Alkaline Battery: Definition & Working Principles

Discover what alkaline batteries are and how they contain different chemicals. Become familiar with the chemistry of batteries, especially alkaline ones.

Introduced as a publicly available product in the 1960s, Alkaline batteries are now produced in their billions every year and are the world’s most popular household battery. They come in disposable or rechargeable varieties and are used in remote controls, toys, cameras, radios, flashlights, and a ton of other items.

In this blog, we’ll explore the alkaline battery. Please keep reading.

What Are Alkaline Batteries?

A battery is an item that uses isolated sites, or cells, to convert energy into electrical energy. The positive part of the battery is called the cathode. The negative side, or cell, is referred to as the anode. The vast majority of all types of batteries have these physical properties. The main difference between different types of batteries is the composition and content of the battery interior.

An alkaline battery is a battery that is created using the chemical reactions between zinc and manganese dioxide. Compared to other battery types, alkaline batteries have a higher energy density. In comparison to other battery types, they are therefore more durable.

When alkaline batteries were first created in 1906, they were not widely used. Alkaline batteries were not widely used until about 50 years ago. They were initially used as components in other consumer goods. For instance, they were found in kids’ toys. They eventually spread like wildfire as standalone consumer goods. Alkaline batteries are currently the most popular battery sold worldwide.

Types of Alkaline Batteries

Based on the makeup of the active components in the plates, there are four different types of batteries. These are their names:

• Edison, also known as nickel-iron.
• Ni-Cd, also known as Nife.
• Silver zinc.
• Alkum battery.

Structure of An Alkaline Battery

To generate electricity, a typical battery requires three components:

• Anode
• Cathode
• An electrolyte

Components of Alkaline Battery

• Steel shell
• Other important accessories: Negative component- primarily made up of a sealing ring, a copper needle, and a base.
• Steel can
• Separator paper
• Conductive graphite
• Cathode mix
• Conductive graphite
• Cathode mix
• Collector’s nail
• Sealing plug
• Sealant
• Negative cap

Construction of An Alkaline Battery

• The steel drum used to construct the battery’s body is hollow. The cathode and all of the battery’s components are housed in this drum.
• The positive battery terminal sticks out of the top of this drum.
• The inner peripheral surface of the empty cylindrical drum is moulded with fine-grained manganese dioxide (MnO₂) powder mixed with coal dust. The cathode mixture for an alkaline battery is this moulded mixture.
• On the inner surface of the thick cathode mixture layer is a paper separator. Zinc powder and an electrolyte of potassium hydroxide are contained in the central chamber of this paper separator.
• The zinc serves as an anode, and the contact surface is expanded by the zinc’s powder form.
• The electrolyte is held in place between the cathode (MnO₂) and the anode by a paper separator soaked in potassium hydroxide (Zn).
• Along the alkaline battery’s longitudinal axis, a metallic pin (preferably made of brass) is inserted to collect the negative charge. Negative collector pins are what this is. A metallic end-sealed cap makes contact with this pin.
• The positive steel drum and negative end cap of an alkaline battery are electrically separated by a plastic cover that sits just inside the metallic end-sealed cap.

Working Principle of An Alkaline Battery

A cell of an alkaline battery is a section of the battery. A dry battery serves as the main battery in a chemical power source. It’s some kind of rechargeable battery. It uses a zinc cylinder as the negative electrode to power an external circuit and manganese dioxide as the positive electrode to convert chemical energy into electrical energy.

Zinc loses electrons and undergoes oxidation in the chemical reaction because it is more reactive than manganese, while manganese gains electrons and undergoes reduction.

Alkaline batteries occasionally explode or leak. An internal short circuit is to blame for this. On removing the sealing ring, the electric fluid inside will flow out. If the liquid makes contact with your skin, wash it off right away with water.

There is no need to worry about explosions because alkaline batteries have very little air volume; at most, the bottom of the negative electrode rushes out, typically within 20 cm, with no serious harm to personnel.

Alkaline batteries do not spontaneously ignite, in contrast to lithium batteries, so they do not contain any spontaneous combustion material.

