What Factors Affect the Service Life of MMO Anode?

Mar 26, 2021

 What Factors Affect the Service Life of MMO Anode?

Mixed metal oxide (MMO) coated titanium anodes comprise a family of electrodes made from commercially pure titanium to which an electrocatalytic layer is applied by thermal decomposition. The electrocatalytic layers are composed of a mixture of noble and valve metal oxides, the selection of which and their ratio is dictated by the electrolyte conditions in which the anode is immersed.

The service life of MMO coated titanium anode range from about 3 years to 70 years. How comes this big difference? Generally, the MMO coating composition, applied current output, the electrolyte and fluorine ion presence, and concentration are all a factor to determine the anode service life.
MMO coating greatly prolongs the life of the anode, the coating component, coating thickness, the uniformity of the coating crystallographic structure.

The component of Iridium in mixed metal oxide coating can increase or deduct the anode service life. For example, if the iridium content is increased, the anode life will increase, no other factors changed.

The coating thickness can also affect the service life. For example, A anode is coated with 10 mg and 6 layers, B anode is coated with 5 mg and 3 layers. The service life of A anode is longer than B anode under the same condition.

Uniformity of MMO coating: When a small number of samples are made, they can apply the MMO coating uniformly. However, when a large number of anodes are produced, the MMO coating application may become sloppy, resulting in less uniformity of the MMO coating. This will cause local anode failure before it reaches the design life in thinly coated areas.