U.S. patent application number 11/556337 was filed with the patent office on 2007-04-05 for method for introducing volatile liquids into the housings of electrical components and for closing the housings.
This patent application is currently assigned to EPCOS AG. Invention is credited to Werner Erhardt, Andree Schwake.
Application Number | 20070074489 11/556337 |
Document ID | / |
Family ID | 27806071 |
Filed Date | 2007-04-05 |
United States Patent
Application |
20070074489 |
Kind Code |
A1 |
Erhardt; Werner ; et
al. |
April 5, 2007 |
Method for Introducing Volatile Liquids into the Housings of
Electrical Components and for Closing the Housings
Abstract
The invention describes a method and a device for introducing
volatile liquids into housings of electrical components, in
particular of passive electrical components or of electrochemical
cells, and for closing the housings. The method can be carried out
using an evacuable chamber, a conveyor device for conveying the
components, a gas pressure device for generating a gas pressure
atmosphere in the chamber, a filling device for introducing a
volatile liquid into a component, a closing device for closing the
component, and using a programmable sequence control means, which
controls the conveyor device, the gas pressure device, the filling
device and/or the closing device in such a way that these devices
interact in a predetermined manner.
Inventors: |
Erhardt; Werner;
(Ballendorf, DE) ; Schwake; Andree; (Heidenheim,
DE) |
Correspondence
Address: |
LERNER GREENBERG STEMER LLP
P O BOX 2480
HOLLYWOOD
FL
33022-2480
US
|
Assignee: |
EPCOS AG
|
Family ID: |
27806071 |
Appl. No.: |
11/556337 |
Filed: |
November 3, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10386172 |
Mar 10, 2003 |
7147675 |
|
|
11556337 |
Nov 3, 2006 |
|
|
|
60383104 |
May 28, 2002 |
|
|
|
Current U.S.
Class: |
53/432 |
Current CPC
Class: |
Y10T 29/49112 20150115;
H01M 10/0525 20130101; Y10T 137/0379 20150401; H01G 9/08 20130101;
H01G 9/10 20130101; H01M 2010/0495 20130101; Y10T 29/49108
20150115; Y02E 60/10 20130101; H01M 50/60 20210101; Y10T 29/53135
20150115; Y10T 29/4911 20150115 |
Class at
Publication: |
053/432 |
International
Class: |
B65B 31/02 20060101
B65B031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 8, 2002 |
DE |
102 10 110.8 |
Aug 26, 2002 |
DE |
102 39 046.0 |
Claims
1. A method for introducing volatile liquids into filling openings
of housings of electrical components and for closing the housings,
the method which comprises: a) conveying the components into an
evacuatable chamber; b) generating an inert-gas atmosphere having a
first pressure in the chamber such that the first pressure is
higher than a vapor pressure of the liquid and below atmospheric
pressure, the first pressure being a variable parameter; c) in a
storage vessel, bringing the liquid to a second pressure that
differs from the first pressure; d) using at least one delivery
device to introduce a quantity of the liquid, which is associated
with a free volume of a housing and which is a variable parameter,
through at least one of the filling openings of the housings; e)
increasing pressure in the chamber to a third pressure being higher
than the first pressure, the third pressure being a variable
parameter; f) repeating steps d) and e) until a predetermined
quantity of the liquid has been introduced into each one of the
housings; and g) closing the filling openings in the housings and
sealing the filling openings in an inert-gas atmosphere having a
fourth pressure.
2. The method according to claim 1, which comprises providing the
components as passive electrical components or as electrochemical
cells.
3. The method according to claim 1, which comprises providing an
inert gas of the inert-gas atmosphere as an element from an eighth
main group of a periodic system.
4. The method according to claim 1, which comprises providing an
inert gas of the inert-gas atmosphere as argon, nitrogen, carbon
dioxide or helium.
5. The method according to claim 1, which comprises cooling an
inert gas of the inert-gas atmosphere.
6. The method according to claim 1, which comprises insuring that a
water content and an oxygen content of the inert-gas atmosphere is
below 100 ppm.
7. The method according to claim 1, which comprises cooling the
liquid to a temperature above a crystallization point.
8. The method according to claim 1, which comprises providing the
liquid as a liquid capable of being gelled or polymerized after it
has been introduced into the filling openings.
