New sustainable cathodes promise better Li-ion EV batteries

Technology News | December 23, 2020

By Rich Pell

The team at the Oak Ridge National Laboratory used a derivative of lithium nickelate and can be used to make the positive electrode of a fast charging lithium-ion battery. Neutron diffraction, Mossbauer spectroscopy and other characterization techniques examined the atomic- and micro-structure of NFA as well as electrochemical properties.

This is part of the US strategy to reduce the reliance on battery suppliers based in China and on materials such as cobalt sourced from unstable areas of the world.

“Our investigations into the charging and discharging behavior of NFA showed that these cathodes undergo similar electrochemical reactions as cobalt-based cathodes and deliver high enough specific capacities to meet the battery energy density demands,” said lead researcher Ilias Belharouak. “We are developing a cathode that has similar or better electrochemical characteristics than cobalt-based cathodes while utilizing lower cost raw materials,” he said.

Belharouak added that not only does NFA perform as well as cobalt-based cathodes, but the process to manufacture the NFA cathodes can be integrated into existing global cathode manufacturing processes.

“Lithium nickelate has long been researched as the material of choice for making cathodes, but it suffers from intrinsic structural and electrochemical instabilities,” he said. “In our research, we replaced some of the nickel with iron and aluminum to enhance the cathode’s stability. Iron and aluminum are cost-effective, sustainable and environmentally friendly materials.”

Future research and development on the NFA class will include testing the materials in large-format cells to validate the lab-scale results and further explore the suitability of these cathodes for use in electric vehicles.

www.ornl.gov

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