We’ve all heard the criticism surrounding lithium-ion batteries and their mining practices. Despite the virtue drums of the EV revolution, enthusiasts get quiet when you bring up the environmental impact of lithium extraction and cobalt mining.
Well good news for the do-gooders, sodium to the rescue!
More specifically, sodium-ion batteries might have a solution to the skeleton in the closet we don’t want to admit. These batteries are made from Na3V2(PO4)3 as an electrode material and aluminum foil as the shared current collector. What’s this mean exactly? I’m not really sure but let’s look at the difference.
Most electric car batteries today are made from lithium-ion (Li-ion) technology. These batteries use a combination of lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), or lithium iron phosphate (LiFePO4) for the cathode and carbon for the anode. (Aka battery innards)
Lithium-ion batteries are widely used in electric vehicles because they offer high energy density, which means they can store a lot of energy in a relatively small and lightweight package. They are also durable and can be recharged many times without losing much of their capacity.
The problem lies in the ingredients.
Lithium mining can have negative environmental impacts depending on the mining method used, the location of the mine, and how the mining company manages the waste and byproducts of mining.
Some of the environmental impacts associated with lithium mining include:
Water depletion: Lithium mining can require significant amounts of water, which can contribute to water scarcity in regions where water resources are already limited.
Soil and air pollution: Lithium mining can generate dust, which can contaminate nearby soil and air. Some mining processes can also generate wastewater and toxic chemicals that can pollute nearby waterways.
Habitat destruction: Lithium mining can result in the destruction of habitats for plants and animals, especially if mining occurs in ecologically sensitive areas.
Carbon emissions: The production of lithium batteries requires significant amounts of energy, which can lead to greenhouse gas emissions and contribute to climate change.
Sodium batteries, however, are made from a natural resource that is in abundance. In fact, the byproduct of producing the sodium is distilled water.
Now, I know it’s not that simple. There are still potential environmental and ecological issues surrounding sodium batteries as well. First and foremost is the method of extraction. Although it can be extracted from salt water, sodium is found in many places and depending on the origin of the production, this may include mining as well.
Energy use is another concern. It takes a lot of energy to separate the sodium from water or the earth and most of this energy currently comes from non-renewable sources. In order to reduce the carbon footprint from the extraction process, more attention is needed to renewable power production.
The cost is also a significant factor. The equipment needed to pump, filter, heat and extract the sodium is not cheap. Companies would be betting on long term returns on their investment, but with the amount of batteries entering the market, it might be a pretty good bet.
There is also the potential damage to wildlife during the extraction process. Small animals and sea life might get sucked into the system. Brine or other waste could also cause a danger to living organisms if improperly disposed of.
Power density is one major hurdle that sodium batteries are still lacking. Compared to lithium-ion, sodium batteries don't pack quite as much punch. In a world where everyone is screaming about mileage, there's still some road ahead for sodium to replace lithium-ion batteries in higher performance situations like EV's and cellphones. Like any new tech, the more research we can do, the better we can expect the technology to get.
Another major concern is the disposal of batteries. With so many end-of-life batteries now threatening environmental and ecological safety, recycling has been a major factor in battery tech. Lithium batteries are notorious for being highly damaging to the environment. Newer sodium batteries can be recycled to a 98% efficiency, making them a very promising solution to the growing battery crisis.
If you would like to learn more about how sodium batteries work, check out this paper that discusses how researchers were able to create a high efficiency, recyclable battery out of an abundant resource.
