TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Parameter: greater than or equal to 85, preferably greater than or equal to 98% of the hydrogen gas is prevented from entering the electrolyte chamber.    TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The crosslinking agent comprises an alkali metal silicate and/or an alkali metal pyrophosphate. It comprises xylitol and/or sorbitol. It comprises formaldehyde. The anode comprises a metal mesh current collector, where metal comprises nickel.    TECHNOLOGY FOCUS - POLYMERS - Preferred Parameter: The electric resistivity of a combination of the anode with the polymeric material is not higher than 1, preferably 0.8 0hm.cm2. The homopolymer and/or copolymer of vinyl alcohol have a weight average molecular weight of not greater than 100000, not less than 30000. A weight ratio of the polymer(s) with a hydrophilic group and the crosslinking agent is 2:1-1:2. Preferred Component: The surface of the anode is covered with a single layer of polymeric material. greater than or equal to 2 layers of polymeric material are arranged on the surface of the anode. They comprise different polymeric materials. The polymeric material comprises layer(s) of polymeric material, where layers have a total thickness of not greater than 200, preferably greater than or equal to 25 microns. The polymeric material comprises a polymer(s) with a hydrophilic group from carboxylic acid COOH, sulfonic acid (SO3H), and/or hydroxide (OH) groups. The polymer(s) with a hydrophilic group comprises a homopolymer and/or a copolymer of vinyl alcohol and ethylenically unsaturated comonomer(s). The copolymer of vinyl alcohol comprises a vinyl alcohol/ethylene copolymer. At least a part of the polymeric material is capable of swelling in an aqueous solution. The polymer(s) with a hydrophilic group is at least partially crosslinked, with a crosslinking agent, which comprises a polymer that has a functional group(s), which is capable of reacting with a functional group of the hydrophilic polymer. It comprises a polymer having OH groups; and the crosslinking agent comprises a polymer from polyethylene glycol and/or polyethylene oxide. The crosslinking agent comprises a polyethylene glycol with a number average molecular weight of 300-10000; a polyethylene oxide with a number average molecular weight of 35000-200000. The polymer(s) with a hydrophilic group is at least partially crosslinked with a crosslinking agent(s) from a silicate, a pyrophosphate, a sugar alcohol, or an aldehyde. The anode comprises a binder, which comprises polytetrafluoroethylene. Preferred Composition: The copolymer of vinyl alcohol comprises greater than or equal to 50 mol.% of vinyl alcohol units. EXAMPLE - A solution was prepared by dissolving polyvinyl alcohol (PVA) (7.31 g) and polyethylene glycol (PEG) (4.69 g) in de-ionized water (88 g) under stirring, and heating the mixture at 70degreesC for 2 hours. One ml of the solution was applied onto one surface of the anode (20 cm2), and was then dried in air at ambient temperature for 20 minutes. Then 1 ml of the same solution was applied onto the first layer, where after the anode was dried at 120degreesC for 2 hours. The resistivity of the resultant coated anode was 0.8 Ohm.cm2, and the gas-blocking efficiency was 99%.