Popular Usage of Alkaline Batteries

With cost and a long shelf life being their major advantages, alkaline batteries are often chosen when a device manufacturer ships a product with ‘batteries included’.

They can also be found in backup power devices that don’t have access to charging, like smoke alarms. Alkaline batteries are generally considered to be a good value for typical household batteries. See Are Alkaline Batteries Allowed on Planes?

Alkaline Batteries Vs Lithium

There are many differences between alkaline batteries and lithium batteries. Alkaline batteries have a higher voltage than lithium batteries, which allows them to provide quick bursts of power to devices like camera flashes. However, both the voltage and the mAh capacity decline as the battery discharges. In contrast, lithium batteries maintain their charge until nearly full discharge, making them better for devices like laptops that require steady power.

Alkaline batteries don’t have the same operating life as their lithium counterparts, which can last up to three times as long. The disadvantage of lithium is that its price is frequently double that of an alkaline, which calls into question its actual utility and financial advantages.

Alkaline batteries are superior in terms of backup power. Like all batteries, it self-discharges when not in use, but only at a rate of around 2% per year. This discharge is similar to lithium metal but much lower than lithium-ion.

Alkaline Batteries Vs Nickel

Alkaline batteries are bulkier and have a shorter lifespan than many rechargeable batteries (like those based on nickel). It all depends on how much the current draws. In a high-drain device like a digital camera, the lifespan of an alkaline battery is much shorter. It will last longer in a device with a low drain, like a remote control.

Alkaline is also a better option for gadgets like smoke alarms that only require standby power. They self-discharge at a rate of about 2% annually as opposed to nickel-based units, which would be nearly flat after a year even if not used.

We have compared Carbon Zinc Batteries Vs Alkaline and Alkaline batteries vs Lead Acid Batteries.

Key Challenges of Alkaline Batteries

Some of the key challenges faced by alkaline battery manufacturers include:

Competition from Alternative Chemistries

In consumer electronics applications, primary lithium batteries and rechargeable batteries pose a threat to alkaline batteries. When compared to alkaline batteries, primary lithium batteries have a higher energy density, which results in better performance and a longer lifespan.

Alkaline batteries are being replaced by nickel metal hydride (NiMH) rechargeable batteries in many high-drain consumer applications because they perform better and last a lot longer than disposable alkaline batteries. Remember to Clean Alkaline Battery Corrosion Safely & Effectively.

The impact of this challenge is likely to be medium in the short- to mid-term but is expected to be high in the long term as we will see alkaline batteries being replaced by alternative chemistries.

Increasing Cost of Raw Materials

The pressure on manufacturing costs for disposable batteries was caused by an increase in the cost of raw materials like zinc and electrolytic manganese dioxide (EMD). EMD’s primary cost is its high price. EMD is essential to alkaline battery performance and is expensive because it must be at a high purity level.

The manufacturers of alkaline batteries are under pressure from this trend because the increase in the price of raw materials has an impact on their profit margin. Manufacturers of alkaline batteries face a significant challenge as a result of the anticipated preference for alternative batteries among consumers brought on by the price increase for batteries.

The impact of this challenge is probably going to be low in the long run and medium in the short and middle terms.

Presence of Counterfeit Batteries

Alkaline batteries which appear identical or confusingly similar to a branded battery are referred to as counterfeit batteries. These batteries intentionally mislead consumers by having an appearance that is strikingly similar to branded batteries. The performance, efficiency, and leak-proof features offered by branded batteries, however, could not be anticipated in these knockoffs.

Branded batteries have vents built into their construction to let out internal pressure, which keeps them from exploding or leaking electrolytes. Therefore, fake batteries not only pose a safety risk but also damage the reputation of major battery manufacturers. Short- to medium-term and long-term effects of this challenge are moderate and low, respectively.

Conclusion: Understanding Alkaline Batteries

Zinc and manganese dioxide serve as electrodes in alkaline batteries, which are disposable batteries. The alkaline electrolyte used is either potassium or sodium hydroxide. These batteries have a steady voltage offering better energy density and leakage resistance than carbon zinc batteries.

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