Recombination system having a recombination device for catalytically recombining hydrogen and oxygen arising in storage batteries to form water, wherein the recombination device comprises at least one catalyst material in at least one subregion above a center line of the recombination device in relation to a position of a retainer of the recombination system for the recombination device has a first partial amount of the catalyst material, wherein the first partial amount is greater than a second partial amount of the catalyst material, which second partial amount is located originating from the center line of the recombination device toward the retainer.

A cathode-active material for a proton-conducting secondary battery, the cathode-active material being for use in a proton-conducting secondary battery, the cathode-active material comprising a compound that is a solid solution that has a composition containing Mn.

Recombination system having a recombination device for catalytically recombining hydrogen and oxygen arising in storage batteries to form water, wherein the recombination device comprises at least one catalyst material in at least one subregion above a center line of the recombination device in relation to a position of a retainer of the recombination system for the recombination device has a first partial amount of the catalyst material, wherein the first partial amount is greater than a second partial amount of the catalyst material, which second partial amount is located originating from the center line of the recombination device toward the retainer.

A lead-acid battery comprises a flame arrestor plug (1) for controlled venting of gases from the battery through the vent hole (3), wherein the flame arrestor plug has a valve element (5) for controlling the venting of gas from the vent hole and a plug portion (4) which is adjacent to or in contact with the battery casing (2) around the vent hole and which, together with the battery casing, defines a flow path through which gases released through the valve element can escape from the battery, at least a portion of the flow path being of sufficiently narrow cross-section to prevent propagation of a flame along the flow path.