To produce lithium-ion battery cathodes without using cobalt, a material beset by price volatility and geopolitical issues, researchers at the University of California, Irvine, and four national laboratories have developed a method.
In a work that was just published in Nature, the researchers explain how they mixed in several additional metallic elements to overcome the thermal and chemical-mechanical instability of cathodes that were mostly made of nickel, a typical cobalt alternative. Hullin Xin, corresponding author, and professor of physics and astronomy at UCI said, “Through a method, we call ‘high-entropy doping,’ we were able to effectively build a cobalt-free multilayer cathode with extraordinarily high heat tolerance and stability across multiple charges and discharge cycles. This accomplishment allays long-standing safety and stability worries regarding high-nickel battery materials, opening the door for several commercial uses. According to the authors of the article, cobalt poses one of the greatest dangers to the supply chain that might prevent the broad adoption of electric vehicles, trucks, and other electronic gadgets that require batteries.
Cobalt usage in battery packs is being restricted by electric car makers, not just to save costs but also to stop the exploitation of child labor in mineral mining, according to Xin. “Additionally, studies have demonstrated that cobalt can cause lithium-ion batteries to lose their ability to store energy by releasing oxygen at high voltage. The necessity for alternatives is made clear by all of this.” However, nickel-based cathodes have their issues, including as low heat tolerance, which can result in battery material oxidation, thermal runaway, and even explosion. Even though high-nickel cathodes can support greater capacities, volume strain from frequent expansion and contraction can lead to poor stability and safety issues. The researchers employed HE-LMNO, an amalgamation of transition metals magnesium, titanium, manganese, molybdenum, and niobium the inside of the structure, with a subset of these minerals used on its surface and contact with other battery materials, to solve these concerns.
