Battery module

Abstract

The case housing a plurality of cells is divided, by a circuit board provided at the same sides of the cells, into a housing space housing the cells and an exhaust duct for releasing a gas from the vents of the cells to outside the case. The vents of the cells communicate with the exhaust duct through openings formed in the flat plate. The exhaust duct is divided into a first space and a second space by a partition provided between the flat plate and an external plate of the case. The first space communicates with the second space through holes formed in the partition.

1 . A battery module in which a plurality of cells are arranged and housed in a case, wherein
 each of the cells has a vent through which a gas generated in the cell is released to outside the cell, each of said vents is formed in the corresponding cell,   the case is divided, by a flat plate provided at same sides of the cells, into a housing space housing the cells and an exhaust duct for releasing a gas from the vents of the cells to outside the case,   each of the vents of the cells communicates with the exhaust duct through an opening formed in the flat plate,   the exhaust duct is divided into a first space and a second space by a partition provided between the flat plate and an external plate or a bottom of the case,   the first space communicates with the second space through a plurality of through holes formed in the partition,   a volume of the first space is adjusted depending on a location or the plurality of through holes, and   a gas from the vent of the cell is released to the first space through the opening formed in the flat plate, is guided to the second space through the through hole formed in the partition, and then is released to outside the case.   
     
     
         2 . A battery module of  claim 1 , wherein the flat plate is in close contact with an end of each of the cells, and the housing space is hermetically sealed by the flat plate. 
     
     
         3 . The battery module of  claim 1 , wherein a volume of the first space is adjusted such that when a gas at a high temperature released from the vent of the cell to the first space by adiabatic expansion is released from the first space to the second space, the gas has a temperature reduced to a predetermined temperature or lower. 
     
     
         4 . The battery module of  claim 3 , wherein the predetermined temperature is a temperature at which the gas released from the vent of the cell does not react with oxygen. 
     
     
         5 . The battery module of  claim 4 , wherein the cells are lithium ion secondary batteries, and the predetermined temperature is 450° C. 
     
     
         6 . The battery module of  claim 3 , wherein a volume of the second space is adjusted such that when a gas released from the first space to the second space by adiabatic expansion is released from the second space to outside the case, the gas has a temperature equal to or lower than a temperature at which no significant problems occur even when the gas is released to outside the case. 
     
     
         7 . The battery module of  claim 6 , wherein the temperature at which no significant problems occur even when the gas is released to outside the case is 200° C. 
     
     
         8 . The battery module of  claim 1 , wherein the vent of each of the cells is provided in a positive electrode projection of the cell, and the positive electrode projection is inserted in the opening of the flat plate. 
     
     
         9 . The battery module of  claim 1 , wherein the flat plate is a circuit board, the circuit board includes a connection plate to which at least an electrode of each of the cells is connected, and
 the electrodes of the cells connected to the connection plate are connected in parallel.   
     
     
         10 . The battery module of  claim 1 , wherein the flat plate is a metal bus bar to which at least an electrode of each of the cells is connected, and the electrodes of the cells connected to the metal bus bar are connected in parallel. 
     
     
         11 . The battery module of  claim 10 , wherein the case of each of the cells constitutes another electrode of each of the cells, and the metal bus bar is in close contact with an end of each of the cells with an insulator interposed therebetween. 
     
     
         12 . The battery module of  claim 1 , wherein the first space is formed between the flat plate and the partition, and the second space is formed between the partition and an external plate or a bottom of the case. 
     
     
         13 . A battery module in which a plurality of cells are arranged and housed in a case, wherein
 each of the cells has a vent through which a gas generated in the cell is released to outside the cell,   the case is divided, by a flat plate provided at same sides of the cells, into a housing space housing the cells and a first exhaust space for releasing a gas from the vent of the cell to outside the case through a release outlet of the case,   each of the vents of the cells communicates with the first exhaust space through an opening formed in the flat plate,   an exhaust duct including a second exhaust space having an aperture communicating with the release outlet is in contact with the case, and   a gas from the vents of the cells is released to the first exhaust space through the opening formed in the flat plate, is guided to the second exhaust space through the aperture, and then is released to outside the case.   
     
     
         14 . The battery module of  claim 13 , wherein a volume of the first exhaust space is adjusted such that when a gas at a high temperature released from the vent of the cell to the first exhaust space by adiabatic expansion is released from the first exhaust space to the second exhaust space, the gas has a temperature reduced to a predetermined temperature or less. 
     
     
         15 . The battery module of  claim 14 , wherein the predetermined temperature is a temperature at which the gas released from the vents of the cells does not react with oxygen. 
     
     
         16 . The battery module of  claim 12 , wherein the flat plate includes a connection plate to which at least an electrode of each of the cells is connected, and the electrodes of the cells connected to the connection plate are connected in parallel.