Meaning
Mixed metal layered oxide cathode material designed for sodium ion batteries to provide a balanced profile of capacity and cost. The incorporation of nickel, iron, manganese and oxygen in nani1/3fe1/3mn1/3o2 allows for stable cycling over a wide voltage range. This material represents a move toward eliminating cobalt from the battery supply chain.
It functions as a host structure where sodium ions intercalate between metal oxide layers.
Redox Activity
Contribution of each metal ion to the total charge storage varies by voltage. Nickel and iron provide the primary capacity through their respective oxidation states while manganese maintains the structural integrity of the lattice. This synergy in nani1/3fe1/3mn1/3o2 helps mitigate the volume changes that occur during cycling.
Thermal Safety
Stability of the crystal structure at high temperatures is superior to many lithium ion equivalents. Because nani1/3fe1/3mn1/3o2 releases less oxygen when overheated, the risk of thermal runaway is reduced.
Hygroscopic Behavior
Sensitivity to ambient humidity requires specialized handling during the electrode manufacturing process. If nani1/3fe1/3mn1/3o2 absorbs water, it can lead to slurry gelation or the formation of resistive surface layers. Processing usually takes place in environments with a dew point below negative forty degrees.
The resulting increase in internal resistance can substantially shorten the life of the battery.
