In general lithium ions move between the anode and the cathode across the electrolyte. Under discharge, electrons follow the external circuit to do electric work and the lithium ions migrate to the cathode. During charge the lithium metal plates onto the anode, freeing O 2 at the cathode. Both non-aqueous (with Li2O2 or LiO2 as the discharge products) and aqueous (LiOH as the disc.
The lithium-air battery works by combining lithium ion with oxygen from the air to form lithium oxide at the positive electrode during discharge. A recent novel flow cell concept involving lithium is proposed by Chiang et al. (2009). They proposed to use typical intercalation electrode materials as active anodes and cathode materials.
What is a lithium air battery?
The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow. [ 1 ] Pairing lithium and ambient oxygen can theoretically lead to electrochemical cells with the highest possible specific energy.
How much energy does a lithium-air battery produce?
Theoretically, lithium–air can achieve 12 kW·h/kg (43.2 MJ/kg) excluding the oxygen mass. Accounting for the weight of the full battery pack (casing, air channels, lithium substrate), while lithium alone is very light, the energy density is considerably lower.
Why is lithium air battery a good choice for electric propulsion?
The lithium air battery has a high theoretical energy density due to the light weight of lithium metal and the fact that cathode material (O 2) does not need to be stored in the battery. It has always been considered as an excellent potential candidate for electric propulsion application.
Theoretically with unlimited oxygen, the capacity of the battery is limited by the amount of lithium metal present in the anode. The theoretical specific energy of the Li-oxygen cell, as shown with the above reactions, is 11.4 kWh/kg (excluding the weight of oxygen), the highest for a metal air battery.
Oxygen gas (O 2) introduced into the battery through the air cathode is essentially an unlimited cathode reactant source due to atmospheric air. Because of this the air cathode is the most important component of the system. The lithium metal reacts with oxygen gas to give electricity according to the following reactions: Discharge