Cell, battery pack, and electric vehicle
A cell, a battery pack, and an electric vehicle are provided. The cell includes a metal housing, and multiple hermetical accommodating cavities, multiple electrode core assemblies, and an encapsulation film arranged in the metal housing. The electrode core assemblies are arranged along a first direction and connected in series. A length of each electrode core assembly extends along the first direction. The electrode core assembly includes an electrode core assembly body, and a first electrode and a second electrode configured to lead out a current and be respectively arranged on two sides of the electrode core assembly body along the first direction. The accommodating cavities are defined by the encapsulation film, and the electrode core assembly body is arranged in the accommodating cavity. A length of the cell extends along the first direction. A thickness of the cell extends along a second direction perpendicular to the first direction.
1 . A cell, comprising a metal housing, and a plurality of accommodating cavities, a plurality of electrode core assemblies, and an encapsulation film arranged between the metal housing and the electrode core assemblies, wherein
the electrode core assemblies are arranged along a first direction and connected in series; a length of each of the electrode core assemblies extends along the first direction; each of the electrode core assemblies comprises an electrode core assembly body, and a first electrode and a second electrode configured to lead out a current; the first electrode and the second electrode are respectively arranged on two sides of the electrode core assembly body along the first direction;
at least one of the accommodating cavities is defined by the encapsulation film; the electrode core assembly body is arranged in the at least one of the accommodating cavities and sealed in the encapsulation film; the encapsulation film is integrally formed to encapsulate the electrode core assemblies; and an encapsulation portion of the encapsulation film is disposed between two adjacent electrode core assemblies;
a length of the cell extends along the first direction; a thickness of the cell extends along a second direction perpendicular to the first direction; and a ratio of the length to the thickness of the cell ranges from 5 to 250, wherein an air pressure between the metal housing and the encapsulation film is lower than an air pressure outside the metal housing, and an air pressure inside the encapsulation film is lower than the air pressure between the metal housing and the encapsulation film.
2 . The cell according to claim 1 , wherein for the two adjacent electrode core assemblies, a first electrode of a first electrode core assembly of the two adjacent electrode core assemblies is electrically connected with a second electrode of a second electrode core assembly of the two adjacent electrode core assemblies to realize series connection.
3 . The cell according to claim 2 , wherein
the first electrode of the first electrode core assembly and the second electrode of the second electrode core assembly are connected at a position corresponding to the encapsulation portion of the encapsulation film.
4 . The cell according to claim 3 , wherein the encapsulation portion is formed at a position on the encapsulation film corresponding to the first electrode and/or the second electrode and to separate the plurality of accommodating cavities; and
at least one of the first electrode of the first electrode core assembly or the second electrode of the second electrode core assembly is arranged at the encapsulation portion.
5 . The cell according to claim 1 , wherein the air pressure between the metal housing and the encapsulation film is P 1 ; and P 1 ranges from −100 Kpa to −5 Kpa.
6 . The cell according to claim 5 , wherein the air pressure P 1 ranges from −75 Kpa to −20 Kpa.
7 . The cell according to claim 6 , wherein the air pressure inside the encapsulation film is P 2 ; and a ratio of P 2 /P 1 ranges from 0.05 to 0.85.
8 . The cell according to claim 7 , wherein the air pressure P 2 ranges from −100 Kpa to −20 Kpa.
9 . The cell according to claim 1 , wherein the metal housing has two opposite first surfaces along the second direction; and at least one of the two opposite first surfaces is recessed into the metal housing.
10 . The cell according to claim 9 , wherein the two opposite first surfaces are both recessed into the metal housing to hold the electrode core assemblies.
11 . The cell according to claim 9 , wherein the metal housing comprises a plurality of recesses, and wherein one of the recesses is arranged corresponding to one of the electrode core assemblies.
12 . The cell according to claim 1 , wherein the encapsulation film comprises an outer film layer and an inner film layer that are stacked; the inner film layer is arranged between the electrode core assemblies and the outer film layer; and a melting point of the outer film layer is greater than a melting point of the inner film layer.
13 . The cell according to claim 12 , wherein a difference between the melting point of the outer film layer and the melting point of the inner film layer ranges from 30° C. to 80° C.
