Electrochemical storage device with improved electrical conduction characteristics

The device (100) has an anode compartment (11) filled with anode material (10), and a cathode compartment (21) filled with cathode material (20). The anode compartment is separated from the cathode compartment by ions conducting solid body electrolytes (30). A wall (40) has an electrically conducting wall section (45) that is attached to the anode compartment. An electrical conducting section (50) is electrically connected with the wall section over a surface (55), where electric conductivity per surface of the conducting section is larger than wall per surface of the wall section. An independent claim is also included for a thermal module.