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We could potentially take vast amounts of CO2 emitted into our atmosphere from fossil fuels and use it as an energy source for a revolutionary rechargeable battery.
Billions of tonnes of carbon dioxide (CO2) are emitted into our atmosphere each year by fossil fuels, and the resulting changes in our climate have driven a number of scientists to try and figure out how to protect our planet’s ecosystem.
While natural solutions exist in the form of large forests, another potential solution is to harvest the atmospheric CO2 and use chemistry to turn it into its own source of energy.
According to Phys.org, researchers from Pennsylvania State University have developed a rechargeable battery called a flow cell, which can be recharged with a water-based solution containing dissolved CO2.
Sourced from fossil fuel power plants, the device works by taking advantage of the CO2 concentration difference between CO2 emissions and ambient air, which can ultimately be used to generate electricity.
In the team’s paper published in Environmental Science & Technology Letters, the CO2 and ambient air are dissolved in separate containers of an aqueous solution, in a process called sparging.
The flow cell battery concept. Image: Kim et al/American Chemical Society
Simpler means to capturing energy
At the end of this process, the CO2-sparged solution forms bicarbonate ions, giving it a lower pH of 7.7, compared to the air-sparged solution with a pH of 9.4.
When injected into two flow channels that contain electrodes and a semi-porous membrane, the pH difference between the two solutions creates a voltage difference between the two electrodes, causing electrons to flow along a wire, connecting the pair.
To recharge the battery, the channels can simply be switched so that the solutions flow through. Extensive lab tests have shown it to maintain performance over 50 charging cycles.
While not an entirely new concept, the battery’s average power density of 0.82 W/sq m makes it 200 times more powerful than any similar designs.
Speaking with Phys.org, Christopher A Gorski of the research team said: “This work offers an alternative, simpler means to capturing energy from CO2 emissions compared to existing technologies that require expensive catalyst materials and very high temperatures to convert CO2 into useful fuels.”
