Materials scientists discover new method to manufacture cathodes for Na ion battery
A new study from the Braun Group demonstrates a generalized electrochemical method to grow thick
energy dense cathodes for Na ion batteries. This is the first demonstration
of electrodeposition of thick ceramic oxide films of importance for sodium-based electrochemical
The research team at the University of Illinois includes Materials Science and
Engineering Professor Paul V. Braun; P.hD. student Arghya Patra and undergraduate student Jerome
Davis III; and collaborators Professor Daniel P. Shoemaker and Professor Jian Min Zuo, along
with members of their respective groups. All are researchers in the Materials Research Laboratory.
The new manufacturing method is of interest to both the basic materials science
community given the new growth method demonstrated, and companies interested in new
cathodes for sodium-ion based energy storage - in particular, companies interested in grid energy
storage. The grown materials exhibit nearly ideal electrochemical properties, and can be grown to
thicknesses of relevance for industry.
“Sodium-ion based batteries have the potential to be much more cost effective for energy storage
than lithium-based systems if new electrode materials and electrode growth technologies can be
developed,” said Paul Braun.
“Prior to our demonstration, only atmosphere stable thin oxide films could be synthesized by
electrodeposition technique,” said Patra. “Also, our work is the first demonstration
of a fabrication method that can synthesize binder and additive free sodium ion cathodes
that can perform similar to the solid-state synthesized slurry cast analogs.”
The electrochemically grown cathodes have higher volumetric and gravimetric capacities than
classically made slurry-based electrodes due to the absence of low-density binder and conductive
additives. One important feature of this electrodeposition process is that the orientation of
the crystals can be controlled such that the fast Na ion conducting directions in the crystal
can be preferentially oriented perpendicular to the current collector. This enables the materials
to charge and discharge quickly, even for very thick electrodes.
“Our molten hydroxide-based electrodeposition method allows access to
multiple electrochemically important polytypes across different transition metal chemistries in the
sodium transition metal oxide class of materials,” the team adds.
The next steps for this research is to further enhance the performance, in particular of the lowest
cost chemistries. Doing so would minimize the performance gap between this new class of Na ion
systems and classical, and more expensive, Li ion chemistries.
The paper, Electrodeposition of atmosphere-sensitive ternary sodium transition metal oxide films
for sodium-based electrochemical energy storage, is published in PNAS.
Significant aspects of the characterization were performed using the shared user facilities of the
University of Illinois Materials Research Laboratory.
Funding for the project was provided by the Office of Naval Research (ONR) through the Navy and
Marine Corps Department of Defense University Research-to-Adoption (DURA) Initiative, the U.S. Army
Construction Engineering Research Laboratory, and the National Science Foundation Engineering
Research Center for Power Optimization of Electro Thermal Systems