The future of renewable energy, electric cars, a smart electrical grid and even just more efficient electronics, relies on better, more sustainable batteries. So far, lithium-ion is the gold standard because it's able to better store and discharge energy in lighter, smaller package compared to other battery types, making it well-suited to electric vehicles and computers and gadgets.

The downside though is that many of the materials used to make those batteries are rare and not sustainable and some are toxic. Plus, end of life recycling hasn't been properly addressed.

Researchers at the Uppsala University in Sweden have come up with a battery that reuses lithium from old batteries, incorporates organic, sustainable materials and is recyclable at the end of its life.

Components of the battery are made from alfalfa and pine resin, and can be recycled using a low energy process and non-hazardous chemicals like water and ethanol, unlike regular lithium batteries that require high energy processes using hazardous chemicals to recover any reusable components.

Researchers have been coming up with ways to use organic and natural materials in batteries for year, like sand, wood fibers and more, but recovering lithium from old batteries and reusing it in another hasn't been focused on. And it's an important step forward as demand for lithium is accelerating.

The university says, "The scientists have shown that the lithium extracted from a spent battery can be used for a new battery: all that needs to be added is more biomaterial. Their battery proved capable of delivering as much as 99% of the energy output from the first. With future modifications, this figure can very probably become even higher, say the researchers.

Reusing lithium and sourcing organic materials for components is not only much better for the environment, but it could also substantially bring down the cost of batteries.

Treehugger