Leclanché Cells
Characteristics
Primary cell with a nominal open circuit voltage of 1.5 Voltsproduced in very high volumes.
Chemistry based on a zinc anode and a cathode/depolariser ofmanganese dioxide which absorbs the liberated hydrogen bubbleswhich would otherwise insulate the electrode from the electrolyte.It uses a carbon rod as the cathode current collector with anelectrolyte of ammonium chloride. Its variants have been in use forover a century. The performance of Leclanché cells improved by 700%between 1920 and 1990.
Also referred to as Zinc- Carbon Cells or Dry Cells (not to beconfused with Solid State Cells) despite having an aqueouselectrolyte since in modern cells the electrolyte of ammoniumchloride and zinc chloride is produced in gel form or held inporous separators to reduce potential leakage if the cell becomespunctured.
Variants include
Zinc carbon (Carbon cathode)
Zinc chloride (Ammonium chloride electrolyte replaced by zincchloride)
Alkaline manganese ( Ammonium chloride electrode replaced bypotassium hydroxide)
See separate page for Alkalinebatteries.
Advantages
Inexpensive materials
Low cost
Available in a wide range of sizes including AAA, AA, C, D and9Volt sizes.
Suitable for a wide range of consumer applications
Interchangeable with alkaline batteries
Shortcomings
Propensity to leak
The basic zinc carbon battery has a lower energy density than thecompeting alkaline batteries
Poor low temperature performance. Do not function well in sub-zerotemperatures.
The use of naturally occurring manganese dioxide from differentsources can lead to wide performance variations due to the presenceof small quantities of impurities such as nickel, copper, arsenic,and cobalt.
Not rechargeable
Applications
General purpose, low cost applications
Toys
Remote controls
Flashlights
Clocks
Consumer applications
Losing market share to alkaline cells and newer technologies
Costs
Lowest cost primary batteries
