Lithium ion battery and lithium ion battery pack
According to one embodiment of the present invention, a lithium ion battery having desirable safety performance is provided. The lithium ion battery includes a battery housing, a battery cover assembled to the battery housing, a pressure relief valve coupled to the battery housing and/or battery cover, and a safety device formed on the housing and/or battery cover and fixed to the pressure relief valve. The safety device includes a shielding plate facing the pressure relief valve, a side wall and an air flow channel structure. The side wall extends from the shielding plate and connects with the battery housing or the battery cover. The air flow channel structure is defined in the side wall.
1. A lithium ion battery, comprising:
a battery housing;
a battery cover assembled to the battery housing; and
a pressure relief valve coupled to the battery housing and/or battery cover;
wherein:
the battery housing and/or the battery cover is assembled with a first safety device fixed to the pressure relief valve,
the first safety device comprises a shielding plate facing the pressure relief valve, a side wall and an air flow channel structure,
the side wall has a longitudinal axis and extends from the shielding plate and connects with the battery housing or the battery cover, and
the air flow channel structure is defined passing through the side wall along an axis perpendicular to the longitudinal axis.
2. The lithium ion battery of claim 1 , wherein the air flow channel structure is only defined in the side wall.
3. The lithium ion battery of claim 1 , wherein the air flow channel structure comprises at least one opening, at least one through holes array, or at least one notch defined in the side wall.
4. The lithium ion battery of claim 3 , wherein the air flow channel structure is a through holes array, and each through hole in the through holes array has an area no less than 1 mm 2 .
5. The lithium ion battery of claim 3 , wherein the pressure relief valve defines a pressure relief hole, and total area of the air flow channel structure is no less than ½ of the area of the pressure relief hole.
6. The lithium ion battery of claim 1 , wherein the shielding plate defines a plurality of through holes, and each through hole in the shielding plate has an area less than 1 mm 2 .
7. The lithium ion battery of claim 1 , wherein the air flow channel structure comprises a first air flow channel and a second air flow channel spaced apart from each other in the side wall, the first air flow channel is configued as an opening, a through holes array, or a notch, the second air flow channel is configured as an opening, a through holes array, or a notch, the first air flow channel and the second air flow channel have different structures.
8. The lithium ion battery of claim 7 , wherein the first air flow channel or the second air flow channel is a through holes array, each through hole in the through holes array has an area no less than 1 mm 2 .
9. The lithium ion battery of claim 1 , further comprising a battery cell received in the battery housing, the first safety device is disposed between the battery cell and the battery cover, the first safety device has a height at least 1 mm less than a minimum distance between a surface of the battery cover facing the battery cell and the battery cell, a width no less 1 mm than a distance between two lateral inner surfaces of the battery housing, and a length at least 1 mm less than a minimum distance between positive and negative tabs of the battery cell.
10. The lithium ion battery of claim 1 , wherein the first safety device comprises a connecting portion formed at one end of the side wall and spaced apart from the shielding plate, and the side wall is connected to the battery housing or the battery cover via the connecting portion.
11. The lithium ion battery of claim 1 , further comprising a second safety device, the first safety device and the second safety device are seated at two sides of the pressure relief valve and cover the pressure relief valve respectively, the second safety device comprises a shielding plate facing the pressure relief valve, a side wall and an air flow channel structure, the side wall extends from the shielding plate and connects with the battery housing or the battery cover, and the air flow channel structure is defined in the side wall and/or the shielding plate.
12. The lithium ion battery of claim 1 , wherein the first safety device is made from metal or inorganic non-metallic ceramic.
13. The lithium ion battery of claim 1 , wherein a surface of the first safety device is formed with a layer of polytetrafluoroethylene, phenolic resin, polyethylene terephthalate, polypropylene, epoxy resin or ceramic.
14. A lithium ion battery pack, comprising a plurality of lithium ion batteries according to claim 1 connected in parallel and/or in series.