Chemistry Batteries and Energy Storage Assignment
- Briefly describe what is happening at each component of a zinc/copper (Zn/Cu) galvanic cell or battery, as listed below.
- The Anode
There are negative and positive electrodes in the battery; the anode is the negative electrode. At this point, the electrode releases electrons through a process known as the oxidation process. This reaction takes place as a result of bonding between the electrons emitted and oxygen. In most batteries, distinct materials are utilized at the two electrodes so that the reaction would take place as one substance is reduced, whereas the other gets oxidized. In our case, zinc is utilized as the negative electrode. The zinc metal gradually dissolves as the process of oxidation continues to take place; this will result in the release of zinc ions into the solution. Oxidation process occurs as follows:
- The Cathode
From the negative and positive electrodes in the battery, the cathode acts as the positive electrode. It is at this point the cathode emits electrons through a process known as reduction. The reduction process takes place as a result of absorbing electrons that are present at the positive electrode. This means that the excess electrons produced at the negative electrodes shift to balance for the missing electrons by the process of reduction that takes place at the positive electrode. In our case, copper is used as the positive electrode, as the reduction of copper takes place, the atoms of copper accumulate on the copper surface of the solid copper at the positive electrode. The reduction process occurs as follows:
- The Salt Bridge
The salt bridge refers to an absorbent barrier that puts off the impulsive combination of the aqueous solution in every compartment but permits the movement of ions in both directions to sustain the neutrality of electrical current. As both processes of reduction and oxidation continue to take place, the positive charge electrons move from the anode to the cathode through the salt bridge. In contrast, the negatively charged electrons move in the opposite direction, i.e., from the cathode to the anode to keep up the electrical at a neutral stance. Therefore, the function of the salt bridge is not to transfer electrons from the electrolyte, relatively it is to keep up the charge balance since the movement of electrons takes place from one half – cell to the other (anode to the cathode).
- In the zinc/copper galvanic cell, what metal or ion is being oxidized, and what metal or ion is being reduced?
Oxidation is a process whereby a metal losses electron and therefore becomes more charged. In our case of zinc/copper galvanic battery, the zinc metal becomes oxidized because it gradually dissolves as it generates ions which enter the solution (salt bridge). The oxidation process of zinc metal occurs as follows:
The reduction is a process whereby a metal gains electrons, and for that reason, the metal reduces its charge. In our situation of zinc/copper galvanic battery, the copper metal becomes reduced because the copper ions increase the number of electrons; hence the ions are changed into copper atoms that later cover the zinc metal at the solution (salt bridge). Below is the equation showing the reduction process of copper in the battery:
- Explain why electrons flow from the zinc electrode to the copper electrode in the zinc/copper galvanic cell and why the voltage generated by this type of cell is always 1.10 volts.
Electrons flow from the zinc electrode to the copper electrode in the zinc/copper galvanic cell because different metals possess a distinct tendency of losing the electrons in them. Between zinc and copper, zinc is more ready to lose electrons as compared to copper, so placing copper and zinc in the solution (salt bridge) of their salts results in the movement of electrons by use of an external wire between them which will now flow from zinc to copper. As the atom of zinc offers the electrons, it turns out to be positive and enters the solution, reducing the zinc electrode mass. On the other hand, the copper ion receives the released electron and becomes converted to copper atom, thus increasing its weight. Below are the reactions that take place:
The voltage produced in this type of cell is always 1.1V because the oxidation process emits electrons from the half-reaction that takes place at the anode; as usual, the anode in the galvanic cell usually is negatively charged. On the other hand, the reduction process that gains electrons from the half-reaction that takes place at the cathode, which is positively charged. This makes the charge to be balanced, and the voltmeter reads 1.1V, which is the energy required to shift a charged element in an electric field.
- Batteries used in flashlights, TV remote controls, and other small electronic devices come in different sizes. What is the difference between the smaller batteries, such as AAA or AA, for example, and the more massive C or D batteries that are used for these purposes?
AAA and AA are designations of batteries that are utilized to show the possible charge capacity and the size of a particular battery. The most important distinction among the two is their size. The AA battery is significant, as contrasted to AAA. This designation is essential because devices that use battery frequently use different sizes. Even though you cannot fit an AAA battery on an AA slot, there might be adaptors present to allow one to use AAA battery on an AA slot.
Both AAA and AA batteries contain the same voltage amount, which is the same case as bigger batteries, like the type D; because they are typically just one cell. The smaller battery of AAA indicates that there equally smaller electrochemical quantity, which composes of the electric charge. Even though this shows directly that AAA battery has a smaller charge amount, this might not be the situation, as there are high ability AAA batteries that may exceed ordinary AA battery capability.
The usage of both AAA and AA batteries frequently changes, and there does not exist fixed standards for when to utilize one and live the other. Still, one may be likely to identify that appliances that consume more power, use the AA battery. For instance, devices that utilize more power are electric torches and toys that are battery-driven. These gadgets may also use more than one AA battery to raise their voltage and time of operation. On the other hand, AAA batteries are found in appliances that consume less power, such as remote controllers and clocks.
- The lead batteries used to start cars and the lithium-ion batteries used in cell phones, electric vehicles, and hybrid electric/gas vehicles must be recharged. How is the recharging of a rechargeable battery achieved? What is happening during the recharging process?
