DE9115597U1 - Electrochemical cell with liquid electrolyte for the on-board electrical system of motor vehicles - Google Patents

Description

No. 24853
10.12.1991 Zr/Hm

ROBERT BOSCH GMBH, 7000 STUTTGART 10

Electrochemical cell with liquid electrolyte for the on-board electrical system of motor vehicles

State of the art

The invention relates to an electrochemical cell with liquid electrolyte for the on-board electrical system of motor vehicles and relates to the avoidance of undesirable layers of different densities in the liquid electrolyte. Such layers occurring in the electrolyte can form both horizontally and vertically in the cell and also occur in cells of the lead/sulfuric acid type.

The horizontal layers of different densities in the electrolyte are created when charging such cells by the fact that the sulphuric acid developed on the electrode plates of the cell sinks into the lower part of the cell due to its density and then causes a higher sulphuric acid concentration here than in the upper part of the electrolyte; this higher sulphuric acid concentration leads to corrosion on the areas of the electrode plates at the bottom of the cell vessel, which can result in the loss of active mass from these electrode areas and thus a loss of capacity of the cell. As a result of this corrosion, however, even the cell

- 2 - R.24853

are destroyed, namely because the active mass that has fallen out of the electrode plates causes a short circuit between neighboring electrode plates of different polarity. As a result of these horizontal layers of different density in the liquid electrolyte, the electrical conductivity in these layers is also different and so is the course of the chemical reactions in the corresponding areas of the electrode plates. This means that during the charging process, the sections of the electrode plates located at the bottom of the cell, which are surrounded by layers of a relatively high-density electrolyte, are charged earlier than the sections of the electrode plates located further up in the cell and surrounded by electrolyte of lower density. In order to fully charge the upper sections of the electrode plates, the charging process must be continued, which, however, due to the above situation, means that the lower sections of the electrode plates are overcharged and thus the lifespan of the cell is reduced.

The vertical layers of different densities in the liquid electrolyte, however, appear during discharge, especially during high-current discharge of such cells, and as a result of the chemical reactions, reaction products, which include water, collect on the surface and in the pores of the positive electrode plates; these reaction products can then more or less isolate the active mass from the electrolyte and thus significantly disrupt the chemical reactions taking place, especially in the areas of the active mass furthest from the surface. These vertical layers in the electrolyte therefore limit the duration for which higher electrical currents can be drawn from the cell.

To eliminate the problems mentioned above, many complex solutions have been developed; stirring or pumping the

- 3 - R.24853

Electrolytes, introducing gas into the electrolyte; rotating or vibrating the electrodes, utilizing the electrolyte’s own movements as a result of changes in speed and direction of vehicles.

An electrochemical cell containing liquid electrolyte is also known from Japanese utility model No. 50-36 171, in the housing of which a vertical channel is arranged on one wall, which is filled with electrolyte, has an opening at the top and bottom and has a floating body that can move freely in the channel; the floating body has a specific weight that essentially corresponds to the specific weight of the electrolyte or deviates only slightly from it. The floating body is intended to move the electrolyte as a result of vibrations acting on the cell.

DE-OS 33 14 174 shows an electrochemical cell which contains vertical partitions for the purpose of automatically circulating its liquid electrolyte; these partitions divide the cell, at least in the area of the electrolyte storage space above the electrode plates and separators, into at least two connected sub-spaces. The partitions can be provided with an opening in the area of the electrolyte storage space with a check valve device (e.g. a flap suspended from above). As a result of changes in the vehicle's movements, electrolyte passes through this opening from one sub-space of the cell to the other sub-space of the cell, which then leads to automatic circulation of the electrolyte due to the different electrolyte levels in the two sub-spaces and their compensation. Due to the check valve device, however, this system only works when the vehicle's movement changes in a single direction.

