Mathematical model breaks through the “pain point” of dendrites
Lithium metal batteries are the “closest relatives” of rechargeable lithium-ion batteries, which are widely used in portable electronics and electric vehicles. As a new generation of energy storage devices, lithium metal batteries have great prospects for development: Compared with lithium ion batteries, lithium metal batteries can store more energy, charge faster, and are lighter.
But at present, the commercial use of rechargeable lithium metal batteries is still limited. One of the main reasons for this is the formation of dendrites, which are metal-like, thin tree-like structures that grow as lithium metal accumulates on the electrodes of the battery. Not only do these dendrites degrade battery performance, they can also lead to battery failure and, in some cases, even fire. Therefore, how to prevent or slow down the formation of dendrites has become a “pain point” for effectively solving the degradation and failure of lithium metal batteries.
This time, Stanford University researchers developed a mathematical model that combines the physical and chemical problems involved in dendrite formation. The model provides a new insight that exchanging certain properties in a new electrolyte can slow or even completely stop dendrite growth. The electrolyte is the medium through which lithium ions move between the two electrodes within the battery.
“The purpose of our research is to help guide the design of lithium metal batteries with longer lifetimes,” said Weiyu Li, lead author of the paper and a doctoral student in energy engineering at Stanford University. physical process. “
“This study provides some specific details about the conditions under which dendrites form, and possible pathways to inhibit their growth.” H. H., a professor in Stanford’s School of Earth, Energy and Environmental SciencesAMDi A Tchelepi said.
Building a “digital avatar” of lithium metal batteries
The Stanford research team has proposed a new approach to electrolyte design, which involves finding materials with anisotropy, that is, materials that exhibit different properties in different directions. Anisotropic electrolyte materials can fine-tune the complex interplay between ion transport and interfacial chemistry to suppress dendrite formation. Some liquid crystals and gels can exhibit relevant properties, the researchers said.
Another theoretical approach found in his research focuses on battery separators, which prevent electrode contact and short-circuiting at both ends of the battery through thin films. The researchers believe that by engineering new separators with pore characteristics, lithium ions can be transported back and forth in the electrolyte in an anisotropic manner.
Based on the aforementioned research results, the team is building a digital representation of a lithium metal battery system, a “digital avatar” (DABS).
“This research is a key component of DABS.” Daniel Tartakovsky, a professor of energy engineering at Stanford University, said that the laboratory is carrying out related research and will use DABS to further improve the technical development level of lithium metal batteries in the future.