Batteries Essay - Grade: 7 PDF

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Chemistry: Electrochemistry Batteries Essay Word count: 2600

Batteries Even though, today, batteries are in almost everything technological around us and provide a simple, compact energy source, they are a liability to humankind. Their disposal and manufacturing poses a major issue to our health and the environment. To really understand the issue, one must understand the cause. Batteries are electric devices that contain electrochemical cells (cells which can through chemical reactions release electricity, or the reactions can be induced by electricity). The battery works on a very simple principle (most commonly) on the Galvanic cell. Electrons flow from the negative anode to the positive cathode, through oxidation and reduction they are created.

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Batteries sometimes possess multiple Galvanic cells and sometimes only one. The anode releases the electrons and they flow through the wires to your device (in this case the voltmeter) and then back to the cathode. There are two types of batteries that differ depending on the amount of times they can be reused (Industrial differentiation): Primary batteries (single use) and Secondary batteries (rechargeable). Batteries come in all shapes and sizes, but also they can be composed of different materials (different chemical reactions would occur inside of the battery due to different electrodes and solutions). The most common types of rechargeable batteries are: 

Nickel Cadmium (Ni-Cd)-this was the most frequent battery in use for many years, however today it got replaced in most of the world in most of the technology. They are much larger than other batteries and have a fault in them which is called “the memory effect” 2. This battery is excellent if it is used on a regular basis and gets fully discharged and charged immediately (charging is fast), however if this doesn’t occur, crystallization occurs on the battery and the battery life will plummet. Another issue with this battery is that it contains Cd, which is poisonous to the environment so the

1 http://chemwiki.ucdavis.edu/Core/Analytical_Chemistry/Electrochemistry/Voltaic_Cells 2 http://batteryuniversity.com/learn/article/whats_the_best_battery

waste must be treated with care and also it loses charge over time. The reaction that happens on the positive electrode is: NiOOH + H20 + e-⇌ Ni(OH)2 + OH- Nickel (3) oxide reacts with water to form Nickel hydroxide and OH- group. The reaction that happens on the negative electrode is: Cd + 2OH ⇌ Cd(OH)2 + 2e- Cadmium reacts with OH to form Cd hydroxide. The overall reaction that happens on this battery is: 2NiOOH + Cd + 2H2O ⇌ 2Ni(OH)2 + Cd(OH)23

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Nickel Metal Hydride (Ni-MH)- This battery was created as a replacement for the Ni-Cd battery as it doesn’t contain Cadmium any more (however it cannot be recycled completely). These batteries are more expensive than Ni-Cd and are mostly used in space by NASA. This battery can generate over a third more energy than Ni-Cd, however their productivity goes down under high/low temperatures, so their total battery life is shorter. These batteries are used most notable in electric vehicles (cars most often). The reaction which occurs on the anode is: H2O + M + e− ⇌ OH− + MH The M in this equation stands for metal. The reaction that occurs on the positive electrode is: Ni(OH)2 + OH− ⇌ NiOOH + H2O + e− Which makes the overall equation that happens in this battery (the OH’s cancel out): NiOOH + MH ⇌ Ni(OH)2 + M4

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Lithium Ion (Li-ion)- This battery is currently the holy grail of batteries, it can contain more energy, limited to no maintenance and no discharge, weigh less and are used as a “standard” in most world technology. Scientists have come to figure that the Lithium Ion battery is less dangerous and more ecofriendly than the Lithium battery for the price of smaller energy storage. These batteries have a high cell voltage thus only single cell batteries are required for most of our daily technology. This simplifies and reduces in size the battery as a whole. Some of the issues of this battery are: its aging (reduces in productivity after years) and not fire friendly (it can easily combust due to sunlight and high temperatures). These compact batteries are used in: toys, phones, clocks, cameras, laptops, pacemakers (almost everything we use that is rechargeable). The following reaction occurs on the cathode: LiCoO2-Li+-e-↔Li0.5CoO2 ⇒ 143 mAh/g The following reaction occurs on the anode: 6C + Li+ + e– ↔ LiC6 ⇒ 372 mAh/g Which means that the overall reaction that occurs in the Li-ion battery is: C + LiCoO2 ↔ LiC6 + Li0.5CoO25 Carbon reacts with the lithium cobalt oxide to

