08. January 2025
(CONNECT) Researchers at the Paul Scherrer Institute (PSI) based in Villigen in the Swiss canton of Aargau have developed a new protective layer for the cathodes of lithium-ion batteries. According to a media release, the new coating is expected to decrease cathode degradation and increase both the battery’s lifespan and power output.
The research team led by Mario El Kazzi from the Center for Energy and Environmental Sciences at PSI has developed a method to stabilize the surface of a battery cathode. A protective layer, which is formed by a thin coating of lithium carbonate reacting with the gas trifluoromethane, is able to resist chemical and electrochemical degradation processes. These arise when the battery operates at above 4.3 volts.
The protective lithium fluoride layer created from the new reaction is not only able to withstand degradation processes but also enables higher voltages of 4.5 to 4.8 volts per battery cell, thus a greater energy density. Mario El Kazzi commented in the announcement: “One way to achieve this is to increase the operating voltage. If the voltage increases, the energy density also increases.”
Tests showed an additional effect of the new protective coating: after 100 charging and discharging processes, without a decrease in the charging speed, the battery capacity was still at 94 percent. Conventional batteries only show a capacity of 80 percent after this.
The trifluoromethane used to create the protective layer is formed as a by-product from the manufacture of plastics such as PTFE, PVDF, and foam. It is a highly effective greenhouse gas and more than 10,000 times more damaging to the environment than carbon dioxide. The new method could become a way to recycle the gas. ce/ww