- 4 - R.24853

DE-PS 78 061 describes a system for this purpose in an electrochemical cell, according to which a vertical channel runs between at least one side wall of the cell box and the plate block consisting of electrode plates and separators; the upper opening of this channel is above the electrolyte level and the lower opening is near the bottom of the cell box. As a result of changes in vehicle movements, electrolyte sloshes into the upper opening of the channel and partially pushes the electrolyte already in the channel out of the lower opening; the channel can be provided in the area of its upper opening with a floating body acting as a check valve device, which only allows electrolyte to pass through the channel from top to bottom.

The invention is based on the object of moving the liquid electrolyte in an electrochemical cell without the aid of external aids more intensively than the previously known internal aids in order to avoid as far as possible the undesirable stratification in the electrolyte described at the beginning; the means provided for the electrolyte movement should be inexpensive, easy to install in the cell and reliably effective in the long term.

This object is achieved in the electrochemical cell containing liquid electrolytes according to the preamble of claim 1 by means of the features listed in the characterizing part of claim 1.

The measures listed in the subclaims enable further developments and improvements of the electrochemical cell specified in claim 1. The at least one channel provided in the cell, which is used for the electrochemical cell

- 5 - R.24853

The channel, which serves to move the electrolyte, can be arranged not only vertically but also horizontally in the cell; the horizontal arrangement of the said channel can be below the electrode plates or the associated separators as well as above them. The effect of the system is advantageously improved by means of valves attached to the openings of such channels, which allow the electrolyte to escape from the respective channel, but prevent previously expelled electrolyte from being sucked back.

The solution according to the invention can be used in particular for such cells combined to form accumulator batteries, which nowadays are mostly designed in block construction for use in motor vehicles.

drawing

Embodiments of the invention are shown in the drawing and are described and explained in more detail below. Figure 1 shows a vertical section running parallel to the large surfaces of the plate block through a first embodiment of an electrochemical accumulator battery cell according to the invention, shown on a reduced scale, which has a vertically movable body for the independent circulation of the liquid electrolyte, Figure 2 shows the body shown in Figure 1, shown in longitudinal section, which is guided within a channel provided with inlet and outlet openings for the electrolyte and is suspended from a spring element, Figure 3 shows the view of the partially sectioned channel (including the body and spring element) according to the arrow III in Figure 2, Figure 4 shows a vertical section running transversely to the large surfaces of the plate block through a second embodiment of an accumulator battery cell according to the invention, shown on a reduced scale, which has a horizontally movable body

- 6 - R.24853

in a channel located above the plate block for the independent circulation of the electrolyte, Figure 5 shows the body shown in an enlarged view in Figure 4 within the channel and with a valve, Figure 6 shows a vertical section running parallel to the large surfaces of the plate block through a third embodiment of an electrochemical accumulator battery cell according to the invention shown on a reduced scale, which has a horizontally movable body in a channel located below the plate block for the independent circulation of the electrolyte and Figure 7 shows a cross section through the lower area of the cell containing the body and the channel along the line VII/VII in Figure 6.

Description of the embodiments

One of the usually six cells 11 of the accumulator battery 10 shown in Figure 1, which is intended for the on-board power supply of vehicles, is partially shown. This accumulator battery 10 installed in the on-board power supply of vehicles is usually of the so-called lead/sulfuric acid type, delivers a nominal voltage of 2 volts per cell 11 and thus, with six cells 11 of the accumulator battery 10, a total nominal voltage of 12 volts. However, the present invention does not only relate to six-row accumulator batteries 10, it can also be used for accumulator batteries with fewer or more cells 11; it can also contain another system instead of the lead/sulfuric acid system.

This accumulator battery 10 has a housing 12 which consists of an electrically insulating, electrolyte-resistant material; nowadays, thermoplastics such as polypropylene are preferably used as the material for this housing 12.

