Scientists from UT Austin’s Cockrell School of Engineering have developed a new class of cathodes to do away with cobalt found in lithium-ion batteries.
According to the scientists, the new cathode is 89% nickel, with the other key elements being manganese and aluminum.
Cobalt is the mainstay of cathodes in high-performance batteries. However, finding a cobalt replacement has been doing the rounds for quite some time now – and for good reason too.
At a price of approximately $28,500 per ton, cobalt is more expensive than nickel, manganese and aluminum combined, and it makes up 10% to 30% of most lithium-ion battery cathodes.
It isn’t eco-friendly and its mining operations have been continuously cordoned and derided by human rights groups the world over.
The Cockrell team led by professor Arumugam Manthiram is the first to devise a cobalt-free high-energy lithium-ion battery. As they point out, more nickel in a battery means it can store more energy.
That increased energy density can lead to longer battery life for a phone or greater range for an electric vehicle with each charge.
Normally, increased energy density leads to certain trade-offs such as a shorter cycle life; eliminating cobalt usually slows down the kinetic response of a battery and leads to lower rate capability.
The Cockrell team has managed to overcome this by finding an optimal combination of metals and ensuring an even distribution of their ions.
According to Manthiram, the UT Austin breakthrough was achieved at the atomic level.
During synthesis, the scientists were able to ensure the ions of the various metals remained evenly distributed across the crystal structure in the cathode, thus avoiding performance loss.
Manthiram, Ph.D. graduate Wangda Li, and former postdoc Evan Erickson have now formed a startup called TexPower to bring the technology to market.
The study was funded by the U.S. Department of Energy (DOE), which has sought to decrease dependency on imports for key battery materials.
Image and content: Cockrell School of Engineering/UT Austin