A new lithium battery discovery could mean greater energy efficiency for electric cars, laptops and phones, and having to re-charge them less often.
The lithium-air battery design sees lithium reacting with oxygen drawn from the air rather than ions in the battery.
Highlighted by the journal Nature, the battery is reported to store five times more than current lithium batteries, suggesting that phone and laptops would require less charging and electric cars going further.
The concept was developed by a US team, led by Amin Salehi-Khojin from the University of Illinois and Larry Curtiss from Argonne National Laboratory.
Photo credit: Amin Salehi-Khojin
Curtiss said one of the main challenges was the recycling charge times.
After further changes to the original design, the prototype ran successfully for 700 charging cycles.
Scientists have known since the 70s that lithium paired with oxygen introduced the potential for light power packs.
But as both are highly reactive, the design had to be perfect. Additional chemical reactions usually resulted in buildup on the electrodes, causing them to degrade quickly after a few charging cycles.
The new battery consisted of a coating of lithium carbonate and amorphous carbon on the anode, with a structure that allowed the lithium ions to pass through while blocking larger, problematic molecules such as oxygen and carbon dioxide.
The team was faced with a quandary: the cathode. The negatively charged electrode through which electrons enter the device, drawn from oxygen from the air.
Salehi-Khojin commented:
“The complete architectural overhaul we performed on this battery by redesigning every part of it, helped us enable the reactions we wanted to occur.”
Researchers connected the battery’s electrolyte innards to the outside air with the use of a spongy lattice, coated with molybdenum disulfate flakes, engineered to have molybdenum atoms on their edges.
The metallic edges and the ionic liquid in the electrolyte combined acted as a catalyst that promoted the desired outcome – lithium reacting with oxygen to form lithium peroxide.