- 7 - R.24853

This housing 12 is made up of a so-called block box 13 and a block cover 14, in such a way that the block box top 15 is connected to the block cover bottom 16 in a liquid-tight manner. The block cover top 17 conventionally contains an electrolyte filling opening 18 with a sealing plug 19 for each cell 11, but can also contain another known electrolyte filling system (not shown) and usually also a known degassing system (not shown).

Figure 1 shows a vertical box wall 20 of the block box 13, a cell partition wall 21 and the box bottom 22 with the mud ribs 23 arranged on its inside; the mud ribs 23 are preferably provided with transverse bores 24.

Within the block box 13, a plate block 25 is arranged in a known manner in each cell 11, which is made up of electrode plates 26 of different polarity and separators 27 arranged between the latter; the separators project beyond the electrode plates 26 on all sides. In each cell 11, the electrode plates 26 of each polarity are connected in parallel to one another by means of a plate connector 28; in modern accumulator batteries 10, this plate connector 28 is further developed into a cell connector, which is then guided in a liquid-tight manner through a cell partition 21 and is connected to a corresponding (not shown) cell connector of the adjacent cell 11 and thus to its electrode plates of the opposite polarity, or the plate connector 28 is connected in a known manner to a connection pole (not shown) which is sealed through the block cover 14.

- 8 - R.24853

A vertically running channel 29 is arranged between the plate block 25 and at least one box wall 20 or a cell partition wall 21; in the present example (see also Figures 2 and 3), the channel 29 is formed by a separate, flat component, which preferably consists of an electrolyte-resistant material (e.g. polypropylene), which is arranged between a box wall 20 or a cell partition wall 21 and the plate block 25 and whose wall is designated 30; the lower edge 31 of this channel 29 rests on the box base 22, but is at least as close as possible to the box base 22. The channel 29 is open at the top and bottom; the opening 32 at the bottom is beveled and directed towards the interior of the cell 11. In the upper area of the channel 29 surrounded by the wall 30, a body 33 is guided, which consists of a material whose specific weight is significantly higher than the specific weight of the liquid electrolyte 34 in the cells 11, and which essentially fills the clear cross-section of the channel 29. This body 33, the material of which must not react electrochemically with the electrolyte 34, consists, for example, of lead. The upper side of the body is designated 35 and is operatively connected to a spring element 36, which allows the body 33 - guided in the channel wall 30 - to make up and down movements in the event of vertically acting shocks or vibrations. In the present example according to Figures 2 and 3, this spring element 36 is formed by a rubber band, which is fixed to a fastening means 37 on the upper side 35 of the body and on the other hand is attached to a holding means 38 at the upper end of the channel; Hooks, eyelets, openings, etc. can be used as fastening means 37 and holding means 38. Instead of a rubber band as spring element 36, one or more coil springs (not shown) can also be used for this purpose. The

- 9 - R.24853

The underside of the body 33 facing the box bottom 22 is designated 39 and is arranged within the channel 29 in such a way that it is located slightly above the electrolyte inlet openings 40 arranged in this area in the channel wall 30. These electrolyte inlet openings 40 in the channel wall 30 preferably point in the direction of the plate block 25 and are located below the electrolyte level 41 in all operating states of the accumulator battery 10. In a preferred embodiment of the channel 29, a valve 42 is arranged on the electrolyte outlet opening 32 at the lower end of the channel 29, which prevents liquid exiting from the channel 29 from flowing back into the channel 29; This valve 42 is shown in dash-dotted lines in Figure 2 and is designed, for example, as a flap which can be pivoted elastically around the lower edge 31 of the channel 29; in the relieved state, this valve 42 is closed.

