Abstract: Disclosed are battery management systems with control logic for battery state estimation (BSE), methods for making/using/assembling a battery cell with a reference electrode, and electric drive vehicles equipped with a traction battery pack and BSE capabilities. In an example, a battery cell assembly includes a battery housing with an electrolyte composition stored within the battery housing. The electrolyte composition transports ions between working electrodes. A first working (anode) electrode is attached to the battery housing in electrochemical contact with the electrolyte composition. Likewise, a second working (cathode) electrode is attached to the battery housing in electrochemical contact with the electrolyte composition. A reference electrode is interposed between the first and second working electrodes, placed in electrochemical contact with the electrolyte composition.

Abstract: A battery cell testing fixture is provided which includes a user interface, a separator assembly and an optional stand. The user interface includes a module for receiving input voltage data from at least one circuit to provide a variety of battery cell conditions. The separator assembly includes an integrated reference electrode or reference component. The separator assembly is operatively configured to be used with a plurality of test batteries in succession. The separator assembly may be operatively configured to communicate with a current collector, a meter and the user interface.

Abstract: Methods for fast-charging batteries while minimizing lithium plating (LP) comprise charging the battery in a first phase at a near-maximum charging current, subsequently charging the battery in a second phase by decreasing the charging current while charging in order to maintain the anode potential equal to or above an anode potential threshold, and subsequently charging the battery in a third phase at constant cell potential such that the cathode potential remains below a cathode potential threshold. LP can be detected by determining the derivative of the charging current and examining the derivative for smooth curves or local discontinuities, wherein a smooth curve indicates the absence of LP and a curve with a local discontinuity indicates the presence of LP. A fast-charging profile can be defined by plotting the cell potential vs. the charging current from the first phase, the second phase, and the third phase to define a fast-charging profile.

Abstract: During the charging of lithium-ion batteries, comprising graphite anode particles, the goal is to intercalate lithium into the anode materials as LiC6. But it is possible to conduct the charging process at a rate that lithium is undesirably plated, undetected, as lithium metal on the particles of graphite. During an open-circuit period of battery operation, immediately following such a charging period, the presence of lithium plating can be detected, using a computer-based monitoring system, by continually measuring the cell potential (Vcell) over a brief period of open-circuit time and then determining dVcell/dt (mV/s) over a like period of time. It is found that the presence of a discontinuity in the derivative curve (a local maximum) reliably correlates with plated lithium on the graphite particles of the anode.

Abstract: Evaluation of a DC power source can include communication with a voltmeter that is arranged to monitor electrical potential across positive and negative electrodes. The method includes determining a full-cell open-circuit voltage (“OCV”), an associated positive half-cell OCV, and an associated negative half-cell OCV at a start-of-life point of the DC power source. A lithium balance model is executed to determine a plurality of beginning states associated with an electrode alignment of the DC power source. An in-use state for the full-cell OCV is determined. An optimization routine is executed employing the lithium balance model to determine in-use states associated with the electrode alignment of the DC power source based upon the in-use state for the full-cell OCV and the beginning states associated with electrode alignment. A negative-to-positive (“N/P”) ratio is determined based upon the in-use states, and battery life is evaluated based upon the N/P ratio.

Abstract: System and methods for estimating a future power capability of a battery system included in a vehicle are presented. In some embodiments, a method for estimating a future power capability of a battery system may include determining an initial battery voltage when the battery operates at a current limit and estimating a future battery current at a first time when the battery operates at the associated voltage limit based on the initial battery current. A future battery voltage at the first time when the battery operates at the associated current limit may be determined based on the initial battery voltage. An estimated voltage-limited power capability of the battery at the first time may be determined based on the future battery current and an estimated current-limited power capability of the battery at the first time may be determined based on the future battery voltage.

Abstract: A number of variations may include a product comprising: an electrochemical device comprising an anode and a cathode, and at least one sensor comprising a plurality of strain sensing components and at least one temperature sensing component wherein each of the anode and the cathode comprises at least one strain sensing component comprising an optical fiber comprising at least one grating, wherein the at least one sensor is constructed and arranged to provide measurements that derive both state of charge and temperature of the anode and the cathode simultaneously.

Abstract: A reference structure and a separator assembly is provided. The separator assembly provides a base layer, a first contact, an optional second contact and a reference component which may be implemented in various applications. The base layer includes a first side and a second side. The first contact is affixed on the first side of the base layer between the base layer and an anode. The second contact is affixed on the second side of the base layer. A reference component is affixed to the second side of the base layer and the optional second contact, if implemented. The reference structure includes a semi-permeable reference component affixed or coupled to a base element.

Abstract: A battery cell system and an associated monitoring system is provided which includes at least an anode, a cathode, a separator formed from a base layer, first and second contacts and a reference component. The anode and cathode are disposed in a lithium ion non-aqueous solution within a housing. The base layer of the separator includes a first side and a second side. The base layer is operatively configured to separate the anode and the cathode within the housing. The first contact of the separator is affixed to the first side of the base layer between the base layer and an anode. The second contact is affixed to the second side of the base layer with the reference component disposed on the second contact.

