breathing batteries could store 10 times the energy - lithium ion battery for solar street light
Lithium-ion batteries used in laptops and mobile phones, as well as lithium-ion batteries used in electric vehicles in the future, are close to their technical limits.
But British chemists say there is a way to break through the upcoming energy capacity barrier-to have the battery "breathe" oxygen from the air.
Standard lithium-ion batteries contain graphite negative electrode, lithium cobalt oxide positive electrode and lithium salt-
Contains electrolyte.
Lithium ion shuttles between the two electrodes during charging and discharging, sending electrons around the external circuit, powering the gadget in the process.
Peter Bruce of the University of St. Andrew says the problem with this design is that lithium cobalt oxide is huge in size and heavy in weight.
"The main obstacle to improving the energy density of these batteries is the positive pole," he said . ".
"Everyone wants to find a way to increase the amount of lithium stored there, which will increase the capacity.
He believes that the answer is to borrow an idea from zinc.
The air battery used in the hearing aid, which causes zinc to react with oxygen in the air.
So Bruce, in collaboration with colleagues at Strathclyde University and Newcastle University, began designing a lithium-air battery.
The energy density of the new battery is higher than that of the existing lithium ion battery because it no longer contains dense lithium cobalt oxide.
Instead, the positive electrode is made of lightweight porous carbon, and the lithium ion is filled into the electrolyte that penetrates into the sponge material.
When the battery is discharged, the oxygen in the air also passes through the membrane (see image, top)
In porous carbon, it reacts with lithium ions in the electrolyte and electrons in the external circuit to form solid lithium oxide.
When the battery is discharged, the solid lithium oxide gradually fills the gap inside the carbon electrode.
But when the battery is charged, the lithium oxide breaks down again, releasing the lithium ion again, releasing the void in the carbon.
Oxygen is released back into the atmosphere.
Most batteries have all the chemicals they need from the start.
"By using the oxygen in the environment, you can reduce the weight and volume because you don't have to carry the reagent inside the battery-you just need the carbon holder," Bruce said . ".
The new design is like a battery.
A fuel cell hybrid, Bruce said.
Like a fuel cell, it uses the reactants outside of the system, and like a battery, it also has the internal reactants.
The prototype equipment of the team has capacity-to-
The weight ratio is 4000 mA hours per gram, which is 8 times the battery of the mobile phone. Even a 10-
Folding improvement is possible, but adjusting the traditional lithium
Bruce estimates that the capacity of the ion design may be only double.
Chemist safer Islam studied batteries at the University of Bath and was not involved in the new design.
"My understanding is that lithium
It's possible that eight air batteries are available. to-10-
The energy density has doubled, "he told the New Scientist.
However, he added that work is still needed to fully understand the process that takes place in the new battery.
This will help optimize the technology and make it commercially viable.
Bruce and his colleagues are now trying to change their evidence. of-
Like the battery used in mobile electronics, the principle version becomes a small working battery.
"But this technology may be just as important for electric and hybrid cars in the future," Bruce noted . ".