­New Battery Design Helps Developing Countries Go Green

Stopping the rise of global temperatures is a problem for the whole world. Often times it is developing countries that need that help the most because of a lack of funding, while developed countries can afford the changeover to more sustainable green energy. It should be easier for developing countries to change, as many of them are situated in the warmest areas of the world, and solar power has been dropping considerably in cost. However, even though solar panels are now comparatively cheap, it is still hard for them to wean themselves off fossil fuels. Part of the reason is that countries near the equator lose sunlight early in the evening, which in many places is just about the time that demand for energy peaks. As in other places, storage would have fill gaps in renewable generation, but storage tends to be as expensive, if not more so, than solar panels. In cases like these, cheap battery technology is required, and preferably technology that has the ability to last a very long time.

A team of researchers from Linköping University, Sweden has been working on developing storage that is cheap enough and has the longevity needed for developing countries. The researchers have designed a battery that is made from zinc and lignin that can be used over 8000 times. The results of the research have just been published in the journal Energy & Environmental Materials.

“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 expensive Li-ion batteries, will eventually offer a solution for these situations,” says Reverant Crispin, professor of organic electronics at Linköping University.

The professor’s research group at the Laboratory of Organic Electronics, together with partners from Karlstad University and Chalmers, have developed the new battery using two cost-effective and environmentally friendly materials. In terms of energy density, it is comparable to lead-acid batteries, but without using toxic lead. The battery can be charged and discharged over 8000 times while maintaining around 80% of its original performance. Additionally, it can hold its charge for around a week, while other zinc-based batteries tend to discharge in only a few hours.

Traditional zinc batteries also have poor durability due to the metal reacting with the water in the electrolyte, which, in turn, leads to hydrogen gas generation and dendritic growth of the zinc, which renders the battery essentially unusable. Potassium polyacrylate based water-in-polymer salt electrolyte (WiPSE) is used to stabilize the battery. The researchers at Linköping have now demonstrated WiPSE used in a battery made from zinc and lignin provides very high stability.

“Both zinc and lignin are very cheap, and the battery is easily recyclable. If you calculate the cost per usage cycle, it becomes an extremely cheap battery compared to lithium-ion batteries,” says Ziyauddin Khana researcher at the Laboratory of Organic Electronics at LiU.

Currently, the batteries developed in the lab are small. However, the researchers believe that they can create large batteries, roughly the size of a car battery, thanks to the abundance of both lignin and zinc at low cost. However, mass production would require external assistance.

https://liu.se/en