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Ch.20 - Electrochemistry
Brown - Chemistry: The Central Science 14th Edition
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook
All textbooksBrown 14th EditionCh.20 - ElectrochemistryProblem 82
Chapter 20, Problem 82

What is the difference between a battery and a fuel cell?

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Begin by understanding the basic definitions: A battery is a device that stores chemical energy and converts it into electrical energy through electrochemical reactions. A fuel cell, on the other hand, is a device that converts chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent.
Explore the structure and components: Batteries consist of one or more electrochemical cells, each containing an anode, cathode, and electrolyte. Fuel cells also have an anode, cathode, and electrolyte, but they require a continuous supply of fuel and oxidant to operate.
Consider the energy source: Batteries store energy internally and can be recharged by reversing the chemical reaction. Fuel cells require a constant external supply of fuel (such as hydrogen) and oxidant (such as oxygen) to generate electricity.
Examine the reaction process: In batteries, the chemical reactions occur within the cell, and the reactants are consumed until the battery is depleted. In fuel cells, the reactants are continuously supplied, allowing for sustained energy production as long as fuel and oxidant are available.
Discuss the applications and efficiency: Batteries are commonly used in portable electronic devices, vehicles, and backup power systems. Fuel cells are used in applications requiring continuous power, such as in vehicles, stationary power generation, and portable power systems, often offering higher efficiency and lower emissions compared to traditional combustion engines.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electrochemical Cells

Electrochemical cells are devices that convert chemical energy into electrical energy through redox reactions. They can be classified into two main types: galvanic (or voltaic) cells, which generate electricity from spontaneous reactions, and electrolytic cells, which require an external power source to drive non-spontaneous reactions. Both batteries and fuel cells are types of electrochemical cells, but they operate under different principles.

Batteries

Batteries are electrochemical devices that store energy chemically and release it as electrical energy when needed. They consist of one or more electrochemical cells connected in series or parallel, typically using a reversible chemical reaction. Once the reactants are consumed, the battery can be recharged by applying an external voltage, allowing the chemical reactions to reverse and restore the original materials.
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Fuel Cells

Fuel cells are electrochemical devices that convert the chemical energy of a fuel, usually hydrogen, and an oxidant, typically oxygen, directly into electricity through a continuous reaction. Unlike batteries, fuel cells do not store energy; instead, they require a constant supply of fuel and oxidant to maintain operation. This makes fuel cells suitable for applications requiring a steady power output over long periods, such as in vehicles and stationary power generation.
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Related Practice
Textbook Question

(a) Which reaction is spontaneous in the hydrogen fuel cell: hydrogen gas plus oxygen gas makes water, or water makes hydrogen gas plus oxygen gas?

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Textbook Question

(b) Can the “fuel” of a fuel cell be a solid?

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Textbook Question

Li-ion batteries used in automobiles typically use a LiMn2O4 cathode in place of the LiCoO2 cathode found in most Li-ion batteries. (b) Which material has a higher percentage of lithium? Does this help to explain why batteries made with LiMn2O4 cathodes deliver less power on discharging?

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