EP2909057A2

EP2909057A2 - Energy storage device and method for the operation thereof

Info

Publication number: EP2909057A2
Application number: EP13776789.3A
Authority: EP
Inventors: Jörg Hempel
Original assignee: H-Tech AG
Current assignee: H-Tech AG
Priority date: 2012-10-19
Filing date: 2013-10-11
Publication date: 2015-08-26
Also published as: WO2014060319A3; US20150333543A1; WO2014060319A2; US10008865B2; DE102012110030A1

Abstract

The invention relates to an energy storage device and to a method for operating an energy storage device. In order to specify an energy storage assembly and a method for the operation thereof that are adapted to complex requirements in the properties of said energy storage assembly and said method for the operation thereof and have both high-current properties and high-energy properties, an energy storage assembly is specified, comprising: at least one high-current cell (20) and at least one high-energy cell (10), wherein the at least one high-energy cell (10) and the at least one high-current cell (20) are connected in parallel, wherein the cells (10, 20) are charged and/or discharged by means of a current pulse and a charge equalization between the cells (10, 20) occurs in the pulse pauses.

Description

Energy storage device and method for operating the same

The present invention relates to an energy storage device and a method of operating an energy storage device. The reorientation in the production of electrical energy based on renewable energy sources, in particular by means of photovoltaic or wind power, increasingly require an efficient storage of the energy generated in order to provide the electrical energy when it is needed. In addition, there is a significant increase in portable or battery-operated devices, in particular for communication and in the artisan sector, recorded, which are operated with rechargeable batteries or cells. In these devices, the capacity of the rechargeable battery is a critical feature. The factors that affect the capacity of the rechargeable battery, on the one hand, are the geometric size, since an increase in capacity is traditionally achieved with an increase in the geometric dimensions of the cell or battery becomes. On the other hand, the durability or the number of maximum possible charging cycles plays a crucial role, since in conventional battery-operated devices usually the battery or cell fails first, i. in the durability of the components of such devices, the rechargeable batteries or cells are among the shortest-lived components.

In particular, in the rapidly evolving field of e-mobility with hybrid or electric vehicles, the capacity, durability and charging time of rechargeable cells is a particular focus. In addition, the geometric dimensions and weight of rechargeable cells also play an important role.

For rechargeable cells, depending on the design, the cell will discharge up to a maximum of 20% of its capacity. That is, 20% of the actual energy stored in the cell is unavailable to the end user, as discharging below a threshold of 20% would result in irreversible cell destruction. Moreover, in today's rechargeable cells, the cell is only charged up to 80% of its capacity, since further charging to 100% of the cell would require exponentially more time, since when the end-of-charge voltage is reached, the current is usually limited, resulting in the last 20% of the charge Capacity can be charged at lower currents, saving less energy per time.

Thus, in the conventional technologies for rechargeable cells, the actual capacity of the cells is not exploited.

Among the rechargeable cells, the lithium ion cell has recently been found to be particularly advantageous since it has a long lifetime and the number of charging cycles is high compared with other technologies. Lithium-ion cells also have a high storage capacity compared to other rechargeable cells. The lithium-ion cells can be subdivided into high current cells and high energy cells. In high-current cells, which are also called high-power cells, for example, a larger or thicker Abieiter is used to provide larger currents. In the case of high-current cells, the coating with active material is thinner compared to high-energy cells than with high-energy cells, in order to improve the bonding of the active compounds and shorten the diffusion distances.

The different types of cells each have characteristics that are advantageous for particular applications. Thus, high-current cells are used precisely when very high currents are required for a short time, for example with cordless drill drivers. In contrast, high-energy cells are used when a high capacity of the battery is required, but the currents are not particularly high.

Among the battery cells used today, in particular lithium-ion high-current cells (HSZ) find their use in electrical equipment that quickly require a very high power, such as battery-powered cordless screwdrivers. Another type of lithium-ion accumulators form the high-energy cells (HEZ), for example used in notebooks because they have a high capacity, which is released over a long period of time.

The disadvantage of high-energy cells is that they can only provide low currents for a short time. The disadvantage with high-current cells is that they can only provide their high current for a short time and generally have a smaller capacity. The combination of high-current cells and high-energy cells allows the advantages of both cell types to be efficiently combined, resulting in lower overall weight and a battery pack that can provide both high currents and the benefits of high-energy cells that can provide flows over a long period of time.

