A team of Cornell University researchers have discovered a new application of the element indium to improve the efficiency of lithium batteries — a fundamental component of electric vehicles.
Indium is a chemical element commonly found in touch screens, televisions and solar panels. In a Jan. 26 study published in Joule, lead author Shuo Jin grad and a Cornell Engineering team identified indium as a battery component that allows for rapid charging and long duration storage of energy. Utilizing the insights from the study, Cornell researchers developed a battery that charges in just under five minutes.
Although the development of electric vehicles has been vital in reducing greenhouse gas emissions, the reality remains that they are too expensive for most consumers. However, the new battery is a step toward consumer access to cheaper electric vehicle options, according to lab leader and Dean of the College of Engineering Prof. Lynden Archer, engineering.
“[Electric vehicle] makers have focused on building bigger batteries to achieve longer range travel,” Archer said. “[Bigger batteries] cost a lot more … the industry ends up building specialized products that only a subset of society can afford.”
According to Archer, indium is a unique battery component due to an unusually fast solid-state diffusivity for lithium. Solid-state diffusivity refers to the ability of a material — in this case charged lithium atoms — to move through the solid materials of the positive electrode — the battery component where electricity flows in. This flow of charged lithium atoms creates an electrical current that is then stored as energy for later use. Because an indium anode allows for faster lithium ion diffusion, the battery charges in a matter of minutes.
Additionally, indium helps distribute charged lithium atoms uniformly, which maintains the integrity of the electrode, especially through repetitive charging cycles. The more stable the electrode in a battery is, the less often the battery has to be replaced.
“[The balance of fast diffusivity and uniform distribution] is the secret for designing very fast-charging batteries that last a long time,” Archer said.
The researchers found that utilizing indium led to a low Damköhler number, a term that captures the relative speed between the transport of matter to a chemical reaction site and the rate the matter is consumed by the reaction. In this specific case, the Damköhler number represents the speed at which charged lithium atoms are transported at the indium anode. As a lower Damköhler number corresponds to a faster transport of reactants, it indicates a faster overall charging of the battery.
An indium battery can be repeatedly charged and used over hundreds of cycles while still maintaining its performance abilities, which is important when considering the sustainability of a car battery, according to Archer. The more lifetimes a battery can serve before getting repaired or replaced, the more it offsets the environmental impacts from its initial production.
While it improves battery charging and lifetime efficiency, indium is heavy. A heavier battery means a heavier car, which is far less efficient and usually requires significantly more power to travel the same distances.
To address the weight concern, Archer and his team blended indium with aluminum, an element much lighter but still chemically similar. Because both share important characteristics, blending the two may address the weight issue without compromising the beneficial properties of indium.
According to Archer, continued search for lighter materials with a consistently low Damköhler number may be aided by generative artificial intelligence — a tool capable of solving complex problems with multiply constrained solutions.
“A machine could excel at such searches because it frankly does not rest,” Archer said.
A significant amount of work lies ahead before batteries utilizing indium will be in cars, said Archer. In order to fully charge a new lithium and indium battery in just five minutes, stations would require an electric current about five to six times higher than what is currently possible.
Archer and the research team plan to continue investigating the capabilities and limitations of indium as well as other similar elements. They hope to lessen the need for large battery electric vehicles and make EVs accessible to a wider range of consumers. By uncovering other materials with potential to further improve car batteries, Archer hopes to contribute to lighter, easier-to-manufacture and lower-costing electric cars.
Madison Kim can be reached at [email protected].