3 http://www.advanced-battery.com/batteryknowledge.html 4 http://www.advanced-battery.com/batteryknowledge.html 5 http://www.nexeon.co.uk/about-li-ion-batteries/

form lithiated graphite and lithium cobalt oxide. Fun fact about lithium batteries, I had a problem transporting a device with a large lithium battery inside it. I bought this device in Los Angeles and transportation over the Atlantic was with ease, however England has much stricter rules on this, and they didn’t allow aerial transportation with such a large battery, even though it flew for more than 14 hours without encountering issues. For the comparison part, I chose lithium ion battery and Nickel metal hydride battery: when evaluating these two batteries the biggest difference is in their structure/materials used- Li-ion has carbon for the electrodes and Li to store all of the energy, while the energy in the Ni-MH batteries the energy is stored inside the H ions and the nickel and the other metal are present to contain the H in the desired space. Of course there are other differences like: Li-ion is more expensive to create, but they are also significantly lighter then Ni-MH. The difference in their energy storage capacity isn’t significant, however Liion batteries can be charged much faster and “the Memory effect” (which I talked about before) doesn’t take such big a toll on this battery as it does on its counterpart. While Liion battery excels in most areas of our modern lives, it has a much lower durability rate to extreme conditions, unlike Ni-MH which can stand high/low temperature and is used in space often. Li-ion is more effective as of now and here, but in space Ni-MH has a bigger advantage.6 Lithium batteries, with alkaline batteries, are today also used as the most common nonrechargeable batteries. They are used in a variety of places: toys, flashlights, remote controls etc.) Today we can substitute all of these single-use batteries for rechargeable batteries. In any larger shop, you can purchase rechargeable batteries that fit in remotes, but can be used more than once. So, which battery type is better? Rechargeable batteries, if you are looking at them for a long run, are economically better as they work for more cycles even though they are more expensive at the start. However, primary batteries are good at times when you don’t use something so frequently and that device doesn’t require that much electricity to work (they have an even lower discharge rate so they can last for a long time). If you have at home a flashlight for when there is no light, just for these types of situations, you could wait years and not use this flashlight and when you really need to it would still work. Each battery is more effective in their expertise. However, batteries aren’t all good. They do have a lot of advantages, but there a several limitations that should be taken into account. Advantages: 

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Certain devices are only used when you can take them around from one place to another (phones, laptops, GPS, flashlight…). These devices are important to mankind and batteries allow us to use them without being connected directly to electricity. Taking in consideration that on some places in the world there is still no power socket to connect your computer, so batteries offer a sanctuary from everything

6 http://auto.howstuffworks.com/lithium-ion-batteries-improve-hybrids1.htm

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around you so that you can go and listen to music on your MP3 player. With batteries you don’t have to be connected (with a wire) to electricity ever. Cars wouldn’t function without batteries; you wouldn’t be able to start your car. Without batteries, all of our transportation would be limited to land and all of it would have to occur within a grid. The only reason planes, rockets and cars (modern) exist is because batteries are transportable power sockets. Without batteries, all of our communication would be limited to land lines. Without batteries Satellites wouldn’t work and without satellites we wouldn’t have any way of knowing what was happening across the world. Even though we don’t look at them that way, batteries are really important for more than phones and flashlights. Batteries are also used for medicinal purposes. Defibrillators, pacemakers, portable EEG and EKG devices, portable ultrasounds and similar devices all work with batteries and without them, in the field (army or mass casualty incidents), many lives would be lost. From all of these examples and many more we can see the importance of batteries in all fields of work.

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Even though they offer a good power supply (depending on type of battery), this energy still isn’t infinite. So, batteries have an expiration date, both power wise and general. Even though some batteries can be recharge, they lose energy storage space over time (“the memory effect”) and are never so efficient as they are in the beginning. While direct energy is much more reliable. They also have to be inspected/maintained sometimes. Batteries are strong, but they aren’t impervious to all conditions. They can be damaged beyond repair. If this happens, you made an investment that backfired and you lost money, amount depending on investment. Equipment that is really power-hungry and portable becomes bulky and heavy due to large batteries. Batteries are small and light, but as the need for electricity grows in a device, so does the battery. This can influence the weight and size of the device drastically in some cases. Batteries aren’t safe- as a matter of fact they are very dangerous. If used improperly, they can explode or catch fire. Humidity, pressure, temperature, age are all factors that affect this. Another major downside in batteries is that batteries still cannot be recycled completely, but rather only partially. Not everyone has the time and place to recycle, so batteries which aren’t treated with care, can lead to chemical pollution and environmental desolation. Batteries still cannot discharge a large enough electrical charge for certain tasks (powering up nuclear reactors, powering up the large hadron collider, releasing enough electricity to power-up a town). Direct electricity is much cheaper for these massive tasks and is more effective. Building a super battery wouldn’t be economically beneficial because it would lose power over time and it still couldn’t discharge as much a power plant can.