9. The method according to claim 1, which comprises providing the
liquid as a substance selected from a group consisting of nitrile,
a glycol, a lactone, a sulphone, a carboxylic acid ester, a ketone,
an aldehyde and a carbonate.
10. The method according to claim 1, which comprises providing the
liquid as a mixture having at least one dissolved conductive salt
and at least two substances selected from a group consisting of
nitrile, a glycol, a lactone, a sulphone, a carboxylic acid ester,
a ketone, an aldehyde and a carbonate.
11. The method according to claim 1, which comprises providing the
liquid as salts that are molten at room temperature.
12. The method according to claim 1, wherein the housings, which
are filled and closed, form lithium ion cells, lithium-thionyl
chloride cells or lithium-sulfur dioxide cells.
13. The method according to claim 1, wherein the housings, which
are filled and closed, form electrochemical double-layer
capacitors, aluminum electrolyte capacitors, hybrid capacitors or
pseudo-capacitors.
14. The method according to claim 1, wherein the step of closing
the filling openings includes riveting, flanging or welding.
15. The method according to claim 1, wherein the fourth pressure is
a subatmospheric pressure or a superatmospheric pressure.
16. The method according to claim 1, which comprises, before
performing step a), drying and then cooling the components.
17. The method according to claim 1, which comprises performing the
step of introducing the quantity of liquid through at least one of
the filling openings and the step of closing the filling openings
in two separate chambers.
18. The method according to claim 1, which comprises conveying the
components on pallets such that the position of each one of the
components can be determined.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional application of application Ser. No.
10/386,172, filed Mar. 10, 2003, which claimed the priority, under
35 USC 119 (e) of provisional application 60/383,104, filed May 28,
2002; the application also claims the priority, under 35 U.S.C.
.sctn.119, of German patent application Nos. DE 102 10 110.8, filed
Mar. 8, 2002 and DE 102 39 046.0, filed Aug. 26, 2002; the prior
applications are herewith incorporated by reference in their
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a method for introducing volatile
liquids into housings of electrical components, in particular of
passive electrical components or of electrochemical cells, and for
closing the housings.
[0004] Components of this type, if they are passive electrical
components, are electrical double-layer capacitors, hybrid
capacitors, pseudo-capacitors or further components which have to
be filled and in particular impregnated with an electrolyte as
liquid. In this context, the term impregnation is to be understood
as meaning the immersion of certain elements of the component which
are arranged in the housing and which, as it were, have to suck up
liquid until they are full. Electrochemical cells include, inter
alia, lithium ion cells or batteries of this type or
lithium-thionyl chloride cells and lithium-sulfur dioxide cells,
which likewise have to be filled or impregnated with an
electrolyte.
[0005] The liquids used as electrolyte are generally volatile and
harmful to health and are also highly flammable, and consequently
have to be processed under particular precautions. Furthermore, the
liquids must be as pure as possible, so that the impregnation of
the components lead to good long-term electrical properties. A
particularly harmful impurity is water, since this is broken down
electrochemically at below the normal cell voltage, which would
irreversibly damage the cells.
[0006] A double layer capacitor is used in the following text to
explain a representative electrical component. However, it will be
readily understood that the invention can also readily be applied
to other components or housings of components.
[0007] Contact can be made with each electrochemical double-layer
capacitor individually at the filling opening using a filling
connection piece. The component housing is first of all evacuated
via this filling connection piece to below the vapor pressure of
the highly volatile organic electrolyte, so that the highly
volatile liquid, such as for example a highly volatile organic
electrolyte, can then be allowed to flow into the evacuated
electrochemical double-layer capacitor. This leads to large-scale
evaporation of the highly volatile solvent in the liquid and
consequently to the feed line becoming blocked by the conductive
salt which remains after evaporation of the highly volatile
electrolyte after just a small number of cells. Furthermore, when
the filling connection piece is removed from the filling opening,
crystals of the conductive salt form as a result of evaporation of
the highly volatile electrolyte. These salts crystals cause leaks
after the filling opening has been closed up, for example with a
rivet, having an adverse affect on the output.
