Batteries
The Physics Hypertextbook™
© 1998-2008 by Glenn Elert -- A Work in Progress
All Rights Reserved -- Fair Use Encouraged
Discussion
introduction
An electrochemical cell is two different metals in contact through an electrolyte (a liquid with free-moving ions). A set of connected cells is called a battery. Batteries come in two basic types: primary and secondary. The chemical reaction that powers a primary cell is one way. Once the chemicals are exhausted the battery is effectively dead. In contrast, the chemical reaction in a secondary cell is reversible. When the reaction runs in its spontaneous direction, the battery produces a potential difference. When the same potential difference is applied to the battery from an external source, the chemical reaction runs in reverse. A battery made up of secondary cells is said to be rechargeable.
| Primary Cells | ||||
| example | cathode (−) | electrolyte | anode (+) | voltage |
|---|---|---|---|---|
| voltaic pile (1799) |
zinc (Zn) |
brine (saltwater) |
copper (Cu) |
? |
| daniell cell (1836) |
zinc (Zn) |
zinc sulphate (ZnSO4) copper sulfate (CuSO4) |
copper (Cu) |
1.1 V |
| leclanché cell (1866) |
zinc (Zn) |
ammonium chloride (NH4Cl) |
manganese dioxide (MnO2) |
1.5 V |
| dry cell | zinc (Zn) |
manganese dioxide (MnO2) |
carbon (C) |
1.5 V |
| lemon | zinc (Zn) |
citric acid (C6H8O7) |
copper (Cu) |
1.1 V |
| Secondary Cells | ||||
| example | cathode (−) | electrolyte | anode (+) | voltage |
| lead acid | lead (Pb) |
sulfuric acid (H2SO4) |
lead oxide (PbO2) |
2.1 V |
| nicad | nickel hydroxide (Ni(OH)2) |
potassium hydroxide (KOH) |
cadmium hydroxide (Cd(OH)2) |
1.2 V |
| nickel metal hydride | nickel (Ni) |
potassium hydroxide (KOH) |
intermetallic compounds | 1.2 V |
| lithium ion | metal hydroxide? | lithium salt in an organic solvent? |
carbon (C) |
3.6 V |
Loose notes:
- Luigi Galvani (1737-1798) Italy discovered biological electricity.
- Alessandro Giuseppe Antonio Anastasio Volta (1745-1827) Italy (Lombardy) constructed the first battery in 1800, the voltaic pile.
- John Frederic Daniell (1790-1845) England, Daniell cell 1836
- Georges Leclanché (1839-1882) France, Leclanché Cell 1866
- William Hyde Wollaston (1766-1828) England showed that electricity from voltaic piles was identical to electricity produced by friction.
Summary
- bullet
Problems
practice
- Write something.
- Answer it.
- Write something.
- Answer it.
- Write something.
- Answer it.
- Write something completely different.
- Answer it.
numerical
- problems
Resources
- general
- Duracell Original Equipment Manufacturers (OEM), technical information on battery systems
- The Mechanical Universe and Beyond (video on demand, login required)
- The Electric Battery, Volta invents the electric battery using the internal properties of different metals.
- lead-acid
- Battery Council International (BCI)
- Electric Vehicle Battery Glossary, Triangle Electric Auto Association
- International Lead and Zinc Study Group (ILZSG)
- International Lead Zinc Research Organization (ILZRO)
- Portable Rechargeable Battery Association (PRBA)
- nickel-cadmium
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