Factors: Environmental: Batteries pose a major environmental issue some to the extreme that they were even banned (Ni-Cd in Europe). This being said, batteries can still be thrown properly in special battery containers located around cities and towns and these batteries are brought to factories where they are harvested for their useful materials (lead, metal casing, carbon electrodes…). However, there are always careless people in the world, who throw away batteries in normal trash or in nature. In such conditions, where water is present, batteries leak and dangerous chemical substances are released. In the past, batteries contained slight traces of mercury to stop side chemical reactions to happen, but this was really dangerous. Mercury is a liquid metal that is poisonous and a pollutant so when disposing of any battery with mercury it is dangerous, however, mercury can be absorbed through the skin so just by handling old batteries we could get poisoned. Most of the battery is made of toxic materials: “toxic heavy metals” (Ni,Li,Cd, Mg, lead, acid…)7 are dangerous because if they aren’t properly dealt with, they can contaminate water and soil of the environment. Any amount of these toxic substances can be a health hazard because they aren’t naturally in our bodies. These substances can lead to cancer, dermatology issues (rashes, skin irritations…), blood poisoning, indigestion poisoning and can even be inhaled (problem with burning batteries as they release these toxic substances in the air). If these batteries are carelessly treated and soil contains these toxic compounds, crops will have them too and animals as well. In the end, we will eat poisonous food. This is a very big global issue because fresh water supplies (which we have little of) are also affected by this and in many places in the world it is impossible to drink water from the faucet because it is dirty or it has poisonous metals. Developing countries lack the funds to make a large enough impact to completely stop this pollution; however developed countries can make a difference. By switching to rechargeable batteries that can be more effectively recycled, making sure that there are an ample amount of places for used batteries to be placed and implementing various penalty laws for people who pollute, all of these factors have limited the pollution of batteries to very little. My personal opinion is that by educating the masses and letting them know that they are hurting themselves in the process, is the only real stop for this pollution.

7 http://www.azocleantech.com/article.aspx?ArticleID=132

Economical & ethical: The major issue with batteries is their cost. Some batteries cost less and have a much wider range of application due to the fact that it isn’t profitable for the company making the device, for it to have an expensive battery. So prices in batteries vary largely. Duracell is most often described as the most expensive type of normal battery, but should you spend a couple more Kuna to ensure that nothing happens to you or your device even though you can never completely be sure how effective a certain battery is? Is it morally correct to spend less money for the sake of being able to buy more batteries, and ensuring your device more running time? You can never be 100% with electronics, everything is about marketing so false advertising is bound to happen sometimes. What if some cheaper batteries actually hold more energy and are safer than the more expensive batteries? This is one question that should be pondered about, however this issue can be approached from a different angle. In the world you have single-use and rechargeable batteries. Rechargeable batteries are more expensive than single-use, but are recyclable and can be used more times. Of course, in a long run rechargeable batteries are way more money per battery efficient, but are they necessarily good for everything? Should you buy single-use batteries because they deplete slower and in some devices they are more effective (flashlights, remote controls...)? Single use batteries cannot be recycled fully, so you are essentially contributing to pollution. Is it morally correct for you to pollute the world and contribute to its downfall, just because you couldn’t spend a few more Kuna for better batteries? I know that I am exaggerating a tad, however in these small steps you are setting an example for your children. The world wasn’t built in one night and it will not be destroyed in one either, but if every family in the world chooses not to recycle because it’s dull and a burden, how long will we last? To sum this all up, I always knew that mankind has become addicted and permanently attached to electricity and technology, but it has also become attached to batteries. Is it moral to use something that will in the end backfire and hurt us back? These and many more are some of the ethical/economic questions bound to batteries.

Bibliography: http://chemwiki.ucdavis.edu/Core/Analytical_Chemistry/Electrochemistry/Voltaic_Cells Website Title: - Chemwiki Article Title: Voltaic Cells Electronically Published: October 01, 2013 Date Accessed: April 13, 2016 http://batteryuniversity.com/learn/article/whats_the_best_battery Website Title: Advantages and limitations of the Different Types of Batteries Article Title: What’s the Best Battery? Date Accessed: April 13, 2016 http://www.advanced-battery.com/batteryknowledge.html Website Title: Battery Knowledge Article Title: Battery Knowledge Date Accessed: April 13, 2016 http://www.nexeon.co.uk/about-li-ion-batteries/ Website Title: Nexeon Silicon anode Liion battery technology Article Title: Nexeon | Silicon anode Li-ion battery technology Date Accessed: April 13, 2016 http://auto.howstuffworks.com/lithium-ion-batteries-improve-hybrids1.htm Website Title: HowStuffWorks Article Title: How can lithium-ion batteries improve hybrids? Electronically Published: December 20, 2010 Date Accessed: April 13, 2016 http://www.azocleantech.com/article.aspx?ArticleID=132 Website Title: Recycling Batteries and The Toxic Hazards of Battery Disposal Article Title: Recycling Batteries and The Toxic Hazards of Battery Disposal Date Accessed: April 13, 2016 http://chemwiki.ucdavis.edu/Core/Analytical_Chemistry/Electrochemistry/Voltaic_Cells/ Case_Study%3A_Battery_Types/Batteries%3A_Electricity_though_chemical_reactions Website Title: - Chemwiki Article Title: Batteries: Electricity though chemical reactions Electronically Published: October 01, 2013 Date Accessed: April 13, 2016 http://www.frost.com/sublib/display-market-insight-top.do?id=20759887 Website Title: Environmental Effects Associated with Battery Disposal Article Title: Environmental Effects Associated with Battery Disposal Date Accessed: April 13, 2016...