[0008] If the impregnation is not carried out with the aid of
evacuation of the housing of the component, but rather by the
electrolyte being forced into the electrochemical double-layer
capacitor with the aid of excess pressure, the displacement of the
internal gas volume by the electrolyte which is forced in leads to
very considerable numbers of gas bubbles being formed. This
ultimately leads to considerable quantities of the electrolyte
escaping again from the electrochemical double-layer capacitor
through the filling opening. The evaporation of the highly volatile
organic electrolyte and the formation of crystals of the conductive
salt at the filling connection piece mean that it is impossible to
close up the filling connection piece, for example using a
rivet.
[0009] A further possible option for introducing a volatile liquid
into one of the abovementioned components can be effected by
dip-impregnation. In this case, by way of example, the entire
electrochemical double-layer capacitor is submerged in the highly
volatile liquid, such as the organic electrolyte. In this case too,
crystals of the conductive salt remain at the filling opening, so
that with this process too leaks occur when the component is being
closed up. Furthermore, it is impossible to control the impregnated
quantity of the highly volatile liquid with impregnation of this
nature, since all the components suck up different amounts of
liquid. Moreover, dip-impregnation leads to wetting of the housing
outer surfaces, which makes further cleaning indispensable.
Finally, this form of impregnation leads to a high level of
consumption of the highly volatile liquid.
[0010] None of the abovementioned options for introducing the
highly volatile liquid into the housing and for closing up the
latter is suitable for production of relatively large numbers of
units, since the process conditions change over the course of time.
The abovementioned procedures are laborious and, in particular,
expensive.
SUMMARY OF THE INVENTION
[0011] The invention is based on the object of providing a method
of the type described in the introduction which allow economic
production of a large number of the abovementioned components.
[0012] The invention has the advantage that the filling and closing
of the components can be carried out quickly and inexpensively and
in an automated fashion. It is easy to adjust to different shapes
of housings or to different liquids.
[0013] As a further advantage, the invention improves the
electrical and mechanical parameters of the finished components,
since the process parameters can be kept within tight tolerance
ranges.
[0014] Another advantage is that the consumption of volatile liquid
can be optimized. Pressure stages with automated control during the
filling of the housings make it possible to achieve rapid
impregnation of the component. At the same time, the liquid is
almost completely used for impregnation, without major losses.
[0015] The invention advantageously enables the number of
components which are preferably arranged on a magazine and are
positioned accurately to be matched to the number of filling steps
and the size of the filling volume.
[0016] Furthermore, the invention enables the set of the plurality
of components to be optimized in terms of number, size, throughput
time. For example, in the case of a chamber with a plurality of
magazines or in the case of a multichamber system, one magazine
with components can be filled while, at the same time, a second
magazine with components which have already been filled is being
closed.
[0017] Finally, the invention can be used for a very wide range of
shapes of housings of the components; both round and prism-shaped
housings as well as housings in which the external electrical
connections are arranged radially or axially, are suitable.
[0018] Furthermore, the invention can be used to introduce highly
volatile liquid into any desired housings, i.e. including to
introduce it into housings of components other than electrical
components.
[0019] The impregnation of the component can take place without
direct contact between the liquid delivery device and the filling
opening in the housing. This avoids possible damage to the filling
opening, which could lead to leaks when the housings are being
closed up. This improves the yield.
[0020] The highly volatile liquid or the highly volatile organic
electrolyte is brought to a defined pressure in a storage vessel
prior to impregnation by means of the device according to the
invention, so that evaporation of the highly volatile electrolyte
is minimized. In this way, the formation of gas bubbles during the
impregnation or filling operation is avoided.
[0021] The highly volatile liquid or the organic electrolyte is
preferably introduced into the housing at a pressure which is
higher than the vapor pressure of the highly volatile organic
solvent by means of the programmable sequence control of the
device. This means that the feed lines do not become blocked.
[0022] Other features which are considered as characteristic for
the invention are set forth in the appended claims.
[0023] Although the invention is illustrated and described herein
as embodied in "Method for Introducing Volatile Liquids into
Housings of Electrical Components and for Closing the Housings", it
is nevertheless not intended to be limited to the details shown,
since various modifications and structural changes may be made
therein without departing from the spirit of the invention and
within the scope and range of equivalents of the claims.
[0024] The construction and method of operation of the invention,
however, together with additional objects and advantages thereof
will be best understood from the following description of specific
embodiments when read in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a diagram of a filling and closing device; and
[0026] FIG. 2 is a detailed diagram of the filling and closing
device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The filling and closing device as shown in the figures is
controlled centrally by a sequence control means 10, for which
manual operation of the overall installation can also be provided
by means of a switch for test and setting purposes. The sequence
control means 10 is preferably a programmable-memory means which
includes one or more microprocessors with associated memory units.