An accumulator battery 10 with such channels 29 and spring-suspended bodies 33 in the cells 11 is exposed to shocks and vibrations during operation of the motor vehicle, which also act on the spring-suspended body 33, in such a way that the body 33 moves up and down within the channel wall 30. Due to these movements of the body 33, with each downward movement, electrolyte 34 that has entered the channel 29 through the electrolyte inlet openings 40 is pressed down into the channel 29 and part of the electrolyte 34 located in this channel 29 is pressed out of the electrolyte outlet opening 32 into the so-called sludge space 43 located between the box base 22 and the plate block 25; Here in this sludge chamber 43 the electrolyte coming from the upper area of the cell 11 mixes with the electrolyte in the lower area of the cell 11

- 10 - R.24853

and causes a balance of the specific weight of the liquid electrolyte 34 within the cell 11. In order not to unnecessarily impair the mixing of the electrolyte consisting of diluted sulphuric acid used in these accumulator batteries 10 within the sludge chamber 43, the sludge ribs 23 formed on the box bottom 22 can be provided with cross holes 24 etc. In order to prevent electrolyte 34 expelled from the electrolyte outlet opening 32 from re-entering the channel 29 when the body 33 rises again, i.e. during its suction movement, the valve 42 located at the outlet opening 32, which had opened when the body 33 descended, is closed. In Figure 1, dash-dotted arrows 44 show how the electrolyte 34 is moved within the channel 29 as the body moves down.

As a result of these lifting movements constantly carried out by the body 33 in the channel 29 and the resulting circulation of the electrolyte 34 in the cells 11 of the accumulator battery 10, the formation of layers of different densities of the electrolyte 34 and consequently the emergence of different charge states in different areas of the plate supports 25 as well as the emergence of local overheating are largely avoided.

Figures 4 and 5 show a second embodiment of a storage battery 10/1 with an automatic circulation of its liquid electrolyte 34/1 in the moving vehicle. This storage battery 10/1 has several cells 11/1, which are enclosed in a housing 12/1, which is made up of a block box 13/1 and a block cover 14/1. The block box 13/1 has box walls 20/1, cell partition walls 21/1, a box base 22/1 and for each cell 11/1 a mud chamber 43/1 provided with mud ribs 23/1. In each cell 11/1

- 11 - R.24853

A plate block 25/1 is again housed in a vibration-proof manner, which is completely surrounded and saturated by liquid electrolyte 34/1. This accumulator battery 10/1 can also be a lead accumulator, whose liquid electrolyte is diluted sulphuric acid.

In this accumulator battery 10/1, each cell 11/1 contains a channel 29/1, which contains a body 33/1 and runs below the electrolyte level 41/1; the body 33/1 has a specific weight that is significantly higher than the specific weight of the electrolyte 34/1 and essentially fills the clear cross-section of the channel 29/1. In this embodiment, the body 33/1 is designed as a sphere that consists essentially of metal (e.g. lead) and is additionally (see Figure 5) provided with a casing 45 made of an electrolyte-resistant material (e.g. polypropylene); the metallic core is designated by reference numeral 46/1. The main difference between this electrolyte circulation system shown in Figures 4 and 5 and the embodiment shown in Figures 1 to 3 is that the channel 29/1 runs horizontally within the respective cell 11/1. The horizontally running channel 29/1 is arranged above the plate block 25/1 and is surrounded by a tubular channel wall 30/1. This channel wall 30/1 has a channel opening 47/1 at each of its two ends, which is provided with means that prevent the body 33/1 from leaving the channel 29/1. When the movement of the motor vehicle containing this accumulator battery 10/1 changes in the direction of the longitudinal axis of the channel 29/1, the body 33/1 is pushed further against the movement change due to its inertial behavior and consequently the electrolyte 29/1 located in the channel 29/1 is pushed out of the channel opening 47/1 located in the direction of movement of the body 33/1; in the case of a

- 12 - R.24853

In the event of an opposite change in movement of the motor vehicle carrying the accumulator battery 10/1, this process is repeated in the opposite direction of the channel 29/1, causing a renewed automatic circulation of the electrolyte 34/1.

