Improvements in Electric Accumulators.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Accumulators.
I, EWALD LEIMER, of 110, Kôpnickerstrasse, Berlin, in the Empire of Germany,
Engineer, do hereby declare the nature of my invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
It is well known that of the three systems, the plate, grid and solid mass plate
accumulators, the first only is capable of being rapidly charged, i.e. within half
an hour to an hour. Grid accumulators can only be charged in from 3 to 10
hours, whilst the solid mass plate accumulators require more than 15 hours to
be charged. These data are of course calculated with a view to reasonable
economy and durability. The charging capacity of these three systems of accu-
mulators is in proportion to the time required for charging and discharging, i.e.
the charging capacity per decimetre of plate surface, the capacity of the systems,
on the other hand, is in inverse proportion i.e. the Plante plate accumulators,
can be quickly charged and charged with strong currents, but possess the smallest
capacity per kilogram weight of plate (about 25 ampere hours per 1 kilo. weight
of plate).
The accumulators having solid mass plates require a long time for charging
and cannot stand a strong current, these accumulators, however show a capacity
which has hitherto not been exceeded riz. 80 ampere hours per kilo. of the
positive electrode.
From the foregoing remarks it will be evident that an accumulator, which
combines the highest capacity with the shortest charging time, and capability
of being charged with strong currents, would be of great commercial importance.
The object of the present invention is to provide an accumulator of this kind.
According to the present invention the solid mass plates are combined with the
Plante system in a special manner, the combination not only attaining the advan-
tages above mentioned but resulting a greater durability of the plates. This
result is attained by removing the gas bubbles, invariably formed on the surface
of the electrodes, when charging with strong currents, and causing the said
bubbles to form at other points, thus protecting the active mass of the plates
gainst the destroying influence (electrochemical and mechanical) of the rapidly
rising bubbles. It has been determined, that the total loss of weight of the
active mass is 85% on charging and 15% on discharging the battery.
This is sufficient to prove that the construction of the accumulators as hitherto
carried out is not suited for the manner of charging and discharging the battery
itherto employed. According to the invention the electrodes are so arranged
s to enable the employment of peculiarly made solid mass plates as discharge
lectrodes, which are charged by means of correspondingly arranged Plante

page_text: The full
plates of hard metal composition and having a large superficial area.
charging current is caused to pass straight through the active mass of the positive
discharging electrodes, without loss, and to charge the said electrode evenly
and positively, a positive charging electrode (Plante) being arranged next the
positive discharging electrode, and at the same time to evenly negatively charge
the negative discharging electrode (mass), next which a negative discharging
electrode (Plante) is arranged. Since the charging electrodes are electrically
insulated from the discharging electrodes of the same kind, and stand in con-
tact with the same through the electrolyte, the gas bubbles when the apparatus
is charged, will only appear on the upper surface of the charging electrodes,
and since these are formed of non-oxydisable metal, the said bubbles will rise,
without attacking the surface of the electrodes.
In order to render the present specification more easily intelligible reference
is had to the accompanying drawing in which similar letters of reference denote
similar parts throughout the several views:
Fig. is a front elevation showing each of the layers in section and
Fig. 2 a sectional plan.
The drawing shows a battery with two positive discharge mass-plates and one
positive charging plate arranged between the same, and two negative discharge
plates with two negative charging plates next the same.
In the receptacle a, which is made of acid resisting material, the carrier
beams are arranged, serving to support the plates and insulating system.
The plates are formed in the following manner :-
of
Next the wall of the receptacle a is a negative charging electrode c, which
is separated from the negative discharging electrode e by means of a grid d
ebonite. At the other side of the discharging electrode is a similar grid or
comb dd, and on this a perforated ebonite plate f, whereon another ebony
grid is placed; on this again rests the positive discharging electrodė g,
having another ebonite grid and on this again the positive charging
electrode h. The further arrangement takes place in the reverse order up to the
second negative charging electrode, the arrangement being capable of repetition
as often as required, and according to the capacity of the cell. The arms of the
electrodes which extend out of the receptacle are for the current connections, the
two outside arms serving only to take up the discharging current and the two
longer inner arms serving to feed the charging current. The arm i belongs to
the negative discharging electrode e, arm k to the negative charging electrode c,
arm to the positive charging electrode and m to the positive discharging
electrode 9. The cell is closed in the usual manner by means of a cover n which
may be rendered tight by means of insulating material.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
1: Accumulator constructed to enable rapid charging with strong current in
short time, and for attaining the greatest possible durability of the electrodes,
characterised by employing the paste or mass electrodes for purposes of dis-
charging only, the said electrodes being charged from separate metal plates
insulated from the same, in such manner, as to cause the charging current to
pass the active mass of the discharging electrodes in a straight line thus charging
the same.
2:-One form of carrying the invention covered by Claim 1 into practice
which consists in arranging the positive charging electrode between two positive
discharging mass electrodes, said electrode being insulated from the latter and
arranged close to the same, and arranging one negative discharging electrode
against each of the said mass electrodes the said negative discharging electrode
being each provided with a negative charging electrode insulated from the same
and mounted close to them substantially as described.

page_text: 3: A modification of the device covered by Claim 2 which consists in multi-
plying the system, within one and the same cell for the purpose of attaining any
desired capacity substantially as described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.