Electricity & Magnetism at Work Batteries Chapter 3 Section 4

Battery Converts Chemical energy to electrical energy

Luigi Galvani 1700’s Italian Was using a brass hook to dissect a frog When the hook touch an iron railing it made the frogs leg jump Electron flow!

Alessandro Volta 1800 Stacked Silver (Ag) and Zinc (Zn) metal plate Italian Designed 1st battery Stacked Silver (Ag) and Zinc (Zn) metal plate Separated by a paper that had been soaked in salt water

Electrochemical Cells A devise that converts chemical energy into electrical energy Electrodes Made of two different metals Electrolyte Substance that conducts electricity Salt water Acid

A Simple Cell Chemical reaction occurs between the electrolyte and the electrodes in the electrochemical cell. These reactions cause one electrode to become negatively charged and the other to become positively charged.

Combining Electrochemical Cells If 2 or more electrochemical cells are connected in series, the “+” terminal of one is connected to the “-” terminal of the next. The voltage of the battery is the sum of the cells.

Wet Cells Wet Cells 12-V car Battery Use liquid electrolytes Acids Salt water 12-V car Battery Sulfuric acid 6 cells

Dry Cells Dry Cells Duracell Use paste electrolytes Zinc can with a carbon rod down the middle

Dead Batteries The battery will continue to produce a current until the electrodes and/or the electrolyte are used up

Rechargeable Batteries Nickle-Cadmium cells Laptops Cell phones iPods Some chemical reactions can be reversed Recharges the battery