May 15 2024Reviewed by Lexie Corner
Linköping University researchers created a battery comprised of zinc and lignin that can be used over 8000 times. This provides a low-cost, long-lasting battery option for countries with limited access to energy. The findings have been published in the journal Energy & Environmental Materials.
Reverant Crispin and Ziyauddin Khan, researchers at the Laboratory of Organic Electronics. Image Credit: Thor Balkhed
Solar panels have become relatively inexpensive, and many people in low-income countries have adopted them. However, near the equator, the sun sets at around 6 PM, leaving households and businesses without electricity. The hope is that this battery technology, even with lower performance than the expensive Li-ion batteries, will eventually offer a solution for these situations.
Reverant Crispin, Professor, Department of Science and Technology, Linköping University
His research group at the Laboratory of Organic Electronics, in collaboration with Karlstad University and Chalmers researchers, has created a battery made of zinc and lignin, two cheap and ecologically beneficial components. It has the same energy density as lead-acid batteries but does not contain hazardous lead.
Stable Battery
The battery is stable—it can be used over 8000 times while retaining around 80 % of its functionality. The battery also holds its charge for around a week, which is substantially longer than traditional zinc-based batteries that drain in only a few hours.
Although zinc-based batteries are currently on the market, primarily as non-rechargeable batteries, once the rechargeability feature is fully implemented, they are expected to supplement and, in some cases, replace lithium-ion batteries in the long run.
While lithium-ion batteries are useful when handled correctly, they can be explosive, challenging to recycle, and problematic in terms of environmental and human rights issues when specific elements like cobalt are extracted. Therefore, our sustainable battery offers a promising alternative where energy density is not critical.
Ziyauddin Khan, Principal Research Engineer, Department of Science and Technology, Linköping University
Cheap and Recyclable
The main problem with zinc batteries has been their short lifespan, which is caused by zinc interacting with the water in the electrolyte solution. This process produces hydrogen gas and dendritic growth of zinc, leaving the battery basically useless.
To stabilize the zinc, a material known as potassium polyacrylate based water-in-polymer salt electrolyte (WiPSE) is employed. The researchers at Linköping have shown that WiPSE is extremely stable when used in a battery containing zinc and lignin.
Khan added, “Both zinc and lignin are super cheap, and the battery is easily recyclable. And if you calculate the cost per usage cycle, it becomes an extremely cheap battery compared to lithium-ion batteries.”
Scalable
Currently, the batteries created in the lab are small. However, the researchers believe they can construct large batteries, around the size of a car battery, because lignin and zinc are abundant and inexpensive. However, mass production necessitates the involvement of a company.
According to Reverant Crispin, Sweden’s status as an innovative country allows it to help other countries embrace more sustainable solutions.
“We can view it as our duty to help low-income countries avoid making the same mistakes we did. When they build their infrastructure, they need to start with green technology right away. If unsustainable technology is introduced, it will be used by billions of people, leading to a climate catastrophe,” stated Crispin.
The study was principally supported by the Wallenberg Wood Science Centre, the Swedish Research Council, Åforsk, the Swedish government’s strategic research area on advanced functional materials (AFM) at Linköping University, Vinnova through Fun-Mat II, and the Knut and Alice Wallenberg Foundation. The Swedish Energy Agency funds the SESBC center's long-term partnership with Ligna Energy AB.
Journal Reference:
Kumar, D., et al. (2024) Water-in-Polymer Salt Electrolyte for Long-Life Rechargeable Aqueous Zinc-Lignin Battery. Energy & Environmental Materials. doi.org/10.1002/eem2.12752