voltaic cell

(noun)

A cell, such as in a battery, in which an irreversible chemical reaction generates electricity; a cell that cannot be recharged.

Related Terms

Examples of voltaic cell in the following topics:

  • Voltaic Cells

    • A voltaic cell is a device that produces an electric current from energy released by a spontaneous redox reaction in two half-cells.
    • This kind of cell includes the galvanic, or voltaic, cell, named after Luigi Galvani and Alessandro Volta.
    • In a typical voltaic cell, the redox pair is copper and zinc, represented in the following half-cell reactions:
    • Voltaic cells are typically used as a source of electrical power.
    • A battery is a set of voltaic cells that are connected in parallel.

  • Electrochemical Cell Notation

    • Cell notation is shorthand that expresses a certain reaction in an electrochemical cell.
    • Cell notations are a shorthand description of voltaic or galvanic (spontaneous) cells.
    • The anode half-cell is described first; the cathode half-cell follows.
    • Using these rules, the notation for the cell we put together is:
    • A typical arrangement of half-cells linked to form a galvanic cell.

  • Dry Cell Battery

    • The dry cell is one of many general types of electrochemical cells.
    • Unlike a wet cell, a dry cell can operate in any orientation without spilling, as it contains no free liquid.
    • A common dry-cell battery is the zinc-carbon battery, which uses a cell that is sometimes called the Leclanché cell.
    • Another example of a dry-cell battery is the alkaline battery.
    • An illustration of a zinc-carbon dry cell.

  • Fuel Cells

    • William Grove developed the first crude fuel cells in 1839.
    • Fuel cells are classified by the electrolyte they use, which is the main difference among the various types of fuel cells.
    • Other types of fuel cells don't face this problem.
    • There are several advantages to hydrogen fuel cells, though.
    • Additionally, current fuel cells cannot be scaled to the small size needed for portable devices such as cell phones.

  • Free Energy and Cell Potential

    • In a galvanic cell, where a spontaneous redox reaction drives the cell to produce an electric potential, the change in Gibbs free energy must be negative.
    • This is the opposite of the cell potential, which is positive when electrons flow spontaneously through the electrochemical cell.
    • If E°cell > 0, then the process is spontaneous (galvanic cell)
    • If E°cell < 0, then the process is non-spontaneous (the voltage must be supplied, as in an electrolytic cell)
    • A demonstration electrochemical cell setup resembling the Daniell cell.

  • The Nernst Equation

    • In electrochemistry, the Nernst equation can be used to determine the reduction potential of an electrochemical cell.
    • In electrochemistry, the Nernst equation can be used, in conjunction with other information, to determine the reduction potential of a half-cell in an electrochemical cell.
    • Find the cell potential of a galvanic cell based on the following reduction half-reactions where [Ni2+] = 0.030 M and [Pb2+] = 0.300 M.
    • First, find the electromotive force for the standard cell, which assumes concentrations of 1 M.
    • The added half-reactions with the adjusted E0 cell are:

  • Concentration of Cells

    • The standard potential of an electrochemical cell requires standard conditions for all of the reactants.
    • When reactant concentrations differ from standard conditions, the cell potential will deviate from the standard potential.
    • The change in Gibbs free energy for an electrochemical cell can be related to the cell potential.
    • Under standard conditions, the output of this pair of half-cells is well known.
    • Discuss the implications of the Nernst equation on the electrochemical potential of a cell

  • Crystal Structure: Closest Packing

    • Closest packing refers to the most efficient way to arrange atoms in a crystalline unit cells.
    • These cells are periodically arranged to give rise to a crystal's lattice structure.
    • In a three dimensional representation of this hypothetical unit cell—with the spheres packed as efficiently as possible—there are two methods to densely pack the cell.
    • Imagine a single layer of spheres packed into the bottom of a unit cell.
    • A CCP arrangement has a total of 4 spheres per unit cell and an HCP arrangement has 8 spheres per unit cell.

  • Electrolytic Cells

    • Electrolysis uses electrical energy to induce a chemical reaction, which then takes place in an electrolytic cell.
    • Electrolysis can sometimes be thought of as running a non-spontaneous galvanic cell.
    • A cell used in elementary chemical experiments to produce gas as a reaction product and to measure its volume.

  • Crystal Structure: Packing Spheres

    • The most common way to describe a crystal structure is to refer to the size and shape of the material's characteristic unit cell, which is the simplest repeating unit within the crystal.
    • In principle, one can reconstruct the structure of an entire crystal by repeating the unit cell so as to create a three-dimensional lattice.
    • These spheres are packed into unit cells.
    • By considering how atomic spheres are arranged relative to one another, their coordination numbers, and the dimensions of the unit cell, it is possible to form a general view of the structure and complexity of particular crystal structures.
    • Notice that this unit cell contains several atoms.