Batteries are a compact portable energy source, we use batteries in our life; it has played a very important role within our modern society such as to operate portables appliances. We use torches as a backup lighting system; we use batteries on our mobile phones, as well as batteries in our cars. Many of us, do not even have the realisation that it is a perfect example of application of chemistry in daily life.The battery industry has become a very profitable market.
The market is saturated and we see more and more brands, each and every one of them claiming that they yield better value and effectiveness. Rechargeable batteries, allow the recharging of the batteries that allows the battery to be used for more than once. They are now available in the market, but they do not come at a cheap price, you will need to invest on a charger, a device you need to acquire to charge up the rechargeable battery.The topic was chosen as this matter has left many of us dazzled, the need of battery is unquestioned but they come at relatively expensive price that vary across different brands.
So which one do we choose among the brands within the market? Is it justified to spend money on investing on a charger so we can use rechargeable batteries? Or is it better to keep using the traditional batteries? What kind of battery usage do we need until it is economical to get rechargeable batteries? This essay will help answer these questions.Theoretical Background:1.1 History of Battery:On 1660 Otto Von Guericke built the first static generator, which is a glass ball turned by hand which rubbed against cloth which create sparks of electricity. After Otto’s discovery, more scientists are involved and fascinated by electricity. But it is not until 20th of March 1800, came one of the greatest breakthroughs in the electricity experiments. A professional disagreement, over the results of an experiment, between Luigi Galvani and Alessandro Volta two leading scientists, led Volta to prove that when certain metals and chemicals come into contact with each other they can produce an electrical current.
He placed together several pairs of silver and zinc discs separated by paper soaked in salt water and an electrical current was produced, Volta had produced the first battery. These are called Voltaic battery, or usually referred in Chemistry as Galvanic Cells. Refer to Figure 3 (P.5) for illustration.1.2 What is a battery?So what exactly are batteries? This seems like an easy question, even someone as young as 5 year old will know it, as they are playing their game-boy or remote control they use batteries. Unfortunately there are more to it than just an apparatus that provide electricity, it is a complex matter that has been researched by scientists since ages ago.1 Batteries come in different varieties and sizes.
Some are small enough to fit in our watches, yet many are strong enough to power cars, and planes. Figure one shows the common household batteries we use on everyday life.”Energy cannot be created nor destroyed, energy can only be changed from one form into another.”2Law of Conservation Energy.In theory energy cannot be created or destroyed, it can only be changed from one form into another.
There are different forms of energy; electrical, chemical, kinetic, sound, heat, and potential energy. A battery is anything that has potential energy. Potential in a sense that it has possibility and capability of having the energy but it is not yet in existence. When you push a boulder on the top of the hill, the amount of energy you put into the boulder as you go up, is stored on potential energy, which then released when the boulder is rolling down the hill. This is a method to conserve energy to be used later. On the case of a household battery, chemical energy is stored and converted into electrical energy. In the case of electrochemical batteries this is done through connecting one or more galvanic cells.1.
3 Background Theory of a Battery:Fig 2. Conceptual Diagram of a “Galvanic Cell”Figure 2. Shows concept of a very simple battery; it is a very important basic knowledge to understand the chemistry of modern batteries. In any galvanic cell, one of reactant has to lose electrons; the lost electrons then gain by the other reactant. In the anode, the reactant that usually is a metal, undergoes oxidation, the electrons lost then travel through conductor to cathode, which then undergoes reduction.
In normal situation, we usually have load that is a device that needs to be powered placed in the middle.The process of losing electron is known as oxidation, this happens on the anode.Li (s) –> Li+ (aq)+ e- E0Oxidation = 3.03VThe process in which electrons are gained are called reduction it happens on the cathode.2H+(s) + 2e- –> H2 (aq) E0Reduction = 0.00VThese reactions are often referred as half equation, the full equation can be produced when the two half equations are combined. E0 refers to (Electromotive Force) or E.
M.F, this indicates the reactivity of the metals. With strongest reductant having the most negative value on the table and the strongest oxidant with the highest positive value.3 The amount of voltage and current a cell produces depends on the type of chemicals used to react with; while the endurance of a battery depends on the amount of active material within the battery and its actual design. The amount a cell gives out can be calculated by looking at their E.M.F. Table 1.
give you numerous E.M.F values of different compounds. Every compound has their own EMF, it is the tendency to gain or lose electrons, in relation with other compounds. The larger the difference will result a higher potential difference, and better battery.
