Types of Lithium Primary Cells
The classification and terminology of lithium batteries is based on the
state of the positive electrode active material. There are four main classes
of lithium primary batteries: solid cathode, liquid cathode, solid
electrolyte, and reserve.
Solid cathode cells utilize a solid positive active material and an organic
electrolyte. These cells are manufactured in coin and cylindrical (bobbin and
spiral wrap) configurations. Commercially available cells range in capacity
from about 30 mAh to 5 Ah.
Liquid cathode cells use liquid cathode materials such as thionyl chloride
and sulfur dioxide. These liquid cathode materials perform a dual function.
They act as the positive active material and as the solvent for the
electrolyte. They are manufactured mainly in cylindrical configurations up to
25 Ah in bobbin, prismatic, and spiral-wrap constructions. These latter cells
deliver the highest rates of all primary batteries and find wide use in
military applications. Prismatic cells up to 100 Ah in size are also
manufactured for special military applications.
Lithium/solid electrolyte batteries consist of all solid components and
include an ion conducting solid electrolyte. The conductivity of these
electrolytes is low compared to most liquid electrolytes. Two types of solid
electrolyte cells are: (1) cells with solid crystalline salt, such as lithium
iodide, and (2) cells with solid polymer electrolyte.
Reserve batteries may be constructed from liquid or solid cathode cells.
However, electrolyte is not added to the cell until the cell is activated for
use. Reserve cells are used in applications requiring extremely long shelf
life before use.