A battery module, comprising: a plurality of battery cells arranged in a horizontal direction, and a plurality of bus bars electrically connected to the plurality of battery cells; each of the battery cells comprising: a battery case, and an electrode assembly accommodated in the battery case; wherein the electrode assembly comprising: a first electrode sheet, a second electrode sheet, and a separator disposed between the first and second electrode sheets (111, 112); wherein the electrode assembly has a wound structure, an outer surface of the electrode assembly comprises two flat faces that face each other in a vertical direction, or the electrode assembly has a laminated structure, the first and second electrode sheets (111, 112) and the separator are stacked in the vertical direction; wherein a dimension of the battery module in the horizontal direction is larger than a dimension in the vertical direction; and the battery module further comprises: a tying band, and two end plates; wherein the tying band comprises two long sides facing a first surface and extending in a horizontal direction, and two short sides facing a second surface and extending in the vertical direction; wherein the two end plates respectively are arranged at two ends of the plurality of battery cells in the thehorizontal direction, and the tying band surrounds an outer periphery of the plurality of battery cells and the two end plates; wherein a surface of the two end plates away from the plurality of the battery cells is provided with a tying band limiting slot, the tying band limiting slot extends along the vertical direction, and the two short sides of the tying band are received in the tying band limiting slot; or the two end plates are internally provided with a tying band limiting hole, the tying band limiting hole extends along the vertical direction, and the two short sides of the two tying bands pass through the tying band limiting hole. a plurality of battery cells arranged in a horizontal direction, and a plurality of bus bars electrically connected to the plurality of battery cells; each of the battery cells comprising: a battery case, and an electrode assembly accommodated in the battery case; wherein the electrode assembly comprising: a first electrode sheet, a second electrode sheet, and a separator disposed between the first and second electrode sheets (111, 112); wherein the electrode assembly has a wound structure, an outer surface of the electrode assembly comprises two flat faces that face each other in a vertical direction, or the electrode assembly has a laminated structure, the first and second electrode sheets (111, 112) and the separator are stacked in the vertical direction; wherein a dimension of the battery module in the horizontal direction is larger than a dimension in the vertical direction; and the battery module further comprises: a tying band, and two end plates; wherein the tying band comprises two long sides facing a first surface and extending in a horizontal direction, and two short sides facing a second surface and extending in the vertical direction; wherein the two end plates respectively are arranged at two ends of the plurality of battery cells in the thehorizontal direction, and the tying band surrounds an outer periphery of the plurality of battery cells and the two end plates; wherein a surface of the two end plates away from the plurality of the battery cells is provided with a tying band limiting slot, the tying band limiting slot extends along the vertical direction, and the two short sides of the tying band are received in the tying band limiting slot; or the two end plates are internally provided with a tying band limiting hole, the tying band limiting hole extends along the vertical direction, and the two short sides of the two tying bands pass through the tying band limiting hole. a tying band, and two end plates; wherein the tying band comprises two long sides facing a first surface and extending in a horizontal direction, and two short sides facing a second surface and extending in the vertical direction; wherein the two end plates respectively are arranged at two ends of the plurality of battery cells in the thehorizontal direction, and the tying band surrounds an outer periphery of the plurality of battery cells and the two end plates; wherein a surface of the two end plates away from the plurality of the battery cells is provided with a tying band limiting slot, the tying band limiting slot extends along the vertical direction, and the two short sides of the tying band are received in the tying band limiting slot; or the two end plates are internally provided with a tying band limiting hole, the tying band limiting hole extends along the vertical direction, and the two short sides of the two tying bands pass through the tying band limiting hole.