Oct 25 2017
Sometimes people may find simple solutions to complex problems, as shown by the group of INRS’s Dr. Lionel Roué, which skillfully enhanced the performance of silicon-based electrodes for lithium-ion batteries.
It is widely known that the electrodes’ robustness in these batteries, which are employed in a large number of devices, is key to their useful life. According to the group’s paper published in the Advanced Energy Materials journal, the performance of the electrode can be enhanced by up to ten times by using a maturation technique.
Professor Lionel Roué © Christian Fleury
Lithium-ion batteries (LiBs)—the most commonly used battery in electric vehicles and electronic devices—have many benefits, including low self-discharge, reduced memory effect, and a high energy density. However, as products advance, manufacturers have to make increasingly more efficient batteries. Making the batteries more flexible will be another challenge.
These new features put immense stress on the electrodes, which are a delicate element of LiBs. Researchers want to improve the electrodes’ mechanical properties in order to meet the above requirements, facilitate manufacturing, and boost the life of LiBs. This is particularly crucial for silicon-based electrodes, whose volume expansion may reach 270% in cycling.
Energy science and materials master’s student Cuauhtémoc Reale Hernandez created a postprocessing treatment for silicon-based electrodes in Dr. Roué’s laboratory, providing practical substance to the improvement sought. Electrodes are placed in a humid condition for two to three days before cell assembly. After that, they are dried and assembled.
Although this is very simple step, it leads to excellent results. It strengthens the connections between silicon particles, which considerably strengthen the electrode structure. In addition, connection between the electrode and the copper current collector film is also strengthened. This results in greater mechanical stability and a quick increase in the number of charge or discharge cycles supported by the LiB. Furthermore, silicon-based electrodes’ storage capacity is three times larger than that of the graphite anodes employed in commercial lithium-ion batteries.
Silicon-based electrodes that have gone through maturation are a simple solution that can be easily incorporated into the manufacturing process in order to produce more durable batteries, which are increasingly sought for both users of electric vehicles and electronic devices and the big companies that design them.