Improvements in and relating to Secondary Batteries.
Year: 1892

page_text: Date of Application, 26th Jan., 1892-Accepted, 27th Feb., 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Secondary Batteries.
We, JUSTUS BULKLEY ENTZ and WILLIAM ALFRED PHILLIPS, both of
Bridgeport in the County of Fairfield and State of Connecticut, United States of
America, Electricians, 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 :-
Our invention relates to secondary batteries in which the electrolyte consists of
a metallic solution, and has special reference to the method of treating the battery
while undergoing the processes of charging and discharging. The object of the
invention is to render the electrolytic action uniform, thereby producing such
advantages as increased capacity, longer life, more rapid charge and general
improvement in the action of the battery.
The invention consists simply in applying heat to the cells, preferably at the
bottom or in mechanically agitating the solution while they are being charged or
discharged, thus setting up a circulation of the electrolyte.
The apparatus which we prefer to employ for carrying out the above process or
method is shewn in the accompanying drawings, in which
Figure represents a sectional elevation of a battery and one form of heating
apparatus, and
Figure 2 a similar view of the battery with another form of heating apparatus.
In the arrangements illustrated A represents secondary battery cells containing
the usual positive and negative plates or electrodes and a metallic solution or
electrolyte, and B is a tray having an open work bottom upon which the battery
cells rest. C (Figure 1) is a gas pipe extending along under the cells and tray
and provided with jets or burners located under. the centre of each cell.
Figure 2D represents steam pipes or coils which may be located in the bottom of
the tray B containing the cells, or be otherwise placed, so that the heat which they
afford may be imparted to the lower portions of the cells.
In
In operation, the complete working cells containing a suitable metallic solution,
while the charging current is being applied to them, are subjected to the heat of
the gas flames or steam coils. We find that when the cells are treated in this
manner, the action of the battery is greatly improved. Its internal resistance is
lowered, it has longer life and the battery will take a more rapid charge. When
cells are charged without the application of heat, the electrolytic action is more
prominent on the lower half of the electrodes, which would indicate that the
metallic solution used was more dense in the lower portion of the cell than nearer
the surface and we have ascertained in effect that the application of heat to the
lower parts of the cells overcomes this defective action by establishing a circulation
in the solution, thereby maintaining its density, or the uniform distribution of the
metallic salts throughout the solution ensuring a correspondingly uniform action
on the plates. The circulation may alternately be maintained by mechanical
agitators, with good results, but we prefer to use heat because it lowers the
resistance of the battery and causes the plating action to take place more easily.
It will be observed that our invention is confined to batteries containing a
metallic solution and that the method is practised after the cells are entirely
completed and in working order. It has been proposed to heat the plates of a
secondary battery as a part of the process of manufacture or "forming" of the
electrodes and to perform that operation in the absence of current, or in the absence
of any effective current and we therefore disclaim such our process having to do
with the perfect battery cell, during working charge and discharge.
Our method of course, is not confined to the application of any particular degree

page_text: of heat so long as one portion of the liquid is maintained warmer than the remaining
portion. Neither is the method confined to any particular apparatus for carrying
it out. In central station work it may be found desirable to similarly heat the
battery while being discharged also we therefore claim this as a part of our
invention.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is,
1. The method herein described of treating a secondary electric battery con-
taining a metallic solution, which consists in agitating or maintaining a circulation
in the solution or electrolyte simultaneously with the operation of charging or
discharging.
2. The method herein described of treating a secondary electric battery con-
taining a metallic solution, which consists in applying heat to the cells simultaneously
with the operation of charging or discharging.
3. The method herein described of treating a secondary electric battery con-
taining a metallic solution, which consists in applying heat to the lower end or
bottom of a cell or cells while the same are being charged or discharged.
Dated this 25th day of January A.D. 1892.
WILLIAM E. HEYS,
Agent for the Applicants.