To demonstrate how to find the theoretical value of a galvanic cell, we can look at the chemical process in a Lithium battery. Lithium is a very promising material as it has high E.M.
F value. Lithium batteries are small and light therefore they are only used when lightweight and small size is an important issue.Li (s) –> Li+ (aq)+ e- E0Oxidation = 3.03VH+(s) + e- –> 1/2 H2 (aq) E0Reduction = 0.00V +Li(s) + H+(s) –> Li+(s) + 1/2 H2 (g) E0 = 3.03V1.
4 Demonstration of Simple Galvanic cell:Aim/Purpose:To help illustrate a simple battery for readers.Figure 3.4 Diagram of Cu(s)/Cu2+(aq)||Zn2+(aq)/Zn(s)Result:The experiment was set up as Figure 3.
for the material and method please refer to Appendix 1.1, and the E.M.F acquired from the experiment was 0.868V.Data Analysis:Electricity does exist within the battery; some of us may ask what actually happened during the experiment? What is oxidation and what is reduction? Why do they give out electricity? And how does it happen? So far we know that oxidation is a process of losing electrons, it happens in Anode.
This is the reaction that happens in the anode side.Anode: Zn (s) –> Zn2+ (aq)+ 2e- 0.76VThe solid Zinc, has lost its electrons and become positively charged. The lost electrons then travel to the cathode side, in which reduction takes place. The electrons that travelled ended up joining the copper, and the load was powered in the process.Cathode: Cu2+(s) + 2e- –> Cu (aq) 0.34VZn (s) –> Zn2+ (aq)+ 2e- E0Oxidation = 0.76VCu2+(s) + 2e- –> Cu (aq)___ E0Reduction = 0.
34V +Zn + Cu2+ –> Zn2+ + Cu2+(s) E0 = 1.1VThis experiment was done in S.T.P, all concentration used were 1M and the temperature was relatively closed to 25?C. The theoretical value can be found by adding the amount of E.
M.F (Electromotive Force), which is the rate in which energy is drawn from a source that produces a flow of electricity in a circuit5. In theory the wet cell can give off 1.1V, (0.
76V + 0.34V) but the procedure was not kept at high detail to get accuracy therefore energy are lost to environment and only 0.868V is detected. Which is around 78.9% of the theoretical value, some of the energy was probably lost into the environment during the process of oxidation, or probably the inaccuracy of the voltmeter used during the experiment may have affected the result.
P.T.OModern Battery / Dry CellFig 46.
Cutaway view of an alkaline battery.Figure 4. shows the new modern battery found in the supermarket nowadays. This type of cell is still based on the wet/ galvanic cell but it is far more complex in comparison to the wet cell discussed earlier. Most of us do not realise the fact that the outer casing of the battery is made by Zinc and is the anode of the battery. The pointy ends, is in-fact a graphite rod that act as the cathode surrounded by paste consisting manganese dioxide and ammonium chloride as well as zinc chloride, which act as the electrolyte.
On the outer casing of the battery the zinc undergoes oxidationZn(s) –> Zn2+(aq)+ 2e-On the cathode, the reaction is as follow:2MnO2 (s) + 2H+(aq) + 2e- –> Mn2O3 (s) + H2O (l)The 2H+(aq) needed in the reduction process is gained from the electrolyte within the paste, the reaction producing 2H+(aq) follows this reaction,NH+4 (aq) –> NH3 (aq) + H+(aq)There are three common dry-cell batteries, and they usually are classified by different electrolyte used in the battery. The battery mentioned at the top is mildly acidic dry-cell battery. In an acid based battery usually sulphuric acid (H2SO4) is used while in an alkaline battery the electrolyte is replaced with 7M KOH, alkaline batteries use powdered zinc anode is used to enhance reaction. Alkaline dry cell can last longer, however it does cost more than normal dry cells. Acid based battery is used in automobile batteries, but not in household battery as they are corrosive and seen as dangerous to be used in normal household battery.Rechargeable Battery:Fig 57. Cutaway view of a rechargeable battery (Nickel-Cadmium/ Ni-Cad Battery).
