NOVELTY - The battery (1) has battery single cells (2) i.e. coffee bag type cells, whose stack (3) is formed as self-contained flat cells, where the stack of the battery single cell is alternatively stacked with an intermediate member. Surfaces of the member of the battery single cells correspondingly form recesses on the surfaces of the battery single cells. The cells are formed, so that electrochemical active materials are welded into a film. The recess is formed, so that an edge area of the intermediate member lies beside the recess without contacting the respective cell in stacking direction.    USE - Battery e.g. heavy-duty battery such as lithium ion battery, for storing traction energy in an electric propelled car and fuel cell car. Can also be used for a hybrid car and a motor car.    ADVANTAGE - The surfaces of the intermediate member of the battery single cells correspondingly form the recesses on the surfaces of the battery single cells, thus realizing assembly of the battery in a simple and reliable manner while ensuring high safety for the battery. The intermediate member is designed as twin tub type between two adjacent battery single cells, thus ensuring safe stacking of the battery single cells with minimum number of components. The recess is formed, so that an edge area of the intermediate member lies beside the recess without contacting the respective cell in stacking direction, thus preventing rubbing contact between the edge area and the battery single cell. The cells are formed, so that electrochemical active materials is welded into the film, thus avoiding damage of the film with vibrations aroused in the vehicle, and hence preventing emerging of an electrolyte and destruction of vacuum of the battery single cell. The stack is automatically switched with appropriate stacking direction in series, so that the pole fits on a side of the stack and the other pole fits on the side of the stack, thus realizing battery in a simple and inexpensive manner.    DESCRIPTION OF DRAWING(S) - The drawing shows a top view of a battery.    Battery (1)    Battery single cells (2)    Stack (3)    End plates (4)    Clamping device (5)