Battery with electrolyte intermixing device

Abstract

The invention relates to a battery comprising liquid electrolyte, used in moving vehicles, wherein the battery includes a battery housing comprising side walls, a housing floor and a cover, a liquid electrolyte, the level of which is within predetermined tolerance limits, electrodes, a flow channel plate arranged at least on one side wall so as to form a flow channel, wherein the upper end of said flow channel serves as exhaust port, a mixing vessel comprising a mixing vessel floor and mixing vessel side walls being arranged above the electrodes wherein the mixing vessel side wall adjoining the exhaust port is formed as an overflow the mixing vessel floor being located below the minimum level for the liquid electrolyte, which minimum level is provided for operational reasons, and at least one floor opening being provided in the mixing vessel floor.

Claims

1. A battery with an electrolyte intermixing device, said battery comprising: a battery housing carrying a liquid electrolyte whose level has predetermined tolerance limits; electrodes arranged within the liquid electrolyte; a flow channel plate disposed distanced from one side wall of the housing so that between the flow channel plate and the side wall, a flow channel is formed with a lower end thereof located in the lower third of a battery volume and at an upper end thereof having an outflow slot; and at least one mixing trough disposed above the electrodes, said mixing trough including a bottom located below a minimum level of the electrolyte provided for during operation of the battery and having at least one bottom opening and sidewalls, wherein one of the mixing trough side walls adjacent the outflow slot is configured as an overflow edge, said electrolyte being moved into and out of the mixing trough through the flow channel and the bottom opening in response to an acceleration of the battery, wherein an opening is provided in an interior facing side wall of the mixing trough.

2. The battery according to claim 1, wherein the bottom opening of the mixing trough is provided at a site where the liquid electrolyte, upon flowing across the overflow edge flows onto the bottom of the mixing trough.

3. The battery according to claim 1, further comprising a second mixing trough adjoining the interior facing side wall of the first mixing trough, said second mixing trough having a bottom which has at least one bottom opening.

4. The battery according to claim 3, wherein the bottom of the second mixing trough is located at an electrolyte maximum level, said second mixing trough located distant from the outflow slot.

5. The battery according to claim 1, wherein the flow channel plate is formed as a double-walled flow channel plate in the shape of a compressed tube with a slot-shaped hollow space cross section.

6. The battery according to claim 3, wherein the at least one bottom opening of the second mixing trough is configured as a small tube inserted in parallel into the bottom of the second mixing trough in order to create a flow resistance.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The present invention is more closely described by means the following example of an embodiment.

(2) FIG. 1 shows a cross section view of a battery case cell and the acid levels in a first phase.

(3) FIG. 2 shows the subject matter according to FIG. 1 and the acid levels in a second phase.

(4) FIG. 3 shows the subject matter according to FIG. 1 and the acid levels in a third phase.

(5) FIG. 4 shows the subject matter according to FIG. 1 and the acid levels in a fourth phase.

(6) FIG. 5 shows the subject matter according to FIG. 1 and the acid levels in a fifth phase, which is identical to the first phase.

(7) FIG. 6a,b shows the subject matter according to FIG. 1 in a modified embodiment and a top view thereof.

(8) FIG. 7 shows a perspective view of an intermixing device with two mixing troughs.

(9) FIG. 8 shows a perspective view of an intermixing device with two mixing troughs in a second embodiment.

(10) FIG. 9 shows a perspective view of an empty battery case with 6 cells.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(11) FIG. 1 shows a cross section view of a battery case cell. The battery case cell 1 has a rectangular cross section with a bottom 2 and four side walls, wherein this illustration shows only side walls 3 and 4. Reference numeral 5 designates the plate-shaped electrodes and reference numeral 6 designates the battery acid, whose level 7 is between a maximum level 7a and a minimum level 7b. As seen in the drawing, the level shown there is at the mark of the maximal level 7a.