A rechargeable battery works the same way as normal battery, but in the rechargeable batteries the reactions that take place can be reversed. In chemistry this term is called electrolysis, it is where external electric current is given, to force the reaction to reverse. After we drain the battery we give external electricity current and “Charge” the battery. What actually happened is that the electric current has forced the reaction to go backward and the battery will be ready again afterward.The process of charging, or forcing a backward reaction to occur by giving electricity is known as electrolysis. To make it easier to understand, let us look at the Ni-Cad battery’s reactions, which is a rechargeable battery.During the process of using the battery,On the Anode we have:Cd(s) + 2OH-(aq) Cd(OH)2(s) + 2e-On the Cathode we have:2NiO(OH)(s) + 2H2O + 2e- 2Ni(OH)2(s) + 2OH-(aq)The overall reaction would be:Cd(s) + 2OH-(aq) +2NiO(OH)(s) + 2H2O Cd(OH)2(s) + 2Ni(OH)2(s) + 2OH-(aq)Reactant ProductLogically speaking, as long as we can turn the product back into the reactant, then the reaction can take place again. In the case of rechargeable we will have external force to run the reaction backward so the product mentioned above, would react to produce the reactant mentioned.
During the process of charging the battery,On the Anode we have:Cd(s) + 2OH-(aq) Cd(OH)2(s) + 2e-On the Cathode we have:2NiO(OH)(s) + 2H2O + 2e- 2Ni(OH)2(s) + 2OH-(aq)The overall reaction would be:Cd(s) + 2OH-(aq) +2NiO(OH)(s) + 2H2O Cd(OH)2(s) + 2Ni(OH)2(s) + 2OH-(aq)Product ReactantThe reactions shown above are the reactions during the recharging of the battery. The reactions are reversed, and the battery will be ready to provide electrical energy again.2. Comparison of Batteries Life.Aim: To test numerous AA batteries available on the market, and examine rechargeable batteries and their capability in terms of long-term use.Materials and Method: Please refer to Appendix 2.
2.1 Comparison of Alkaline batteries’ lifeResults: Table 2. Comparison of duration of Alkaline batteries.Battery TypePrice (AUD)Single PriceInitial StrengthDuration (Mins)Final StrengthRayovac Maximum$4.98 (Pack of 4)$1.25100%700 Mins35%Energiser MAX$6.28 (Pack of 4)$1.57100%540 Mins43%Energiser T2 Titanium$8.
97 (Pack of 4)$2.25100%620 Mins38%Eveready Gold$5.44 (Pack of 4)$1.36100%560 Mins44%Eveready Heavy$3.98 (Pack of 4)$0.
96100%405 Mins42%NB*: The strength of the battery was tested using Dick Smith’s battery tester2.2 Observation:This experiment assumes that variables that may affect the experiment will be distributed evenly on each and every battery; assumption is also made that the time difference in which battery has been stored inside the store will not significantly affect the result. The batteries are acquired from Dick Smith’s in Australia, therefore there may be a price variance, but the results can definitely be used as a guideline.Initially, the brightness of each bulb was not very subjectively different. However, after 4 hrs, Eveready Gold and Eveready Heavy Duty both became significantly dimmer in brightness compare to the other batteries.
A check was made after 4 hrs, and showed that all the circuits were in good contact. At 6 hours, all the batteries have decreased their brightness with Eveready Heavy Duty down to the last spark of light. By 10 hrs, Energiser T2 Titanium was not glowing at all, but a contact check showed that by providing greater pressure to the poles, it was still able to give a little spot of light. However, soon after the light was gone. Only Rayovac Maximum was able to reach just before the 12-hour observation.Discussion:Based on the results, it might seem obvious that Rayovac Maximum is the best non-rechargeable battery within the sample. However, there are a few arguments that need to be considered. Firstly, Rayovac is not particular popular within the market.
Therefore, it may be hard to obtain Rayovac Max. In the experiment, each Rayovac Maximum is about $1.25 while each Energiser MAX is $1.
57. But we should realise that batteries like Energiser MAX and Eveready Heavy Duty or Eveready Super Heavy Duty can be bought in packs of 6 (buy four get two free) or even in packs of ten. This will significantly reduce the price the batteries. Thus, even though Rayovac Maximum is significantly longer lasting, in the long run, with bulk buying Energiser MAX may be more cost effective. Nevertheless, even though Eveready Heavy Duty could be most economical (at $0.96 per battery), consumers would have to change batteries lot more frequently. This is also an important issue to needs to be considered.Energiser E2 Titanium is very expensive even though it is relatively durable.
However we must realise that E2 Titanium was introduced to the market to be used in a more high-tech electronic systems. Therefore it is unfair to have it running a 1.5V Globe as a test.
