A new particle-level cathode coating will increase the life and safety of lithium-ion batteries. The development is an effort of researchers at the Argonne National Laboratory, U.S. Department of Energy in collaboration with Hong Kong University of Science and Technology. The research was funded by the Office of Renewable Energy and Energy Efficiency, Vehicle Technologies, at the Department of Energy.
“The advancement is an exciting one,” said a distinguished fellow at Argonne and head of the Technology Development group, Department of Electrochemical Energy Storage within Chemical Sciences and Engineering division, Argonne National Laboratory.
Current Cathode Technology shows Limitations
Lithium batteries find extensive use. These are used to power electric cars to computers and cell phones, and are based on cathode coating technology for more than 15 years.
But this comes with limitations. The cathode coating is a partial one and covers only a small part of the exterior of the cathode particle. Also, the coating does not protect the cathode when operating at a high temperature or a high voltage.
Meanwhile, metal oxides composed of manganese, nickel, and cobalt are the cathodes that researchers were examining. A cathode with a high voltage charge generates oxygen, oxidizing the electrolyte, to create an unwanted layer on the cathodes and result in energy loss. The speed of these reactions increase at high temperatures, resulting in compromised performance of the battery itself.
Synthesized of a conducting polymer called PEDOT – this marks a ground-breaking one in lithium-ion battery technology. This is because the particle fully and completely protects, inside and out, each particle of the cathode from reactivity with the electrolyte.
The oxidative chemical vapor deposition method at Argonne is used to apply PEDOT. The technique uses gas to ensure the coating is applied to the cathode completely, forming a robust skin.