This principle described above is improved by equipping both channel openings 47/1 with a valve 42/1, which prevents the electrolyte 34/1 previously forced out of the channel 29/1 by means of the body 33/1 from flowing back into the channel 29/1. Preferably, this valve 42/1 is designed with two legs and can be folded about a pivot point 48/1; the leg of the valve 42/1 pointing upwards is designated 49/1 and the leg pointing downwards is designated 50/1. At the height of the meeting point of the upper valve leg 49/1 and the lower valve leg 50/1, a horizontal pivot pin 51/1 is formed on both sides, each of which is guided and held in an eyelet-like pivot bearing 53/1 at approximately the height of the channel floor 52/1. These pivot bearings 53/1 are attached to a vertical wall 54/1 running between the plate block 25/1 and the box wall 20/1 or the cell partition wall 21/1 - each at a distance - which leads as far down as possible into the sludge chamber 43/1, but does not quite reach the box floor 22/1. This vertical wall 54/1, one of which is arranged on either side of the plate block 25/1, forms an electrolyte intake line 56/1 together with the plate block 25/1 or a vertical wall 55/1 close to the plate block 25/1; the electrolyte intake opening located at the lower end of the electrolyte intake line 56/1 is designated 57/1 and is bevelled towards the interior of the cell 11/1. The clear cross-section of the electrolyte intake line 56/1 can be circular, rectangular or similar. The space formed between the vertical wall 54/1 and the box wall 20/1 or a cell partition wall 21/1

- 13 - R.24853

vertical gap serves as electrolyte pressure line 58/1; the distance between the vertical wall 54/1 and the nearby box wall 20/1 or cell partition wall 21/1 can be achieved by spacers (not shown) supported on one of the walls mentioned.

In the two channel openings 47/1 of channel 29/1, the upper area 59/1 is bevelled in such a way that the upper valve leg 49/1 rests against it in a sealing manner in the suction position of the valve 42/1 described below. In the suction position of the valve 42/1 mentioned above, a lower area 60/1 is not closed by the upper valve leg 49/1, so that a connection between channel 29/1 and electrolyte suction line 56/1 then remains open. The two legs 49/1 and 50/1 are thus angled towards each other in such a way that in the suction position the upper valve leg 49/1 closes the upper area 59/1 of the channel 29/1, but leaves the lower area 60/1 of the channel opening 47/1 open, and also leaves it connected to the electrolyte suction line 56/1, but that in the pressure position of the valve 42/1 the upper valve leg 49/1 allows the exit of electrolyte 34/1 from the channel 29/1 into the electrolyte pressure line 58/1. The electrolyte 34/1 flowing from top to bottom through the electrolyte pressure line 58/1 reaches - as shown by the arrows in Figure 4 - the sludge chamber 43/1 of the block box 13/1 and from there from below into the plate block 25/1; if openings (not shown) have been arranged on the side of the electrolyte pressure line 58/1, the electrolyte 34/1 that has already been conveyed from top to bottom through the pressure line 58/1 can also be fed laterally to the plate block 25/1.

If, as a result of changes in the movement of the battery 10/1 carrying the accumulator battery in the direction of the channel 29/1,

- 14 - R.24853

When the body 33/1 moves in the channel 29/1 of a motor vehicle, it forces the electrolyte in the channel 29/1 out of the channel 29/1 (see Figure 4, right valve) and presses it into the pressure line 58/1 and further - as described above - from below (possibly also from the side) to the plate block 25/1, while on the other side of the channel 29/1 (see Figure 4, left channel opening) electrolyte is sucked in from the electrolyte suction line 56/1 from the sludge chamber 43/1 of the block box 13/1. On the suction side, the upper valve leg 49/1 is then in contact with the channel opening 47/1, while the lower valve leg 50/1 releases the suction line 56/1.

If the motor vehicle then moves in the opposite direction and, as a result, the body 23/1 moves in the opposite direction in channel 29/1, the two valves 42/1 switch to the other working position.