Finest electrical equipments such as, digital cameras and mini-discs, may need more constant and stabile voltage running within the system. In the test E2 glows the bulb more intensely, and the bulb showed less flickers when it was run by the E2. Therefore the usage of E2 should only be considered when running high technology equipments.In a child’s toy such as those giving out loud noises it is practically pointless to have excessive amount of energy outputted. For radios and walkmans that do not require high and consistent input to operate the equipments, cost effective Rayovac MAX will be sufficient. It would be quite unreasonable to pay $2.
25 for an Energiser E2 battery that lasted 80 minutes less than a battery that is only $1.25 (Rayovac).On the other hand, Eveready Gold is definitely not the best choice according to the results of this experiment.
It cost $1.36 per battery and usually cannot be purchased in bulk to reduce cost. In addition, following the observation during the trials, the brightness of the bulbs was disappointingly dimmed. In normal equipments for example, the need to change the battery is more vigorous than the 1.5V bulb.
Maybe walk-man needs to operate at a certain voltage in which the Eveready Gold may not be able to provide after a relatively short time.Summing up the non-rechargeable batteries, the most economical and durable battery would have to be Rayovac Maximum. It is a battery that is more of an all-rounder, the battery is the cheapest, and it last the longest. However, as this conclusion is only based on one trial of a small sample of five batteries, it may not be conclusive evidence but certainly is very suggestive.2.
2 Comparison of Rechargeable Batteries lifeResults: Table 3. Comparison of duration of rechargeable batteries.First Trial:Battery TypePrice / PackCharge RateStrengthDurationBIG Alkaline 1500mAh$30 (4 Packs) & Charger14 Hours100%570 MinsDickSmith NiCad 1000mAh$5.98 Each15 Hours100%550 MinsDick Smith NiCad 600mAh$3.98 Each9 Hours100%515 MinsSecond Trial:Battery TypePrice / PackCharge RateStrengthDurationBIG Alkaline 1500mAh$30 (4 Packs) & Charger14 Hours97%560 MinsDickSmith NiCad 1000mAh$5.98 Each15 Hours95%520 MinsDick Smith NiCad 600mAh$3.98 Each9 Hours95%490 MinsThirdTrial:Battery TypePrice / PackCharge RateStrengthDurationBIG Alkaline 1500mAh$30 (4 Packs) & Charger14 Hours95%540 MinsDickSmith NiCad 1000mAh$5.98 Each15 Hours95%520 MinsDick Smith NiCad 600mAh$3.
98 Each9 Hours95%490 MinsObservations:After all the batteries were fully charged, they were set off. Evidently, Dick Smith NiCad 600mAh was not as bright as BIG Alkaline and Dick Smith NiCad 1000mAh. Thus at the 8hr check, it was already difficult to observe any significant glow other than a fine spot of light. By approximately 10hrs, both remaining battery was removed. All three trials were nearly identical; the brightness and duration of each of the bulbs where quite predictable by the third trial.Limitations:The limitations of this experiment are due to three main factors:1. The variety of batteries,2.
The number of trials, and3. The amount of time and resources available.The types of batteries used in this experiment are only a small fraction of the range on the market. In addition to that, due to time constraints, excessive amount of trials cannot be enforced for both the rechargeable and non-rechargeable batteries to produce a more accurate result and the ability to claim uncertainties and variables within the battery.
The number of trials on rechargeable batteries may not describe the relationship and function that may be able to be used to picture how the depletion rate of their efficiency in long-term use. Another factor is the technical support provided is restricted and in-depth research and values cannot be obtained from the prac. As this essay was done under a very limited timeline and resources available, the experiment done in this essay was relatively simple and was unable to give specific and detailed value, and therefore it can only discuss the essay question in a very general manner.Discussion:Comparing amongst the rechargeable batteries, BIG Alkaline batteries are both economical and relatively long lasting. For $29.97 which includes four batteries and a specialised charger, it makes the package very easy to operate and cost-effective. The charger will switch off when the batteries are fully charged with makes it hassle-free and probably time consuming as most batteries are not fully de-charged before they are non-functional to the electrical item. Extra BIG Alkaline batteries can be purchased at Dick Smith for $14.
48 per pack of 4 ($3.62 each). Dick Smith rechargeable are expensive because they cannot be purchased in a pack and do not include a charger.
The charger used in the experiment is an Eveready Ni-Cad charger. Although the charger works perfectly, it makes the package less attractive to consumers as there is no option of bulk buying.The most important issue in using rechargeable batteries is its use in the long term and its depletion rate in efficiency over time.
