Battery pack

Abstract

A battery pack includes battery cells; a battery cell holder in which the battery cells are accommodated; and an exhaust pipe, wherein the battery cell holder includes a first cell holder to which upper end portions of the battery cells are assembled, a second cell holder to which lower end portions of the battery cells are assembled, and a first separation member on the first cell holder, the exhaust pipe extends from an outer sider surface of the battery cell holder, and the exhaust pipe is in fluid communication with an exhaust path between the first separation member and an outer side surface of the first cell holder.

What is claimed is: 
     
         1 . A battery pack, comprising:
 battery cells;   a battery cell holder in which the battery cells are accommodated; and   an exhaust pipe,   wherein:   the battery cell holder includes:
 a first cell holder to which upper end portions of the battery cells are assembled, 
 a second cell holder to which lower end portions of the battery cells are assembled, and 
 a first separation member on the first cell holder, 
   the exhaust pipe extends from an outer sider surface of the battery cell holder, and   the exhaust pipe is in fluid communication with an exhaust path between the first separation member and an outer side surface of the first cell holder.   
     
     
         2 . The battery pack as claimed in  claim 1 , wherein:
 the battery cell holder includes an accommodation space of the battery cells defined by the first cell holder and the second cell holder assembled together,   the exhaust pipe is arranged at a position vertically between an upper surface of the first holder and a lower surface of the second holder, and   the exhaust pipe is in fluid communication with an exhaust duct that is separated from the accommodation space of the battery cells.   
     
     
         3 . The battery pack as claimed in  claim 2 , further comprising a circuit board on the first cell holder and electrically connected to at least some of the battery cells,
 wherein the exhaust pipe is at a position vertically closer to the upper surface of the first cell holder than to the lower surface of the second cell holder.   
     
     
         4 . The battery pack as claimed in  claim 3 , wherein the exhaust pipe protrudes outside of the first cell holder at an outer side surface of the first cell holder. 
     
     
         5 . The battery pack as claimed in  claim 2 , wherein:
 the battery cells include a first group of battery cells and a second group of battery cells arranged in a vertically inverted pattern,   the first cell holder includes an upper exhaust hole on the upper surface thereof, exhaust gas exhausted from an upper end portion of the first group of battery cells being directed toward the upper exhaust hole, and   the second cell holder includes a lower exhaust hole on the lower surface thereof, exhaust gas exhausted from a lower end portion of the second group of battery cells being directed toward the lower exhaust hole.   
     
     
         6 . The battery pack as claimed in  claim 5 , further comprising a circuit board on the first cell holder,
 wherein the upper exhaust hole is in the upper surface of the first cell holder at a position that is spaced apart from the circuit board.   
     
     
         7 . The battery pack as claimed in  claim 5 , wherein:
 the upper exhaust hole is at an edge of the first cell holder, and   the lower exhaust hole is at an edge of the second cell holder.   
     
     
         8 . The battery pack as claimed in  claim 7 , further comprising an exhaust duct continuously extending in a height direction at edges of the first cell holder and the second cell holder,
 wherein:   the upper exhaust hole and the lower exhaust hole are connected to the exhaust duct at both ends of the exhaust duct in the height direction, and   the exhaust pipe is connected to the exhaust duct at a position vertically between ends of the exhaust duct in the height direction.   
     
     
         9 . The battery pack as claimed in  claim 8 , wherein the upper exhaust hole and the lower exhaust hole are at ends of the exhaust duct and form a single tubular shape continuously extending in the height direction. 
     
     
         10 . The battery pack as claimed in  claim 5 , wherein the exhaust path includes:
 an upper exhaust path on the upper surface of the first cell holder and in fluid communication with an upper end portion of the first group of battery cells and the upper exhaust hole, and   a lower exhaust path on the lower surface of the second cell holder and in fluid communication with a lower end portion of the second group of battery cells and the lower exhaust hole.   
     
     
         11 . The battery pack as claimed in  claim 10 , further comprising a second separation member on the lower surface of the second cell holder and forming one boundary of the lower exhaust path,
 wherein the first separation member is on the upper surface of the first cell holder and forms one boundary of the upper exhaust path.   
     