The object of the invention is to provide an energy storage arrangement and a method for operating the same, which are adapted in their properties to complex requirements and have both high-current and high-energy properties.

The object is solved by the features of the independent claims. Advantageous embodiments emerge from the subclaims. The invention is based on the idea of connecting both high-energy cells and high-current cells in a battery pack and controlling the charging or discharging process such that the battery pack experiences a uniform capacitance distribution over the different cells in and after the respective load states by means of capacity equalization or charge equalization and thus a longer service life but also an increased usable capacity compared to battery packs, which consist only of high energy cells or high current cells.

In this case, a current pulse is advantageously used for charging or a pulsed discharge is carried out. This current pulse or the timing when discharging is set depending on the characteristics and the number of cells in the battery pack, which are pauses between the current pulses, which allow a charge balance between the two types of cells. As a result, the battery pack is capable of following a load demand that requires a high current to recharge the high current cells with energy from the high energy cells. This allows the high current cells to supply this current at a next high current demand without the high energy cells reaching their load limit. Likewise, with a long-lasting constant load demand served by the high energy cells, the high current cells can recharge the high energy cells. As a result, a balancing of the charge between the high-current cells and high-energy cells is achieved, which ultimately leads to an increased usability of the capacity.

The energy storage arrangement according to the invention has a longer life compared to conventional energy storage arrangements, in particular by the controlled and / or uniform charging / discharging operations.

For this purpose, the properties of the different cell types are optimally combined. With the energy storage device according to the invention can thus be provided by the combination of high-current and high energy cells in a battery pack both high currents and a high capacity.

Through the use of an adaptive current pulse for charging, a charge equalization between the two cell types can take place in a targeted manner, during which the high-energy cell can act as a load for the high-current cell during the charging pauses, resulting in an improved charging process for the high-current cell by the load of the high energy cell in the high current cell, a negative current pulse occurs, which counteracts the formation of dendrites in the high current cell. This further causes an increase in the life cycles of the energy storage arrangement according to the invention.

By monitoring during unloading and an adaptive activation of a timing during unloading, charge balancing between the two cell types can take place deliberately. The timing thus represents a short current limit, in which the cells can make a charge balance with each other via a controlled bridge switch. Consequently, the energy storage device according to the invention can be used in applications in which high currents are needed for a short time, but also for longer periods a sustained base load is applied with lower currents. In addition to battery-operated machines, the energy storage device according to the invention is particularly suitable for use in electric vehicles, since high currents are retrieved during acceleration and flow at constant speed over longer periods and lower currents. In addition, the current demand profile is very different in electric vehicles, which both the properties of high-current cells, eg. When strong acceleration, as well as high-energy cells, for example, come at a constant average speed to fruition.

A parametrically controlled parallel connection of high-current cells and high-energy cells within this load cycle and zero-load stress promotes a charge balance between the high-current cells and high-energy cells. By using an adaptive current pulse for charging or by adapting or controlling the discharge based on the states of the cells, it is possible to set a targeted optimum capacity, so that the cells can be charged quickly and completely, but can also be discharged deeper than without a combination and thus the stored energy can be fully utilized.

In particular, an energy storage arrangement is provided, comprising: at least one high-current cell and at least one high-energy cell, wherein the at least one high-energy cell and the at least one high-current cell are connected in parallel, wherein the cells are charged and / or discharged with a current pulse and in the pulse pauses a charge balance between the Cells takes place.

Preferably, the energy storage arrangement comprises a control unit for controlling the pulse lengths and / or pulse amplitudes of the current pulse for charging or discharging the cells. Preferably, the number of high current cells is less than the number of high energy cells, thereby controlling the charge balance between the two cells. Preferably, the number of high current cells is about 1/3 and the number of high energy cells is 2/3. In a preferred embodiment, at least the high-energy cell is preceded by a first and / or at least the high-current cell is preceded by a second switching unit. In particular, the switching unit controls the discharging and / or charging process of the high-energy cell and / or the high-current cell. In this case, a clocking of the at least one switching unit by means of the control unit for controlling the pulse lengths and / or pulse pauses of the current pulse when charging and / or discharging the cells is advantageous.

