Lead Acid batteries
Lead acid batteries are the leading component for the electric car industry today. The reason is clear: their ability to provide the high surge currents needed for an automobile’s starter motor makes them a reliable power source at an affordable cost. For the energy required to run an electric car, the typical car normally has 8-12 kWh lead acid batteries installed, so price is a significant consideration. Their ease of installation makes them that much more attractive as a power source. The disadvantage is their short lifespan of only three years, at which point they can no longer be recharged and must be disposed of. Still, this simple technology is cheap and easily manufactured. Lead acid batteries use a high amount of reused materials. Flat or disposed batteries are recycled into new batteries, keeping the carbon footprint low on the lead acid used in the next batch of batteries and giving about 15 kg CO2 with the normal l kWh lead acid battery.
The value of raw materials has spiked up the recycling market for recycled lead acid batteries when they are disposed of. Nearly all of the components of a lead acid battery are recyclable – 97 percent. The battery case is made of polypropylene; the plates are made of lead, with water and acid mixed as an electrolyte. The casing and plates can be easily melted down and reformed, since lead’s melting point is low. In this way, little energy is required to convert melted lead to the required raw material for reuse.
This ability to keep costs down by reusing materials makes recycling attractive and easily doable. Europe recycles 100 percent lead acid batteries, while the U.S. boasts a 98 percent recycling rate.
If an electric vehicle with eight lead acid batteries were replaced once in three years, the batteries’ carbon footprint over the vehicle’s lifetime would be:
Estimated carbon footprint per battery: 15 kg
Estimated carbon footprint per battery pack (8 batteries): 120 kg
Estimated number of battery packs required during the vehicle’s lifetime: 4
Carbon footprint over vehicle lifetime: 480 kg
C02/km over 50,000 miles (80,000km): 6g
Such configuration can be found in REVA i (G-Wiz), Aixam Mega City, and the NEVs (Neighborhood Electric Vehicles).
Lithium Ion
Lithium ion batteries have a longer life than lead acid batteries, with a 5-7 year lifespan. There are some car manufacturers and car owners who prefer to use this higher and more costly battery technology, which are in some cases designed to last the vehicle’s lifetime.
To manufacture a lithium ion battery for an electric car, the carbon cost is about 22 kg per kWh energy storage. Most small electric cars are outfitted with 12-16 kWh lithium ion batteries. The carbon footprint is about 264-352 kg per vehicle.
At the end of their lifespan, the metals from lithium ion batteries can be extracted. However, only 50 percent of the batteries’ materials can currently be reused to make new batteries. Hopefully, with technological advancements, this figure will rise to 95 percent recyclability by 2015.
Calculations show that recycled