If the body 33/1 is spherical - as shown in the example - then the depth of the channel 29/1, which is not visible in Figure 4, is approximately corresponding; due to this small depth of the channel 29/1, several of these channels 29/1 can be installed next to each other in each cell 11/1. The body 33/1 can, however, also have a different cross-section, e.g. rectangular, oblong.

Figures 6 and 7 show an accumulator battery 10/2, which again has several cells 11/2 with plate blocks 25/2 and electrolytes 34/2; the housing of this accumulator battery 10/2, which is preferably manufactured in block construction, is marked with 12/2 and is composed in a known manner of a block box 13/2 and a block cover 14/2; the block box 13/2 has box walls 20/2, cell partition walls 21/2 and a box base 22/2 in a known manner.

- 15 - R.24853

Like the second embodiment according to Figures 4 and 5, the third embodiment shown in these Figures 6 and 7 has a channel 29/2 running horizontally in each cell 11/2 and a body 33/2 guided therein, movable in the direction of the channel 29/2, whose specific weight is significantly higher than that of the electrolyte 34/2; the body 33/2 can in turn consist of a metal resistant to the electrolyte 34/2, such as lead, and preferably be surrounded by a plastic casing (not shown). In the present third embodiment, the channel 29/2, in contrast to the second embodiment, is guided underneath the plate block 25/2 and is preferably formed by a C-shaped channel wall 30/2, the two legs 61/2 of which stand on the box base 22/2 and the channel cover plate 62/2 of which supports the plate block 25/2 located in the respective cell 11/2. This channel wall 30/2 can either be placed with its legs 61/2 only on the box base 22/2, but the free ends of the channel legs 61/2 can also be attached to the box base 22/2 by welding or the like. Such channels 29/2 preferably run within the cells 11/2 in the direction of the longitudinal extension of the electrode plates (see Figure 6), but they can also extend transversely thereto.

At each end, such a channel 29/2 has a channel opening 47/2, which is connected to an electrolyte line 63/2 formed between the plate block 25/2 and the box wall 20/2; the channel openings 47/2 are preferably bevelled in the direction of the respective electrolyte line 63/2. The usual gap between the plate block 25/2 and the box wall 20/2 or the cell partition wall 21/2 is usually sufficient as the electrolyte line 63/2, but it is also possible to use plastic pipes leading over the plate block 25/2 instead.

- 16 - R.24853

if necessary, these plastic tubes (not shown) can be provided with holes along their length so that electrolyte 34/2 can also reach the plate block 25/2 from the sides.

As a result of changes in the movement of the motor vehicle carrying this accumulator battery 10/2, the body 33/2 is moved back and forth within the channel 29/2 and ensures the circulation of the electrolyte 34/2 within the cells 11/2 by sucking in and displacing electrolyte 34/2 within the channel 29/2. In Figure 6, the possible circulation flow of the electrolyte 34/2 is shown by arrows, for example, with the body 33/2 moving to the right and consequently pushing electrolyte into the electrolyte line 63/2 located on the right in Figure 6, while on the left side of the body 33/2 electrolyte 34/2 is sucked out of the electrolyte line 63/2 located on the left in Figure 6.

In this third embodiment, the two channel openings 47/2 could also be provided with valves (not shown) that prevent the electrolyte 34/2 previously displaced from the channel 29/2 from being sucked back, and the electrolyte lines 63/2 could also be divided into a suction line and a pressure line - similar to the second embodiment shown in Figures 4 and 5. Depending on the profile of the channel wall 30/2 and its width, several such channels 29/2 can optionally be arranged in each cell 11/2.

