Improvements in Electric Batteries.
Year: 1897

page_text: Date of Application, 6th July, 1897-Accepted, 7th Aug.,
1897
COMPLETE SPECIFICATION.
Improvements in Electric Batteries.
I, LEON WILBUR PULLEN, of 412 South Third Street, Camden, State of New
Jersey, United States of America, Electrical Contractor, 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:-
The object of my invention is to provide a suitable construction of
battery which shall be light in weight, efficient in operation, capable of being
readily charged and discharged without injury, inexpensive in construction and
durable in operation.
My invention is especially designed for secondary batteries but may be used
with primary batteries also, hence I do not confine myself to any special use.
Heretofore oxide of manganese has been used in primary batteries as a de-
polarizer without an attempt to increase the voltage of the battery, but in my
invention the peroxide of manganese is employed as an impalpable of fine powder
mixed with finely divided carbon and a concentrated solution of sulphuric acid
for the purpose of producing a salt of manganese as the basis of the cathode for
increasing the voltage, and when combined with the other elements as set out in
this application, capable of being charged like a secondary battery with a still
further increase in voltage.
In carrying out my invention I employ a negative electrode formed by mixing
together powdered coke, graphite or plumbago and an oxide of manganese
(preferably the peroxide of manganese) made into a thick paste with concentrated
sulphuric acid. The oxide of manganese is the oxidizing element. This electrode
is provided with one or more terminals preferably in the form of a piece of carbon
extending down into the mass of the electrode. An electrode of this character is.
preferably arranged in a sealed condition within the battery case and is separated
from the positive electrode by means of a porous diaphragm, cell or cup containing
sulphuric acid, preferably in a dilute condition. The positive may be formed of
zine and preferably arranged centrally within the porous cell. In operation, the
powdered coke or amorphous carbon and graphite act as the conductor for the
current from all portions of the negative electrode, the carbon tending to reduce
the weight of the same while acting as a conductor and the graphite acting to keep
down the internal resistance. In practice the amorphous carbon, which is prefer-
ably finely crushed gas retort coke such as would pass through a No. 80 mesh, is
thoroughly mixed with the graphite or crystalized carbon so that all particles of
the former are practically incased or enclosed in graphite, and at the same time
is also internately mixed with powdered peroxide of manganese and the entire
ingredients formed into a pasty condition by the addition of concentrated sulphuric
It will be seen
acid. This changes the oxide into the sulphate of manganese.
from this that the particles of graphited amorphous carbon acts as an excellent
conductor cf electric current and at the same time maintain the entire negative
electrode in a porous condition so that the decomposition necessary for the proper
electrolytic action may take place throughout its entire mass with the greatest
facility. The best results are secured by having the plumbago ground as fine as
5

page_text: The
possible such for instance as is used for polishing by lithographers.
manganese should be ground to about the same fineness as the plumbago, though
inferior results can be secured when it is not so finely subdivided. The electrode
formed of this mixture is enclosed. to hold it against expansion, and may be
employed in a primary or secondary battery as desired.
My invention will be better understood by reference to the accompanying
drawings, in which:
Fig. 1 is a sectional elevation of a secondary battery embodying my invention
taken on line of Fig. 2; and
.
j
Fig. 2 is a sectional plan view of same taken on line y-y of Fig. 1.
A is the outer case or box and may be formed of glass, rubber, metal or other
material if desired. C is an inner porous diaphragm, cup or chamber preferably
of asbestos, unglazed porcelain or terra cotta. E is a centrally disposed electrode
of zinc arranged within the porous cup. B is the negative electrode and consists
of the intimate pasty mixture of amorphous carbon, graphite, sulphate of
manganese and concentrated sulphuric acid herein before described.
'
The
The preferred portions of these ingredients which I have found excellently
adapted to the purpose in practice are:-1 part of graphite by measure, a half
part of crushed gas retort coke, one quarter part of peroxide of manganese, and
sufficient concentrated sulphuric acid to produce a thick spongy mass.
sponge so formed is forced into the case, between its walls and the porous cell or
diaphragm, and preferably surrounds the latter. The terminal D may be made
of carbon, metal or any conducting substance and is inserted into the electrode B
and projects above. This electrode is then sealed permanently in position by a
suitable sealing substance as sealing wax E. Any form of wax not capable of
ready melting by, low heat will suffice. The porous cell is filled with dilute
sulphuric acid G and may be sealed by a cap which prevents evaporation and
at the same time centralizes the positive electrode F. H is the positive and I the
negative conductor leading from the electrodes. When mixing the ingredients
certain reactions occur producing great heat and converting the concentrated
sulphuric acid and peroxide of manganese into manganic sulphate.
In the subsequent operation of this cell in discharging the sulphuric acid attacks
the zinc, forming the sulphate of zinc, the concentrated sulphuric acid in the
negative electrode becomes diluted. These reactions produce a current between
the electrodes and in the external circuit. In charging the battery the reverse
operation takes place, namely: the dilute sulphuric acid is decomposed, setting
free oxygen which combines with the manganese to form a higher oxide; and the
sulphate of zine is decomposed with the deposition of metallic zinc on the positive
electrode. The hydrogen set free in the negative electrode combines with the
oxygen from the decomposed sulphate of zinc and forms water which dilutes the
sulphuric acid, in the porous cup while the sulphuric acid in the negative electrode
is again brought to the concentrated condition. These reactions will explain the
nature, of what mainly takes place, and may be assumed as the reactions of the
battery, notwithstanding that some more complex reactions no doubt occur in
conjuncture therewith. In the operation of my improved battery when used as a
primary battery, at the start it delivers a difference of potential of 2.2. volts, and
when used as a secondary battery after recharging its voltage increases to 2.5.
volts...
1.
It is evident that any number of terminals may be employed in connection with
the negative electrode, and it is also to be understood that the proportions of the
several ingredients may be varied without departing from the spirit of the inveu-
tion. The number, shape, or configuration of the. battery cell or its parts is
immaterial as its shape and materials of the porous diaphragm or cell may be
varied to suit the ideas of the designer, the form shown being the simplest
construction and excellently suited as an illustration of the general features, of
the invention.
+
I do not confine myself to the mere details of construction of these improvements

page_text: as the same may be more or less modified without departing from the spirit of my
invention.
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. The electric battery having the cathode arranged in a depolarizing mass
of substantially the composition described.
2. The electric battery having the cathode arranged in a depolarizing mass
consisting of finely divided carbon, a salt of manganese and concentrated sulphuric
acid uniformly distributed throughout said mixture.
3. The electric battery of the character specified in Claim 2 in which the finely
divided carbon of the depolarizing mass consists of plumbago and amorphous
carbon, such as coke.
Dated this 6th day of July 1897.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.