How Do Batteries Work?

Ever wonder how that little battery powers your favorite devices? We give you an inside look at how alkaline batteries work.

You can think of a battery as a small power plant that converts a chemical reaction into electrical energy. Various dry cell (or alkaline) batteries can differ in several ways, but they all have the same basic components.

Battery Parts

  • Container

    Battery_Parts_ContainerA steel can housing the cell’s ingredients to form the cathode, a part of the electrochemical reaction.

  • Cathode

    Manganese dioxide mixture and carbon. Cathodes are the electrodes reduced by the electrochemical reaction.

  • Separator

    A non-woven, fibrous fabric that separates the electrodes.

  • Anode

    Powered zinc metal. Anodes are the electrodes that are oxidized.

  • Electrodes

    Where the electrochemical reaction takes place.

  • Electrolyte

    A potassium hydroxide solution in water. The electrolyte is the medium for the movement of ions within the cell and carries the iconic current inside the battery.

  • Collector

    A brass pin in the middle of the cell that conducts electricity to the outside circuit.

Constructing The Battery

  • Container

    It all starts with an empty steel can – the battery container.

  • Cathode Mix

    A cathode mix – finely ground powders of manganese dioxide and conductors carrying a naturally-occurring electrical charge – is molded to the inside wall of the empty container.

  • Separator

    A separator paper is inserted to keep the cathode from touching the anode.

  • Separator

    A separator paper is inserted to keep the cathode from touching the anode.

  • Anode

    The anode, which carries a negative electrical charge, and potassium hydroxide electrolyte are then pumped into each container.

  • Collector

    The brass pin, which forms the negative current collector, is inserted into the battery which, is then sealed and capped.

Powering The Device

  • Chemical Reacts

    The chemical reaction starts when you insert a battery into a device and complete the circuit.

  • Device Responds

    The electrolyte oxides the anode’s powered zinc. The cathode’s manganese dioxide/carbon mix reacts with the oxidized zinc to produce electricity.

  • Voltage Drops

    Interaction between the zinc and the electrolyte produces reaction products, which gradually slows the cell’s action and lowers its voltage.