portion of the first region is formed between the first fixing portion and the second fixing portion.   
     
     
         8 . The prismatic secondary battery according to  claim 1 , wherein
 the tubular portion of the conductive member and the periphery rib of the inversion plate are connected at a position corresponding to the first fixing portion.   
     
     
         9 . A prismatic secondary battery comprising:
 a bottomed, hollow, prismatic outer casing that has a mouth;   an electrode assembly that is housed inside the prismatic outer casing and has positive electrode plate and negative electrode plate;   a positive electrode collector that is electrically connected to the positive electrode plate;   a negative electrode collector that is electrically connected to the negative electrode plate;   a sealing body that seals the mouth of the outer casing;   at least one external terminal that is inserted into a through-hole provided in the sealing body;   a conductive member that has a tubular portion;   an inversion plate containing conductive material, that is deformed when the battery interior pressure exceeds a particular value, the inversion plate having a periphery edge with a periphery rib standing in a direction toward the battery interior; and   an insulating member that is interposed between the inversion plate and at least one of the positive electrode collector and the negative electrode collector, and in which a through-hole is formed,   at least one of the positive electrode collector and the negative electrode collector being connected to the inversion plate through the through-hole formed in the insulating member,   one end of the tubular portion of the conductive member being electrically connected to the external terminal, and the other end being sealed by the inversion plate,   the tubular portion of the conductive member and the periphery rib of the inversion plate being connected,   at least one of the positive electrode collector and the negative electrode collector having a first region that is parallel to the sealing body and a second region that extends from the first region in the direction of the electrode assembly and is connected to the positive electrode plate or negative electrode plate,   the first region having: a connecting portion with the inversion plate; a first opening; and a second opening,   the insulating member having projections formed at positions corresponding to each of the first opening and the second opening,   the first opening and the second opening, each engaging with the projections formed in the insulating member to form a first fixing portion and a second fixing portion, respectively.   
     
     
         10 . The prismatic secondary battery according to  claim 9 , wherein an inner surface of the tubular portion of the conductive member and an outer surface of the periphery rib of the inversion plate are in contact physically. 
     
     
         11 . The prismatic secondary battery according to  claim 9 , wherein the tubular portion of the conductive member and the periphery rib of the inversion plate are welded. 
     
     
         12 . The prismatic secondary battery according to  claim 9 , wherein
 the tubular portion of the conductive member has a fitting portion having an inner diameter larger than that of the other part of the tubular portion,   the periphery edge of the inversion plate fits into the fitting portion.   
     
     
         13 . The prismatic secondary battery according to  claim 9 , wherein
 the inversion plate has a slant portion formed at an interval from the sealing plate, the interval increases gradually from the periphery edge toward the center of the inversion plate.   
     
     
         14 . The prismatic secondary battery according to  claim 9 , wherein
 the inversion plate has   a protruding portion having a circular shape, formed on the center of the inversion plate, and   a slant portion formed at an interval from the sealing plate, the interval increases gradually from the periphery edge toward the center of the inversion plate.   
     
     
         15 . A prismatic secondary battery comprising:
 a bottomed, hollow, prismatic outer casing that has a mouth;   an electrode assembly that is housed inside the prismatic outer casing and has positive electrode plate and negative electrode plate;   a positive electrode collector that is electrically connected to the positive electrode plate;   a negative electrode collector that is electrically connected to the negative electrode plate;   a sealing body that seals the mouth of the outer casing;   at least one external terminal that is inserted into a through-hole provided in the sealing body while being electrically insulated from the sealing body with first insulating member interposed therebetween;   a conductive member that has a tubular portion;   an inversion plate containing conductive material, that is deformed when the battery interior pressure exceeds a particular value, the inversion plate having a periphery edge with a periphery rib standing in a direction toward the battery interior; and   a second insulating member that is interposed between the inversion plate and at least one of the positive electrode collector and the negative electrode collector, and in which a through-hole is formed,   at least one of the positive electrode collector and the negative electrode collector being connected to the inversion plate through the through-hole formed in the second insulating member,   one end of the tubular portion of the conductive member being electrically connected to the external terminal, and the other end being sealed by the inversion plate,   the tubular portion of the conductive member and the periphery rib of the inversion plate being connected,   at least one of the positive electrode collector and the negative electrode collector having a first region that is parallel to the sealing body and a second region that extends from the first region in the direction of the electrode assembly and is connected to the positive electrode plate or negative electrode plate,   the first region having a connecting portion with the inversion plate.   
     
     
         16 . The prismatic secondary battery according to  claim 15 , wherein an inner surface of the tubular portion of the conductive member and an outer surface of the periphery rib of the inversion plate are in contact physically. 
     
     
         17 . The prismatic secondary battery according to  claim 15 , wherein the tubular portion of the conductive member and the periphery rib of the inversion plate are welded. 
     
     
         18 . The prismatic secondary battery according to  claim 15 , wherein
 the tubular portion of the conductive member has a fitting portion having an inner diameter larger than that of the other part of the tubular portion,   the periphery edge of the inversion plate fits into the fitting portion.   
     
     
         19 . The prismatic secondary battery according to  claim 15 , wherein
 the inversion plate has a slant portion formed at an interval from the sealing plate, the interval increases gradually from the periphery edge toward the center of the inversion plate.   
     
     
         20 . The prismatic secondary battery according to  claim 15 , wherein
 the inversion plate has   a protruding portion having a circular shape, formed on the center of the inversion plate; and   a slant portion formed at an interval from the sealing plate, the interval increases gradually from the periphery edge toward the center of the inversion plate.