Secondary battery, battery module and electric vehicle
Disclosed are a secondary battery, a battery module and an electric vehicle. The battery module includes a plurality of secondary batteries arranged in sequence. The secondary battery includes an electrode assembly, a housing and a top cover assembly. The electrode assembly is accommodated in an accommodating chamber of the housing. The electrode assembly includes a plurality of electrode units, the plurality of electrode units being stacked in an axial direction of the accommodating chamber. The top cover assembly includes a top cover plate and an insulating member arranged on an inner side of the top cover plate, the top cover plate being connected to the housing, the insulating member being located on a side of the electrode assembly in the axial direction. A first buffer gap is provided between the insulating member and the top cover plate.
1. A secondary battery, comprising an electrode assembly, a housing and a top cover assembly, wherein
the housing has an accommodating chamber, the accommodating chamber having an opening, and the electrode assembly being accommodated in the accommodating chamber;
the electrode assembly comprises a plurality of electrode units, the plurality of electrode units being stacked in an axial direction of the accommodating chamber;
the top cover assembly comprises a top cover plate and an insulating member arranged on an inner side of the top cover plate, the top cover plate being connected to the housing, and the insulating member being located on a side of the electrode assembly in the axial direction; and
a first buffer gap is provided between the insulating member and the top cover plate,
wherein one side of the insulating member close to the top cover plate is provided with a first recess to form the buffer gap, one side of the top cover plate close to the insulating member is provided with a fixing hole, the insulating member is provided with a connecting portion extending from a bottom wall of the first recess, and the connecting portion is inserted into the fixing hole of the top cover plate and is fixed to the top cover plate, the fixing hole comprises a first hole and a second hole, the first hole extending from a surface of the top cover plate close to the insulating member, and the second hole extending from an end of the first hole away from the insulating member, and a hole diameter of the second hole is larger than a hole diameter of the first hole.
2. The secondary battery according to claim 1 , wherein a size of the first buffer gap is positively correlated to a thickness of the electrode assembly in the axial direction, and the size of the first buffer gap is 0.8 mm to 1.5 mm.
3. The secondary battery according to claim 1 , wherein the electrode unit comprises a first electrode plate, a second electrode plate and a membrane, which are coiled as a whole; and
the electrode unit has a main body region and corner regions, the corner regions being arranged at two ends of the main body region in a width direction, the main body regions of the two adjacent electrode units being in contact with each other, and the main body region of the electrode unit being opposite the insulating member.
4. The secondary battery according to claim 3 , wherein a ratio of a width of the main body region to a thickness of the top cover plate is 10-60.
5. The secondary battery according to claim 3 , wherein the width of the main body region is 30 mm to 60 mm, and the thickness of the top cover plate is 1 mm to 3 mm.
6. The secondary battery according to claim 3 , wherein in the main body region, a second buffer gap is formed between the first electrode plate and the second electrode plate.
7. The secondary battery according to claim 6 , a size of the second buffer gap is 2 μm to 20 μm.
8. The secondary battery according to claim 1 , wherein a plurality of connecting portions are provided, the plurality of connecting portions each comprising a first connecting portion and a second connecting portion, and two ends of the first recess in the width direction are respectively provided with a first side wall and a second side wall; and
the first connecting portion is arranged close to the first side wall, and the second connecting portion is arranged close to the second side wall.
9. The secondary battery according to claim 1 , wherein
the connecting portion comprises a first region and a second region, the first region extending from a bottom wall of the first recess, and the second region extending from an end of the first region away from the bottom wall and being inserted into the fixing hole.
10. The secondary battery according to claim 1 , wherein the material of the insulating member is plastic.
11. The secondary battery according to claim 10 , the Young's modulus of the insulating member is 0.5 Gpa to 1.2 Gpa.
12. A battery module, comprising a secondary battery, the secondary battery comprising an electrode assembly, a housing and a top cover assembly, wherein
the housing has an accommodating chamber, the accommodating chamber having an opening, and the electrode assembly being accommodated in the accommodating chamber;
the electrode assembly comprises a plurality of electrode units, the plurality of electrode units being stacked in an axial direction of the accommodating chamber;
the top cover assembly comprises a top cover plate and an insulating member arranged on an inner side of the top cover plate, the top cover plate being connected to the housing, and the insulating member being located on a side of the electrode assembly in the axial direction; and
a first buffer gap is provided between the insulating member and the top cover plate,
wherein a plurality of secondary batteries are provided and are arranged in sequence, and an arrangement direction of the plurality of secondary batteries is perpendicular to the axial direction;
wherein one side of the insulating member close to the top cover plate is provided with a first recess to form the buffer gap, one side of the top cover plate close to the insulating member is provided with a fixing hole, the insulating member is provided with a connecting portion extending from a bottom wall of the first recess, and the connecting portion is inserted into the fixing hole of the top cover plate and is fixed to the top cover plate, the fixing hole comprises a first hole and a second hole, the first hole extending from a surface of the top cover plate close to the insulating member, and the second hole extending from an end of the first hole away from the insulating member, and a hole diameter of the second hole is larger than a hole diameter of the first hole.
13. The battery module according to claim 12 , further comprising two end plates, the two end plates being respectively located at two ends of the plurality of secondary batteries in the arrangement direction, and the two end plates clamping the plurality of secondary batteries.
14. The battery module according to claim 12 , wherein a size of the first buffer gap is positively correlated to a thickness of the electrode assembly in the axial direction, and the size of the first buffer gap is 0.8 mm to 1.5 mm.
15. The battery module according to claim 12 , wherein the electrode unit comprises a first electrode plate, a second electrode plate and a membrane, which are coiled as a whole; and
the electrode unit has a main body region and corner regions, the corner regions being arranged at two ends of the main body region in a width direction, the main body regions of the two adjacent electrode units being in contact with each other, and the main body region of the electrode unit being opposite the insulating member.
16. An electric vehicle, comprising a battery module, the battery module comprising a secondary battery, the secondary battery comprising an electrode assembly, a housing and a top cover assembly, wherein
the housing has an accommodating chamber, the accommodating chamber having an opening, and the electrode assembly being accommodated in the accommodating chamber;
the electrode assembly comprises a plurality of electrode units, the plurality of electrode units being stacked in an axial direction of the accommodating chamber;
the top cover assembly comprises a top cover plate and an insulating member arranged on an inner side of the top cover plate, the top cover plate being connected to the housing, and the insulating member being located on a side of the electrode assembly in the axial direction; and
a first buffer gap is provided between the insulating member and the top cover plate,
wherein a plurality of secondary batteries are provided and are arranged in sequence, and an arrangement direction of the plurality of secondary batteries is perpendicular to the axial direction;
wherein one side of the insulating member close to the top cover plate is provided with a first recess to form the buffer gap, one side of the top cover plate close to the insulating member is provided with a fixing hole, the insulating member is provided with a connecting portion extending from a bottom wall of the first recess, and the connecting portion is inserted into the fixing hole of the top cover plate and is fixed to the top cover plate, the fixing hole comprises a first hole and a second hole, the first hole extending from a surface of the top cover plate close to the insulating member, and the second hole extending from an end of the first hole away from the insulating member, and a hole diameter of the second hole is larger than a hole diameter of the first hole.
17. The electric vehicle according to claim 16 , wherein a size of the first buffer gap is positively correlated to a thickness of the electrode assembly in the axial direction, and the size of the first buffer gap is 0.8 mm to 1.5 mm.