Science & Technology, UK (Commonwealth Union) – Lithium metal solid-state batteries (Li-SSBs) are a type of rechargeable battery technology that utilize lithium metal as the anode (negative electrode) and a solid-state electrolyte instead of the conventional liquid electrolyte found in traditional lithium-ion batteries (Li-ion). In Li-SSBs, the solid-state electrolyte serves as a medium for lithium ions to travel between the anode and the cathode (positive electrode) during the charging and discharging process. The use of solid-state electrolytes can mitigate safety concerns linked to liquid electrolytes. Solid-state electrolytes are typically non-flammable, reducing the risk of fire or explosion in the event of battery damage or failure. This enhanced safety feature makes Li-SSBs attractive for various applications, including portable electronics, electric vehicles, and grid energy storage.
An enhanced electric vehicle (EV) battery may become a reality as a result of new research led by the University of Oxford scientists, that recently appeared in Nature. With the utilization of advanced imaging steps, this demonstrated mechanisms that bring about the failure of lithium metal solid-state batteries (Li-SSBs). The ability to eliminate this could lead to, solid-state batteries utilizing lithium metal anodes that can provide a step-change enhancement in EV battery range, safety, and performance, and assist in moving forward electrically powered aviation.
A co-lead author of the study Dominic Melvin, a PhD student at the University of Oxford, Department of Materials, says “Progressing solid-state batteries with lithium metal anodes is one of the most important challenges facing the advancement of battery technologies. While lithium-ion batteries of today will continue to improve, research into solid-state batteries has the potential to be high-reward and a game-changer technology.”
As the application of the solid electrolyte enhances safety, and the utilization of lithium metal results in greater energy storage, making it a great option. A key issue with Li-SSBs, however, is their vulnerability to short circuit as it is charged as a result of the growth of ‘dendrites’: filaments from lithium metal able to crack via the ceramic electrolyte. As a component of the SOLBAT project of the Faraday Institution, scientists from the University of Oxford, Departments of Materials, Chemistry, and Engineering Science, took the lead in a series of in-depth evaluations to gather vital information related to the way this short-circuiting occurs.
In this most recent research, the scientists applied an advanced imaging process known as X-ray computed tomography at Diamond Light Source for the visualization of dendrite failure in extraordinary detail as the charging process took place. The new imaging research demonstrated that the commencement along with the propagation of the dendrite cracks are different methods, took place by clear-cut underlying procedures. Dendrite cracks emerge as lithium gathers up in sub-surface pores. As the pores fill up, more charging of the battery will elevate the pressure, which brings about cracking. In contrast, propagation takes place with lithium only in part filling the crack, via a wedge-opening procedure that leads to the crack opening from the back.
These new details can pave the way ahead to overcome the technological obstacles of Li-SSBs, according to the scientists of the study. Dominic Melvin says “For instance, while pressure at the lithium anode can be good to avoid gaps developing at the interface with the solid electrolyte on discharge, our results demonstrate that too much pressure can be detrimental, making dendrite propagation and short-circuit on charging more likely.”
As indicated in a recent report by the Faraday Institution, SSBs have the ability to meet the requirements of 50 percent of the demand across the world for batteries in consumer electronics, 30 percent in transportation, and more than 10 percent in aircraft by the year 2040.
The recent finding on overcoming the obstacles in the use of Li-SSBs may pave the way for their increased usage.
