Page 322 - Handbook of Battery Materials

292 11 Separators

2
Electrical (Ω cm )
Resistance
0.1

Legend: r = σ 1 = 1.26 Ωcm
g
(H 2 SO 4 1.28 ; 25°C)
cm 3
d = 0.25 mm
0.05 T 2 P = 1 (Approximation)

50 60 70 80 90 100 (%)
Porosity

Figure 11.6 Electrical resistance as a function of porosity.
Reprinted from W. B¨ ohnstedt, Automotive lead/acid bat-
tery separators: a global overview. J. Power Sources, 1996,
59, 45–50, with kind permission from Elsevier Science S.A.,
Lausanne [3].

Table 11.1 World battery markets 1998 (US $ million, estimate).

Lead–acid batteries
Automotive batteries 8200
Industrial batteries 2300
VRLA batteries 1000
Total 11 500
Alkaline batteries
Vented 500
Sealed 2800
Total 3300
Lithium-ion batteries 1300
Consumer batteries 9400
Total markets 25 500

The remaining 40% or more are split among the recently introduced lithium-ion
batteries as well as a multitude of primary systems in the portable battery sector.
This distribution of battery production is not geographically uniform; whereas in
Europe and the USA automotive and industrial batteries are in the lead, in the
Asia-Pacific area consumer batteries are more strongly represented. In this section
separators for mainly those rechargeable batteries which have aqueous electrolyte
will be discussed individually, whereas separators for batteries with nonaqueous