Researchers in India have combined two chemistries to boost the capacity retention of an anode material in lithium-ion batteries.
The team from the Indian Institute of Technology (IIT) Madras combined the lithium ion insertion reaction from lithium-ion batteries and the sulfur redox reaction from lithium-sulfur batteries to increase the battery’s overall capacity.
The team developed a novel carbon nanotube (CNT) composite that can deliver specific capacity retention of 1,120 mAh/g after 10,000 cycles.
CNT has advantages as an anode material, but suffers from discharged lithium ions not fully exiting the carbon nanotube, which affects the irreversible capacity of the carbon nanotube anode.
This means not all lithium ions inserted into the carbon nanotube contributes to the battery’s useful capacity.
The team overcome this by using carbon nanotubes with a few layers ‘unzipped’.
“These can be called as partially exfoliated carbon nanotubes,” said Sripada Raghu from the Department of Physics, IIT Madras and an author of the paper.
The joining of the two technologies helped the researchers achieve high capacity retention even after 10,000 cycles at high current density, said Ananya Gangadharan from the Department of Physics, IIT Madras and the first author of the paper.
“We have already patented our anode material. We are now trying to combine the anode with suitable cathodes and test the enhancement in efficiency and capacity retention so we can replace the commercial anodes with ours,” said professor Sundara Ramaprabhu from the Department of Physics, IIT Madras, a corresponding author of the paper.
The team are now working on using the material as an electrode in both lithium-ion and lithium-sulfur batteries to further enhance the capacity.
The results were published in the Journal of Materials Chemistry.
PIC: (From left) Prof. Sundara Ramaprabhu, Ananya Gangadharan and Sripada Raghu from the Department of Physics, IIT Madras have combined two storage mechanisms in one battery to achieve high capacity retention.