IMPROVEMENT
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Alexander Watt at the Office of the
Commissioners of Patents on the 30th June 1882.
ALEXANDER WATT of Liverpool in the County of Lancaster
IN SECONDARY BATTERIES"
"IMPROVEMENTS
According to one part of my present invention I produce an alloy or mixture
of lead and zinc or other metal electropositive to lead in granulated form by
preference by pouring the alloy in. a molten condition into water, or by disinte-
grating it so as to form a fibrous or woolly mass by subjecting the metal to the
action of a jet of high pressure stean, air or other fluid. This product is then
formed into cohering inasses or slabs by pressure, which slabs may then be
surrounded by a framework of lead cast on, or it may be placed in a perforated or
permeable casing or box of insulating material, such as insulite, slate, earthenware
and the like. The connections of the conducting wires with the said mass may be
conveniently effected by means of a band of lead cut into strips or fingers which
are interlaced or imbedded in the mass, as described, in the Specification to my
previous Patent N° 4255 of 1881.
The slabs prepared, as above described are then immersed in a solution of a salt
of lead or dilute acid, whereby the zinc will be removed and, in the former case,
replaced by a deposit of spongy lead spread over the original granulated lead of
the alloy or mixture.
According to another modification the zinc is simply removed by the acid,
leaving the original lead in a more porous condition. The slabs produced according
to either method, after having been freed from the zinc salt by washing, may
then be subjected to moderate pressure in order to impart sufficient coherence to
the mass.
One or more pairs of slabs thus prepared are then placed together in a bath
of dilute sulphuric, phosphoric or boracic acids, or a mixture of any of these
acids, the slabs being separated from each other by strips of insulating material
placed between or adhering to their edges, thus forming a battery which is then
charged in the usual manner.
Another improvement relates to the forms of secondary batteries described in the
Specification to my said Patent N° 4255 of 1881.

page_text: I employ for the negative plates of the said-batteries one of the following
forms:
1, a carbon plate surrounded with a mixture of granulated peroxide of
manganese and granulated carbon enclosed between perforated insulating plates as
above described: In order to insure a good conducting connection with the carbon, I
form a groove or trough in the upper edge of the carbon plates, into which I introduce
mercury or a fluid-amalgam, into which the conductor is introduced and is retained
in position by an insulating cover to the trough, which prevents the escape of the
mercury. The plates thus formed may be immersed in solutions of dilute sulphuric,
phosphoric or boracic acids, or mixtures of these or of a salt of manganese, or of a
permanganate.
2, The negative plates may also be formed by a mixture of granulated oxide
of manganese and of granulated or fibrous lead, prepared as above described, and
enclosed in a perforated casing and connected as above described.
The positive plates for either of the above forms of negative plates may consist
of the slabs prepared as first above described.