Researchers Develop Cobalt-Free Cathodes for High-Density Lithium-Ion Batteries

Researchers from Oak Ridge National Laboratory (ORNL) have developed a new family of cathodes that could replace existing cobalt-based cathodes used in today’s lithium-ion batteries (LIBs). This new family on the block has been designed to improve LIB energy density, be fast charging, be more sustainable, and less costly to produce. 

 

ORNL researchers develop a cobalt-free family of cathodes. Image used courtesy of Oak Ridge National Laboratory 

 

LIB Materials in Demand

Consumer wearables and electric vehicles (EVs) are continually being developed and innovated to provide users with the best experience. The new family of cathodes generated at the ORNL could be a new alternative for use in next-generation LIBs used to power these types of applications. According to the lead scientist of the cobalt-free cathode research, Ilias Belharouak, over 100 million EVs are forecast to be on the road by 2030. The research by the ORNL researchers being highlighted here will be valuable for contributing to materials that are in high demand due to the high demand of LIBs for EVs. 

 

The Research 

The new family of cathodes is known as NFA and stands for nickel-, iron- and aluminum-based cathode. This is a derivative of lithium nickelate and can be utilized as a positive electrode within LIBs. The research concerning the testing of NFA performance was published in the journal Advanced Materials and the Journal of Power Sources.

The ORNL scientists used techniques known as neutron diffraction, Mossbauer spectroscopy and other advanced characterization to test NFA’s electrochemical properties, atomic- and micro-structures. The researchers preliminary results indicated that NFA’s displayed desirable properties that might mean that cobalt may no longer be needed to produce next generation LIBs. 

In a news release from ORNL, Belharouak provided his comments: “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.”

 

Dr. Ilias Belharouak. Image used courtesy of Oak Ridge National Laboratory 

 

Belharouak went on to explain that the usual go to cathode material is lithium nickelate, however, the material has certain deficiencies that come from intrinsic structural and electrochemical instabilities. This is one of the reasons why Belharouak and his team chose to use iron and aluminum to replace some of the nickel. These materials were also chosen as they are environmentally friendly, less costly, and sustainable. 

“We are developing a cathode that has similar or better electrochemical characteristics than cobalt-based cathodes while utilizing lower cost raw materials,” said Belharouak.

 

Cobalt-Free Cathodes

The cobalt-free nature of NFA is an important feature of the research. Cobalt sourcing from mines like those located in the Democratic Republic of the Congo (DRC) is known to be an unsustainable practice with negative consequences for miners and the surrounding habitat. This metal resource is also rare and as it is not locally sourced for a majority of buyers, can be costly. The research from ORNL could be a new avenue for using a cost-effective and more sustainable material for LIB production.

Further research by the ORNL team will involve testing the NFA class materials in large-format cells. This will help confirm the lab-scale results and allow for further study into the suitability of these cathodes for use in EVs.