The sequence control means 10 uses a plurality of communication
lines K to control the temperature, vacuum and filling-level means
of the device as well as the corresponding valves and motors, e.g.
of the conveyor devices 2 and of the doors 7. The sequence control
means 10 is in communication with measurement and detection systems
(not shown) for the process parameters of the installation or
device, which comprise corresponding optical, mechanical or
electrical sensors, likewise via correspondingly assigned
communication lines K.
[0028] The components 4 which are to be filled, e.g. the
electrochemical double-layer capacitors which are to be
impregnated, are positioned on magazines 3 and first of all are
dried in a chamber 16. The components are dried in a drying oven of
this type in order to condition them before the liquid is
introduced.
[0029] One or, depending on the size of the installation, more
magazines 3 can be conveyed into the chamber 1 on a conveyor belt 2
passing through a closeable door 7. The magazine 3 can be
positioned in the chamber 1 with the aid of the conveyor belt 2.
The positioning may take place, for example, linearly in the x
direction or in two dimensions with a further direction in the x/y
direction with the y direction being transverse with respect to the
conveying direction of the conveyor belt (as per the system of
coordinates shown in FIG. 2).
[0030] The components may be positioned in n*m matrix form where
n,m=1, 2, 3, . . . . . , i.e. including as a single row, on each
magazine. They are at defined spacings from one another, so that
their position is unambiguously defined. If appropriate, it may be
sufficient to measure the position of one component in order to
determine the positions of the other components. Of course, it is
also possible to measure the position of one column of the matrix
or one row of the matrix or of each component and to communicate
this information to the sequence control means 10. A subatmospheric
pressure, which can be selected as desired and is preferably above
the vapor pressure of the liquid to be introduced, can be generated
in the chamber 1 with the aid of a vacuum pump 9.
[0031] In the chamber 1 there is one or more delivery devices 5 for
the liquid. The delivery devices include, for example, valves. The
delivery devices 5 have to be able to move relative to the housings
which are to be filled. Therefore, if, for example, the magazine 3
has been placed in a fixed position in the chamber 1 or can only be
moved linearly, a delivery device 5 can move freely in the x and/or
y direction and can be positioned above the filling opening(s) of
the components 4 with the aid of the sequence control means 10 and
one or more detection systems (not shown separately). If the
delivery device is in a fixed position, it must be possible for the
magazine to be positioned as desired; in this case, however, a
larger chamber is required.
[0032] The highly volatile organic electrolyte can be metered out
of a storage vessel 11 by the delivery device 5, for example with
the aid of a mass flow controller 8. There is no need for any
direct contact between the delivery nozzle of the delivery device
and the opening of the component during the filling operation.
[0033] Each component may have one or more filling openings 20. In
extreme circumstances, this may be the entire cross section of the
component, if it does not yet have a cover, in which case the cover
must subsequently be welded or flanged or folded on. Otherwise, the
filling openings 20 are preferably riveted, pinched or welded
shut.
[0034] The highly volatile organic electrolyte in the storage
vessel 11 can be degased with the aid of the vacuum pump 9 at a
subatmospheric pressure which is higher than the vapor pressure of
the highly volatile organic electrolyte. The storage vessel 11 is
fed with undegased, highly volatile organic electrolyte from a drum
15.
[0035] A subatmospheric pressure is generated in the chamber 1 with
the aid of a gas pressure device. The gas pressure device comprises
a vacuum pump 9 and a means 12, 13, 14 for generating an
atmosphere, e.g. with an inert gas, which is not shown in FIG. 1.
The means comprises, in a manner which known per se, valves 12, if
appropriate a cooling means 13 and a gas reservoir 14 for supplying
the chamber 1 with the gas atmosphere.
[0036] The subatmospheric pressure which is generated by means of
the vacuum pump 9 correlates with the pressure of the storage
vessel 11 and is above the vapor pressure of the highly volatile
organic electrolyte. Then, the delivery device 5 is positioned
above the filling opening in a component 4 with the aid of the
detection system. If there are a plurality of delivery systems,
this step may be carried out in parallel for a plurality of
components. Then, a quantity of the highly volatile electrolyte
which is controlled by means of the mass flow controller 8 is
metered through the filling opening into the component(s) by means
of the mass flow controller 8. The quantity is set in such a way
that the free space which is present in the component is filled in
a defined way with the highly volatile organic electrolyte.
