Abstract: Rechargeable electrochemical cell, with a negative electrode, which in charged state contains an active metal selected from the group of the alkaline metals, the alkaline-earth metals and the metals of the second subgroup of the periodic table of elements; an electrolyte solution based on sulfur dioxide; and a positive electrode containing the active metal, from where ions come out into the electrolyte solution during the charging process. A self discharge reaction takes place at the negative electrode, for which the sulfur dioxide of the an electrolyte solution reacts with the active metal of the negative electrode to form a poorly soluble compound. According to the invention, the electrochemical charge quantity of the sulfur dioxide in the cell, calculated with one faraday per mole sulfur dioxide, is smaller than the charge amount of the active metal which can be theoretically electrochemically accumulated in the positive electrode.

Abstract: Nonaqueous electrochemical cell (9) with a negative electrode (4), an electrolytic solution and a positive electrode (3). The operational safety is increased by the fact that the cell contains a salt (10) in solid state in the area of at least one of the two electrodes (3,4).

Abstract: An electrochromic unit (1) having an electrochemical cell with at least two electrodes (3, 4) applied to a carrier, an electrolyte (2) located between the electrodes (3, 4) and an electrochromic material (7), such as an electrochromic polymer, applied to one of the electrodes (3), is characterized by a proton exchange membrane (2) as a solid electrolyte and carrier for the bilaterally applied electrodes (3, 4), the electrochromic material (7) being positioned on the side of the electrode (3) carrying it remote from the membrane (2).