Abstract: A battery cell testing fixture is provided which includes a user interface, a separator assembly and an optional stand. The user interface includes a module for receiving input voltage data from at least one circuit to provide a variety of battery cell conditions. The separator assembly includes an integrated reference electrode or reference component. The separator assembly is operatively configured to be used with a plurality of test batteries in succession. The separator assembly may be operatively configured to communicate with a current collector, a meter and the user interface.

Abstract: A battery assembly includes a battery having first and second electrodes and an electrolyte. A controller is operatively connected to the battery. The controller includes a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for estimating a charge acceptance capability of the battery. Interaction of the electrolyte and at least one of the first and second electrodes produces a discharge product. The controller is programmed to quantize and track both accumulation and removal of the discharge product when at least one enabling condition is met. The controller is programmed to initialize a timer when the enabling condition is met and increment the timer by a calculation time interval (?t).

Abstract: A system and method for estimating internal parameters of a lithium-ion battery to provide a reliable battery state-of-charge estimate. The method uses a two RC-pair equivalent battery circuit model to estimate the battery parameters, including a battery open circuit voltage, an ohmic resistance, a double layer capacitance, a charge transfer resistance, a diffusion resistance and a diffusion capacitance. The method further uses the equivalent circuit model to provide a difference equation from which the battery parameters are adapted, and calculates the battery parameters from the difference equation.

Abstract: Adaptive estimation techniques to create a battery state estimator to estimate power capabilities of the battery pack in a vehicle. The estimator adaptively updates circuit model parameters used to calculate the voltage states of the ECM of a battery pack. The adaptive estimation techniques may also be used to calculate a solid-state diffusion voltage effects within the battery pack. The adaptive estimator is used to increase robustness of the calculation to sensor noise, modeling error, and battery pack degradation.

Abstract: System and methods for estimating a future power capability of a battery system included in a vehicle are presented. In some embodiments, a method for estimating a future power capability of a battery system may include determining an initial battery voltage when the battery operates at a current limit and estimating a future battery current at a first time when the battery operates at the associated voltage limit based on the initial battery current. A future battery voltage at the first time when the battery operates at the associated current limit may be determined based on the initial battery voltage. An estimated voltage-limited power capability of the battery at the first time may be determined based on the future battery current and an estimated current-limited power capability of the battery at the first time may be determined based on the future battery voltage.

Abstract: System and methods for estimating a relationship between a SOC and an OCV of a battery system included in a vehicle are presented. In certain embodiments, an initial relationship between an open circuit voltage (“OCV”) and a state of charge (“SOC”) of a cell of the battery system may be determined at a beginning of life of the cell. Changes in one or more stoichiometric points of a half-cell of the cell may be determined as the cell ages. Based on the determined stoichiometric point changes of the half-cell, an initial relationship between the OCV and the SOC of the cell may be adjusted to generate an updated relationship between the OCV and the SOC of the cell.

Abstract: A magnetic sensor for measuring the magnetic properties of a battery cell, and converting the magnetic properties to a battery cell SOC. The magnetic sensor includes a magnetic core formed of laminated high permeability plates provided in a C-shape. An extended portion of the battery cell extends through a transverse opening in the core so that it is positioned within the core. A driving coil is wrapped around one end of the magnetic core and generates a magnetic field in the core that extends across the transverse opening and through the battery cell. A receiving coil is wrapped around an opposite end of the core that receives the magnetic field, and converts the magnetic field to a representative current. A detection circuit converts the receiving coil current to the battery cell SOC.

Abstract: Methods and systems are provided for determining a state of charge of a battery. A magnetic force between the battery and a magnet is detected. The state of charge of the battery is determined based on the detected magnetic force.

Abstract: A system and method for estimating the state-of-charge (SOC) of a battery cell in a vehicle using a magnetic sensor that measures changes in magnetism of the battery cell. The method provides an offset correction to a current output signal from the magnetic sensor that calibrates the current output signal to a known magnetic field strength, provides a temperature correction to the current output signal that corrects the current output signal based on a temperature of the magnetic sensor, and provides a current correction to the current output signal that removes portions of the magnetic field caused by other battery cells, where the corrected current output signal is converted to the battery cell SOC.

Abstract: System and methods for determining battery system power capability in a vehicle are presented. Peak power capability estimation systems and methods disclosed herein may compensate regressed parameters in a battery system circuit model for an effect of current magnitude. Utilizing the disclosed methods for accurately estimating peak power capability of a battery system may provide for, among other things, improved battery system performance modeling and/or improved battery system control and management decisions.

Abstract: A battery state estimator which combines an electrochemical solid-state concentration model with an empirical equivalent-circuit model. The battery state estimator uses a reduced-order physics-based electrochemical solid-state concentration model to calculate open circuit voltage of a battery cell, and uses the calculated open circuit voltage in an equivalent-circuit model to evaluate a diffusion voltage drop and other battery cell parameters. The battery state estimator is implemented in an online estimator framework using an extended Kalman filter, with a measured terminal voltage and measured current as inputs. A state of charge of the battery cell can be determined from the calculated open circuit voltage, and the state of charge along with the other parameters from the equivalent-circuit model are used to evaluate battery pack performance and to control battery pack charging and discharging.