Micro Life Zone
Asked by halle to Dirk, Elise, Janette, Renee, Yusuf on 13 May 2012.
Keywords: batteries, battery, energy, store
While there are many different forms of batteries, they are all based on same principal of the electrochemical cell, which converts stored chemical energy into electrical energy. Despite the first battery being made in 1800 (by Alessandra Volta), no completely different alternatives have been developed and released. Two potential ones do exist that I’m aware of but both still have similarities to standard batteries. These are capacitors and fuel cells. Capacitors have the drawback of only being able to release energy all at once, and may not be able to hold charge for long. As for fuel cells, one of the most common types is known as a flow battery.
Instead of storing the energy in chemical form and gradually being depleted like a conventional battery, a flow battery creates the energy “on the go” by being supplied with the necessary electrolytes which flow through the electrochemical cell and are converted from chemical energy to electricity. While the principle is the same as a regular battery, the advantage of a flow battery or fuel cell is that as long as the chemicals are topped up it will never go flat. The downside is that flow batteries are far more complex than standard batteries. I did see an recent news story on a fuel cell that will power your mobile phone for up to two weeks, so these alternatives may become common in the not to distant future. As for something completely different to the standard principles of storing and converting chemical energy to electrical energy – I have no idea, but who knows what the future holds?
There is not much I can add to Janette’s answer regarding traditional batteries. There are some related technologies related to capacitors, “super capacitors” and “ultrabatteries” [great names huh?] that bridge the gap, but are not quite practical for consumer electronics. Although they have been used in some hybrid car prototypes (see link 1) below).
There are other ways to store energy for later use though. Batteries are a convenient form that work for the devices we use everyday. However, for large amounts of energy, like that generated by some forms of solar power plants, batteries are impracticable. Remember, there is no sun at night to generate energy *grin* So, to overcome this the energy collected during the day is stored as heat in some kind of dense fluid, usually salt or salt water. That heat is then released at night to produce steam to drive the turbines that make electricity (see link 2) below).
Wood is also a way to store the sun’s energy. The tree takes the sun’s energy and drives a few chemical reactions to form food and then its body. We get the energy back by burning the wood and the energy is released as heat. This is just an example of how one could store chemically energy from an external source in this case the sun. I’ve read of non-biological chemical energy stores but do not remember the details.
Finally dams are also “batteries” after a fashion. Here the water behind the dam wall is stored potential energy that when allowed to flow (becoming kinetic energy) through a turbine will generate electricity.
When I have some extra energy, I carry a bucket of water up the stairs. This way when I need some energy, I can pour down all the water I have stored, have it go through a turbine and generate some electricity. My friends don’t think this is a great way to store energy. What do you think?
Classical mechanics tries to divide energy into “kinetic” energy and “potential” energy. This division is not perfect, but usually good enough. The water upstairs has potential energy. The water running down, going through the turbine has kinetic energy. More on different forms of energy at http://en.wikipedia.org/wiki/Forms_of_energy
Of course, having a swimming pool of water is not going to work well to power my car, so we need something else. Petrol and LPG (Liquid Petroluem Gas) are types of stored energy. They can store a lot of energy. Much better than my bucket of water solution. Unfortunately, once we burn them up and convert them to make our cars go. They are gone forever. There is no getting them back or recharging them.
What do we want out of our energy storage? 1) Easy to convert one form of energy to another, so we do not lose much energy in the conversion 2) Be compact, so we do not need lots of space and 3) Be rechargeable, so we can use the same materials again and again.
Batteries are a great source of storing energy. The innovation comes from having batteries from different materials. Donald Sadoway set out to find a better way to store energy. He has been working on this probelm for a couple of years and looks like he might have found a solution. Here is the video
http://www.ted.com/talks/lang/en/donald_sadoway_the_missing_link_to_renewable_energy.html It will take time, but this is the latest and most exciting research on new types of batteries.
There is also a great talk about wireless electricity at http://www.ted.com/talks/eric_giler_demos_wireless_electricity.html but that is more about electricity transmission than storage.
In the meantime, you might want to create your own battery out of lemons: http://www.quantumbalancing.com/news/lemon_battery.htm
Other great examples of things that contain potential energy are rubber bands and springs. Think of a rubber band that you stretch out, it is full of potential energy, once you let it go the kinetic energy propels it through the air! The same with springs, like in a jack-in-the-box. The potential energy is hiding inside antuil you turn the handle enough and jack springs to life!
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