A team of researchers at the University of Maryland have announced a transformative development in the race to produce batteries that are at once safe, powerful and affordable.
The researchers are developing game-changing solid-state battery technology, and have made a key advance by inserting a layer of ultra-thin aluminum oxide between lithium electrodes and a solid non-flammable ceramic electrolyte known as garnet. Prior to this advance, there had been little success in developing high-performance, garnet-based solid-state batteries. This is because the high impedance, more commonly called resistance, between the garnet electrolyte and electrode materials limited the flow of energy or current, hampering the battery's ability to charge and discharge.
The ultrathin aluminum oxide solved this problem by reducing the impedance 300-fold. This virtually eliminates the barrier to electricity flow within the battery, leading to efficient charging and discharging of the stored energy. A paper describing the research is published in Nature Materials.
"This is a revolutionary advancement in the field of solid-state batteries – particularly in light of recent battery fires, from Boeing 787s to hoverboards to Samsung smartphones," said Liangbing Hu, associate professor of materials science and engineering and one of the corresponding authors of the paper. "Our garnet-based solid-state battery is a triple threat, solving the typical problems that trouble existing lithium-ion batteries: safety, performance and cost."
"Our garnet-based solid-state battery is a triple threat, solving the typical problems that trouble existing lithium-ion batteries: safety, performance and cost."Liangbing Hu, University of Maryland
Lithium-ion batteries typically contain a liquid organic electrolyte that can catch fire, as shown by numerous battery fires in consumer electronic devices and even the temporary grounding of the Boeing 787 fleet for a series of battery fires. This fire risk is eliminated by the use of the non-flammable garnet-based solid-state electrolyte.
"The work by [the University of Maryland research team] effectively solves the lithium metal-solid electrolyte interface resistance problem, which has been a major barrier to the development of a robust solid-state battery technology," said Bruce Dunn, a materials science and engineering professor at the University of California, Los Angeles. Dunn, a leading expert in energy storage materials, was not involved in this research.
In addition, the high stability of these garnet electrolytes allow the team to use metallic lithium anodes, which contain the greatest possible theoretical energy density and are considered the 'holy grail' of batteries. Combined with high-capacity sulfur cathodes, this all solid-state battery technology offers a potentially unmatched energy density that far outperforms any lithium-ion battery currently on the market.
"This technology is on the verge of changing the landscape of energy storage. The broad deployment of batteries is critical to increase the flexibility of how and when energy is used, and these solid-state batteries will both increase the safety and decrease size, weight and cost of batteries," said Eric Wachsman, professor and director of the University of Maryland Energy Research Center and the other corresponding author of the paper.
"This [finding] is of considerable interest to those working to replace the flammable liquid electrolyte of the lithium-ion rechargeable battery with a solid electrolyte from which a lithium anode can be plated dendrite-free when a cell is being charged," said acclaimed lithium-ion battery pioneer John Goodenough at the University of Texas, who was unaffiliated with the study.
This story is adapted from material from the University of Maryland, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.