Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/44—Methods for charging or discharging
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
  • H01M2010/4271—Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention is based on a method, a device, a computer program and a machine-readable storage medium for operating an electrical energy storage unit according to the independent patent claims, wherein a first mechanical state variable and an electrochemical state variable of the electrical energy storage unit are determined and based on the variables thus determined Actuator is controlled. Likewise, an electrical energy storage unit and its use are described.
• Electric energy storage units in particular based on the lithium-ion technology, find increasing popularity in the automotive sector in particular as an important component in the drive train.
• the electrodes of an electrical energy storage unit are subject to volumetric changes due to the storage and removal processes of the lithium ions.
• the corresponding extent of the electrodes changes, in particular orthogonal to a layer arrangement of the electrodes.
• a model-based monitoring and determination of the aging and state of charge of an electrode or an electrical energy storage unit are helpful for ensuring the safe operation of the to ensure electrical energy storage unit.
• lithium ion cells have increased rates of aging due to excessive mechanical pressure on the electrode. Due to the intercalation-related expansion of the electrodes within the lithium-ion cells and the formation of passivation layers, mechanical pressures are generated on the electrodes by limiting the mechanical installation space.
• new active materials for the electrodes for example based on silicon, have a potential hysteresis, which makes it difficult to determine the state of charge on the basis of the electrode potential.
• electrochemical models are suitable for describing the electrochemical processes, for example the well-known Newman model, in order to describe electrochemical processes in an electrode.
• this does not yet provide any information about the mechanical state of the electrical energy storage unit, for example an expansion of the electrodes or one of them exerted on a housing surrounding the electrodes force.
• the document DE 10 2012 209 271 A1 describes a battery management system of a battery, wherein a pressure-sensitive film sensor is mounted within a battery cell on an electrode winding, the measured values of which are evaluated by a battery state detection and used for detecting the battery condition.
• the document US 2015/0188198 A1 describes a battery module which has a battery cell and a force meter and a control module, wherein the force meter measures a force due to the swelling of the battery cell and the control module is arranged based on the received force measurement data, the remaining life of Estimate battery module.
• a first mechanical state variable which represents a mechanical state of the electrical energy storage unit, in particular a mechanical pressure or a displacement, is determined using a first mathematical model of the electrical energy storage unit.
• This first mechanical state variable may include, for example, the mechanical pressure exerted by the housing of the electrical energy storage unit or also the pressure exerted by an electrode of the electrical energy storage unit.
• the first mathematical model can for example be stored in a memory module of a battery management control unit.
• the first mathematical model can include, for example, differential equations, in particular partial differential equations, and / or algebraic equations.
• a data-based map can also be part of the first mathematical model.
• an electrochemical state variable which represents an electrochemical state of the electrical energy storage unit, in particular a concentration of a substance in the electrical energy storage unit, is determined using a second mathematical model of the electrical energy storage unit, wherein the first mathematical model and the second mathematical model are coupled ,
• This coupling causes the mechanical state variable affects the electrical state variable and vice versa.
• the porosity of an electrode or a separator and / or more generally the flow behavior of an electrolyte in the electrical energy storage unit can be influenced by the mechanical state of the electrical energy storage unit.
• the coupling of the models reflects this mathematically.
• the second mathematical model may for example be stored in a memory module of a battery management control unit and include, for example, differential equations, in particular partial differential equations, and / or algebraic equations.
• differential equations in particular partial differential equations, and / or algebraic equations.
• One known model of this type is Newman's proposed electrochemical model of an electrical energy storage unit based on the concentrated solution and porous electrode theories.
• suitable starting values should be chosen for the investigations with the presented models. This applies in particular to mathematical models based on differential equations. These start values can be determined, for example, before the actual operation and stored in a data memory. If necessary, they are then used for model initialization, possibly depending on boundary conditions.
• an actuator is controlled as a function of the determined first mechanical state variable and / or the determined electrochemical state variable, the actuator being set up in such a way that it changes the mechanical state of the electrical energy storage unit in response to the activation.
• a piezoelectric actuator or a fluidic actuator element can be used for this purpose.
• corresponding relationships between the mechanical state variable, the electrochemical state variable and the pressure exerted by the actuator can be stored in a characteristic map, with the characteristic map in turn being stored in a data memory. It is also possible to determine a corresponding drive signal of the actuator from the first mathematical model, for example via an inversion of the first mathematical model.