     
         12 . The battery pack as claimed in  claim 11 , wherein:
 the upper exhaust path is between the upper surface of the first cell holder and the first separation member, and   the lower exhaust path is between the lower surface of the second cell holder and the second separation member.   
     
     
         13 . The battery pack as claimed in  claim 11 , wherein:
 the first separation member includes opening regions in fluid communication with cooling flow paths between adjacent battery cells of the first and second groups of battery cells, and a block region forming the boundary of the upper exhaust path, and   the second separation member includes opening regions in fluid communication with the cooling flow paths between adjacent battery cells of the first and second groups of battery cells, and a block region forming the boundary of the lower exhaust path.   
     
     
         14 . The battery pack as claimed in  claim 13 , wherein:
 the upper exhaust path is between the upper surface of the first cell holder and the block region of the first separation member, and   the lower exhaust path is between the lower surface of the second cell holder and the block region of the second separation member.   
     
     
         15 . The battery pack as claimed in  claim 13 , wherein:
 the block region of the first separation member has a closed shape such that one side of the first separation member facing battery cells is not in fluid communication with another side of the first separation member facing away from the battery cells, and   the block region of the second separation member has a closed shape such that one side of the second separation member facing battery cells is not in fluid communication with another side of the second separation member facing away from the battery cells.   
     
     
         16 . The battery pack as claimed in  claim 13 , wherein:
 the battery cell holder includes hollow protrusion portions in fluid communication with the cooling flow paths and protruding in a direction away from the battery cells, and   the hollow protrusion portions penetrate the first separation member and the second separation member through the opening regions in the first separation member and the second separation member.   
     
     
         17 . The battery pack as claimed in  claim 16 , wherein:
 the upper exhaust path is between the upper surface of the first cell holder and the first separation member and has a shape in which spaces between the hollow protrusion portions fitted to the opening regions of the first separation member are continuously connected in fluid communication, and   the lower exhaust path is between the lower surface of the second cell holder and the second separation member and has a shape in which spaces between the hollow protrusion portions fitted to the opening regions of the second separation member are continuously connected in fluid communication.   
     
     
         18 . The battery pack as claimed in  claim 1 , further comprising an upper duct and a lower duct arranged to face each other with the battery cell holder therebetween,
 wherein one of the upper duct and the lower duct is an inlet through which a cooling medium is introducible and the other of the upper duct and the lower duct is an outlet through which the cooling medium is exhaustible, the inlet and the outlet being in fluid communication with cooling flow paths between adjacent battery cells.   
     
     
         19 . The battery pack as claimed in  claim 18 , wherein:
 the battery cells are packed together such that the battery cells are contained within an imaginary rectangular envelope including a pair of long sides and a pair of short sides extending to linearly surround outer peripheries of the battery cells across outer circumferences of the battery cells, and   the inlet and outlet of the cooling medium are at diagonal positions of the battery pack in a diagonal direction such that the inlet and the outlet are vertically spaced apart in a height direction of the battery cells and laterally spaced apart in a direction parallel to the long sides of the envelope.   
     
     
         20 . The battery pack as claimed in  claim 18 , wherein:
 the upper duct is the inlet of the cooling medium, the upper duct including an opening, and   the lower duct is the outlet of the cooling medium, the lower duct including a coupling portion of a fluid device to which a suction type fluid device is connectable.   
     
     
         21 . The battery pack as claimed in  claim 1 , further comprising a first output terminal and a second output terminal respectively connected to the battery cells having a lowest potential and the battery cells having a highest potential among the battery cells. 
     
     
         22 . The battery pack as claimed in  claim 21 , wherein:
 the battery cells are packed together such that the battery cells are contained within an imaginary rectangular envelope including a pair of long sides and a pair of short sides extending to linearly surround outer peripheries of the battery cells across outer circumferences of the battery cells, and   the first output terminal and the second output terminal are on a long side of the envelope.   
     
     
         23 . The battery pack as claimed in  claim 22 , further comprising bus bars electrically connecting the battery cells to each other,
 wherein the bus bars include:   an arrangement in a transverse direction extending in a zig-zag proximate to a short side direction of the envelope, and   an arrangement in a column direction parallel to a long side direction of the envelope.   
     
     
         24 . The battery pack as claimed in  claim 23 , wherein a number of bus bars in the arrangement in the transverse direction is greater than a number of bus bars in the arrangement in the column direction.