In particular, the at least one switching unit allows a controlled power supply or a controlled current consumption from the associated cell for a predetermined time and causes a periodic timing of the power supply or the current drain.

At least one current measuring device and / or voltage measuring device and / or temperature measuring device may be provided, the measured values of which are used to control the charging or discharging process.

Furthermore, a third switching unit is arranged before the parallel connection of the at least one high-current cell and the at least one high-energy cell, which serves to limit the current for both cells. Advantageously, the timing of the first switching unit for the at least one high-current cell is tuned to the timing of the second switching unit for the at least one high-energy cell.

In a further refinement, the at least one high-current cell and the at least one high-energy cell are coupled via a fourth switching unit in order to enable or actively control charge balancing or to connect one or the other cell as a load to the other cell.

The fourth switching unit is closed to allow current to flow from the high current cell into the high energy cell or vice versa, and / or the fourth switching unit is pulsed to provide current limiting during discharging or charge equalization. By closing the fourth switching unit during the pulse pauses, the at least one high-current cell is loaded with a load pulse. In this case, depending on the state of charge of the at least one high-energy cell, the high-energy cells can also be loaded by closing the fourth switching unit with a load pulse or represent a load or sink for the high-current cells.

Preferably, the third switching unit is controlled depending on the state of charge of the at least one high-current cell and / or the at least one high-energy cell. In this case, during a current pulse, the charging current flows via the third and fourth switching units into the at least one high-current cell and the at least one high-energy cell. The first or fourth switching unit is pulsed during discharge when reaching the final discharge voltage of the high-energy cells or the high-current cells. In particular, during a pulsed discharge process in the pulse pauses or during rest periods without load with the fourth switch closed, a current flows from the at least one high-energy cell into the at least one high-current cell in order to recharge it. In principle, the current from the energy storage arrangement can be limited during a discharge process by means of one of the switching units. For this purpose, at least one of the switches is controlled so that upon reaching the discharge end voltage of one of the two cell types, a current limitation by clocking one of the switches takes place. The current pulse switches between a low level of zero amps and a fixed positive current value. The control unit is advantageously connected to the first, second, third and / or fourth switching unit, in order to supply each a switching pulse to effect opening or closing of the respective switch, wherein the control unit further with the current, voltage, and / Temperature measuring devices is connected to receive from these measurement signals. In particular, the length of the current pulses or the pauses between pulses can be adjusted depending on the measured state of the two cell types. A further object of the invention is to provide a method for charging an energy storage arrangement comprising a parallel connection of at least one high-current cell and at least one high-energy cell, comprising the steps of: supplying a current pulse to the high-current cells and the high-energy cells; upon reaching the charging voltage of the high current cells or the high energy cells, switching off the supply of the current pulse to the corresponding at least one cell; Continue to charge the other of the two cells until reaching the end-of-charge voltage of the other of the two cells.

Preferably, during a pulse pause between the current pulses, a switch between the two high current cells and high energy cells connected in parallel is closed to allow current to flow from the high current cells to the high energy cells.

In addition, a method for discharging an energy storage arrangement is disclosed, comprising at least one high-current cell and at least one high-energy cell connected in parallel, comprising the steps of monitoring the discharge end voltage, current flow and / or temperature of the at least one high-current cell and / or at least one high-energy cell; when a limit value of the states, eg. End of discharge voltage, current flow or temperature, limiting the discharge current from the high energy cell or from the high current cell by clocking a switch, wherein by closing a switch between the two parallel high current cells and high energy cells, a charge balance between the high current cells and high energy cells takes place. In particular, the switch is controlled and / or clocked between the two parallel-connected high-current cells and high-energy cells as a function of a state of the high-current cells and / or high-energy cells.

In the following, exemplary embodiments of the invention will be explained with reference to figures, which serve the general understanding, but are not to be understood as limiting the invention. Fig. 1 shows a circuit arrangement according to a first embodiment of the invention;

Fig. 2 shows a circuit arrangement according to a second embodiment of the invention;

FIG. 3 shows an alternative circuit arrangement according to a third exemplary embodiment; FIG.