• the operating method thus advantageously allows the operation of the electrical energy storage unit under optimum mechanical conditions, since An adaptation of mechanical parameters is possible at any time via the actuator as a function of the current state of the electrical energy storage unit. This allows operation of the electrical energy storage unit without an increased rate of aging. Premature failures of the electrical energy storage unit can thus be avoided and a longer life can be achieved.
• Parameters of the electrical energy storage unit in particular a Porig- keitskennonnes an electrode of the electrical energy storage unit, depending on the determined mechanical state variable, wherein the determination of the electrochemical state variable then in dependence of the determined parameter value, in particular the Portechnikskennyess takes place.
• This has the advantage that mechanical forces acting on the electrical energy storage unit, which have an effect on electrochemical properties of the electrical energy storage unit, are taken into account in the determination of the electrochemical state variable.
• Energy storage unit increased. This contributes in particular to an increased service life of the electrical energy storage unit.
• a second mechanical state variable which represents the mechanical state of the electrical energy storage unit, is detected by means of a sensor mounted within the electrical energy storage unit and / or in physical contact with the electrical energy storage unit.
• the sensor may include, for example, a strain gauge or piezoelectric element.
• This is followed by a first comparison of the determined first state variable with the detected second state variable and then, depending on the comparison, a change of at least one parameter of the first mathematical model and / or of variables determined by means of the first mathematical model.
• This has the advantage that a kind of model tracking, ie a type of model update, is carried out by means of the acquired second mechanical state variable. For example, this can be done by means of a control-technical observer structure or within an optimization process.
• the accuracy of the operating method is increased, since the first mathematical model provides correct results in the determination of the first mechanical state variable even under changing conditions or mechanical boundary conditions by the model tracking.
• a second comparison of the determined first mechanical state variable with a predefined mechanical state variable threshold value is expediently carried out. Subsequently, when the mechanical state variable threshold value is exceeded, a signal is generated in order to indicate the result of the comparison.
• This has the advantage that, for example, a user of the electrical energy storage unit is given the opportunity by the display to change his behavior in order, for example, to reduce the mechanical load on the electrical energy storage unit. Also can be given by the display an indication, for example, visit a specialist workshop to check the electrical energy storage unit and repair if necessary. Thus, the safe operation of the electrical energy storage unit is ensured.
• the electrical energy storage unit is charged or discharged with a predefined current, for example a predefined current trajectory or a predefined current profile, or with a predefined charging method, wherein the activation of the actuator takes place as a function of the predefined current.
• a pressure exerted by the actuator pressure on the electrical energy storage unit is reduced at a current flow above a first predefined threshold and increased at a current flow below a second predefined threshold.
• the subject matter of the disclosure is a device for operating an electrical energy storage unit which has an actuator and at least one Means, such as an electronic battery management control device, which are arranged to perform the disclosed methods.
• an electronic battery management control device which are arranged to perform the disclosed methods.
• the subject matter of the disclosure is a computer program comprising instructions which cause the disclosed apparatus to carry out the method steps of the disclosed method.
• the advantages of the method are realized in an advantageous manner.
• the subject matter of the disclosure is a machine-readable storage medium on which the disclosed computer program is stored.
• the disclosed computer program is stored.
• the subject matter of the disclosure is an electrical energy storage unit which comprises the disclosed device for operating the electrical energy storage unit. This is advantageous because the life of the electrical energy storage unit is extended and its safety is increased.
• the subject matter of the disclosure is the use of the disclosed electrical energy storage unit in electrically driven vehicles including hybrid vehicles, in stationary electrical energy storage systems, in electrically operated hand tools, in portable devices for
• Telecommunications or data processing and in household appliances.
• An electrical energy storage unit may in particular be understood to be an electrochemical battery cell and / or a battery module having at least one electrochemical battery cell and / or a battery pack having at least one battery module.
• the electric energy storage unit may be a lithium-based battery cell or a lithium-based battery module or a lithium-based battery pack.
• the electrical energy storage unit may be a lithium-ion battery cell or a lithium-ion battery module or a lithium-ion battery pack.
• the bat be cell of the type lithium polymer accumulator, nickel-metal hydride accumulator, lead-acid accumulator, lithium-air accumulator or lithium-sulfur accumulator or quite generally an accumulator of any electrochemical composition.
• a capacitor is possible as an electrical energy storage unit.
• porous electrodes can be used in the construction of the electrical energy storage unit.
• Corresponding electrolytes for use in such electrical energy storage units may be, for example, gel-like or liquid.
