Ellen Phiddian
Cosmos science journalist
A team of Chinese researchers have made a lithium-sulphur battery that can provide power even after being folded or cut in half.
The researchers, who have published their findings in ACS Energy Letters, say their battery demonstrates the potential for safer, cheaper lithium batteries.
Lithium-sulphur batteries could be more energy-dense and cheaper than lithium-ion, but it’s difficult to make them long-lasting.
The sulphur in the cathode of the battery tends to react with the electrolyte surrounding it, forming a hardened substance that can’t be used by the battery and so depletes its capacity.
This team, which is based at the University of Electronic Science and Technology of China, trialled coatings of battery cathodes to see if they could prevent the sulphur from reacting.
They found that polyacrylic acid was the most effective coating for sulphur-iron battery cathodes.
A cathode covered in polyacrylic acid was stable for 300 charge and discharge cycles.
The researchers used this coating to build prototype lithium-sulphur batteries, both in coin and pouch cell form (a flat, flexible pouch).
The pouch cell battery could last for 100 charge-discharge cycles without any obvious signs of decay.
It could also survive being folded and cut in half, still working afterwards.
The coin cell battery, meanwhile, lasted 300 charge-discharge cycles, keeping 72% of its original capacity.
“This study underscores the potential of conversion-type lithium batteries for achieving long cycle life and high safety,” write the researchers in their paper.
