Lead-acid batteries

Definition

Lead-acid batteries are a type of rechargeable battery that uses lead dioxide as the positive plate and sponge lead as the negative plate, submerged in a sulfuric acid solution. These batteries are widely used due to their ability to deliver high surge currents, making them ideal for applications such as starting vehicles and providing backup power. Their design allows for both primary and secondary battery characteristics, showcasing how they can be recharged and reused multiple times.

5 Must Know Facts For Your Next Test

1. Lead-acid batteries have a nominal voltage of 2 volts per cell, and most common configurations include six cells to create a 12-volt battery.
2. These batteries have a cycle life that typically ranges from 500 to 1,200 cycles, depending on the depth of discharge and maintenance practices.
3. They are relatively inexpensive compared to other rechargeable batteries, which contributes to their widespread use in automotive and backup power applications.
4. Lead-acid batteries can experience sulfation if left discharged for extended periods, which can permanently reduce their capacity.
5. Recycling is an important aspect of lead-acid batteries; about 98% of their components can be recycled, making them one of the most environmentally friendly battery technologies.

Review Questions

• How do lead-acid batteries operate in terms of chemical reactions during charging and discharging?
  • Lead-acid batteries function through redox reactions involving lead dioxide and sponge lead plates immersed in sulfuric acid. During discharge, lead dioxide at the positive plate reacts with sulfuric acid, producing lead sulfate and releasing electrical energy. Conversely, during charging, an external current reverses the reaction, converting lead sulfate back into lead dioxide and sponge lead while regenerating sulfuric acid. This cyclical process allows for the reuse of the battery multiple times.
• Discuss the advantages and disadvantages of using lead-acid batteries compared to other types of rechargeable batteries.
  • Lead-acid batteries offer several advantages including low cost, robustness, and the ability to deliver high surge currents, which makes them ideal for applications like starting engines. However, they also have disadvantages such as lower energy density compared to lithium-ion or nickel-metal hydride batteries, which means they are heavier and bulkier for the same amount of stored energy. Additionally, their lifespan can be significantly reduced if they are not properly maintained or if they frequently undergo deep discharges.
• Evaluate the role of lead-acid battery recycling in sustainability efforts and its impact on environmental concerns.
  • Recycling lead-acid batteries plays a critical role in sustainability as it helps mitigate environmental hazards associated with lead and sulfuric acid disposal. Approximately 98% of materials from these batteries can be recycled, including lead and plastic components, reducing the need for raw materials and minimizing landfill waste. This high recycling rate not only addresses environmental concerns but also supports the circular economy by ensuring that valuable resources are reused rather than discarded. Additionally, responsible recycling practices can significantly lessen the ecological footprint associated with battery production.

Related terms

Electrolyte: The medium through which ions move in a battery; in lead-acid batteries, this is usually a dilute sulfuric acid solution.

Deep cycle battery: A type of lead-acid battery designed to be discharged to a significant extent before being recharged, often used in applications like renewable energy storage.

Voltage regulation: The process of maintaining a constant voltage level in a battery system, crucial for the safe and effective operation of lead-acid batteries.