What if your cup of coffee could contribute to a fossil-free future? A BioInnovation project has tested the use of coffee grounds as an alternative to fossil graphite in battery production, and the results show that the idea actually works.
Illia Dobryden, RISE.
The coffee grounds are dry, compressed and available in large quantities. It’s a perfect bio-based raw material, researcher Illia Dobryden remarked, as he took his usual morning cup from the coffee machine at Rise’s headquarters in Stockholm. As a researcher with a particular interest in bio-based solutions for batteries, he was struck by the idea that coffee grounds might be able to replace the hard carbon used in sodium ion batteries and potentially fossilised graphite for lithium ion batteries.
This was the start of a BioInnovation project that Rise has carried out, together with coffee supplier Selecta and battery manufacturer Granode Materials. The aim of the project was to develop a first prototype, and that goal was reached.
– Coffee generates 17 million tonnes of waste per year globally, and this waste is available locally. Imagine if we could get that coffee waste into the circular economy instead, and also contribute to battery production that consists of fossil-free materials to a greater extent. Thanks to electrification, there is a huge and growing demand for raw materials for batteries. We can see great potential in this project, says Illia Dobryden.
He describes how the coffee grounds in the Rise lab were first converted into hard carbon, by heating them to a thousand degrees in a controlled oxygen-free environment. The hard carbon was then used to make prototypes of sodium ion batteries.
From coffee cherries to coffee batteries. As part of the BioInnovation project, Rise developed a prototype of a button cell battery.
From waste to prototype
Ulf Gustafsson, Selecta.
Now Ulf Gustafsson, sustainability manager at Selecta Norden holds the prototype of a ‘coffee grounds battery’ in his hand.
– It’s pretty amazing that we now have the very first battery. We can make hard carbon from the wood industry’s lignin residues already, but that lignin is supposed to be used for so many things, and instead here we have a raw material that is not being utilised anywhere else. Just imagine, something that currently is an expense to take care of can become a source of income, and can be used for such a socially critical activity as battery production, says Ulf Gustafsson.
Seeking funding for further research
Lars Schedin, Granode Materials.
Another factor in favour of such a solution is the geopolitical dimension, according to Lars Schedin, CEO of project partner Granode Materials. Their unique mechanical production process uses a combination of graphite and silicon to manufacture anodes for car batteries. Using silicon instead of graphite results in higher energy density, which means batteries weigh less, without losing capacity. However, all of the graphite can’t be replaced by silicon, and one possible approach could be to replace the remaining graphite with coffee grounds.
– Whilst we are becoming increasingly dependent on graphite in batteries, solar cells, and so on, at present almost all graphite is controlled by China, and we can see the way they are restricting graphite exports at the moment. This makes the whole of society vulnerable and it could have serious consequences for battery production and, by extension for electrification, says Lars Schedin, adding:
– Currently, the production of anodes causes high emissions of carbon dioxide equivalents (CO2eq). By using a fossil-free raw material such as coffee grounds, our process allows us to produce an anode that has significantly lower emissions.
The detailed performance of the ‘coffee grounds battery’ is not yet in the public domain, but the researchers see great potential, and are seeking funding to continue exploring the remaining challenges in a larger project. These include the fact that only 20% of coffee grounds are converted into hard carbon, that coffees from different countries and with different roasting methods behave differently, and that hard carbon from coffee grounds has a lower energy density than graphite.
The project partners meet and Rise presents the first prototype to Selecta.
Regulations can complicate circular solutions
Marie-Claude Béland, RISE.
Marie-Claude Béland, research and business developer at Rise, also sees a need to study the logistical challenges. A large portion of the cost lies in transporting the coffee grounds, and current legislation sees coffee grounds as waste. This means that a stakeholder such as Selecta, which could collect the grounds efficiently, is currently not allowed to do this.
– The regulatory framework is adapted to a linear economy and to some extent this obstructs circular solutions. We need to explore how we can collect and manage this stream in a economically sustainable way. There is a lot of value in the grounds, and with the right logistics and the right technology, we can create a sustainable and profitable solution, says Marie-Claude Béland.
Read more on the project page Valorization of coffee waste for battery materials “Waste to Watt?” – step 1.