Lithium ion battery and battery pack

Abstract

The present invention discloses a lithium ion battery, including a battery shell, a battery top cap mounted on the battery shell, and a relief valve provided on the battery shell and/or the battery top cap; the lithium ion battery further includes a safety protection device that is provided on the battery shell and/or the battery top cap and that fixedly fits with the relief valve; where the safety protection device includes a baffle plate opposite to the relief valve, a side wall and a gas flow channel structure; the side wall extends, from the baffle plate, toward the battery shell or the battery top cap, and is connected with the battery shell or the battery top cap; and the gas flow channel structure is formed on the side wall. By forming the gas flow channel structure on the side wall, the baffle plate and the gas flow channel structure form a relatively separate design, so that the baffle plate may be used for effectively baffling solid spark particles, and meanwhile the lateral gas flow channel structure may be used for effectively discharging gases, thereby improving the safety performance of the lithium ion battery.

1 . A lithium ion battery, comprising a battery shell, a battery top cap mounted on the battery shell, and a relief valve provided on the battery shell and/or the battery top cap; wherein the lithium ion battery further comprises a safety protection device that is provided on the battery shell and/or the battery top cap and that fixedly fits with the relief valve; the safety protection device comprises a baffle plate opposite to the relief valve, a side wall and a gas flow channel structure; the side wall extends, from the baffle plate, toward the battery shell or the battery top cap, and is connected with the battery shell or the battery top cap; and the gas flow channel structure is formed on the side wall. 
     
     
         2 . The lithium ion battery according to  claim 1 , wherein the gas flow channel structure is only provided on the side wall. 
     
     
         3 . The lithium ion battery according to  claim 1 , wherein the gas flow channel structure formed on the side wall comprises at least one opening structure, at least one through-hole array or at least one gap. 
     
     
         4 . The lithium ion battery according to  claim 3 , wherein when the gas flow channel structure is a through-hole array, an area of each through hole in the through-hole array is not less than 1 mm 2 . 
     
     
         5 . The lithium ion battery according to  claim 1 , wherein the baffle plate is provided with a plurality of through holes, and an area of each through hole on the baffle plate is less than 1 mm 2 . 
     
     
         6 . The lithium ion battery according to  claim 1 , wherein the gas flow channel structure comprises a first gas flow channel and a second gas flow channel separately formed on the side wall; the first gas flow channel is one of the opening structure, the through-hole array and the gap; the second gas flow channel is one of the opening structure, the through-hole array and the gap; and the first gas flow channel is different from the second gas flow channel in structure. 
     
     
         7 . The lithium ion battery according to  claim 3 , wherein the relief valve comprises a relief hole; and a sum of an area of the gas flow channel structure is not less than 0.5 times of that of the relief hole. 
     
     
         8 . The lithium ion battery according to  claim 6 , wherein when the first gas flow channel or the second gas flow channel is a through-hole array, an area of each through hole in the through-hole array is not less than 1 mm 2 . 
     
     
         9 . The lithium ion battery according to  claim 1 , wherein the lithium ion battery further comprises a cell housed in the battery shell; the safety protection device is provided between the cell and the battery top cap; a height of the safety protection device is at least 1 mm less than a minimum distance from the cell to a surface of the battery top cap that is adjacent to the cell; a spacing between a side of the safety protection device and an internal surface of the battery shell is not less than 1 mm; and a length of the safety protection device is at least 1 mm less than a minimum spacing between a positive tab and a negative tab of the cell. 
     
     
         10 . The lithium ion battery according to  claim 1 , wherein the safety protection device further comprises a connection part; the connection part is provided at an end of the side wall and is provided separately from the baffle plate; and the side wall is connected, by means of the connection part, with the battery shell or the battery top cap. 
     
     
         11 . The lithium ion battery according to  claim 1 , wherein the lithium ion battery further comprises another safety protection device; the another safety protection device and the safety protection device are provided at two sides of the relief valve, and respectively cover the relief valve; the another safety protection device comprises a baffle plate opposite to the relief valve, a side wall and a gas flow channel structure; the side wall extends, from the baffle plate, toward the battery shell or the battery top cap, and is connected with the battery shell or the battery top cap; and the gas flow channel structure is formed on the side wall and/or the baffle plate. 
     
     
         12 . The lithium ion battery according to  claim 1 , wherein the safety protection device is made of a metallic material or an inorganic non-metal ceramic material. 
     
     
         13 . The lithium ion battery according to  claim 12 , wherein a surface of the safety protection device is provided with a teflon coating, an epoxy resin coating, a phenolic resin coating, a polyethylene terephthalate coating, a polypropylene coating or a ceramic coating. 
     
     
         14 . A lithium ion battery pack, comprising a plurality of lithium ion batteries connected in parallel and/or in series according to any one of  claim 1 . 
     
     
         15 . The lithium ion battery according to  claim 6 , wherein the relief valve comprises a relief hole; and a sum of an area of the gas flow channel structure is not less than 0.5 times of that of the relief hole