Messi Biology states that the main applications of magnesium hydroxide in lithium-ion batteries include the following:
(1) As an Electrolyte Additive to Improve Thermal Stability
Lithium-ion batteries are prone to thermal runaway at high temperatures, leading to short circuits and even fires.
Magnesium hydroxide possesses excellent thermal stability and heat absorption capabilities, making it suitable as a flame-retardant additive in electrolytes. It can inhibit the decomposition of lithium salts and reduce the risk of thermal runaway.
Magnesium hydroxide can also capture free hydrofluoric acid (HF), reducing the corrosion of battery internal materials by the electrolyte and thus extending battery life.
(2) As a Modifier for Cathode Materials to Enhance Battery Performance
Magnesium hydroxide can be used as a coating material, applied to cathode materials such as lithium nickel cobalt manganese oxide (NCM), lithium iron phosphate (LFP), or nickel cobalt aluminum (NCA) to prevent material structural degradation and improve battery cycle life.
A magnesium hydroxide coating can reduce side reactions between the electrode and the electrolyte, improve interface stability, and reduce capacity decay.
Research shows that a magnesium hydroxide coating can effectively improve the stability of cathode materials under high voltage (>4.3V) conditions, helping to develop high-energy-density batteries.
(3) As a Separator Coating to Improve Safety
Coating the surface of lithium battery separators (such as polyolefin separators) with magnesium hydroxide can significantly improve the separator’s heat resistance and mechanical strength.
Magnesium hydroxide can inhibit lithium dendrite penetration through the separator, reducing the risk of internal short circuits and improving battery safety performance.
This coating can also reduce internal side reactions and thermal decomposition of the battery, improving cycling stability.
(4) As a Modifier for Anode Materials to Improve Electrode Performance
Doping magnesium hydroxide into lithium battery anode materials (such as silicon-based or graphite anodes) can improve their electrochemical performance and enhance cycle life.
Magnesium hydroxide can buffer the volume expansion of silicon anodes during charging and discharging, reducing electrode pulverization and improving battery stability.
By controlling the nano-structure of magnesium hydroxide, the lithium-ion transport rate of the anode can be further optimized, improving rate performance.