What You Should Know About Batteries Knowledge

By Gerald, Updated on February 6, 2024

There are many battery types. Generally, there are three main types of batteries: chemical, physical, and biological. Let’s take a brief look at physical and biological batteries first.

Part 1. Battery types

Physical battery

Physical batteries include photovoltaic batteries. This device converts light energy into electricity using substances that produce an electric current when light is shone on them. For example, solar cells are typical photovoltaic cells. There are also temperature-difference batteries, which convert the temperature difference of a substance into electrical energy. There are also atomic energy batteries, which can use the rays emitted by radioactive substances to obtain electrical energy, so they have a long life and are mostly loaded on artificial satellites.

Biological battery

Biological batteries currently include two main types. One is the enzyme biofuel cell. Its principle is through the use of enzymes, a catalyst, at room temperature so that materials such as hydrogen, methanol, glucose, etc., and oxygen chemical reaction to obtain electrical energy. Another type is the microbial battery. It is based on using microorganisms to carry out the same reaction as the enzyme battery.

Chemical battery

Chemical batteries, which occupy an important position in the large family of batteries, can be divided into two categories.

1. Disposable batteries

Disposable batteries can be thrown away when they run out of power. Zinc-manganese dry battery batteries and lithium batteries represent disposable batteries.
The anode of these three kinds of batteries is manganese dioxide. The cathode is zinc, zinc, and lithium, respectively.

2. Rechargeable batteries

Another type of rechargeable batteries is rechargeable ones that can be recharged when they run out of power. Representatives of rechargeable batteries are lead-acid, nickel-cadmium, and nickel-metal hydride batteries. Lithium-ion batteries are also used in our mobile phones and computers.

The anode of these four types of batteries is lead dioxide, nickel hydroxide, nickel hydroxide, and lithium cobaltate. In contrast, the cathode is lead, cadmium, hydrogen storage alloys, and graphite.

3. Fuel battery

In addition to these two main categories, chemical batteries have a special presence. This is the fuel cell. Its principle is to use a fuel such as hydrogen to react with oxygen and thus produce electricity. For example, suppose hydrogen is used as a fuel. In that case, the opposite reaction to the electrolysis of water occurs to produce electricity, and the reaction product of the hydrogen fuel cell is only water. Therefore, there is no pollution to the environment.

Part 2.Chemical battery principle

Physical batteries, biological batteries, and fuel cells to generate electricity are not difficult to understand in principle, so the traditional chemical battery is how to generate electricity.

Simply put, a chemical battery is a device that generates electricity through a chemical reaction. The oxidation reaction releases electrons, while the reduction reaction gets electrons. These two reactions take place on separate occasions. If they are connected with wires, a flow of electrons is generated in the wires, producing an electric current.

To cause each reaction to take place at the anode and cathodes, an “electrolyte” exists around them. In actual batteries, the anode and cathode terminals are separated by an insulated separator to prevent short-circuiting of the anode and cathode terminals.

Part 3. Chemical battery voltage

We know that different chemical cells have different voltages. What is the reason for this? This is because the ease of releasing electrons or obtaining electrons varies with the substance.

The battery’s voltage is determined by the ease of release of electrons from various substances and the ease of obtaining them. It is easy to release electrons of substances, according to the degree of ease from high to low, including lithium, potassium, calcium, sodium, magnesium, aluminum, zinc, and so on. So, these substances can be the cathode of the battery.

The substances that can easily gain electrons include gold, platinum, silver, mercury, copper, etc., in descending order of ease. So, these substances can be the anode of the battery. The greater the difference between the ionization tendency of the anode and cathode metals, the greater the number of electrons moving simultaneously, and the higher the voltage of the battery can be made.

Part 4. Battery capacity

The capacity of a battery is expressed in terms of how many milliamps of current flow through it for how many hours. The unit is mAh, mA stands for milliamps, and h stands for hours. Nickel-metal hydride batteries are usually marked with 1000mAh or 2500mAh. This 1000mAh means aluminum can be discharged for 10 hours with a current of 100mA.

Lithium-ion batteries loaded into today’s smartphones generally have a 2,000-3,000 mAh capacity. However, the standby time felt when using a mobile phone is determined by more than just the battery capacity. How energy-efficiently you can activate only the unit inside the mobile phone depends on the respective intelligence of the different brands of mobile phones.

Part 5. Battery structure

1. Alkaline dry battery structure

Alkaline dry batteries use manganese dioxide as the anode and zinc as the cathode. The battery’s cathode is a paste of zinc particles mixed with potassium hydroxide solution as an electrolyte. Here, the zinc releases electrons into ions.

At the battery’s anode, manganese dioxide gains electrons and hydrogen ions to form alkaline manganese oxide. In this way, electrons flow from the zinc side, where electrons are easily released, to the manganese dioxide side, where electrons are easily gained, generating an electric current.

2. Rechargeable battery structure

The representative of rechargeable batteries is the nickel-metal hydride battery. At the cathode terminal of the battery, the hydrogen stored in the hydrogen storage alloy loses electrons and is converted into hydrogen. At the battery’s anode terminal, alkaline nickel oxide binds hydrogen ions and gains electrons.

The separator of a nickel-metal hydride battery is a thin plate. It serves to prevent the metal powder at the electrode from moving. Also, to move the ions, a potassium hydroxide solution, which serves as the electrolyte, is infiltrated into the separating device. Hydrogen ions are transferred between the cathode and anode, enabling charging and discharging.

3. Lithium-ion battery structure

Lithium-ion battery composition is important; it is composed of an anode, cathode, non-aqueous electrolyte, diaphragm, and battery shell. Among them, the anode and cathode poles contain active electrode substances, conductive agents, binders, etc., which are uniformly coated on the copper and aluminum foil collectors.

FAQs

What is the cycle life of rechargeable batteries?

The cycle life of rechargeable batteries varies depending on the type and quality of the battery. Generally, rechargeable batteries can endure hundreds to thousands of charge/discharge cycles before their capacity significantly decreases.
What does battery mAH mean?

mAh stands for milliampere-hour, which represents the capacity of a battery to store electrical charge. It indicates how long a battery can sustain a specific current before requiring recharging.
Is higher mAh better?

A higher mAh rating generally indicates a higher capacity battery, which can theoretically provide longer runtime. However, higher mAh alone does not necessarily make a battery better, as other factors like voltage, quality, and intended usage should also be considered.
What does battery capacity mean?

Battery capacity refers to the amount of electrical charge a battery can store. It is typically measured in ampere-hours (Ah) or milliampere-hours (mAh). It indicates the total energy a battery can deliver over time.
What are dry batteries?

Dry batteries, also known as primary batteries, are non-rechargeable batteries that come pre-charged and are intended for single use. They cannot be recharged and are commonly found in household devices like remote controls, flashlights, and toys.