Page 99 - Handbook of Battery Materials

2.6 Coin-Type Lithium Secondary Batteries 65

Table 2.16 Specifications of secondary niobium oxide–vanadium oxide batteries.

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

VN621 1.5 1.2 6.8 2.1 0.3
VN1616 1.5 8 16 1.6 1.2

2.6.8
Secondary Titanium Oxide–Manganese Oxide Batteries

These batteries are new systems which use a lithium–manganese composite oxide
for the active material of the positive electrode – a lithium–titanium oxide with
a spinel structure for that of the negative electrode, and an organic solvent for
the electrolyte. Lithium ions enter the manganese oxide from the titanium oxide
during discharge and lithium ions enter the titanium oxide from the manganese
oxide during charge.
The lithium–titanium oxides are prepared by heating a mixture of anatase
◦
(TiO 2 ) and LiOH at a high temperature. The product heated at 800–900 C has
a spinel structure of Li 4/3 Ti 5/3 O 4 . When the charge and discharge cycles are
performed between 2.5 and 0.5 V versus a lithium electrode, good cyclability (>400
cycles) is obtained in the plateau region. The open-circuit potential in the charge
plateau is 1.58 V relative to lithium electrode and polarization during charge and
−1
discharge is small. The capacity density in the plateau is about 147 mAh g , which
corresponds to a 0.84-electron transfer for Li 4/3 Ti 5/3 O 4 [57, 58].
The batteries feature a 1.5 V operating voltage. The energy density of the MT920
−1
(diameter 9.5 mm, height 2.0 mm) is 45 Wh L . It is applicable to watches in
which the power source is rechargeable with a solar battery, and it can serve as a
memory backup power source. Table 2.17 shows the specifications of TiO 2 –MnO 2
batteries [59].

Table 2.17 Specifications of secondary titanium oxide–manganese oxide batteries.

Model Nominal Nominal Discharge current Dimensions Weight
voltage capacity (mA) (mm) (g)
(V) (mAh)
Maximum Standard Diameter Height

MT621 1.5 1.2 – 0.1 6.8 2.1 0.3
MT920 1.5 3 – 0.2 9.5 2.0 0.3
MT1620 1.5 11 – 0.5 16.0 2.0 0.3