Improvements in Galvanic Cells.
Year: 1897

page_text: Improvements in Galvanic Cells.
I, ALBRECHT HEIL, of Fränkisch-Crumbach, Grand Duchy of Hesse, German
Empire, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention has for object to produce a galvanic cell which will generate a con-
stant current of high intensity without employment of an acid, and which can be used
either as a primary or as a secondary cell.
It possesses the great advantage over other primary and secondary cells that it is not
subject during rest to the injurious influence of local action, and that the electrolyte
is not materially altered during supply of current.
In the Leclanché cell, as is known, the ammonium of the ammonium chloride is
substituted by zine during supply of current ; ammonia is formed, which escapes into
the air; while in the case of the lead-sulphuric acid accumulator, sulphate of lead is
formed during rest, by the action of the sulphuric acid upon the lead and its oxides.
Injurious alteration thus takes place in the cells, which is not the case with the
cell hereinafter described.
My improved cell is produced as follows:-A carbon electrode is surrounded with a
mixture of equal parts by volume of graphite, black oxide of manganese (MnO2) and
peroxide of lead (PbO₂). The graphite is added to the mixture of manganese peroxide
and peroxide of lead to improve the conductivity. The manganese peroxide is
employed on account of its entirely neutral behaviour and of its high capacity of
absorption of the oxygen in the solution; the peroxide of lead on account of the
increased intensity which it gives to the cell. The electrode thus produced is placed
in a solution of sine sulphate in water, to which solution soda is added in such pro-
portion that basic carbonate of zinc hydroxide is precipitated in the form of small
flocks. In order that these flocks, which would either sink to the bottom or float
upon the solution, may remain permanently and regularly distributed the solution is
stirred with gypsum and sawdust to a pulp, and the electrode manufactured as before
described is then immersed therein. Zinc is employed as the exciting or negative
electrode.
As thus employed the cell has an intensity of 1.8 volt and acts as a primary cell.
If it be desired to employ the cell as a secondary cell, the zinc sulphate is omitted
from the solution, and there is employed as the electrolyte a pure soda solution, the
zinc electrode being coated with zinc dust. The zinc then remains insoluble during
delivery of current (discharging) and simply oxidizes, while the oxides which the
carbon electrode carries (manganese peroxide and peroxide of lead) are reduced.
charging on the other hand the mixture surrounding the carbon electrode and
reduced during discharging, is again oxidized. The intensity of this secondary cell
or accumulator can be brought by charging up to 2.8 volts.
Dated this 23rd day of October 1897.
In

page_text: I, ALBRECHT HEIL, of Fränkisch-Crumbach, Grand Duchy of Hesse, German
Empire, Electrical Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention has for object to produce a galvanic cell which will generate a
constant current of high intensity without employment of an acid, and which can be
used as a primary cell.
It possesses the great advantage over other primary cells that it is not subject
during rest to the injurious influence of local action, and that the electrolyte is not
materially altered during supply of current.
In the Leclanché cell, as is known, the ammonium of the ammonium chloride is
substituted by zinc during supply of current; ammonia is formed, which escapes
into the air. Injurious alteration thus takes place in the cells, which is not the case
with the cell hereinafter described.
My improved cell is produced as follows:-A carbon electrode is surrounded with a
mixture of equal parts by volume of graphite, black oxide of manganese (MnO₂) and
peroxide of lead (PbO₂). The graphite is added to the mixture of manganese
peroxide and peroxide of lead to improve the conductivity. The manganese peroxide
is employed on account of its entirely neutral behaviour and of its high capacity of
absorption of the oxygen in the solution; the peroxide of lead on account of the
increased intensity which it gives to the cell. The electrode thus produced is placed
in a solution of zinc sulphate in water, to which solution soda is added in such
proportion that hydrated carbonate of zinc is precipitated in the form of small flocks.
In order that these flocks, which would either sink to the bottom or float upon the
solution, may remain permanently and regularly distributed, the solution is stirred
with a suitable absorbent material such for example as a mixture of gypsum and
sawdust to a pulp, and the electrode manufactured as before described is then
immersed therein. Zinc is employed as the exciting or negative electrode.
As thus employed the cell has an intensity of about 1.8 volt and acts as a primary
cell.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A primary galvanic cell comprising a carbon electrode surrounded by equa. parts
by volume of graphite, manganese peroxide and lead peroxide, a zinc electrode and
an absorbent material holding an electrolyte of zine sulphate containing flocks of
hydrated carbonate of zinc evenly distibuted throughout the mass of said electrolyte
substantially as described.
2. The manufacture of primary galvanic cells substantially as hereinbefore
described.
A
11
T
1000
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.