The main structure of electrolytic bath

electrode
The anode
The effect of anode and cathode, on the material requirements also vary.
Points two categories, soluble and insoluble.In the refined copper electrolytic cell, for soluble anode materials for refining crude copper.It into in the process of electrolytic solution, to replenish from the precipitate in the solution on cathode copper.In electrolytic solution (such as salt aqueous solution) using electrolytic cell, for insoluble anode, basic don't change them in the electrolytic process, but for the electrode on the surface of the anode reaction often has a catalytic role.In the chemical industry, USES mostly insoluble anode.titaniumCN
Anode material should meet the basic requirements of general electrode materials (such as electrical conductivity, catalytic activity intensity, processing, source and price), still need strong in anodic polarization and high temperature of the fluid of the anodic dissolution and passivation, has the very high stability.For a long time, graphite anode materials is the most widely used.But porous graphite, mechanical strength is poor, and easily oxidized to carbon dioxide, are constantly in the process of electrolytic corrosion spalling, electrode spacing increases gradually, slot voltage rise.Used in electrolytic salt aqueous solution, the analysis on the graphite electrode overpotential is higher also.
The cathode
With metal or alloy as the cathode, due to the work under more negative potential, often can play a role of cathodic protection, corrosion resistance is small, so easy to choose cathode materials.In aqueous solution in the electrolytic cell, cathode generally produce hydrogen evolution reaction, higher overpotential.So the cathode material of the main improving direction is to reduce hydrogen evolution overpotential.In addition to lead must be used when using sulfuric acid as electrolyte and graphite as cathode, low carbon steel is a common cathode materials.Methods used to reduce power consumption, the current preparation of high specific surface area, and has the catalytic activity of the cathode, such as porous nickel plating cathode.
The diaphragm
In order to prevent the product mix, Yin and Yang poles to avoid the possibility of harmful reaction, in the electrolytic cell, basically use the diaphragm to Yin and anode chamber is separated.Diaphragm needs to have certain porosity, can make the ions, and not make the molecules or bubbles through, when have a current flows through the diaphragm of the ohmic voltage drop.These performance requirements in use process, and requirements in the Yin, the anode chamber under the action of the electrolyte, good chemical stability and mechanical strength.Electrolysis of water, the Yin and the anode chamber with liquid electrolyte, electrolytic cell membrane to separate Yin and anode chamber, in order to ensure the purity of hydrogen, oxygen, and to prevent hydrogen and oxygen mixture explosion.More complex situation is Yin in electrolytic cell anode chamber, different composition of the electrolyte.At this time also need to prevent Yin, anode diaphragm chamber and electrolyte in electrolytic product diffusion effect, such as chlor-alkali production in the diaphragm electrolyzer diaphragm method, can increase the cathode chamber hydroxyl ion diffusion into the anode chamber and migration resistance.