By College of Engineering, Carnegie Mellon University.

Credit: Carnegie Mellon University and Northeastern University.

A team of researchers believes a paradigm shift is necessary to make a significant impact in battery technology for these industries.

This shift would take advantage of the anionic reduction-oxidation mechanism in lithium-rich cathodes.

Findings published in Nature mark the first time direct observation of this anionic redox reaction has been observed in a lithium-rich battery material.

Collaborating institutions included Carnegie Mellon University, Northeastern University, Lappeenranta-Lahti University of Technology (LUT) in Finland, and institutions in Japan including Gunma University, Japan Synchrotron Radiation Research Institute (JASRI), Yokohama National University, Kyoto University, and Ritsumeikan University.

Researchers attribute this to the anionic redox mechanism — in this case, oxygen redox.

Although this redox mechanism has emerged as the leading contender among battery technologies, it signifies a pivot in materials chemistry research.

The researchers observed how the electronic orbital that lies at the heart of the reversible and stable anionic redox activity can be imaged and visualized, and its character and symmetry determined.

While previous research has proposed alternative explanations of the anionic redox mechanism, it could not provide a clear image of the quantum mechanical electronic orbitals associated with redox reactions because this cannot be measured by standard experiments.

“We realized that our analysis could image the oxygen states that are responsible for the redox mechanism, which is something fundamentally important for battery research,” explained Hasnain Hafiz, lead author of the study who carried out this work during his time as a postdoctoral research associate at Carnegie Mellon.

“We have conclusive evidence in support of the anionic redox mechanism in a lithium-rich battery material,” said Venkat Viswanathan, associate professor of mechanical engineering at Carnegie Mellon.

Reference: “Tomographic reconstruction of oxygen orbitals in lithium-rich battery materials” by Hasnain Hafiz, Kosuke Suzuki, Bernardo Barbiellini, Naruki Tsuji, Naoaki Yabuuchi, Kentaro Yamamoto, Yuki Orikasa, Yoshiharu Uchimoto, Yoshiharu Sakurai, Hiroshi Sakurai, Arun Bansil and Venkatasubramanian Viswanathan, 9 June 2021, Nature.

June 10, 2021