Claims (14)

R. 24853 10.12.1991 Zr/Hm ROBERT BOSCH GMBH, 7000 STUTTGART 10 Claims 1. Electrochemical cell (11) for the on-board power supply of vehicles, with a housing (12) made up of a box (13) and a cover (14) in a sealing manner, in which at least one positive and one negative electrode plate (26), at least one separator (27) separating the electrode plates (26) from one another and liquid electrolyte (34) are contained, the predetermined level (41) of which, facing the cover (14), lies above the electrode plates (26) and the at least one separator (27), is spaced from the cover (14) and fills at least one channel (29) located in the housing (12), which is provided with openings (32, 40) for the electrolyte inlet and outlet, and in which a body (33) is contained which is longitudinally movable as a result of changes in the movement of the vehicle and does not react electrochemically with the electrolyte (34), thereby characterized in that the body (33) consists essentially of a material whose specific weight is significantly higher than that of the liquid electrolyte (34), and that this body (33) essentially fills the clear cross-section of the channel (29). 2. Electrochemical cell according to claim 1, characterized in that the body (33) consists of metal (e.g. lead). - 2 - R.24853 3. Electrochemical cell according to claim 2, characterized in that the body (33/1) is provided with a casing (45/1) that does not react chemically or electrochemically with the electrolyte (34/1), preferably with a casing (45/1) made of plastic (e.g. polypropylene). 4. Electrochemical cell according to one of claims 1 to 3, characterized in that the channel (29) is arranged vertically in the housing (12), contains a body (33) hanging on a spring element (36) in the normal position at the top, below which at least one electrolyte inlet opening (40) is located at a short distance in the channel wall (30) and which has an electrolyte outlet opening (32) in its lower region. 5. Electrochemical cell according to claim 4, characterized in that the electrolyte outlet opening (32) is provided with a valve (42) which prevents the electrolyte (34) previously forced out of the channel (29) from flowing back into the channel (29). 6. Electrochemical cell according to one of claims 4 and 5, characterized in that the spring element (36) is a rubber band. 7. Electrochemical cell according to one of claims 4 to 6, characterized in that the channel (29) is designed as a separate, flat component which is arranged between the box wall (20) or cell partition wall (21) and a plate block (25) and rests with its lower edge (31) on the box bottom (22) or is located as close as possible to the box bottom (22). 8. Electrochemical cell according to one of claims 1 to 3, characterized in that the channel (29/1, 29/2) is arranged horizontally in the housing (12/1, 12/2) and has an opening (47/1, 47/2) in each end region which cannot be left by the body (33/1, 33/2). - 3 - R.24853 9. Electrochemical cell according to claim 8, characterized in that the channel (29/1) is arranged above the plate block (25/1). 10. Electrochemical cell according to claim 8, characterized in that the channel (29/2) is arranged below the plate block (25/2). 11. Electrochemical cell according to one of claims 9 or 10, characterized in that at least one of the openings (47/1) of the channel (29/1) is provided with a valve (42/1) which prevents the electrolyte (34/1) previously expelled from the channel (29/1) from flowing back into the channel (29/1). 12. Electrochemical cell according to one of claims 8 to 11, characterized in that the horizontal channel (29/1, 29/2) in the area of its openings (47/1, 47/2) is connected to at least one vertical electrolyte line (56/1, 58/1; 63/2) filled with electrolyte (34/1, 34/2) between the box wall (20/1, 20/2) or cell partition wall (21/1, 21/2) and the plate block (25/1, 25/2). 13. Electrochemical cell with the features of claims 11 and 12, characterized in that the valve (42/1) has a two-legged valve (42/1) pivoting about a pivot point (48/1) which, in the case of a suction movement caused by the body (33/1), closes a vertical pressure line (58/1) for the electrolyte (34/1) with its one (upper) leg (49/1) and opens a suction line (56/1) for the electrolyte (34/1) with its other (lower) leg (50/1), while the valve (42/1) in the case of a pressure movement caused by the body (33/1) closes the - 4 - R.24853 opens a vertical pressure line (58/1) for the electrolyte (34/1) and closes a suction line (56/1) for the electrolyte (34/1) with its lower leg (50/1). 14. Electrochemical cell according to one of the preceding claims, characterized in that several of the cells (11) are combined to form an accumulator battery (10) in block construction.