Battery module

1. A battery module, comprising a substrate, a plurality of battery units, a pair of end plates, a pair of side plates and a plurality of fastening pieces; wherein,

the plurality of battery units are located on the substrate, and are stacked in sequence along a thickness direction of the battery unit;

the pair of end plates are respectively located on two sides of the plurality of battery units in their stacking direction, and are adjacent to outermost ones of the battery units and extend along a length direction of the battery unit; and an end of the end plate in the length direction of the battery unit is curled into a pipe and forms a curling pipe section, an axial direction of the curling pipe section is the same direction with a height direction of the battery unit;

the pair of side plates are respectively located on two sides of the plurality of battery units in the length direction of the battery unit, extend along the thickness direction of the battery unit, and are fixedly connected with the curling pipe section;

the fastening piece is inserted in the curling pipe section, extends in the curling pipe section toward the substrate and protrudes out of the curling pipe section, and are fixed on the substrate,

wherein, an end of the end plate in the height direction of the battery unit extends toward a side where the curling pipe section is located and forms an edge-wrapped section that wraps on the curling pipe section; the edge-wrapped section is provided with an opening on a position corresponding to a pipe hole of the curling pipe section; the fastening piece extends through the opening to the substrate, and is fixedly connected on the substrate.

2. The battery module according to claim 1 , wherein, the curling pipe section is located on a side of the end plate opposite to the battery unit.

3. The battery module according to claim 2 , wherein, the side plate extends along the thickness direction of the battery unit until covering on curling pipe section, and is welded and fixed with the curling pipe section.

4. The battery module according to claim 2 , wherein, the curling pipe section includes, along a curve direction of curling, a curling pipe fixing end that is connected with a plate surface of the end plate and a curling pipe free end that is connected with the curling pipe fixing end; the curling pipe free end contacts with the plate surface of the end plate and is kept inside the pipe of the curling pipe section.

5. The battery module according to claim 4 , wherein, the curling pipe free end contacts and is connected with the plate surface of the end plate, and at a contacting and connecting position, is abutted with the plate surface of the end plate and extends toward an outside of the pipe so as to form an extending section.

6. The battery module according to claim 5 , wherein, the extending section is welded and fixed with the plate surface of the end plate with which the extending section is abutted.

7. The battery module according to claim 1 , wherein, the curling pipe section and the edge-wrapped section are fixedly connected through welding.

8. The battery module according to claim 1 , wherein, two ends of the end plate in the height direction of the battery unit are provided with a pair of the edge-wrapped sections; the edge-wrapped section comprises an edge-wrapped fixing end that is connected with the plate surface of the end plate and an edge-wrapped free end that is connected with the edge-wrapped fixing end; a pair of edge-wrapped free ends of the edge-wrapped section respectively extend toward each other along an axial direction of the curling pipe section until being connected with each other, and form a firm connection between two edge-wrapped sections at a connecting position through welding.

9. The battery module according to claim 1 , wherein, a material of the end plate and the side plate is stainless steel, magnesium alloy, galvanized steel or carbon steel.