Lithium, widely used in batteries for its long-lasting and stable energy storage properties, is a finite resource. As concerns grow over its limited availability, researchers are actively seeking alternative materials for battery production. A team from McGill University, utilizing the Canadian Light Source at the University of Saskatchewan, has recently developed a method to replace most of the lithium in batteries with sodium.
The primary obstacle in using sodium for batteries lies in the cathode material's instability when exposed to air. This poses a significant challenge for retooling existing manufacturing facilities currently producing lithium-ion batteries. Eric McCalla, an associate professor in McGill's Department of Chemistry, explains that sodium reacts with carbon dioxide and water vapor in the air, forming sodium carbonate and other products. Water can infiltrate the material, converting it into a structure unsuitable for battery use.
McCalla's team employed what they term "wild substitutions" to simultaneously test the impact of 52 different elements on the stability of a sodium-ion battery. The HXMA beamline at the Canadian Light Source facility provided detailed, localized information about the battery after use, enabling researchers to identify which elements effectively maintained battery stability when used alongside sodium.
To process the vast amount of data generated, which included numerous interrelated variables, McCalla's team leveraged machine learning. This powerful tool helped rationalize large quantities of complex information by decoupling variables and creating sophisticated functions that account for all competing parameters. This approach allowed researchers to discern which materials genuinely affected performance and which variables played lesser roles.
While sodium-ion batteries show promise, they still have a considerable journey ahead before fully displacing lithium-ion batteries, especially in electric vehicles. McCalla acknowledges that lithium batteries have benefited from over 40 years of research and development, setting a high bar for alternatives. However, he remains optimistic about the progress made and emphasizes the team's commitment to further improving these materials.
The research conducted at the Canadian Light Source facility represents a significant step towards more sustainable energy storage solutions. As a national research facility of the University of Saskatchewan and one of Canada's largest science projects, the CLS hosts over 1,000 academic, government, and industry scientists annually, facilitating innovative research in health, agriculture, environment, and advanced materials.
With continued support from organizations such as the Canada Foundation for Innovation, Natural Sciences and Engineering Research Council, Canadian Institutes of Health Research, the Government of Saskatchewan, and the University of Saskatchewan, the pursuit of sustainable alternatives to lithium batteries remains a critical area of research and discovery.
