Positioning assembly and battery string conveying mechanism

The positioning assembly comprises a transmission belt, a diaphragm, a welding strip and a battery piece, the diaphragm, the welding strip and the battery piece are sequentially laid on the transmission belt, the width of the diaphragm is smaller than the width of the battery piece and the transmission belt, and the area, exceeding the two sides of the diaphragm, of the transmission belt is a first ventilation area. A first ventilation area is formed in the conveying belt, first-class ventilation holes are formed in the position, in the first ventilation area, of the conveying belt, the tops of the first-class ventilation holes correspond to the bottom faces of the battery pieces, and the bottoms of the first-class ventilation holes are connected with an external air source. The lower surface of the battery piece is adsorbed through the ventilation holes, so that the transmission belt is adsorbed and fixed on the transmission belt while driving the battery piece, the welding strip and the diaphragm to move, a