Page 175 - Battery Reference Book

Lithium solid electrolyte primary batteries 9/15

Table 9.11 Characteristics of lithium-carbon monofluoride cells
Open Volts Discharge Gravimetric Volumetric Gravimetric
circuit under voltage energy energy power
volts load proJile density density density
07 (VI (W mg-' ) (W h/dr~-~) (Wkg-')
3.3-3.5 2.5-2.8 Flat 235 max 587 rnax 23 rnax

Volumetric Storage Operation Selj' Calendur Types
power temperature temperature discharge life available
density ("C) ("C) rate
Cm-3)
57 max -45 to 85 -45 to 85 1% pla 1 OY Coin: prismatic,
pin available

to accommodate discharge temperatures up to 125°C 4. High voltage density The thin cell structure and
without degradation in performance. Similarly, the cell high cell voltage (1.9V) gives a high voltage-to-
may be stored at temperatures up to 200°C without height ratio.
serious losses. Perhaps the most interesting quality is 5. No gassing, corrosion or leakage The use of solid
the 15-20 years' projected storage life at room temper- cell components and the absence of chemical reac-
ature. This is compatible with the design life of profes- tions eliminates gassing and leakage.
sional equipment containing microprocessors, making 6. Hermetic, leakproof design Only one 'seal' is
it possible to fit the cell as a permanent component. required per battery.
The solid electrolyte cell relies on ionic conduction 7. Safety Neither short-circuit nor voltage reversal
in the solid state. This is a low-rate process where causes pressure build-up or chemical reaction.
temperature is ,an important variable. Discharge effi-
ciency on maximum load is particularly affected and a Solid electrolyte batteries are currently available in a
350mA h cell is typically rated at 1 pA at room tem- button or circular disc configuration, with a nominal
perature - well below its maximum capability. This 25.4mm diameter and rated at 350mAh. Table 9.12
reduces its dependence on temperature and guaran- summarizes the major physical and electrical charac-
tees a high discharge efficiency over a wide range of teristics of these batteries.
temperatures. The closely rnatched temperature charac-
teristics of solid electrolyte batteries and CMOS logic Tab,e 9.12 Durace,l sol,d e,ectrolyte batter,es
circuits is another property which makes the solid
electrolyte battery ideally suited for memory-retention Duracell type no.
applications. The major advantages of the solid elec-
trolyte battery are as follows: 305127 305159
1. Virtuallv unlimited shelf life The Duracell solid Nominal voltage (V) 2.0 4.0
d I I No. of cells 2
electrolyte battery has a projected shelf life in 1
excess of 20 years under normal storage conditions Rated capacity* (mA h) 350 350
and is capable of extended storage at temperatures Dimensions 28.9 i 0.13 29.7 i 0.13
as high as 120°C. Diameter (mm) 2.54 + 0.25 5.8 zk 1.8
Height (mm)
Wide operating temperature range Solid elec- Volume (cm3) 1.44 4.04
trolyte cells can operate from 40 to over 120°C. Weight (g) 7.25 15.85
Operation at higher temperatures is possible with
modified designs. The current capability is a func- *Rated at 1 discharge at 21°C
tion of temperature. At 95°C the current capability
is 10-20 times the room temperature performance;
however, at -48°C it is only 2-3% of that at room Duracell solid electrolyte batteries are designed
temperature. primarily for low-power, long-service-life applications,
High energy density A volumetric energy density and should be used in accordance with the manufac-
of 308-500WWdm' is superior to most conven- turer's specifications. Although such conditions should
tional battery systems. be avoided, these cells can withstand short-circuit or