Until recently, it seemed that lithium-ion batteries would be the standard for many years to come. Analyses by researchers at Tsinghua University suggest that this variant is slowly being displaced by others.
One idea is to replace graphite anodes with lithium metal anodes. Batteries designed in this way should have a higher energy density, although, at the same time, problems in the form of reduced stability and susceptibility to reacting with the electrolyte could not be overlooked. Consequently, such batteries prove to have an unsatisfactory service life.
The detailed findings of the Chinese engineers who highlighted the SEI, or so-called interphase between the solid and the electrolyte. Such an interphase could, in theory, limit side reactions that have a negative impact on battery life. According to the Asian researchers, ASEI - an artificial solid electrolyte interphase - could be the key to success. With its involvement, the negative effects on the lithium metal anode could be reduced. If this were to happen, it would be possible to realistically think about producing batteries for use in electric vehicles or for storing resources supplied by renewable energy sources.
Details of the latest findings were presented at the Energy Materials and Devices. A solid-electrolyte interface usually forms on the lithium surface during battery operation. In addition to this, dendrites, or harmful microstructures, form, exacerbating the risk of battery failure and negatively affecting battery life. As both of these problems affect lithium-metal batteries, researchers are looking for ways to combat them. In the course of their analysis, they concluded that a uniform distribution of lithium ions would be needed.
Lithium-ion batteries have been a key option for many years, but recently researchers have been focusing more attention on alternatives
According to the researchers, such a treatment should translate into reduced dendrite formation, i.e. a decrease in battery failure rate. In addition to this, the study showed that a breakthrough in the distribution of lithium ions and the provision of electrical isolation of the layers should help maintain the integrity of the overall structure. As if that were not enough, the reduction in stress between the electrode-electrolyte interface should improve the connectivity between the layers, which also has a beneficial effect on the batteries.
Inorganic-hybrid and polymeric ASEI layers should work best, the research team believes. The former are proving particularly useful due to a reduction in layer thickness and a noticeable improvement in the distribution of components in the layers. The result is an increase in battery performance. Variant number two, on the other hand, is associated with extensive strength and flexibility adjustment capabilities. In addition, they feature compatibility, which is rarely seen otherwise. As for the challenges awaiting the engineers involved in this research, they will undoubtedly have to improve the adhesion of the ASEI layers to the metal surface and work on stability in the layers and limiting the thickness of the layers to increase the energy density of the metal electrodes.