• the at least one means may include, for example, a battery management control unit and corresponding power electronics, for example an inverter, as well as current sensors and / or voltage sensors and / or temperature sensors.
• An electronic control unit in particular in the form of a battery management control unit, can also be such a means.
• An electronic control unit may, in particular, comprise an electronic control unit which, for example, has a microcontroller and / or an application-specific hardware component, e.g. an ASIC may be understood, but may also include a personal computer or a programmable logic controller.
• an electronic control unit which, for example, has a microcontroller and / or an application-specific hardware component, e.g. an ASIC may be understood, but may also include a personal computer or a programmable logic controller.
• FIG. 1 shows a flow chart of the disclosed method according to a first embodiment
• FIG. 2 is a flowchart of the disclosed method according to a second embodiment
• FIG. 3 is a flowchart of the disclosed method according to a third embodiment
• FIG. 4 is a flow chart of the disclosed method according to a fourth embodiment
• FIG. 5 is a flowchart of the disclosed method according to a fifth embodiment
• Figure 6 is a schematic representation of the disclosed apparatus arranged to carry out the disclosed method.
• Figure 1 shows a flow chart of the disclosed method according to a first
• a mechanical force acting on an electrical energy storage unit is determined using a first mathematical model of the electrical energy storage unit.
• the use of a force sensor can thus be dispensed with if necessary.
• the force acting on the electrical energy storage unit is known, this force having an effect on the performance of the electrical energy storage unit.
• a lithium concentration within the electrical energy storage unit is determined using a second mathematical model of the electrical energy storage unit based on differential equations.
• the lithium concentration is determined as a function of the mechanical force determined in the first step Sil.
• the second mathematical model and the first mathematical model are thus coupled.
• a piezoelectric element which is located on or optionally in the electrical energy storage unit is subsequently actuated, the activation taking place as a function of the determined mechanical force and the determined lithium concentration.
• the piezoelectric element is set up in such a way that it changes the mechanical state, for example the force acting on the electrical energy storage unit, in response to the activation.
• the force acting on the electrical energy storage unit force changes, which favors in particular their slower aging.
• FIG. 2 shows a flowchart of the disclosed method according to a second embodiment.
• a mechanical pressure acting on an electrical energy storage unit is determined using a first mathematical model of the electrical energy storage unit.
• the use of a pressure sensor can thus be dispensed with if necessary, while still being known by the model-based determination of the pressure acting on the electrical energy storage unit.
• a porosity or a porosity characteristic value of an electrode of the electrical energy storage unit as a function of the mechanical pressure determined in the first step S21 is determined as an electrochemical parameter value of the electrical energy storage unit.
• the thus determined electrochemical parameter is used in a second mathematical model.
• the porosity or porosity of the separator and / or both electrodes can be determined.
• a third step S23 an electrical potential of an electrode of the electrical energy storage unit is subsequently determined using the second mathematical model, wherein the parameter value determined in the second step S22 is used within this model-based determination by means of the second mathematical model, whereby the determination result is improved ,
• a fourth step S24 an actuator in dependence of the determined mechanical pressure and optionally the determined electrical Potentials driven.
• the actuator is set up in such a way that it changes the mechanical pressure on the electrical energy storage unit upon activation, for example reduces the pressure exerted with an increased current flow and increases the pressure exerted with a reduced current flow. This helps in particular to prevent unwanted lithium deposition in the electrodes, in particular at the interface between the negative electrode and separator
• FIG. 3 shows a flowchart of the disclosed method according to a third embodiment.
• a mechanical expansion experienced by an electrical energy storage unit or one of its electrodes is determined using a first mathematical model of the electrical energy storage unit or of the electrode.
• a lithium concentration within the electrical energy storage unit is determined using a second mathematical model of the electrical energy storage unit.
• the lithium concentration is determined as a function of the mechanical expansion determined in the first step S31 in order to take account of the fact that a changed mechanical state of the electrical energy storage unit results in a change in electrochemical state variables.
• a third step S33 the mechanical expansion is detected by means of a strain sensor mounted on a housing of the electrical energy storage unit. Accordingly, there are both an expansion value determined by means of the first mathematical model and also an expansion value detected by means of a strain sensor.
• a fourth step S34 the determined strain value is then compared with the detected strain value.
• a fifth step S35 at least one parameter of the first mathematical model, which Ches for model-based determination of the mechanical expansion was used in the first step S31 changed. This change may, for example, take place using a mathematical optimization method.