Recharging is achievable in a rechargeable battery because when a battery is recharged, that means that electrochemical reduction and oxidation processes are reversible in both electrodes of the battery.
All batteries, both non-rechargeable and rechargeable, undergo the reaction of electrochemical. When a battery gets discharged, the oxidation reaction process takes place at the anode (negative electrode), and the reduction reaction process proceeds at the positive electrode (cathode). When a person tries to recharge a battery, he/she is attempting to reverse the electric flow of current, and the opposite of the discharge process happens. A reduction reaction process now takes place at the anode, whereas the oxidation reaction process occurs at the cathode. So when a battery is recharged, the entire electrochemical reaction of both oxidation and reduction takes place reversibly. The process that reduction undergoes in the negative electrode during recharging is similar to the process that oxidation undergoes in the negative electrode during the discharge process and the reverse of all that happens too.
- What is the advantage of using lithium ions to carry charge in rechargeable batteries over, for example, lead ions?
Lithium ions battery has many advantages than lead ions battery in the following ways:
The density of energy in a lithium-ion battery is typically two times higher than that of lead ion battery.
The maintenance of the lithium-ion battery is deficient as compared to that of lead ion battery, there is no schedule, and no memory for cycling is needed to prolong the life of the battery.
The self-discharge of lithium-ion is less by half as contrasted to that of the lead ion; this characteristic makes lithium-ion the most suitable battery for the present application of fuel gauge.
The lithium-ion battery has specialty cells that can generate very high electric current suitable for the application of powerful appliances.
Lithium-ion battery cells result in little destruction when disposed of as compared to the lead ion battery.
- Explain why electric vehicles are more energy-efficient than gasoline-powered cars.
Vehicles that consume electricity are better and favorable for the environment as compared to the cars that use gasoline, not just because these vehicles that use gasoline depends on fossil fuel. Still, the reason being that electric car is more effective. Vehicles move because they are capable of converting energy from fuel (electricity, gasoline, or diesel) into the energy of motion. Effectiveness measures the amount of energy in a given fuel is converted to the energy of motion that allows tires to get rolling.
No gadget can be effective 100% because some amount of energy is continuously lost in the process of generating heat. This is present because of the physical car limitations; energy tends to be lost due to resistance of wind and resistance from rolling tires. But generally, the higher the effectiveness, the little the energy required to power the vehicle. Efficiency simply means that to achieve identical performance with the consumption of minimum energy. This has enormous repercussions for shifting towards less-carbon emission in the future. For each unit of energy evaded because of improved effectiveness, the more we are lowering the energy demand and making it more possible for renewable to take control of our electrical network.
- Hydrogen (H2) might be the fuel of the future for transportation purposes. What are the advantages and disadvantages of using Hydrogen as a fuel for vehicles in place of gasoline or electric power?
The Merits of Hydrogen Energy
- Hydrogen is abundant in supply and a renewable source of energy.
Hydrogen is an abundant energy source for numerous reasons; the principal being that it is plentiful in supply. Whereas it may consume ample resources to exploit it, no other source of energy is infinite as hydrogen gas. The advantage is that there is no probability of the energy source to run out.
- Hydrogen is a clean source of energy.
When Hydrogen is used as a source of fuel, the consequences are safe, which indicates that they have no recognized side-effects. Organizations of aeronautical typically use Hydrogen as a source of water for drinking. After Hydrogen has been used, it is usually changed to water for drinking for astronauts on space.
- The energy from Hydrogen is not poisonous.
Hydrogen energy does not cause destruction or harm to the health of persons. This characteristic makes it to be utilized over other known sources of energy, such as natural gas and nuclear energy, because they are harmful to the safety of living beings. The aspect also permits Hydrogen to be utilized where other sources cannot.
- Hydrogen is more effective than other energy sources
It is a solidly effective type of energy as it can convey enough energy for each fuel pound. This categorically indicates that an automobile that uses energy from Hydrogen will cover more kilometers than a machine with an identical amount of gasoline.
- Utilized to power the spaceships
The power and effectiveness of hydrogen energy make it a supreme source of fuel for spaceships. Its power is strong enough to propel rockets to the exploration missions. The energy from Hydrogen is thrice more powerful than other fuel sources such as gasoline. Only less Hydrogen is required to perform a considerable task.
The Demerits of Hydrogen Energy
- Energy from Hydrogen is expensive
The process of separating Hydrogen from water known as electrolysis is costly. It consumes a lot of resources—this the principal reason why hydrogen energy is not utilized across the globe.
- Hydrogen energy has storage difficulties.
One of the properties of Hydrogen is that it has a lower density; this characteristic makes it difficult to store because it requires be compressing to a liquid state and storing under higher pressure to guarantee its efficiency and effectiveness.
- Not the safest energy source
The hydrogen power should not be underestimated; it is highly flammable and often makes headlines of its possible dangers.
- Hydrogen is complicated to be transported.
It is a discouraging job to transport Hydrogen luminously due to its weightlessness property. It can only be carried at smaller quantities.
- Energy from Hydrogen cannot keep up the population.
Regardless of Hydrogen being plentiful in supply, its harnessing cost limits its widespread use. Even if energy from Hydrogen were to be the cheapest form of energy in the entire world, it would require years to be the most utilized energy source because cars would need customization to meet the requirements of hydrogen energy.