Improvements in Electrodes for Secondary Batteries.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electrodes for Secondary Batteries.
PERCY WILBRAHAM NORTHEY, Receiver and Manager, Epskid Electric Accu-
mulator Co. Ltd., 28, Victoria Street, Westminster, Electrical Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention consists of an improvement in the design of cast plates for the
electrodes of secondary batteries, & in particular to a device for obtaining the
maximum amount of active material with the minimum of weight & entire
freedom from buckling or distortion.
My electrode consists of a cast plate consisting of a series of small sections or
groups of parallel ribs supported grating-wise at their ends so as to allow free
circulation of acid through the plate.
I am aware a plate of this grating section has been made by burning together
strips of lead parallel to one another, but for an efficient battery the rib must
not be too long, or high resistance & insufficient mechanical strength will
result.
Moreover there must not be too many ribs, otherwise the total amount of cur-
vature caused by expansion is great.
My plate consists of a main frame sufficient for the conduction of the current
to the point or points of collection, & for the support & rigidity of the plate.
Between the members of the main frame are formed groups of parallel ribs,
1 to 2 millimetres in thickness, & sufficiently far apart to allow free circulation
of the acid when the plate is fully oxidised.
Each group of ribs is bounded on all sides by a portion of the main frame
thus enabling each group to be independant & readily capable of taking up
any possible amount of expansion within the limits of its own frame without
distorting the main frame or the plate as a whole.
I prefer that the ribs shall not be longer than 5 centimetres, & where the
form of the main frame would necessitate a greater length of rib unsupported,
may add an auxiliary bar transverse to the ribs which fulfils the double office
of tieing the ribs at their proper distances apart and forming a further conductor
for the current.
For the convenience of construction of the mould it is preferable that the
various groups of ribs shall be parallel throughout the plate, where it is advis-
able that all the groups shall not be parallel I build up a composite mould con-
sisting of a separate section for each series of parallel ribs.
For example may build up my electrode from 9 squares of parallel groups
of ribs enclosed as light panels by the main frame, the panels may if required be
divided vertically by an auxiliary rib. In the case where the current is collected
from one of the top corners of the plate I may provide a diagonal bar to assist
in conducting the current to the point of collection.
For certain purposes it is necessary that the current should be conducted from

page_text: the centre & the corners of the plate, in such case the main frame would take
the square form with diagonals, while the groups of parallel ribs might be
divided up into four sections included within the main square, so that, one half of
each diagonal of the main frame will form the diagonal of one of the groups of
parallel ribs.
The ribs of each parallel series will be at right angles to the diagonal con-
ductor which passes across them.
Auxiliary ribs may be provided where necessary, as in the former case.
I, PERCY WILBRAHAM NORTHEY, of 28, Victoria Street, Westminster, S.W.,
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:―
My invention consists of an improvement in the design of cast plates for the
electrodes of secondary batteries, and in particular to a device for obtaining the
maximum amount of active material with the minimum of weight and entire
freedom from buckling or distortion.
In the accompanying drawings.
Figure 1 shows in elevation and
Figure 2 in transverse section an electrode embodying my invention.
Figure 3 is a similar view to Figure 1 illustrating a modification.
My electrode consists of a cast plate or grid a composed of a series of distinctly
independent sections or groups of parallel ribs 6 supported grating-wise at their
ends so as to allow free circulation of acid through the plate. Each section there-
fore represents a lattice work having air spaces between the ribs so that the ex-
pansion and contraction which initially occurs during "formation" is provided
for and taken up by each section separately without distorting the plate as a
whole.
I am aware a plate of this grating section has been made by burning together
strips of lead parallel to one another, but for an efficient battery the rib must
not be too long, or high resistance and insufficient mechanical strength will
result.
Moreover there must not be too many ribs, otherwise, the total amount of cur-
vature caused by expansion is great.
The main frame a is sufficient for the conduction of the current to the lug c or
other point or points of collection and for the support and rigidity of the plate.
Between the members of the main frame the groups of parallel ribs b prefer-
ably one to two millimetres in thickness, are formed and they are sufficiently far
apart to allow free circulation of the acid when the plate is fully oxidised. Each
group of ribs is bounded on all sides by a portion of the main frame a thus
enabling each group to be independent and readily capable of taking up any
possible amount of expansion within the limits of its own frame without distort-
ing the main frame or the plate as a whole.
I prefer that the ribs shall not be longer than five centimetres, and where the
form of the main frame would necessitate a greater length of rib unsupported I
may add an auxiliary bar such as those indicated at 7, transverse to the ribs

page_text: which bars fulfil the double function of tying the ribs at their proper distances
apart and of forming a further conductor for the current.
For convenience of construction of the mould it is preferable that the various
groups of ribs shall be parallel throughout the plate. Where it is advisable that
all the groups shall not be parallel I build up a composite mould consisting of
a separate section for each series of parallel ribs.
For example I may as illustrated in Figure 1, build up my electrode from nine
squares of parallel groups of ribs benclosed as light panels by the main frame a.
The panels may if required be divided vertically by the auxiliary ribs d. In the
case where the current is collected from one of the top corners or lugs c of the
plate I may provide a diagonal bar e to assist in conducting the current to the
point of collection.
For certain purposes it is necessary that the current should be conducted from
the centre and the corners of the plate. In such case the main frame as
illustrated in Figure 3 would take the square form with diagonals, while the
groups of parallel ribs b might be divided up into four sections, included within
the main square, so that one half of each diagonal of the main frame will form
the diagonal of one of the groups of parallel ribs.
The ribs of each parallel series will be at right angles to the diagonal
conductor which passes across them. Auxiliary ribs a may be provided where
necessary, as in the former case.
It will be understood that Figure 2 and the left-hand corner of Figure 1 show
the true mechanical construction of the ribs b, but such ribs are merely indicated
diagrammatically in, or are omitted from,' the remainder of the figures.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In electrodes for secondary batteries, a cast plate or grid constructed in such
a way that it is entirely made up of distinctly independent sections of ribs, each
section representing a lattice work having air spaces between the ribs so that the
expansion and contraction which initially occurs during "formation" is provided
for and taken up by each section separately without distorting the plate as a
whole, the bars, parts of which go to form the sides of the various sections of lat-
tice work being of such a section as to provide the necessary conductivity for
current.
2. In electrodes for secondary batteries, the provision of a diagonal bar across
the plate for the purpose of carrying current from the sections of open ribs to
the lug.
3. The electrode for secondary batteries constructed substantially as described
with reference to Figures 1 and 2, or to Figure 3, of the accompanying drawings.
Dated this 21st day of December 1898
A. F. SPOONER,
323, High Holborn, London, Agent for the Applicant.
A. F. SPOONER,
323, High Holborn, London, Agent for the Applicant.