Page 347 - Lindens Handbook of Batteries

14.12 PriMAry BATTerieS

14.3.3 Solid-Cathode Lithium Primary Cells
The solid-cathode lithium batteries are generally used in low- to moderate-drain applications and
are manufactured mainly in small flat or cylindrical sizes ranging in capacity from 25 mAh to about
11 Ah, depending on the particular electrochemical system. Larger batteries have been produced in
cylindrical and prismatic configurations. A comparison of the performance of solid-cathode lithium
batteries and conventional batteries is presented in Chap. 8.
The solid-cathode batteries have the advantage, compared with the soluble-cathode lithium pri-
mary batteries, of being nonpressurized and thus not requiring a hermetic-type seal. A mechanically
crimped seal with a polymeric gasket is satisfactory for most applications. On light discharge loads,
the energy density of some of the solid-cathode systems is comparable to that of the soluble-cathode
systems, and in smaller battery sizes it may be greater. Their disadvantages, again compared with
the soluble-cathode batteries, are a lower rate capability, poorer low-temperature performance, and
a more sloping discharge profile.
To maximize their high-rate performance and compensate for the lower conductivity of the
organic electrolytes, designs are used for these lithium cells to increase electrode area, such as a
larger-diameter coin cell instead of button cells, or the spirally wound jelly-roll construction for the
cylindrical cells.
A number of different cathode materials have been used in the solid-cathode lithium cells. These
are listed in Tables 14.4 and 14.6, which present some of the theoretical and practical performance
data of these cells. The major features of the solid-cathode lithium cells are compared in Table 14.7.
Many of the characteristics are similar, such as high specific energy and energy density and good
shelf life. An important property is the 3 V cell voltage obtained with several of these cathodes. Some
cathode materials have been used mainly in the coin or button cell designs while others, such as the
manganese dioxide cathode, have been used in coin, cylindrical, and prismatic cells, as well as in
both high (spirally wound) and low (bobbin) rate designs.
Although a number of different solid-cathode lithium batteries have been developed and even
manufactured, more recently the trend is toward reducing the number of different chemistries that are
manufactured. The lithium/manganese dioxide (Li/MnO ) battery was one of the first to be used com-
2
mercially and is still the most popular system. it is relatively inexpensive, has excellent shelf life, good
high-rate and low-temperature performance, and is available in coin and cylindrical cells. The lithium/

TABLE 14.7 Characteristics of Typical Lithium/Solid-Cathode Batteries
Operating
Type of battery voltage, V Characteristics
Li/MnO 2 3.0 High specific energy and energy density; wide operating temperature range (-40 to +85°C);
performance at relatively high discharge rates; minimal voltage delay; relatively low cost;
available in flat (coin) and cylindrical batteries (high and low rates).
Li/CFx 2.8 Highest theoretical specific energy, low- to moderate-rate capability; wide operating tempera-
ture range (-20 to 85°C); flat discharge profile; available in flat (coin), cylindrical and pris-
matic designs.
Li/CuO 1.5 Highest theoretical volumetric coulombic capacity (Ah/L); long storage life; low- to moderate-
rate capability; operating temperature range up to 125 to 150°C; no apparent voltage delay.
Potential replacement for alkaline-manganese but not currently available.
Li/FeS 1.5 replacement for conventional zinc-carbon and alkaline-manganese dioxide batteries; higher
2
power capability than conventional batteries and better low-temperature performance and
storability. Currently available in AA and AAA sizes as a direct replacement for alkaline-
manganese. Finding increasing use in digital cameras.
Li/AgV O 3.2 High specific energy and energy density multiple-step discharge; good rate capability; used in
2 5.5
implantable and other medical devices. See Sec. 31.5.4.
Li/V O 3.3 High energy density; two-step discharge; used in reserve cells (See Chap. 35).
2 5