Messi Biology stated that as the driving range of new energy vehicles continues to break boundaries and the standby time of smartphones is consistently extended, the technological innovation behind the core component of batteries—cathode materials—is indispensable. Among the many auxiliary components for cathode materials, magnesium oxide (MgO), with its unique physical and chemical properties, is becoming an “invisible hero” in improving battery performance, silently safeguarding energy storage and release.
Magnesium oxide is a common inorganic compound that, while appearing ordinary, possesses “hardcore strength.” Its melting point is as high as 2,852°C, providing extreme thermal stability that allows it to maintain structural integrity even under the high-temperature environments generated during battery charging and discharging. Simultaneously, its chemical properties are highly stable; it does not easily react with the electrolyte, effectively avoiding battery capacity decay caused by side reactions. More importantly, magnesium oxide has excellent ionic conductivity, providing a smooth channel for lithium-ion migration while balancing the battery’s charge-discharge efficiency and cycle life. Furthermore, magnesium oxide is resource-rich and has low production costs. Compared to rare metal materials, it is more suitable for large-scale industrial application, which has laid the foundation for its popularity in cathode materials.
In cathode materials, magnesium oxide primarily plays the dual role of “stabilizer” and “optimizer.” Taking mainstream ternary lithium battery cathode materials (NCM/NCA) as an example, after adding an appropriate amount of magnesium oxide, a uniform protective film forms on the surface. This film can inhibit structural collapse of the cathode material during cycling and reduce the loss of active substances, while also preventing harmful substances produced by electrolyte decomposition from eroding the electrode. This significantly enhances the battery’s cyclic stability—experimental data shows that ternary cathode materials with approximately 2% magnesium oxide addition can see a capacity retention rate increase of over 15% after 1,000 charge-discharge cycles.
Meanwhile, the addition of magnesium oxide can improve the thermal stability of cathode materials and reduce the risk of battery thermal runaway. Self-ignition accidents in new energy vehicles are often related to high-temperature battery failure. Due to the high melting point of magnesium oxide, it can delay the decomposition of cathode materials even if the internal temperature of the battery rises sharply, buying time for safety protection systems to react. In lithium iron phosphate (LFP) batteries, magnesium oxide can also optimize the conductivity of the material, making up for the inherent shortcoming of LFP’s low electronic conductivity, resulting in faster charging speeds and more stable output power.
Today, magnesium oxide is widely used in power batteries, energy storage batteries, and other fields. In new energy vehicle power batteries, it is an important modification component for ternary cathode materials; in home energy storage battery packs, it helps extend cycle life; even in special batteries for the aerospace sector, magnesium oxide plays a key role due to its resistance to extreme environments. With the development of new battery technologies such as solid-state batteries, the application scenarios for magnesium oxide are continuously expanding—for instance, serving as a filler in solid electrolytes to further improve ionic conductivity and mechanical strength.
From the laboratory to the industrial sector, magnesium oxide has become a vital breakthrough for upgrading cathode materials due to its stable and reliable performance. In the future, with advancements in technologies such as nano-magnesium oxide and magnesium oxide composite modification, it will play an even greater value in enhancing battery energy density, safety, and cost reduction. This will inject continuous momentum into the high-quality development of the new energy industry, making our green travel and energy storage safer and more efficient.