Page 97 - Handbook of Battery Materials

2.6 Coin-Type Lithium Secondary Batteries 63

does not occur and the coulombic efficiency is high, because lithium metal is not
deposited.
The active material of the negative electrode is an alloy which contains 50%
Bi, 25% Pb, 12.5% Sn, and 12.5% Cd. The active material of the positive elec-
trode is an activated carbon in which the specific surface area is about 1000 m 2
−1
g , and it has an electrical capacity through the large electric double layer.
Table 2.13 shows the specifications of the batteries [49]. The operating voltage
is 2–3 V. The energy density of the CL2020 (diameter 20 mm, height 2 mm)
−1
is 4.0 Wh L . Long-term charge and discharge are possible. The batteries are
used as a memory-backup supply for microcomputerized equipment and as
maintenance-free power sources for solar-battery hybrid clocks, watches, and
pocket calculators [50, 51].

2.6.5
Secondary Li-LGH–Vanadium Oxide Batteries

The active material of the negative electrode is a newly produced
linear-graphite-hybrid (LGH) as the supporting carrier of lithium, and the
active material of the positive electrode is made of amorphous V 2 O 3 –P 2 O 5 .
By use of these active materials, the short cycle life of the charge–discharge
characteristics due to lithium dendrite can be improved and the capacity decrease
due to overdischarge can be reduced.
The battery features an operating voltage of 1.5–3 V. The energy density of the
−1
VG2025 (diameter 20.0 mm, height 2.5 mm) is 96 Wh L . It can serve as a memory
backup power source. Table 2.14 shows the specifications of the batteries [52].

Table 2.13 Specifications of secondary lithium–carbon batteries.

Model Nominal Nominal Dimensions (mm) Weight Recommended
voltage capacity (g) discharge
(V) (mAh) Diameter Height current

CL2020 3 1.0 (3−2 V) 19.7–20.0 2.0 ± 0.2 1.9 1 µA − 5mA

Table 2.14 Specifications of secondary Li–LGH–amorphous V 2 O 5 batteries.

Model Nominal Nominal Dimensions (mm) Weight Recommended
voltage capacity (g) discharge
(V) (mAh) Diameter Height current

VG2025 3 25 20.0 2.5 2.5 −20 to 60 C
◦
◦
VG2430 3 50 24.5 3.0 4.3 −20 to 60 C