Lithium Ion Technology By Teddy Reiss
D
o you have an iPod, iPad or iPhone? Do you use a cell phone? Laptop computer? If you do, then you already experience the benefits of lithium batteries. Lithium-ion technology is a new type of rechargeable battery in chemistry. It has recently become very popular in portable devices. These batteries last longer than most other batteries and are much lighter than NiMh types, which are a common type of rechargeable battery, made from nickel metal hydride. The automotive industry has started to use lithium batteries, specifically for purely electric cars. When used in cars, lithium is very different than gasoline. There are two main types of cars that are powered by lithium: hybrid cars and plug-in cars. Hybrid cars are much more fuel efficient than regular cars, because when the car is moving, it uses an electric motor, while it only uses gasoline when the car needs extra power. Plug-in electric cars are run entirely by an electric motor and lithium is used in the batteries of these cars. Both cars are improvements from common gasoline cars because hybrids use much less gasoline and plug-ins don’t use any. Lithium batteries also have a use in gasoline cars. If we use lithium in regular car batteries, they too will become more efficient because lithium is lighter. If we make cars lighter, they will be easier to move, thus requiring less fuel. Plug-in/electric cars can also be lighter then traditional gasoline cars because they will not need the heavy gasoline engine and the components required to run a gasoline engine (such as catalytic converters, mufflers, head gaskets and more.) There are many advantages to using lithium batteries. One of the major advantages is that lithium batteries have a relatively high energy density. This means that for a specific size, you can include much more energy then other types of rechargeable batteries. Lithium batteries also discharge slower than most other rechargeable batteries, meaning once they get charged they will stay charged. In addition, MIT says that if they use carbon nanotubes as electrodes, the battery’s power will significantly increases. Also, when
12 Horace Mann Spectrum ■ April 2011
lithium batteries are used in cars, the cars will require a different type of maintenance because a lot of common problems (cracked distributor caps, bent valves, leaky rings) will become irrelevant with electric cars, which have no gasoline engines. Along with the advantages, there are some apparent disadvantages. For one thing, lithium batteries are significantly more expensive than other types because they are harder to manufacture, among other reasons. Lead-acid batteries are somewhere around $40 and $50 per kWh (kilowatt hour). NiCd(Nickel Cadmium) or NiMH (Nickel Metal Hydride) are approximately $350 per kWh. Lithium, unfortunately, is approximately $450 per kWh. Lithium batteries also need to be carefully charged. In addition, they might not be completely compatible with common appliances made to be used with regular AA type batteries, or other sizes, because they produce different voltages and might be made at a different size. Finally, a major disadvantage is the fact that like all batteries, they die. And because these batteries are so expensive, they are difficult to replace. Lithium batteries in cars can be better for the environment. They are commonly used in electric cars, which will create less pollution than standard batteries. The difference between electric cars and gasoline cars is that electric cars don’t have any of the gasoline parts such as engines, exhaust systems and fuel injectors. Instead, these have been replaced with electronic parts. When it becomes possible to charge Lithium batteries with alternative energy sources like wind or solar power, they will have next to no environmental impact. Also, Lithium-based electric cars use less hazardous material. Lead, which is well known to be harmful, is currently used in car batteries. If we remove the lead, we use less harmful materials. Lithium technology will continue to advance, and will start to play an even more important role in society as time passes.