Post date: Sep 1, 2010 12:07:31 AM
Nissan LEAF batteries. Photo: Michael Graham Richard
Copper and Aluminium Actually Worse than Lithium
Speaking of lithium-ion batteries, a recent life-cycle analysis (a type of study that aims to find the complete environmental impact of something, taking into account manufacturing, usage, and disposal) of the lithium-ion batteries used in electric cars had some very interesting findings. It turns out that batteries have an even lower impact than most of us thought. Read on for the details.
Tesla Roadster battery pack. Photo: Michael Graham Richard
Lithium's the Least of Our Problems
The LCA study finds that the environmental burden caused by the lithium-ion battery is of at most 15% of the total impact of the electric car (which includes making it, using and maintaining it, and disposing of it at the end of its useful life). Interestingly, the lithium itself represents just a small part of that; about 7.5% of the impact occurs when "refining and manufacturing the battery's raw materials, copper and aluminium". The lithium itself is only responsible for 2.3% of total.
This seems an argument in favor of making extra sure to recycle batteries properly at the end of their lives, and to use non-virgin sources of materials whenever possible (recycled aluminium has a much lower impact: "Recycling scrap aluminium requires only 5% of the energy used to make new aluminium.")
"Lithium-ion rechargeable batteries are not as bad as previously assumed," according to Dominic Notter, coauthor of the study which has just been published in the scientific journal "Environmental Science & Technology."
Lithium Shortage? Not Anytime Soon
As for those who worry about Lithium supply, just know that Bolivia alone has enough of it for billions of electric cars and they only have about 1/3 of known world supplies (if there's ever a big shortage, higher prices would probably lead to new discoveries), and lithium isn't destroyed when used in a battery, so it can be recycled and reused.
Further Reducing Impact of Batteries
The total impact of EV batteries can be further reduced if at the end of their "vehicle" life they are used for other forms of energy storage. Indeed, they can still hold up to 80% of their charge even after having been used for years in a vehicle, so before recycling them, they could be used to store power on the grid (such as intermittent power from wind farms).
But the most important thing when it comes to electric cars will be to clean up the power grid. That's the best bang for the buck when it comes to fighting global warming; a cleaner source of power for homes and industry combined with an electrified transportation sector would drastically cut greenhouse gas emissions.
Via Science Daily