4 shows a pulse course during charging;

Fig. 5 shows a pulse waveform during discharging for normal discharging (A), for discharging high demand (B) and (C) at too high a temperature at the HSZ; Fig. 1 shows a circuit arrangement for an energy storage device according to the invention in a simple embodiment. As shown in FIG. 1, the energy storage arrangement comprises high-energy cells 10 and a high-current cell 20, which are preferably arranged in a battery pack, not shown. In the figures, only one cell is shown. The invention also works with the parallel connection of only one high-energy cell and one high-current cell, however, the advantages of the invention can be observed in particular when using a plurality of similar cells which are connected in series and the respective parallel connection of the two different series connections. These two cell groups 10 and 20 are connected in parallel, wherein the individual high-energy cells 10 and high-current cells 20 are each connected in series within the two cell groups 10 and 20. The energy storage device is also connected to a control unit 30, a drive unit 40 and a charging unit 50. The charging unit 50 provides the power or voltage required for charging the high-energy cells 10 and high-current cells 20. According to the invention, a current pulse is used here. The drive unit 40 includes, for example, an electric motor, but can also be represented by any other load. In order to control or switch on the motor 42 or the load depending on the user, a switch or a switching unit SM is provided, which is arranged in the supply line to the drive unit 40. The switching unit SM is open in particular when charging the high-energy cells 10 and high-current cells 20, since otherwise the motor would be driven. In the exemplary embodiment according to FIG. 1, the control unit 30 (PCU Power Control UNIT) is connected to the switches S 1 and S 3 in order to control these two switches S 1 and S 3. The PCU can be designed as a microcontroller. The switches used in the following in all exemplary embodiments, for example, Sl, S2, S3 SP or SM, may be formed as a simple switch, or as a switching unit and be realized by an electronic circuit.

During normal charging of the high-energy cells 10 and high-current cells 20, the switch S1 is, for example, clocked by the control unit 30 with a pulse which, when closed, allows a current pulse to flow to the high-energy cells 10 and high-current cells 20. As an alternative to the clocked switch S1, the charging unit 50 can also supply a current pulse. During the pulse break, in which the switch Sl is opened, a charge exchange takes place between the high-energy cells 10 and the high-current cells 20. Immediately after the switch S1 has been opened, i. That no more current flows to the two cell groups 10 and 20, the individual similar cells start a balancing process with each other, since the cells are not all identical and thus balancing between the similar cells takes place, to compensate for capacity and thermal compensation achieve.

During the charging process, the switch S3 is constantly closed, i. During the current pulse, the current flows into both the high-energy cells 10 and the high-current cells 20. If the switch S1 is open, the high-current cells 20 represent a drain for the high-energy cells 10, so that a current from the high-energy cells 10 in FIG the high current cells 20 flows. This has the advantage that the at least one high-energy cell is gently charged and the dendrite formation is prevented by the negative current pulse due to the load of the at least one high-current cell.

In a second possibility for charging the energy storage arrangement according to FIG. 1, the switch S3 is opened while the switch S1 is closed, ie with the current pulse from the charging unit 50, which is generated by opening and closing the switch S1, a current pulse flows into the high-energy cells 10 and not in the high-current cells 20. Only when the switch Sl is opened, the bridge switch S3 is closed, so that a Current flow from the high energy cells 10 takes place to the high current cells 20 and thus a slow charging of the high current cells 20 takes place. The time in which the switch S1 is closed, ie in which current flows into one or both cell groups, is preferably longer than the time in which the switch S1 is open and the charge equalization takes place.

According to the embodiment in FIG. 1, only the high-energy cells 10 can be charged separately, whereas the high-current cells 20 are not.

In one embodiment, not shown, only one switch is provided for limiting the discharge current after the parallel connection of the cells, as is the switch S1 in FIG. 3. The charging of such an energy storage device takes place with a current pulse generated by a charging unit and supplied to both cell types simultaneously becomes. During discharging, when a discharge end voltage of one of the two cell types is exceeded, the switch in the common line is clocked to the load, wherein in the pauses in which the switch is open, and no current flows to the load, a charge equalization takes place between the two different groups of cells.

