Page 418 - Battery Reference Book

Lithium-iodine 3815
38.6 bithium-silver chromate Matsuchita (Panasonic) discovered this type of
cell. Other manufacturers (Eagle Picher, Royovac,
These batteries are used in cardiac stimulators, other Eveready, Duracell, etc.) have agreements with
human implantable devices, high-reliability memory Matsuchita to manufacture these cells.
protection, inertial navigation systems and RAM back- Its applications are: electric watches, calculators,
up power sources. cameras, back-up power in electronic devices. lighted
night time fishing boats, low current continuous drain
38.7 Lithium-lead bisrnuthate applications, airborne instrumentation, safety controls,
These are used in analogue quartz watches and pulsing space applications, defence, CMOS -RAM applica-
electronic devices . tions.
Three-volt cylindrical cells are available in the nom-
inal capacity range 600-50OmA h, 3-volt coin cells
38.8 Bithiurn - polycarbcan in the range 25-500mAh and 3-volt pin cells in the
monofluoride range 5.4 mA h.
These batteries are suitable for use in applications
that require high-rate pulses of power, in low-current 38.9 Lithium solid electrolyte
continuous drain applications and as a stable long-
term reference voltage. They provide a high energy These have a 15-20-year life, which is compatible
density when compared with other battery chemistries. with the design life of microprocessors, making it
These batteries ,are designed for applications requiring possible to incorporate these batteries as a permanent
micropower sources in advanced application areas such component of the equipment. The closely matched
as airborne instrumentation, undersea communications, temperature characteristics of solid electrolyte batteries
mineral exploration, remote site monitoring and safety and CMOS logic circuits is a property that makes this
controls. type of battery ideally suited for memory protection
While lithium-iodine batteries suit low-current applications. Basically, these batteries are suitabie for
applications, the lithium-carbon monofluoride is any low-power long service life application.
becoming economically attractive for both low- The Harwell development lithium-vanadium pen-
and high-current requirements. The cost factor was toxide solid state battery is being investigated as a
improved when Panasonic convinced Eastman Kodak possible power source for satellite power and vehicle
that thk chemistry should be used in the mass- propulsion.
produced Kodak disc camera. In this camera, Current research is attempting to develop a portable
cylindrical cells., slightly smaller than AA size, produce equipment battery that operates not at its noma1
the high 1.5A pulses needed to recharge the flash operating temperature of 120°C but at room tem-
and run the motor during automatic picture taking. perature. (polyethylene oxide)g LICF3S03 electrolytes
This type of ceil is not only being used in consumer hold such promise. The y-alumina-lithium fluoride
products. Indeed, configured as small button- or coin- primary solid state battery has some applications in
sized cells, lithium-carbon monofluoride batteries are the cardiac pacemaker field.
being used by at least one computer manufacturer The lithium-titanium disulphide solid state re-
for CMOS-RAM data retention. The button cells are chargeable-battery was at one time considered by
small enough to fit right on top of RAM dual-in-line P.R. Mallory (now Duracell) as a candidate for large-
packages and th'ese button cells cost only 69-90 cents. scale energy storage applications but, due to lack of
This lithium-based composition also has its disad- durability, interest in this application has now declined.
vantages. Batteries are packaged with crimped rather A secondary 2.5 V lithium-titanium disulphide
than welded seals and are therefore subject to leakage. battery developed in the mid-eighties by Eveready,
As a result, UL requirements dictate that a 1 kC2 series employing a LiI-Li8PqOo.25Si13.75 vitreous inorganic
resistor be used to limit current if load short-circuiting electrolyte, has reached the semi-commercial stage.
does occur, or if an isolation diode fails to block
forced charging from the main power source. However,
according to Panasonic, the lithium-carbon monoflu- 38.10 Lithium-iodine
oride chemical combination forms a safe mixture; even
if it does leak out past the seals, it is non-toxic. The Many lithium cells are now available to the watch and
wide distributions and use of the Kodak disc camera, calculator industry, but the designer should take care
using two UL-listed 1200mA h cylindrical cells (Pana- in selecting the right lithium cell for the application.
sonic model BR.21 3A) connected in series, is cited as Factors such as reliability, energy density, internal
proof thiat this chemistry will not pose regulatory prob- resistance and hermeticity should be considered. Since
lems for designers. Panasonic warn prospective users, almost all lithium cells work best with a large
however, that there can be regulatory restrictions for area package, Catalyst Research Corporation propose
air shipment on passenger-carrying aircraft if the prod- standard button cell sizes of three diameters, 19,23 and
uct has more than two cells connected in series. 27 mm, and a-range of thicknesses from 1 to 3 mm in