[0037] Then, the delivery device 5 is positioned above the filling
opening of the next component 4. These method steps are repeated
until all the components 4 located on the magazine 3 have been
filled once. Then, a higher pressure, e.g. atmospheric pressure, is
established in the chamber 1 with the aid of a gasification valve
12 and/or the vacuum pump 9. As a result, the highly volatile
organic electrolyte is forced into the components 4, e.g. the
electrode windings of electrochemical double-layer capacitors.
[0038] If necessary, all the steps which have been described thus
far can be repeated, with suitable adjustments to the process
parameters, e.g. different pressures, until the required quantity
of the highly volatile electrolyte has been impregnated into each
of the components 4.
[0039] Furthermore, the device includes one or more closing devices
6, 17, of which one or more automated closure units 6, e.g.
automated riveting units, are located in the chamber 1. These are
likewise moveable with respect to the housings and can move freely,
for example, in the x and/or y directions. An automated closure
unit is equipped with one or more detection units (not shown in the
drawing) which are in communication with the sequence control means
10 and with the aid of which it is possible, following the
impregnation, to accurately close up the filling openings of the
components, for example using a rivet. The closing device is
supplied with closure means, e.g. rivets, by means of a storage
container 17, which is only shown in FIG. 2. This may be a blind
cup rivet in which the rivet cup is placed with the rivet shank
onto the opening which is to be closed. After the rivet shank has
been drawn through, the opening is closed up by the burr
formed.
[0040] During the method step of closing the housings, the filling
openings in the impregnated components are closed up using the
automated closure unit 6, for example by a rivet, at a freely
programmable pressure which is higher than the vapor pressure of
the highly volatile liquid.
[0041] If the chamber is of a suitable size or if there are two
chambers, it is also possible for a plurality of magazines to be
processed simultaneously and in parallel, i.e. to be filled and
closed simultaneously.
[0042] Then, the contaminated atmosphere can be exchanged for a
fresh atmosphere in a manner which is known per se, the door 7 can
be opened and the magazine(s) 3 together with the closed components
4 can be removed from the chamber 1, for example via the conveyor
belt 2. If there are two doors 7, it is possible, as illustrated,
for the magazine to be conveyed out of the chamber on the opposite
side from the introduction side, for example into a third chamber
(not shown) or into a further drying oven.
[0043] The filling and closing of the components take place in the
chamber, preferably using a gas pressure device comprising vacuum
pump, gasification valve and storage reservoir under an inert gas
atmosphere. The inert gas used is an element from the eighth main
group of the periodic system, in particular argon, nitrogen, carbon
dioxide or helium.
[0044] The inert gas which has been provided from a storage vessel
14 is preferably cooled by means of a cooling means 13, e.g. a heat
exchanger. The water content and the oxygen content of the
inert-gas atmosphere should be below 100 ppm.
[0045] The liquid to be introduced is preferably cooled to a
temperature which is above its crystalization point. This reduces
the filling volume and the vapor pressure. However, lower pressures
mean smaller amounts of gas forming during the impregnation.
[0046] The liquid used may, inter alia, include liquids which can
be gelled or polymerized after they have been introduced.
Furthermore, it is possible to introduce nitrites, such as
acetonitrile, a glycol, a lactone, a sulphone, a carboxylic acid
ester, a ketone, an aldehyde or a carbonate or mixtures thereof, in
which one or more conductive salts are dissolved. Finally, the
liquid introduced may be salts which are molten at room
temperature. It is also possible to use salt mixtures or mixtures
of salts with the abovementioned liquids, if appropriate using
solvents.
[0047] The electrical components which are filled and closed may be
lithium ion cells, lithium-thionyle chloride cells or
lithium-sulfur dioxide cells, electrochemical double-layer
capacitors, aluminum electrolyte capacitors, hybrid capacitors or
pseudo-capacitors.
[0048] Before they are introduced into the chamber, the components
can be dried as described and then cooled.
[0049] It will be understood that the device according to the
invention can also use methods other than that described for
introducing liquids into and closing up component housings. In
these cases, the sequence control means is accordingly to be
programmed differently.
* * * * *