Laminate cell, assembled battery, battery module and electric vehicle

Abstract

A laminate cell comprises a power generating element formed by sequentially stacking positive electrode plates and negative electrode plates while interposing separators therebetween; a positive tab connected to the positive electrode plates through a plurality of positive leads; a negative tab connected to the negative electrode plates through a plurality of negative leads; and a cell package formed of a metal composite film, the cell package hermetically sealing the power generating element and an electrolyte. According to the laminate cell, the heat capacity of a portion of the positive tab, onto which a plurality of the positive leads are joined, and the heat capacity of a portion of the negative tab, onto which a plurality of the negative leads are joined, are made larger than that of other portions of the positive tab and the negative tab.

What is claimed is:  
     
         1 . A laminate cell, comprising: 
 a power generating element formed by sequentially stacking positive electrode plates and negative electrode plates while interposing separators therebetween;    a positive tab connected to the positive electrode plates through a plurality of positive leads;    a negative tab connected to the negative electrode plates through a plurality of negative leads; and    a cell package formed of a metal composite film, the cell package hermetically sealing the power generating element and an electrolyte,    wherein a heat capacity of a portion of the positive tab, onto which a plurality of the positive leads are joined, and a heat capacity of a portion of the negative tab, onto which a plurality of the negative leads are joined, are made larger than that of other portions of the positive tab and the negative tab.    
     
     
         2 . A laminate cell according to  claim 1 , 
 wherein a thickness of the portion of the positive tab, onto which the plurality of positive leads are joined, and a thickness of the portion of the negative tab, onto which the plurality of negative leads are joined, are made larger than that of the other portions of the positive tab and the negative tab.    
     
     
         3 . A laminate cell according to  claim 1 , 
 wherein a resin having a larger heat capacity per unit weight than that of the positive tab and the negative tab is provided on the portion of the positive tab, onto which the plurality of positive leads are joined, and the portion of the negative tab, onto which the plurality of negative leads are joined.    
     
     
         4 . A laminate cell according to  claim 3 , 
 wherein the resin contains at least polyolefin.    
     
     
         5 . A laminate cell according to  claim 4 , 
 wherein the resin is formed of a composite material made by mixing at least either metal particles or ceramic particles into polyolefin.    
     
     
         6 . A laminate cell according to  claim 4 , 
 wherein the resin is formed of a composite material made by mixing a phase change material, which absorbs heat by a phase change, into polyolefin, the phase change material being mixed in a state of at least either microparticles or microcapsules.    
     
     
         7 . A laminate cell, comprising: 
 a power generating element formed by sequentially stacking positive electrode plates and negative electrode plates while interposing separators therebetween;    a positive tab connected to the positive electrode plates through a plurality of positive leads;    a negative tab connected to the negative electrode plates through a plurality of negative leads; and    a cell package formed of a metal composite film hermetically sealing the power generating element and an electrolyte,    wherein insulating tapes having an electrical insulating property are adhered to a portion of the positive tab, onto which the plurality of positive leads are joined, and to a portion of the negative tab, onto which the plurality of negative leads are joined.    
     
     
         8 . An assembled battery, comprising: 
 a single cell including a power generating element formed by sequentially stacking positive electrode plates and negative electrode plates while interposing separators therebetween; a positive tab connected to the positive electrode plates through a plurality of positive leads; a negative tab connected to the negative electrode plates through a plurality of negative leads; and a cell package formed of a metal composite film, the cell package hermetically sealing the power generating element and an electrolyte,    wherein a heat capacity of a portion of the positive tab, onto which a plurality of the positive leads are joined, and a heat capacity of a portion of the negative tab, onto which a plurality of the negative leads are joined, are made larger than that of other portions of the positive tab and the negative tab, and    the assembled battery is formed by interconnecting any of a plurality of the single cells and a plurality of single cell groups electrically in series, each of the single cell group being formed by interconnecting a plurality of the single cells electrically in parallel.    
     
     
         9 . A battery module, comprising: 
 an assembled battery having a single cell including a power generating element formed by sequentially stacking positive electrode plates and negative electrode plates while interposing separators therebetween; a positive tab connected to the positive electrode plates through a plurality of positive leads; a negative tab connected to the negative electrode plates through a plurality of negative leads; and a cell package formed of a metal composite film, the cell package hermetically sealing the power generating element and an electrolyte,    wherein a heat capacity of a portion of the positive tab, onto which a plurality of the positive leads are joined, and a heat capacity of a portion of the negative tab, onto which a plurality of the negative leads are joined, are made larger than that of other portions of the positive tab and the negative tab,    the assembled battery is formed by interconnecting any of a plurality of the single cells and a plurality of single cell groups electrically in series, each of the single cell group being formed by interconnecting a plurality of the single cells electrically in parallel, and    the battery module is formed by electrically interconnecting a plurality of the assembled batteries and housing the plurality of electrically interconnected assembled batteries in a module case.    
     
     
         10 . An electric vehicle, comprising: 
 a battery module comprising: an assembled battery having a single cell including a power generating element formed by sequentially stacking positive electrode plates and negative electrode plates while interposing separators therebetween; a positive tab connected to the positive electrode plates through a plurality of positive leads; a negative tab connected to the negative electrode plates through a plurality of negative leads; and a cell package formed of a metal composite film, the cell package hermetically sealing the power generating element and an electrolyte,    wherein a heat capacity of a portion of the positive tab, onto which a plurality of the positive leads are joined, and a heat capacity of a portion of the negative tab, onto which a plurality of the negative leads are joined, are made larger than that of other portions of the positive tab and the negative tab,    the assembled battery is formed by interconnecting any of a plurality of the single cells and a plurality of single cell groups electrically in series, each of the single cell group being formed by interconnecting a plurality of the single cells electrically in parallel,    the battery module is formed by electrically interconnecting a plurality of the assembled batteries and housing the plurality of electrically interconnected assembled batteries in a module case, and    the battery module is used as a power source of a driving motor driving drive wheels.