2, a further embodiment of the energy storage device according to the invention is shown. Similar to FIG. 1, high-energy cells 10 and high-current cells 20, which are connected in parallel, are used in each case. The energy storage device according to FIG. 2 is also connected to a control unit 30, a charging unit 50 and a drive unit 40. The drive unit 40 has a similar structure to the drive unit 40 according to FIG. 1. A switch or a switching unit SM is arranged in the supply line to the drive unit 40. In addition, it is provided in this embodiment to switch an ammeter 41 in the supply line to the drive unit 40. Analogously, an ammeter 51 is connected between the charging unit 50 and the supply line to the cells. The charging unit 50 includes a voltmeter 52 and a switch SP. For monitoring in this embodiment, in each case an ammeter 11 is connected in front of the high-energy cells 10 and an ammeter 21 in front of the high-current cells 20. The voltage in the high energy cells 10 is monitored with a voltmeter 12 and in the high current cells 20 with a voltmeter 22. The circuit further includes the switches S1, S2 and S3, which are connected to the control unit 30 and be addressed according to the charging method or discharge method according to the invention. For a better overview, the connections to these switches and the control unit are not shown. The circuit according to FIG. 2 also has thermocouples 23, 24 which monitor the temperature in the two cell groups 10 and 20 and transmit their measurement results to the control unit 30. Also, the measurement results of the current and voltage meters 11, 12, 21, 22, 41, 51 and 52 are supplied to the control unit 30.

3 shows a similar embodiment to FIG. 1. In the exemplary embodiment according to FIG. 3, the switch S1 is located in the path from the charging unit 50 to the high-current cells 20. The energy storage device according to FIG Motor 42 or other load connected. A switch or a switching unit SM are arranged in the supply line to the drive unit 40. The energy storage device is controlled by a control unit 30, which is connected to the switch Sl and the bridge switch S3 for the control thereof. The bridge switch S3 is connected in the connection between the high-energy cells 10 and high-current cells 20. During charging, either a current pulse is supplied from the charging unit 50 or the switch S1 is clocked so that the high-current cells 20 and the high-energy cells 10 are each supplied with a current pulse for charging. During charging, the bridge switch S3 is closed.

When a load request, the switch SM is closed. The current flow from the high-energy cells 10 or from the high-current cells 20 to the load 42 can then be controlled via the switch S1 or S3 by means of the control unit 30, wherein the switch S3 can control or limit too high a current flow from the high-energy cells 10 by clocking this switch S3. If the load decrease from the high-current cells 20 is too large, this current flow can be limited with the switch Sl, during the times in which the switch Sl is open and the switch S3 is closed, a charge exchange between the high-energy cells 10 and the high-current cells 20th takes place to recharge the high-current cells 20 with energy from the high-energy cells 10. Both the exemplary embodiment according to FIG. 1 or FIG. 3 can be supplemented by elements from FIG. 2, for example by insertion of voltage and ammeters or temperature sensors.

Referring to FIG. 4, a method of loading cell groups 10 and 20 based on the circuit of FIG. 2 will be described. During the normal charging process, a voltage is applied to the terminals in the charging unit 50 so that a current can flow when the switch SP is closed. The switch SP is pulsed under the control of the control unit 30, so that a current pulse flows to the cell groups 10 and 20. The switches Sl and S2 are closed. The bridge switch S3 is also closed. Since the high-current cells have a lower charge end voltage U _LS , for example 4.2V, this end-of-charge voltage U _{LS is} reached faster in the high-current cells 20, ie fewer current pulses are required to charge the high-current cells 20. When, as shown in Fig. 4, the end-of-charge voltage U _{LS of} the high current cells 20 is reached, the switch S2 and the bridge switch S3 are opened. The switch SP continues to be pulsed and the switch S1 is closed. With this constellation, it is achieved that the high-energy cells 10 continue to be charged until they reach their charge end voltage U _LS , for example 4.3V. With the aid of the control unit 30 it is possible to monitor the current and voltage values of the cell groups and, with the thermocouples 23 and 24, in each case also the temperatures of the two cell types in the respective cell groups. Should one of the detected values be outside of predefined values, the timing of the individual switches SP can be changed with the aid of the control unit 30 such that a total current limitation for both cell groups or by individual clocking of the switches S1, S2 or S3 restricts the current one or another group of cells is reached in order to prevent, for example, overheating of one of the cell groups.

