D. Pavlov et al., A new generation of highly efficient expander products and correlation between their chemical composition and the performance of the lead-acid battery, J POWER SOU, 85(1), 2000, pp. 79-91
Citations number
24
Categorie Soggetti
Physical Chemistry/Chemical Physics","Environmental Engineering & Energy
A family of eight lignosulphonates produced by Borregaard LignoTech (Norway
) is investigated with the aim to determine their efficiency as expanders i
n the negative plates of SLI lend-acid batteries. The lignosulphonates are
introduced during preparation of the paste from which the negative active m
ass is formed. All battery tests were performed employing the DIN43539-2 te
st protocol. Besides the battery tests, all lignosulphonates were character
ized with regard to their chemical composition (i.e., the content of variou
s functional groups such as -COOH, Ar-OH, -O . CH3 and organic sulphur in t
he structure of the lignins), average molecular weight and purity. It has b
een found that the lignins UP-393, M, D, Vaniperse-A (VS-A) and UP-414 have
a very strong beneficial effect as expanders on the performance of the neg
ative plates. It has also been established that the cycle life of the batte
ries is limited by the conversion of the energetic NAM structure into skele
ton one. As a result of this conversion, large shapeless lead crystals were
formed with small surface area and large macropores in-between. The benefi
cial effect of the expander has been found to correlate positively with low
number average molecular weight of the lignins and their derivatives, high
-COOH content, low -O . CH3 and organic S content, optimum Ar-OH content a
nd high lignin purity. Expanders with different chemical composition should
be selected for different battery type applications. (C) 2000 Elsevier Sci
ence S.A. All rights reserved.