Longer Lasting And Sustainable Sodium-sulfur Batteries To Replace Lithium Batteries
The combination of abundant, accessible, economical and sustainable materials, such as sodium, sulfur and iron, allows the development of batteries that can be charged and discharged more than 2,000 times.
The use of mobile phones, laptops, electric cars, tablets or smart watches requires functional batteries that provide sufficient energy and do not take too long to charge, but that are also environmentally friendly. The main batteries that dominate the market, however, use a component, lithium, which is scarce, geographically concentrated and accompanied by toxic metals. For this reason, research by the Inorganic Chemistry group at the University of Córdoba, based on the doctoral thesis of researcher Álvaro Bonilla, has developed a sodium and sulfur battery capable of charging and discharging more than 2,000 times.
“On average,” explains Álvaro Caballero,
a lithium battery used in phones or cars is considered to be charged every 3 days, which means more than 120 charges per year.
The team has therefore managed to develop a battery that, following this estimate, could operate for more than 15 years with sustainable and abundant elements.
Specifically, the team has replaced all toxic metals on the battery’s positive electrode, the cathode, with sulfur, an abundant, low-cost, environmentally sustainable material that has the capacity to provide twice as much practical energy as those metals. On the other side of the battery, the negative electrode or anode, they have replaced the more inconvenient material, lithium, with sodium, a more abundant, accessible resource with energy similar to lithium.
However, this new sodium-sulfur battery faced a major challenge that made it difficult to operate: the sodium atom is larger than the lithium atom, so its movement when charging and discharging the battery was more difficult. To solve this, the team added a metallic and organic structure (called MOF) based on iron, an abundant, cheap and sustainable metal, to the cathode, along with the sulfur. Thanks to the porosity of this structure and the iron atom, the team managed to get the battery to work for more than 2,000 charge cycles through laboratory tests,
Álvaro Caballero, adds :
a performance that is difficult to achieve with batteries of this type,
In addition, the team has managed to get the battery to work at room temperature, since this type of battery that combines sodium and sulfur already existed on the market but only worked at temperatures of 300 degrees. Even so, there are still many steps to take and research continues its studies to try to get the battery to charge as quickly as possible, going from the hour it currently takes to 10 minutes.
The research, published in the Journal of Power Sources and carried out in collaboration with the National University of San Luis (Argentina), is part of the project
Transition from Lithium to Sodium in Sulfur batteries: Towards a technology based on abundant, economic and sustainable elements
(PID2020-113931RB-I00), funded by the Ministry of Science and Innovation.
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Longer Lasting And Sustainable Sodium-sulfur Batteries To Replace Lithium Batteries, source
