Lithium-air Batteries

Usage of lithium-air for storage

  The lithium–air (Li–air) battery is battery chemistry which uses reduction of oxygen at the cathode and oxidation of lithium at the anode to induce a current flow or a metal–air electrochemical cell. Lithium-air batteries (LABs) have great potential for efficient applications of energy storage so as to resolve future energy and environmental problems  

Lithium-air battery technology

The lithium-air batteries would work by combining lithium existing in the anode with air’s oxygen to produce lithium peroxide on the cathode during the phase of discharge. The cathode is simply the area where air enters the battery Combining lithium and oxygen can in theory lead to electrochemical cells with the highest potential specific energy which is comparable to the gasoline’s theoretical specific energy. This is nearly 5 times greater than that of Li-ion battery. Yet, Li–air batteries practical power and life cycle need significant advances before going mainstream. A huge market driver for batteries is the electrical vehicle sector. The Li–air batteries potentially have shown 5 to 15 times the specific energy of a Li-ion battery in 2016.  

Applications of Lithium-air batteries

 

• Grid backup

Using hybrid solar cell batteries was first reported in 2014. Nearly 20% of the produced energy by normal solar cell systems is wasted during transfer and charge of the battery. The system using LAB can theoretically store nearly 100% of the produced energy.

• Electrical Vehicles

Lithium–air cells are of extreme importance to electric vehicles sector, due to their theoretically high volumetric and specific energy density, in comparison to petrol. Electric motors can achieve much high efficiency than internal combustion engine (95% compared to 35%).    

Current Limitations of Lithium-air batteries

 

• Electrochemistry

The charge over potential is a lot higher than the discharge over potential. Significant charge over potential shows the occurrence of secondary reactions. Therefore, electric efficiency is only about 65%  

• Cathode

The cathode of the Lithium-air battery is the source of its potential advantages, yet it offers the most limitations as well. Incomplete discharge of the batteries, because of the blockage of the porous carbon cathode with different discharge products like lithium peroxide.

• Stability

Long term battery operation needs chemical stability of all components of the cell. Available cell designs show poor oxidation resistance to oxidation reaction byproducts. Aqueous electrolytes are volatile and evaporate over time and overall stability is hampered by the parasitic chemical reactions.