• a mechanical actuator is then activated as a function of the mechanical expansion and the lithium concentration, wherein the actuator changes the mechanical state of the electrical energy storage unit as a function of the activation, in particular increases or decreases the pressure on the energy storage unit.
• FIG. 4 shows a flowchart of the disclosed method according to a fourth embodiment.
• a first step S41 an electrical potential of an electrode of the electrical energy storage unit is determined using a second mathematical model, which is coupled to a first mathematical model. If necessary, this coupling necessitates that suitable boundary conditions or starting values for the corresponding models be selected within the framework of the model-based determination.
• a mechanical pressure which acts on the electrical energy storage unit is determined using the first mathematical model of the electrical energy storage unit.
• the use of a pressure sensor can thus be dispensed with if necessary, while still being known by the model-based determination of the pressure acting on the electrical energy storage unit.
• a third step S43 the determined mechanical pressure is compared with a predefined mechanical pressure threshold value.
• This pressure threshold value can be selected, for example, such that exceeding it Threshold indicates irreversible damage to the electrical energy storage unit, which, for example, a visit to a specialist workshop is necessary.
• a signal is generated in order to indicate the result of the comparison. This may be, for example, a graphic signal on a screen as well as a flashing of a signal light, which indicate, for example, a necessary workshop visit.
• an actuator is then activated as a function of the determined mechanical pressure and the determined electrode potential.
• the actuator is set up in such a way that it changes the mechanical pressure on the electrical energy storage unit upon activation, for example reduces the pressure exerted with an increased current flow and increases the pressure exerted with a reduced current flow. This helps in particular to prevent unwanted lithium deposition in the electrodes, in particular at the interface between the negative electrode and separator. If the determined mechanical pressure exceeds the predefined mechanical pressure threshold value, this can be taken into account in the actuation of the actuator such that the actuator reduces the mechanical pressure on the electrical energy storage unit in such a way that the pressure threshold is again undershot.
• the fifth step S45 is executed after the third step S43. Since the mechanical pressure of the electrical energy storage unit is consequently in a normal range, the activation of the actuator takes place, for example, with changed control parameters, as a result of which the electrical energy storage unit is exposed to increased pressure fluctuations, for example. However, this is not a problem because their mechanical pressure is within the normal range.
• FIG. 5 shows a flowchart of the disclosed method according to a fifth embodiment.
• a lithium concentration is added is determined within the electrical energy storage unit using a second mathematical model of the electrical energy storage unit based on differential equations.
• a mechanical force acting on an electrical energy storage unit is determined using a first mathematical model of the electrical energy storage unit.
• the use of a force sensor can thus be omitted if necessary.
• the force acting on the electrical energy storage unit is known.
• the second mathematical model and the first mathematical model are thus coupled, whereby, if appropriate, suitable starting values and boundary conditions for the first and / or the second mathematical model are to be selected.
• These starting values can be stored, for example, in a map which is stored in a data memory, or determined by means of suitable sensors, for example a pressure sensor.
• a control of an actuator which is set up to change the mechanical state of the electrical energy storage unit, takes place after the activation.
• an actuator which is set up to change the mechanical state of the electrical energy storage unit, takes place after the activation.
• Corresponding activation values for the actuator can be obtained either model-based or from a characteristic map in which current values are linked to a force state of the electrical energy storage unit.
• Figure 6 shows a schematic representation of the disclosed apparatus 70 arranged to carry out the disclosed method.
• a mechanical state variable of an electrical energy storage unit is determined by means of a first mathematical model 71 stored in a first data memory.
• the determined mechanical state variable is then used in a second mathematical model 72, which is stored in a second data memory, in the determination of an electrochemical state variable.
• the battery management control unit determines from the determined state variables 74 suitable control commands for the actuator 73, which is configured to change the mechanical state of the electrical energy storage unit in response to the driving.
• the life of the electrical energy storage unit is extended or allows a gentler operation of the electrical energy storage unit.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Secondary Cells (AREA)

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Citations (5)

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• 2017
  • 2017-09-13 DE DE102017216219.8A patent/DE102017216219A1/de active Pending
• 2018
  • 2018-09-10 CN CN201880059194.9A patent/CN111095661A/zh active Pending
  • 2018-09-10 WO PCT/EP2018/074306 patent/WO2019052943A1/de active Application Filing

Patent Citations (5)

Non-Patent Citations (1)

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