Page 350 - Lindens Handbook of Batteries

LiTHiUM PriMAry BATTerieS 14.15

2. Size and capacity of cell and battery. Safety is directly related to the size of the cell and the
number of cells in a battery. Small cells and batteries, containing less material and, therefore, less
total energy, are “safer” than larger cells of the same design and chemistry.
3. Amount of lithium used. The less lithium that is used, implying less energetic cells, the safer
they should be.
4. Cell design. High-rate designs, capable of high discharge rates, versus low-power designs
where discharge rate is limited, use of “balanced” cell chemistry, adequate intra- and intercell
electrical connections, and other features affect cell performance and operating characteristics.
5. Safety features. The safety features incorporated in the cell and battery will obviously influence
handling procedures. These features include cell-venting mechanisms to prevent excessive inter-
nal cell pressure, thermal cutoff devices to prevent excessive temperatures, electrical fuses, PTC
devices, and diode protection. Cells are hermetically or mechanically crimped-sealed, depending on
the electrochemical system, to effectively contain cell contents if cell integrity is to be maintained.
6. Cell and battery containers. These should be designed so that cells and batteries will meet the
mechanical and environmental conditions to which they will be exposed. High shock, vibration,
extremes of temperature, or other adverse conditions may be encountered in use and handling,
and the cell and battery integrity must be maintained. Container materials should also be chosen
with regard to their flammability and the toxicity of combustion products in the event of fire.
Container designs should also be optimized to dissipate the heat generated during discharge and
to release pressure in the event of cell venting.

14.4.2 Safety Considerations
The electrical and physical abuses that may arise during the use of lithium cells are listed in
Table 14.8 together with some generalized comments on corrective action. The behavior of
specific cells is covered in the other sections of this chapter. The manufacturer’s data should be
consulted for more details on the performance of individual cells. Material safety data sheets
(MSDSs) should also be obtained.

High-Rate Discharges or Short-Circuiting. Low-capacity batteries, or those designed as low-rate
batteries, may be self-limiting and not capable of high-rate discharge. The temperature rise will thus

TABLE 14.8 Considerations for Use and Handling of Lithium Primary Batteries
Abusive condition Corrective procedure
High-rate discharging or short-circuiting Low-capacity or low-rate batteries may be self-limiting
electrical fusing, thermal protection
Limit current drain; apply battery properly
Forced discharge (cell reversal) Voltage cutoff
Use low-voltage batteries
Limit current drain
Special designs (“balanced” cell)
Use of diode in parallel across cells to bypass current
Charging Prohibit charging
Diode protection to prevent or limit charging current
Overheating Limit current drain
Fusing, thermal cutoff, PTC devices
Design battery properly
Do not incinerate
Physical abuse Avoid opening, puncturing, or mutilating cells
Maintain battery integrity