In the following, the current profile for the two cell groups 10 and 20 in various situations will be described in FIG. In situation A, unloading is described for moderate requirements. For this purpose, all switches are closed according to Figure 2, so that a current to the motor 42 can flow. Only the SP switch is open. A moderate requirement means, for example, In the case of an electric vehicle, no maximum power demand or power demand is called up, but an average power demand takes place. In this case, a normal current flows from both cells within the performance limits described by the battery manufacturer. In situation B, the maximum power is requested, for example at full acceleration. The load request can also be above the manufacturer's specifications. In particular, in this case, the high current cells 20 can play their properties, the high current cells 20 provide a continuous stream. The high-energy cells are overwhelmed with such a maximum power requirement and are limited by a pulsating switch Sl in the current flow, so that the high-energy cells 10 are spared. Due to the pulsating switch Sl and an open bridge switch S3, the current from the high-energy cells 10 can thus be limited.

In situation C, it is shown that the temperature sensor 24 has detected an increased temperature value at the high-current cells 20. In such a state, the switch Sl is closed and the switch S2 is pulsed, so that the current flow from the high-current cells is limited and these are thus protected. The high energy cells provide a continuous current that flows through the closed switch Sl to the motor 42.

When charging, it is also possible to let a current pulse flow only in the high energy cells and in the pulse pause to load the high current cells from the high energy cells. However, since the charge pulse into the high energy cells is longer than the sink pulse or the pulse pause, the high current cells can not be fully charged in this way. Therefore, the invention proposes that the next current pulse flows back into both cell groups and both cell groups get the current pulse together.

The timing will be at discharge depending on current value, i. In the case of high-energy cells, the current is limited in order to get the maximum out of the high-energy cells. While the current drain from the high energy cells is limited, the current delivered by the high current cells increases again as they can give off more current. As a result, the cells are spared and not overloaded.

Claims

claims

An energy storage device comprising:

at least one high-current cell (20) and at least one high-energy cell (10), wherein the at least one high-energy cell (10) and the at least one high-current cell (20) are connected in parallel, wherein the cells (10, 20) are charged and / or discharged with a current pulse and in the pulse pauses a charge balance between the cells (10, 20) takes place.

2. Energy storage arrangement according to claim 1, further comprising:

a control unit (30) for controlling the pulse lengths and / or pulse amplitudes of the

Current pulse for charging or discharging the cells (10, 20).

3. Energy storage arrangement according to claim 1 or 2, wherein the number of high current cells (20) is less than the number of high energy cells (10), whereby the charge balancing between the two cells (10, 20) is controlled.

4. Energy storage arrangement according to one of the preceding claims, wherein the number of high-current cells (20) is about 1/3 and the number of high-energy cells (20) 2/3.

5. Energy storage arrangement according to one of the preceding claims, wherein in each case at least the high-energy cell (10) a first and / or at least the high-current cell (10) is preceded by a second switching unit (Sl, S2).

6. energy storage arrangement according to claim 5, wherein the switching unit (Sl, S2) which controls the discharging and / or charging of the high energy cell (10) and / or the high current cell (20).

7. Energy storage arrangement according to one of the preceding claims, wherein a clocking of the at least one switching unit (Sl, S2, S3, SP) by means of the control unit (30) for controlling the pulse lengths and / or pulse pauses of the current pulse during charging and / or discharging the cells ( 10, 20) is provided.

8. Energy storage arrangement according to one of the preceding claims, wherein the at least one switching unit (Sl, S2, S3, SP) interrupts the power supply in or the current drain from the associated cell for a predetermined time and preferably a periodic clocking of the power supply or the current drain causes.

9. Energy storage arrangement according to one of the preceding claims, wherein at least one current measuring device (11, 21, 41, 51) and / or voltage measuring device (12, 22, 52) and / or temperature measuring device (23, 24) is provided, wherein the measured values for controlling be used the loading or unloading.

10. Energy storage arrangement according to one of the preceding claims, wherein a third switching unit (SP) before the parallel connection of the at least one high current cell (20) and the at least one high energy cell (10) is arranged, which serves the current limit for both cells.

11. Energy storage arrangement according to one of the preceding claims 5 to 10, wherein the timing of the first switching unit (S2) for the at least one high current cell (20) on the timing of the second switching unit (Sl) for the at least one high energy cell (10) is tuned.

