Recycled Li-ion batteries made with alfalfa seeds and pine resin
Thanks to their high power ratings and relative reliability, lithium-ion (Li-ion) batteries are an efficient and reliable source of power, widely used in modern electronic equipment. On the downside, however, expired Li-ion batteries are also difficult to dispose of, with their potentially toxic content and the complex methods required for their recycling. Researchers at Uppsala University’s Ångström Laboratory think that they may have a solution: combine the salvaged remnants of a Li-ion battery with completely organic materials derived from alfalfa and pine resin, to create a recycled biomaterial Li-ion hybrid battery.
Current Li-ion battery production relies on huge quantities of lithium, the future mining of which may be limited. Additionally, after these batteries have reached the end of their useful life, it is very difficult to recover the lithium from the inorganic materials used to make them in the first place.
To help address these problems, Sweden's Uppsala University has developed a technique to extract the lithium from spent batteries and combine this with renewable biological material, to create a battery with a similar energy capacity to that of ordinary Li-ion batteries. The materials used include substances made from alfalfa and pine resin with the added bonus that, once the batteries are no longer usable, they can be recycled using low-energy methods and relatively innocuous chemicals, such as ethanol and water.
"We think our discovery can open several doors to more environment-friendly, energy-efficient solutions for the batteries of the future," said team member Dr. Daniel Brandell, Senior Lecturer at Uppsala's Department of Chemistry.
The researchers have demonstrated that the lithium harvested from an expired battery can be used to create a new power cell just by adding more biomaterial, with the scientists claiming that their creation is able to deliver nearly 99 percent of the energy of the original. With more research and development, the researchers also believe that this output may be increased sometime in the future.
According to the team's research, using a dimethyl carbonate/lithium bis (trifluoromethane sulfonyl) imide electrolyte produced the best results for their organic battery. A process using a moderate temperature was sufficient to extract lithium from the organic material (as lithium carbonate) for recycling.
Though this is certainly not the first time batteries composed of renewable materials have been created – the USC organic redox reflow and the Harvard organic flow batteries being two recent notable examples – the method used by the team to recycle and recover lithium is claimed to be a wholly new concept.
"The use of organic materials from renewable sources makes it possible to solve several of the problems that would arise from a huge rise in the use of lithium batteries," said Dr. Brandell. "But above all, it’s a major step forward that, to a high degree and in a simple, environment-friendly way, the lithium from these batteries can be recovered. These solutions are also potentially very cost-effective."
No information on power levels, electrical output, or capacity of the recycled battery was released.
A paper on the research was published in the journal of chemistry and sustainability, Chemsuschem.
Source: Uppsala University