Mesh electrodes for underwater high-voltage direct current transmission, and parts and fittings thereof; electrodes; electrodes for use in connection with electrolysis apparatus and electricity power supplies; electrodes used in producing green hydrogen; electrodes for use in electrolysis and for transmission of electrical power; anodes; cathodes; negative poles; negative pole anticorrosion installments; electrochemical cells; electrolysis apparatus and installations; parts of electrolysis ce...