12. Energy storage arrangement according to one of the preceding claims, wherein the at least one high-current cell (20) and the at least one high-energy cell (10) via a fourth switching unit (S3) are coupled.

The energy storage device of claim 12, wherein the fourth switching unit (S3) is closed to allow current to flow from the high current cell (20) into the high energy cell (10) or vice versa and / or the fourth switching unit (S3) is pulsed to one To achieve current limitation.

14. Energy storage arrangement according to one of claims 12 or 13, wherein by closing the fourth switching unit (S3) during the pulse pauses the at least one high current cell (20) is loaded with a load pulse.

15. Energy storage arrangement according to one of the preceding claims, wherein depending on the state of charge of at least one high energy cell (10) and the high energy cells (10) by closing the fourth switching unit (S3) are loaded with a load pulse or represent a sink for the high current cells (20) ,

16. Energy storage arrangement according to one of the preceding claims, wherein the third switching unit (SP) depending on the state of charge of the at least one high current cell (20) and / or the at least one high energy cell (10) is controlled.

17. Energy storage arrangement according to one of the preceding claims, wherein the charging current flows during a current pulse via the third and fourth switching unit (SP, S3) into the at least one high-current cell (20) and the at least one high-energy cell (10).

18. energy storage arrangement according to one of the preceding claims, wherein the first or fourth switching unit (Sl, S3) when discharging upon reaching the discharge end voltage of the high energy cells (10) or the high current cells (20) is pulsed.

19. Energy storage arrangement according to claim 1, wherein a current flows from the at least one high-energy cell into the at least one high-current cell during a pulsed discharging process during the pauses or during no-load rest periods in a closed fourth switching unit. to recharge these.

20. Energy storage arrangement according to one of the preceding claims, wherein the current from the energy storage arrangement during a discharge by means of one of the switching units can be limited.

The energy storage assembly of any one of the preceding claims, wherein the current pulse switches between a low level of zero amps and a predetermined positive current value.

22. Energy storage arrangement according to one of the preceding claims, wherein the control unit (30) with the first, second, third and / or fourth switching unit (Sl, S2, S3 SP) is connected to supply each of these a switching pulse to open or Effecting closing of the respective switching unit, wherein the control unit is further connected to the current, voltage, and / or temperature measuring means to receive from these measurement signals.

23. Energy storage arrangement according to one of the preceding claims, wherein at least one of the switching units (Sl, S2, S3) is controlled so that upon reaching the discharge end voltage of one of the two cell types, a current limitation by clocking one of the switches (S 1, S2, S3) he follows.

24. Energy storage arrangement according to one of the preceding claims, wherein the length of the current pulses or the pauses between pulses is set depending on the measured state of the two cell types.

25. A method for charging an energy storage arrangement comprising a parallel connection of at least one high-current cell (20) and at least one high-energy cell (10), comprising the steps:

- supplying a current pulse to the high current cells (20) and the high energy cells (10);

- Upon reaching the end-of-charge voltage from the high current cells (20) or from the high energy cells (10) switching off the supply of the current pulse to the corresponding cell;

- Continue to charge the other of the two cells until reaching the end of charge voltage of the other of the two cells.

26. The method of claim 25, wherein during a pulse pause between the current pulses, a switching unit (S3) between the two high current cells (20) and high energy cells (10) connected in parallel is closed to provide a current flow from the high current cells (20) to the high energy cells (10).

27. A method for discharging an energy storage arrangement comprising at least one high-current cell (20) and at least one high-energy cell (10) connected in parallel, comprising the steps:

Monitoring discharge end voltage, current flow and / or temperature of the at least one high-current cell (20) and / or at least one high-energy cell (10); when a limit value of the states is exceeded, for example discharge end voltage, current flow or temperature,

Limiting the discharge current from the high energy cell (10) or from the high current cell (20) by clocking a switching unit (Sl, S2), wherein by closing a switching unit (S3) between the two parallel high current cells (20) and high energy cells (10), a charge balance between the high current cells (20) and high energy cells (10) takes place.

A method of discharging an energy storage device according to claim 27, wherein the switching unit (S3) controls between the two high current cells (20) and high energy cells (10) connected in parallel depending on a state of the high current cells (20) and / or high energy cells (10). or is clocked.