HOW DO LITHIUM-AIR BATTERIES WORK?
During discharge, lithium metal releases lithium ions and electrons.
The electrons flow through an external circuit to produce electrical power, while lithium ions migrate through the electrolyte toward the cathode.
At the cathode, lithium ions react with oxygen to form lithium oxide compounds that store energy within the discharge products.
The reaction is reversed during charging. Because oxygen participates in the reaction rather than being stored as a solid material inside the battery, lithium-air systems can dramatically reduce the mass of active materials required for energy storage.
Air Energy has unlocked a four electron reaction that allows for transformational energy storage to triple the range of drones and make electric aviation feasible.
Lithium-Air Reaction Pathways
Lithium-air batteries can operate through different electrochemical reaction pathways depending on the system architecture.
Three reactions are commonly discussed in lithium-air research: lithium superoxide, lithium peroxide, and lithia.
Lithium Peroxide Pathway (Li₂O₂)
Most lithium-air batteries studied historically operate through the formation of lithium peroxide (Li₂O₂).
This reaction occurs through a two-electron process during discharge.
The lithium peroxide pathway has a theoretical energy density of approximately 3,500 Wh/kg.
While this is already significantly higher than lithium-ion batteries, it is not the ultimate theoretical limit of lithium-air chemistry.
A second reaction pathway involves formation of lithium oxide (Li₂O) through a four-electron electrochemical reaction.
This pathway offers significantly higher theoretical energy density. The lithium oxide reaction has a theoretical energy density approaching ~5,000 Wh/kg; although the practical energy density is 1000-2000 Wh/kg.
Enabling stable lithium oxide formation and decomposition is one of the most important challenges in lithium-air battery research.
Air Energy is pursuing transformational improvements in energy density, including over 1,000 Wh/kg by unlocking the four-electron reaction.
The Four-Electron Lithium-Air Reaction
In advanced solid-state lithium-air batteries, the discharge product can form a mixed ion-electron conducting phase that enables the lithium oxide four-electron reaction.
Reaction Characteristics:
Discharge product
Mixed ion-electron conducting lithium oxide
Ionic transport
Solid electrolyte
Electronic transport
Solid cathode structure
Outcome
A properly engineered solid-state lithium-air architecture enables formation of lithium oxide through the four-electron pathway, unlocking extremely high theoretical energy density while maintaining stable reaction control.
Solid-state electrolytes also enable safer battery architectures by eliminating flammable liquid electrolytes.
This architecture creates Air Energy’s pathway toward safe, reliable, ultra-high-energy lithium-air batteries.
Learn more in our complete lithium-air battery guide.