However, due to the limitations of time and resources, only three trials were performed. This has made it impossible to demonstrate any comparison between the two types of batteries as desired. However, it can be argued that whether or not rechargeable batteries are more economical in the long-term, the length of recharge time is an important consideration depending on what electrical items these AA batteries are used for.
For example, four batteries running a game-boy last for about four hours but it takes fifteen hours to recharge the batteries? This would make the use of rechargeable batteries less desirable. Another alternative is to keep extra sets of batteries that will push the cost to be much higher. Therefore, unless it is obviously more economical to use rechargeable batteries, it would be unnecessary and could cause a lot of hassle, as consumers may find it troublesome to recharge the rechargeable battery.3. Conclusion:The initial cost of setting up a rechargeable battery may be more expansive, the cost of the charger of the battery itself may cost approximately $32, while the battery costing around $5 each. On the case of an appliance need four batteries we will have a set up cost of $52, which can buy 40 Rayovac Maximum batteries. Yet those 40 Rayovac batteries only means 12 times of recharging and reusing the rechargeable batteries.
Therefore using rechargeable batteries is obviously more economical. As the cost of a battery after the initial set up will only cost around $4 more expansive than normal alkaline battery.Aside from economical value, there are further considerations we need to take place when we choose a type of battery. RBRC (Rechargeable Battery Recycling Corporation) suggest that in United States alone 3 Billion batteries weighing 125,000 tons of batteries are discarded. Should environmental issue be considered when choosing batteries be taken into consideration then there will be a whole lot of range of matter we should take into account, such as chemical composition of the battery itself and so on.
Appendix4.1 Operation of a simple battery:Aim/Purpose:To help illustrate a simple battery for readers.Materials:** 2 x Strips of Copper Foil* 2 x Strips of Zinc Foil* 0.5M Copper Sulphate* 0.5M Zinc Nitrate* 0.1M Potassium Nitrate* Emery paper* Voltmeter* Wire (Conductor)* Safety Glasses* 2 x Beaker* 1 x Filter paperMethodology/Procedure:(a) Place the Copper Sulphate into one beaker.(b) Place the Zinc Nitrate on the other beaker.
(c) Clean the strips of metal with emery paper.(d) Make a salt bridge by folding filter paper, and soaked in Potassium Nitrate solution.(e) Join the metal salt solutions’ beakers with the salt bridge.
(f) Dip Copper Foil inside Copper Sulphate and Zinc Foil inside Zinc Nitrate.(g) Connect the voltmeter on the battery then take the readings.4.2 Comparison of Batteries Life.Aim:To test numerous AA batteries available on the market, and examine rechargeable batteries and their capability in terms of long-term use.
Material:* A pack of Rayovac Maximum AA 1.5V alkaline battery* A pack of Eveready Gold AA 1.5V alkaline battery* A pack of Energiser E2 Titanium Technology AA 1.5V alkaline battery* A pack of Energiser MAX AA 1.5V alkaline battery* A pack of Eveready Heavy Duty AA 1.5 alkaline battery* 10 X 1.5V bulbs.
* 10 X Insulated copper wires* A Battery tester (Dick Smith’s)* Reusable Adhesive* double-tape.* Stopwatch* Different type of rechargeable batteries and their chargersProcedure:PART A:1. Take out one of each of the non-rechargeable batteries and test them using the battery tester.2. Record the initial strength in percentage in Table 1.3.
Attach one end of the wire to the negative side of the battery and the other end of the wire on the side of the bulbs.4. Test the bulb by placing the other end of the wire at the anode.
If the bulb did not glow or not brightly, re-adjust the bulb and re-test again.5. After testing and ensuring the light of the bulb, make sure that the bulb are firmly connected and in contact at all times without the need of holding it.6. When all circuits are set to go, start the timer.7.
Make observation of the relative brightness of the glowing bulb initially and then within 2 hours interval.8. Record their relative brightness, be investigative and sensitive during the process.9. When the bulbs does not seem to glow to the naked eye, detach the bulb and wire from the battery. Record the time in Table 1.10.
Test the battery for its strength on the battery tester.11. Record the final strength in percentage in Table 1.PART B:1.
Test the rechargeable batteries using the tester and make sure they are all fully charged (>95%). Always charge batteries for the duration as instructed by using compatible chargers.2. Repeat steps 3 to 10 in Part A.
3. Recharge the batteries and then repeat steps 3 to 10 in Part A again.4. Repeat procedures, to obtain depletion rates.