Manganese

Manganese is part of the cathode materials of various batteries, including some alkaline batteries and lithium-ion rechargeable batteries. Manganese dioxide is used in alkaline batteries, while certain manganese oxides allow energy storage and release through reversible electrochemical reactions. Its cost and availability are attractive for developing energy storage technologies. However, stability during charge and discharge cycles remains an important factor for improving the performance of some manganese-based batteries.

Manganese dioxide acts as the active material of the cathode in conventional alkaline batteries. During discharge, it participates in electrochemical reactions that allow converting stored chemical energy into electricity. It combines with other components, such as zinc at the anode and an alkaline electrolyte, to complete the operation of the battery. The quality and structure of the manganese dioxide influence its discharge capacity and the device's performance, so it is carefully selected and processed.

Manganese is an essential component of the complex that allows splitting water molecules during photosynthesis in plants, algae and cyanobacteria. This complex, integrated in photosystem II, uses a set of manganese and calcium atoms to facilitate a sequence of reactions that releases oxygen and electrons. The electrons then contribute to processes that allow converting light energy into chemical energy. Without adequate manganese supply, photosynthesis can be impaired and plant growth can decrease.

Manganese compounds are investigated as catalysts to accelerate chemical reactions in which bonds are reorganised or electrons and oxygen atoms are transferred. They can participate in oxidation, reduction and synthesis of organic molecules processes. One of their potential advantages is that manganese is more abundant and, in general, less costly than some metals traditionally used in catalysis. However, each system must be evaluated according to its activity, selectivity, stability and operating conditions.

Manganese improves the properties of many steels and facilitates their manufacture. During production, it helps reduce the harmful effects of sulphur by favouring the formation of manganese sulfide, which reduces certain problems during hot working. It can also increase mechanical and wear resistance. Steels with high manganese content, such as those used in certain impact- and abrasion-resistant parts, can harden during use and are especially suitable for demanding industrial applications.

Certain manganese compounds can modify the colour of glass because they absorb light at specific wavelengths. Historically, some compounds were added to compensate for the greenish tint that small amounts of iron as impurities produce. Depending on composition and manufacturing conditions, manganese can also contribute to achieving violet or pink tones. The result depends on the chemical state of manganese, the concentration used and the overall composition of the glass, not just the amount added.

Manganese is a necessary micronutrient for plant growth, as it participates in enzymatic processes and photosynthesis. When soil contains little available manganese, fertilisers containing this element can be used to correct deficiency. Application must be adjusted to the characteristics of the soil and the crop, because manganese availability changes with factors such as pH and aeration conditions. A insufficient amount can affect plant development, but excess can also be harmful.