Emerging research champions an iron-centric cathode for lithium-ion batteries, favoring affordability and heightened safety in comparison to standard components.
An endeavor jointly headed by Oregon State University’s chemistry expert Xiulei “David” Ji proposes iron as a feasible and eco-friendly cathode substance for lithium-ion batteries, potentially substituting high-priced elements such as cobalt and nickel. This breakthrough is likely to lead to greater energy capacity, a significant reduction in expense, and improved security. The prevalence of iron assures consistent availability, positioning this advancement as a pivotal move toward more eco-friendly battery systems.
The study, chronicled in a new edition of Science Advances, holds significance for numerous reasons. “We’ve altered iron metal’s reactivity, the most affordable metal on the market. Our electrode may surpass the current cathode solutions in electric vehicles in terms of energy density. And utilizing iron, which may cost below one dollar per kilogram – a minute portion compared to indispensable nickel and cobalt in today’s high-capacity lithium-ion batteries – the potential cost of our batteries is substantially decreased,” explains Ji.
Fiscal and Ecological Gains from Iron-Centric Cathodes
Presently, the cathode represents half the manufacturing cost of a lithium-ion battery unit. Iron-centric cathodes could diminish expenses while simultaneously heightening battery dependability and sustainability. The surging demand for lithium-ion batteries to energize electric vehicles puts stress on the limited supply of nickel and cobalt, with forecasted scarcities posing challenges for forthcoming production.
Moreover, the energy capacity of those components is approaching its limit. Reaching beyond could lead to the discharge of oxygen during the process of charging, potentially causing ignition of the batteries. Moreover, cobalt possesses a toxic nature, which holds the risk of environmental contamination and water pollution if released from disposal sites.
Collectively, said Ji, it’s straightforward to comprehend the worldwide pursuit for novel, more sustainable battery chemistries.
Comprehending the Constituents and Operation of Batteries
A battery accumulates energy as chemical potential and through specific reactions transforms it into electric energy for powering vehicles, portable computers, among other apparatus and machinery. A multitude of battery types exist, but the majority function in a fundamentally identical manner and encompass similar key elements.
A battery is made up of two electrodes – the anode and cathode, which are typically crafted from distinct substances – as well as a separator and electrolyte, a chemical concoction facilitating the transit of electric charge. Throughout battery operation, electrons migrate from the anode through an external pathway before congregating at the cathode.
In a lithium-ion battery, as its moniker suggests, lithium ions undertake the charge transfer as they journey in the electrolyte from the anode to the cathode while discharging, and reverse during the recharge phase.
“Our iron-based cathode isn’t restricted by resource scarcity,” articulated Ji, signifying that iron, apart from being the most frequently occurring element on Earth by mass, is also the fourth most prevalent element in Earth’s crust. “Iron won’t be depleted until the sun evolves into a red giant,” he postulated.
Inventive Chemical Formulation Elevates Iron’s Reactivity
Ji, along with associates from several universities and national research facilities, have heightened the iron’s reactivity within their cathode through the creation of a chemical milieu composed of a mixture of fluorine and phosphate anions – negative ions.
This composition, intricately blended into a homogenous solution, permits the reversible formation – denoting the battery’s ability to recharge – of a refined fusion of iron particles, lithium fluoride, and lithium phosphate into iron salts.
“We have proven that with the inventive design using anions, we can surpass the energy density ceiling for batteries that are more cost-effective and environmentally sound,” Ji stated. “We aren’t employing any lavish salt alongside iron – just standard ones used in the battery sector, plus iron particles. To integrate this novel cathode into applications, everything else remains unchanged – no new anodes, no inventive production methods, no redesign of the battery. We are merely substitifying one element, the cathode.”
Anticipated Advances and Ecological Repercussions
Although the storage efficacy still requires refinement, as currently not all the electric power input during charging is retrievable upon discharging, improvements are expected, Ji foresees. Once realized, the culmination will be a battery that outperforms existing models in effectiveness, cost, and environmental impact.
“Should investments flow into this innovation, it wouldn’t take long to reach the commercial market,” Ji suggested. “The pioneering minds of the industry must focus resources on this burgeoning sector. The globe could benefit from a cathode market grounded on a metal that, in contrast with cobalt and nickel, is almost without cost. And whereas cobalt and nickel require meticulous recycling efforts, recycling iron isn’t imperative – when discarded, it merely rusts away.”
Reference: “Unleashing iron metal as a cathode for ecofriendly Li-ion batteries through an anion solid solution” by Mingliang Yu, Jing Wang, Ming Lei, Min Soo Jung, Zengqing Zhuo, Yufei Yang, Xueli Zheng, Sean Sandstrom, Chunsheng Wang, Wanli Yang, De-en Jiang, Tongchao Liu and Xiulei Ji, 23 May 2024, Science Advances.
DOI: 10.1126/sciadv.adn4441
This exploration was financed by the Basic Energy Sciences program of the U.S. Department of Energy, with collaborative leadership by Tongchao Liu of Argonne National Laboratory, including Oregon State’s own Mingliang Yu, Min Soo Jung, and Sean Sandstrom. Researchers from Vanderbilt University, Stanford University, the University of Maryland, Lawrence Berkeley National Laboratory, and the SLAC National Accelerator Laboratory also made contributions.
Image Source: Korawat photo shoot @ Shutterstock