(12) Between the side wall 3 and the electrodes 5, a flow channel plate 8 is vertically disposed thus forming a flow channel 9. The end of the flow channel 9 thus forms an outflow port 9a.

(13) Adjacent the outflow port 9a, a mixing trough (10) is provided having sidewalls 11a, 11b, 11c and a bottom 12, wherein the side walls 11a, 11b are visible only in the perspective view of FIG. 8. The upper end of the flow channel plate 8 forms an overflow edge 13. The bottom 12 of mixing trough 10 is located always below the operationally determined minimum level 7b of battery acid 7 and provided with at least one bottom opening 14 of a predetermined cross section. Adjacent the mixing trough 10, an additional mixing through 15 with a bottom opening 16 is optionally provided for improved intermixing.

(14) Following is a description of the function of the intermixing device.

(15) FIG. 1 shows a battery at rest with a horizontal electrolyte level 7. It is assumed that an acid stratification has taken place in the battery, that is, the acid at the bottom of the battery has a higher density than the acid in the upper battery section and also that residing in the mixing trough.

(16) FIG. 2 shows the motion of the acid at a positive acceleration of the vehicle to the right in direction of the arrow. The same effect appears at a negative acceleration to the left, that is, upon braking the vehicle that moves in direction of the arrow. Thereby, a sloped acid level 7 occurs in the mixing trough 10. Through the flow channel 9 acid with greater density streams upwards and flows across the overflow edge 13 into the mixing trough 10. In this motion phase, acid of a lower density flows through the bottom opening 14 also into the mixing trough 10. As a result, in mixing trough 10 there is now a mixed acid that has a density that is lower than the acid density at the bottom of the battery but higher than the acid density in the area of the acid level.

(17) From the optional mixing trough 15, due to the sloping acid level, some acid is guided upwardly through the bottom opening 16.

(18) FIG. 3 illustrates the situation where the constant acceleration is still in effect, but where no equalizing streams occur any longer. This is indicted by the absence of the flow arrows.

(19) FIG. 4 illustrates the situation where the acceleration is equal to zero, that is, the vehicle is either driving at constant speed or is at a stand still. Accordingly, the acid levels are horizontal. The flow arrows indicate that equalizing of the acid level occurs via all three openings 9a, 14 and 16. It is especially emphasized that through the spatial distribution of the openings by which the acid is thus flowing into and out from these various points, a faster intermixing is realized.

(20) FIG. 5 illustrates the situation as in FIG. 1 where the levels have equalized though the acid is now intermixed.

(21) FIGS. 6a and 6b show a variant embodiment of the present invention in side view and in top view. In mixing trough 10, the bottom opening 14 is located near the outflow port 9a. This leads to an especially effective intermixing of the acid volumes of different densities that flow into each other and is symbolized with the ring arrow. Furthermore, three bottom openings 16 are provided in the second mixing trough. These openings are configured as small tubes inserted obliquely into the bottom in order to create a flow resistance and thus effect an additional turbulence and intermixing of the acid. This effect is further increased by the oblique position of the small tubes 17.

(22) FIG. 7 shows a perspective view of the intermixing device with two mixing troughs 10 and 15, wherein the bottom 18 of the second mixing trough 15 lies in the same plane as the maximum level of the battery acid and shows a recess 19.

(23) FIG. 8 shows an intermixing device according to FIG. 7, which differs however in that the interior side wall of the first mixing trough 10 is provided with a slot shaped opening 20.

(24) It is noted that the cross sections of the bottom and side openings of the first mixing trough 10 can be optimized by the person skilled in the art. The cross sectional shape of the bottom and side openings does not have to be circular. In conventional passenger motor vehicle batteries, the cross sections of the circular openings in the bottom and side walls correspond to a cross section of 1.2 to 10 mm and in truck batteries openings with a cross section of 5-20 mm.

(25) FIG. 9 shows an empty battery case with 6 cells, wherein an intermixing device can be disposed in each cell, for example, according to FIG. 8.