Abstract: The present invention relates to batteries having explosion preventive safety features, comprising a rectangular shell having an open end, and an electrode core in the shell, and the open end of the shell sealed by a battery cover. An explosion-preventive groove is located on a large rectangular surface of the rectangular shell, where at least one point of the explosion-preventive groove is located on a diagonal of the large rectangular surface. In particular, the distance between the endpoint of the diagonal and the intersection point of the said explosion-preventive groove with the diagonal is less than one third (?) of the length of the diagonal. By adopting this invention, a battery can completely vent its air buildup, achieving the goal of complete pressure release.