A cell, a power battery pack, and an electric vehicle are provided. The cell includes a cell body, and the cell body has a length L, a width H and a thickness D. The length L of the cell body is greater than the width H, the width H of the cell body is greater than the thickness D, the length L of the cell body is greater than 600 mm, and the length L and the width H of the cell body satisfy L/H=4-21.