This invention discloses a composite expander and its application in the negative
electrode plate of a lead-acid battery, belonging to the field of lead-acid battery technology.
Ammonium persulfate is used as an oxidant, added to an
ethanol solution mixture of
pyrrole /
aniline monomers (conductive monomers),
sodium lignosulfonate, and
acrylamide, causing an oxidation reaction. Subsequently, it is calcined at high temperature under a
nitrogen or
argon atmosphere to obtain a compound in which a
composite polymer encapsulates
sodium lignosulfonate. After
calcination under a protective gas
atmosphere, some of the
composite material carbonizes, forming a carbon-encapsulated
sodium lignosulfonate composite expander. The carbon-encapsulated composite expander can slow down the consumption of
sodium lignosulfonate. Using the composite expander results in a higher
hydrogen evolution
overpotential and more durable low-temperature performance. The application of the composite expander in the negative
electrode plate of a lead-acid battery improves the
sulfation problem of the negative
electrode plate operating under high efficiency
partial charge conditions, extending the cycle life of the lead-acid battery.