Scientists from the National Laboratory OK Ridge, working under the auspices of the US Department of Energy, have made significant progress in the development of solid batteries known as TTB (Transformational Transport Based on Batteries). The team focused on the mechanical aspects of these devices, aiming to enhance their performance and durability.
Their findings have been published in the journal Science and the Service Life of Batteries. Sergiy Kalnaus, a scientist from the group of multiple physical processes and ORNL streams, highlighted the importance of considering battery mechanics. The study covers various disciplines such as computational sciences, chemistry, and materials science, offering an interdisciplinary perspective on the factors influencing TTB performance.
One of the main advantages of TTB is the use of solid electrolytes, commonly made from glass or ceramics. This choice of materials significantly enhances safety and strength compared to the liquid electrolytes used in conventional lithium-ion batteries. Kalnaus emphasized that the presence of a solid electrolyte eliminates the risk of fire, making TTB less dangerous.
However, the development of TTB faces several challenges. The components of these batteries expand and contract during the charging process, which can lead to damage in the solid electrolytes. To prevent this, a significant amount of pressure is required to maintain the integrity of the system. Kalnaus stated that creating more flexible materials capable of withstanding stress without cracking is crucial for overcoming this obstacle.
Another critical aspect of TTB is the anode, which is often made of pure lithium, the most energy-intensive metal. However, this choice creates pressure that can damage the electrolytes. Eric Herbert, the head of ORNL’s mechanical properties and mechanics group, emphasized the need to develop new generations of anodes and solid electrolytes capable of maintaining stable mechanical interfaces.
The research group also highlighted the successes of using the LIPON (lithium-phosphorus-oxinitride) electrolyte, developed at ORNL in the early 1990s. This material demonstrates high resistance to mechanical stress and chemical corrosion.
A study funded by the US Department of Energy underscores the importance of understanding the factors influencing the lifespan of TTB. According to Kalnaus, the team has provided the scientific community with a roadmap for considering material mechanics in the development of new batteries.