Partition member and assembled battery

Abstract

A partition member has a thickness direction and a surface direction perpendicular to the thickness direction, and which separates single cells that make up an assembled battery in the thickness direction, or a single cell that makes up the assembled battery in the thickness direction and a member other than the single cells. The partition member includes, in the interior thereof, a fluid having a boiling point at normal pressure of 80° C. to 250° C., and a flow channel of the fluid extending along the surface direction. The fluid is held in a fluid holding part, and the fluid holding part is hermetically sealed by a packaging material.

What is claimed is: 
     
         1 . A partition member which has a thickness direction and a surface direction perpendicular to the thickness direction, and which separates single cells that make up an assembled battery in the thickness direction, or a single cell that makes up the assembled battery in the thickness direction and a member other than the single cells, the partition member comprising:
 in the interior thereof, a fluid having a boiling point at normal pressure of 80° C. to 250° C.; and   a flow channel of the fluid extending along the surface direction,   wherein the fluid is held in a fluid holding part, and the fluid holding part is hermetically sealed by a packaging material, and   wherein volatilization of the fluid causes a decrease in thermal conductivity.   
     
     
         2 . A partition member which has a thickness direction and a surface direction perpendicular to the thickness direction, and which separates single cells that make up an assembled battery in the thickness direction, or a single cell that makes up the assembled battery in the thickness direction and a member other than the single cells, the partition member comprising:
 in the interior thereof, a fluid holding part capable of holding a fluid having a boiling point at normal pressure of 80° C. to 250° C.; and   a flow channel of the fluid extending along the surface direction,   wherein the fluid holding part is hermetically sealed by a packaging material, and wherein volatilization of the fluid causes a decrease in thermal conductivity.   
     
     
         3 . The partition member according to  claim 1 ,
 wherein the flow channel includes a continuous space through which the fluid is capable of moving and which has a length of 1 mm or greater, and the space is a space in which a sphere capable of being inscribed in a region of the space has a diameter of 0.1 mm or greater, the region taking up 90% or more of the volume of the space.   
     
     
         4 . The partition member according to  claim 1 ,
 wherein the fluid contains at least one selected from the group consisting of water, alcohols, esters, ethers, ketones, hydrocarbons, fluorine-based compounds and silicone-based oils.   
     
     
         5 . The partition member according to  claim 1 ,
 wherein a porous body containing the fluid is provided in the interior of the partition member, and   the flow channel is formed in the porous body.   
     
     
         6 . The partition member according to  claim 5 ,
 wherein the porous body contains at least one from among a fibrous layer and a particle layer.   
     
     
         7 . The partition member according to  claim 6 ,
 wherein the porous body contains a fibrous layer, and is at least one selected from a group consisting of a glass fiber sheet, a ceramic fiber sheet, paper, a cotton sheet, a porous ceramic plate, a porous glass plate, a polyimide fiber sheet, an aramid fiber sheet and a polytetrafluoroethylene fiber sheet.   
     
     
         8 . The partition member according to  claim 6 ,
 wherein the porous body contains a particle layer, and is at least one selected from a group consisting of silica particles, alumina particles, zeolite particles, glass particles and carbon particles.   
     
     
         9 . The partition member according to  claim 1 ,
 wherein the length of the flow channel in a height direction or a width direction of the partition member is a half or more of the length of the partition member in the height direction or the width direction.   
     
     
         10 . The partition member according to  claim 5 , comprising
 the packaging material that encloses the porous body.   
     
     
         11 . An assembled battery, comprising the partition member according to  claim 1 . 
     
     
         12 . The assembled battery according to  claim 11 ,
 wherein the surface direction of the partition member includes a width direction of the partition member; and   the length of the partition member in the width direction is greater than the length of single cells, which are separated by the partition member, in the width direction.   
     
     
         13 . The assembled battery according to  claim 11 ,
 wherein one of two thickness-direction surfaces of the partition member has a first region opposing a first single cell in the assembled battery and a second region not opposing the first single cell, and, in the second region, opposes at least one from among a second single cell in the assembled battery different from the first single cell, and a member other than the single cells.   
     
     
         14 . The assembled battery according to  claim 13 ,
 wherein the other of the two thickness-direction surfaces of the partition member opposes at least one from among a third single cell and a member other than the single cells in the assembled battery, the third single cell being different from the first single cell and the second single cell, and present at a position not opposing the first single cell across the partition member.   
     
     
         15 . The assembled battery according to  claim 11 ,
 wherein one of the two thickness-direction surfaces of the partition member opposes a first single cell among a plurality of single cells included in the assembled battery, and the other of the two thickness-direction surfaces opposes at least one from among a single cell in the assembled battery and a member other than the single cells in the assembled battery, the single cell being different from the first single cell, and present at a position not opposing the first single cell across the partition member.   
     
     
         16 . The partition member according to  claim 1 ,
 wherein the packaging material includes an opening.   
     
     
         17 . The partition member according to  claim 1 ,
 wherein the packaging material includes an opening, and the opening is opened at temperatures of a melting point of a liquid or more.   
     
     
         18 . The partition member according to  claim 17 ,
 wherein the flow channel is a consecutive channel of first flow segments extending in a height direction of the partition member and second flow channel segments extending in a width direction of the partition member, and a total length of the first flow channel segments and the second flow channel segments is longer than a sum of the height direction and the width direction of the partition member.   
     
     
         19 . A partition member which has a thickness direction and a surface direction perpendicular to the thickness direction, and which separates single cells that make up an assembled battery in the thickness direction, or a single cell that makes up the assembled battery in the thickness direction and a member other than the single cells, the partition member consisting essentially of:
 in the interior thereof, a fluid having a boiling point at normal pressure of 80° C. to 250° C.; and   a flow channel of the fluid extending along the surface direction,   wherein the fluid is held in a fluid holding part, and the fluid holding part is hermetically sealed by a packaging material.