Quan Nguyen is a chemical and biomolecular engineering doctoral alum and lead author on the study. Credit: Jeff Fitlow/Rice University
Key points:
- Engineers developed a process for coating silicon anodes to aid in mitigating lithium loss.
- The new method improved battery life up to 44%.
- The team is working to optimize cycling strategies to allow for higher energy density of silicon-based anodes.
Silicon anode batteries have the power to revolutionize energy storage capabilities, which is key to unlocking the full potential of electric vehicles. The one drawback is the irreversible depletion of lithium ions in silicon anodes, which is a major impediment to the development of next-generation lithium-ion batteries.
In a study published in ACS Applied Energy Materials, scientists at Rice University have developed a scalable method to optimize prelithiation, a process that helps mitigate lithium loss and improves battery life cycles by coating silicon anodes with stabilized lithium metal particles (SLMPs).
Replacing graphite with silicon in lithium-ion batteries would significantly improve their energy density because graphite can pack fewer lithium ions than silicon. However, silicon presents other challenges. It continually forms a solid-electrolyte interphase, or SEI layer, that actually consumes lithium.
The prelithiation method developed by Rice researchers stops that consumption by spray-coating the anodes with a mixture of SLMPs and a surfactant. The study showed this improved SEI layer stability, which in turn improved battery life by 22% to 44%.
While SLMPs and prelithiation are not new, the researchers were able to enhance the process in a way that is readily incorporated into existing battery manufacturing processes.
“One aspect of the process that is definitely new and that [researchers] developed was the use of a surfactant to help disperse the particles,” said Rice engineer Sibani Lisa Biswal. “This has not been reported before, and it's what allows you to have an even dispersion. So instead of them clumping up or building up into different pockets within the battery, they can be uniformly distributed.”