The key difference between lead acid and lithium ion battery is that lead acid battery requires regular maintenance, has a shorter lifespan, and is inexpensive, whereas lithium ion battery has a longer lifespan, higher efficiency, and is expensive.
Lead acid battery and lithium ion battery are important technologies in the rechargeable battery industry. These two types have different chemical and physical features.
CONTENTS
1. Overview and Key Difference
2. What is a Lead Acid Battery
3. What is a Lithium Ion Battery
4. Lead Acid vs Lithium Ion Battery in Tabular Form
5. Summary – Lead Acid vs Lithium Ion Battery
What is a Lead Acid Battery?
Lead acid battery is a rechargeable battery that was invented in 1859 by the French physicist Gaston Plante. It was the first type of rechargeable battery that was ever made. This battery is different from modern batteries, and these batteries have relatively low energy density. In addition, these batteries are able to supply high surge currents, which means that the cells have a large power-to-weight ratio. Moreover, lead acid batteries are less expensive, which makes them attractive in the automobile industry. This is because it can provide a high amount of current as required by starter motors.
Figure 01: A Lead Acid Car Battery
Since this type of battery is inexpensive compared to modern batteries, these are useful even when surge current is insignificant, and other designs are able to provide a high energy density. The sale of lead acid batteries in 1999 was around 40-50% of the total value of sold batteries all around the world.
A typical lead acid battery contains lead sulfate (PbSO4) and dilute sulfuric acid (H2SO4). In the state of discharge, both positive and negative plates become PbSO4, and the electrolyte tends to lose most of the dissolved sulfuric acid to form primarily water. The negative plate reaction is as follows:
Pb(s) +HSO4–(aq) → PbSO4(s) + H+(aq) + 2e
Two conducting electrons are released at this step which gives this electrode a negative charge. The accumulation of these electrons creates an electric field that can attract hydrogen ions and repel sulfate ions. This, in turn, causes the formation of a double layer near the surface.
Concerning the positive plate reaction, it can be expressed as follows;
PbO2(s) + HSO4–(aq) + 3H+(aq) + 2e → PbSO4(s) + 2H2O(l)
Therefore, the overall reaction that is taking place inside the lead acid battery is;
Pb(s) +HSO4–(aq) + 3H+(aq) → 2PbSO4(s) +2H2O(l)
However, in a fully charged state, the negative plate contains lead, and the positive plate contains lead dioxide. There is an electrolytic solution having a higher concentration of aqueous sulfuric acid. This electrolyte stores most of the chemical energy.
What is a Lithium Ion Battery?
Lithium ion battery is a rechargeable battery with cells in which lithium ion move from the negative electrode to the positive electrode through an electrolyte during discharging. The reverse process happens when charging. Typically, lithium ion cells tend to use an intercalated lithium compound that acts as the material at the positive electrode. Generally, graphite is used at the negative electrode.
Figure 02: Lithium Ion Battery
Moreover, lithium ion battery has a high energy density. But it has no memory effect and a low self-discharge. The cells of the battery are manufactured, prioritizing either energy or power density. However, lithium ion batteries can be a safety hazard because they contain flammable electrolytes, which can lead to explosions and fires upon damage or incorrect charging.
Typically, the negative electrode of a conventional lithium-ion cell is made of carbon. The positive electrode is a metal oxide. Moreover, the electrolyte is a lithium salt in an organic solvent. Depending on the direction of current flow through the cell, the electrochemical roles of the electrodes reverse between anode and cathode. In a commercial scale, the most common anode is graphite, while the positive electrode is one of three materials: a layered oxide, a polyanion, or a spinel.
What is the Difference Between Lead Acid and Lithium Ion Battery?
Lead acid battery was the very first rechargeable battery that was ever made. Lithium ion battery is another type of rechargeable battery. The key difference between lead acid and lithium ion battery is that lead acid battery requires regular maintenance, does not last long, and is inexpensive, whereas lithium ion battery has high efficiency, has a longer lifespan, and is expensive.
Summary – Lead Acid vs Lithium Ion Battery
Generally, lithium ion batteries are often superior to lead acid batteries due to their relatability and efficiency. The key difference between lead acid and lithium ion battery is that lead acid battery requires regular maintenance and does not last long, and is inexpensive, whereas lithium ion battery has a higher efficiency, a longer lifespan, and is expensive.
Reference:
1. “BU-201: How Does the Lead Acid Battery Work?” Battery University.
Image Courtesy:
1. “Photo-CarBattery” Shaddack assumed (based on copyright claims). – No machine-readable source provided. Own work assumed (based on copyright claims). (Public Domain) via Commons Wikimedia
2. “Nokia Battery” By Kristoferb (CC BY-SA 3.0) via Commons Wikimedia