The key difference between alkaline and lithium batteries is that the lifetime of lithium batteries is much higher than that of the alkaline batteries.

We need batteries every day in our household necessities. Although most of the equipment is now directly working with electricity, a lot of other small or portable devices need batteries. For example, alarm clocks, remote controllers, toys, torches, digital cameras, radios are working with the current supplied by a battery. Using batteries are safer than using the main electricity directly. There are lots of batteries under various brand names in the market today. Except for the brand names, we can divide these batteries into two types according to the chemistry of generating electricity.

CONTENTS

1. Overview and Key Difference
2. What are Alkaline Batteries
3. What are Lithium Batteries
4. Side by Side Comparison – Alkaline vs Lithium Batteries in Tabular Form
5. Summary

What are Alkaline Batteries?

Alkaline battery is an electrochemical cell with an anode and a cathode that produces electricity through a chemical reaction. The anode or the negative electrode of the alkaline battery is made of zinc powder. And the positive terminal or the cathode is made of manganese dioxide. The electrolyte in the battery is potassium hydroxide. Following are the two half-reactions taking place in the electrodes.

Zn Zn(S) + 2OH– (aq) →  ZnO(s) + H2O(l) + 2e

2MnO2(s) + H2O(l) + 2e  → Mn2O3(s) + 2OH–(aq)

The usual voltage for an alkaline battery is 1.5 V, and we can increase the voltage by having a series of batteries. There are different sizes of the battery (AA-, AA, AAA, etc.), and the current produced by the battery depends on the size. For instance, AA battery produces 700 mA current.

Figure 01: Different Alkaline Batteries

Also, now there are rechargeable alkaline batteries too. However, we have to dispose the normal alkaline batteries after a certain period of usage. Since alkaline batteries are not so toxic, we can dispose them with domestic waste, but it is always good to be careful when disposing. There is about 1 mV voltage left in the battery when it is fully discharged. Moreover, alkaline batteries may have a chance of leaking the inside potassium hydroxide electrolyte which causes skin and respiratory irritation. Therefore, when there is damage in the outer shell of the battery, we should not use those batteries.

What are Lithium Batteries?

In Lithium battery, we use lithium or lithium compounds as the anode. Lithium batteries produce voltage 1.5 V or more than that depending on the design. We need to dispose them after using because we cannot recharge them.

Figure 02: A Lithium Battery

Lithium batteries are useful in small devices such as watches, calculators, car remotes. Furthermore, we can use them in powerful large devices like digital cameras. Since lithium batteries are toxic, we need to handle and dispose them with care.

What is the Difference Between Alkaline and Lithium Batteries?

Alkaline battery is an electrochemical cell with an anode and a cathode that produces electricity through a chemical reaction while a Lithium battery is a type of battery that uses lithium or lithium compounds as the anode. The key difference between alkaline and lithium batteries is that the lifetime of lithium batteries is much higher than the alkaline batteries. Moreover, Lithium batteries are lighter in weight than alkaline batteries. Thus, this makes lithium batteries ideal for portable devices.

As another difference between alkaline and lithium batteries, usually, lithium batteries give 1.75 V or more whereas alkaline batteries give 1.5V. Thus, the power is higher in the lithium battery. (Lithium battery gives a brighter light beam when used in a torch). Moreover, an important difference between alkaline and lithium batteries is that the lithium batteries are toxic, and alkaline batteries are not so. Therefore, lithium batteries should be disposed of with care.

The below illustration provides a detailed description of the difference between alkaline and lithium batteries.

Summary – Alkaline vs Lithium Batteries

Batteries are very important in portable devices. Alkaline batteries and lithium batteries are two major types of batteries that we use in these devices. The key difference between alkaline and lithium batteries is that the lifetime of lithium batteries is much higher than the alkaline batteries.

Reference:

1. Byrom, Jack. “What Are the Elements of an Alkaline Battery?” Sciencing.com, Sciencing, 6 Dec. 2018. Available here  

Image Courtesy:

1.”Alkali battery 5″By Aney – Own work, (CC BY-SA 3.0) via Commons Wikimedia  
2.”Energizer lithium”By Lukas A, CZE – Own work, (Public Domain) via Commons Wikimedia 

ncG1vNJzZmivp6x7pbXFn5yrnZ6YsqOx07CcnqZemLyue8OinZ%2Bdopq7pLGMm5ytr5Wau26ty6SYpaGemnqiusNmraxlnJ7BqbXUpmSbmaSpsrO1xKxm