14 . The cell according to claim 12 , wherein the outer film layer comprises one or more of polyethylene terephthalate, polyamide, and polypropylene; and the inner film layer comprises one or more of polypropylene, polyethylene, and polyethylene terephthalate.
15 . The cell according to claim 12 , wherein the outer film layer and the inner film layer are bonded with each other.
16 . The cell according to claim 15 , further comprising a binder that bonds the outer film layer and the inner film layer, wherein the binder is a polyolefin binder.
17 . The cell according to claim 1 , wherein the encapsulation film is an aluminum-plastic film.
18 . The cell according to claim 1 , wherein the metal housing comprises a housing body with an opening and an end cover; the end cover is hermetically connected with the opening of the housing body; the electrode core assemblies are connected in series to form an electrode core string; two ends of the electrode core string respectively comprise a third electrode and a fourth electrode; and one of the third electrode and the fourth electrode is led out through the end cover.
19 . The cell according to claim 18 , wherein an exhaust hole is provided on the metal housing; and a sealing member is arranged in the exhaust hole.
20 . The cell according to claim 1 , wherein a thickness of the metal housing ranges from 0.05 mm to 1 mm.
21 . A battery pack, comprising a cell array comprising a plurality of cells, wherein each of the cells comprises a metal housing, and a plurality of accommodating cavities, a plurality of electrode core assemblies, and an encapsulation film arranged between the metal housing and the electrode core assemblies;
the electrode core assemblies are arranged along a first direction and connected in series; a length of each of the electrode core assemblies extends along the first direction; each of the electrode core assemblies comprises an electrode core assembly body, and a first electrode and a second electrode configured to lead out a current; the first electrode and the second electrode are respectively arranged on two sides of the electrode core assembly body along the first direction;
at least one of the accommodating cavities is defined by the encapsulation film; the electrode core assembly body is arranged in the at least one of the accommodating cavities and sealed in the encapsulation film; the encapsulation film is integrally formed to encapsulate the electrode core assemblies; and an encapsulation portion of the encapsulation film is disposed between two adjacent electrode core assemblies;
a length of each of the cells extends along the first direction; a thickness of each of the cells extends along a second direction perpendicular to the first direction; and a ratio of the length to the thickness of each of the cells ranges from 5 to 250, wherein an air pressure between the metal housing and the encapsulation film is lower than an air pressure outside the metal housing, and an air pressure inside the encapsulation film is lower than the air pressure between the metal housing and the encapsulation film.
22 . The battery pack according to claim 21 , wherein the cells are arranged in sequence along the second direction to form the cell array;
a gap is provided between two adjacent cells of the cells; and a ratio of the gap to a thickness of a cell of the two adjacent cells ranges from 0.001 to 0.15.
23 . The battery pack according to claim 22 , wherein the metal housing comprises a housing body with an opening and an end cover; the end cover is hermetically connected with the opening of the housing body;
the gap between the two adjacent cells comprises a first gap d 1 ; the first gap is a minimum distance between two end covers of the two adjacent cells along the second direction; the thickness of the cell of the two adjacent cells is equal to a dimension of one of the two end covers along the second direction; and a ratio of the first gap d 1 to the thickness of the cell of the two adjacent cells ranges from 0.005 to 0.1.
24 . The battery pack according to claim 23 , wherein
the metal housing has two opposite first surfaces along the second direction; the gap between the two adjacent cells comprises a second gap d 2 ; and the second gap is a minimum distance between the two first surfaces of the two adjacent cells facing each other.
25 . The battery pack according to claim 24 , wherein the second gap d 2 before use of the battery pack is larger than the second gap d 2 after use of the battery pack.
26 . The battery pack according to claim 22 , further comprising a battery pack cover and a tray, wherein the battery pack cover is hermetically connected with the tray to form a cell accommodating cavity; the cell array is arranged in the cell accommodating cavity; the tray comprises a support member to form a support region on the metal housing; and the cells are supported on the support member.
27 . The battery pack according to claim 26 , wherein the tray comprises a side beam as the support member; and two ends of each of the cells along the first direction are supported on the side beam.
28 . An electric vehicle, comprising the battery pack according to claim 21 .