Battery Charging Based on Real-Time Battery Characteristics

Abstract

This application relates to battery charging based on real-time battery characteristics. Specifically, a battery charging circuit can generate a pulsed charging current to charge a battery during charging, and can perform EIS measurements without disconnecting the pulsed charging current from the battery. In other words, the pulsed charging current can be used for two purposes, for battery charging and as a drive signal for EIS measurements. EIS measurements can be used to change the parameters of the pulsed charging current to improve battery life. In some cases, the parameters of the pulsed charging current can be instantaneously changed for the purpose of performing EIS measurements and then restored after measurements of parameters suitable for battery charging are made.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201780034688.7, titled "Battery Charging Based on Real-Time Battery Characteristics", with a filing date of April 10, 2017.

[0002] Citation of Related Applications

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 319,973, filed on April 8, 2016, under 35 U.S.C. § 119(e), the entire content of which is incorporated herein by reference for all purposes.

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 449,445, filed on January 23, 2017, under 35 U.S.C. § 119(e), the entire content of which is incorporated herein by reference for all purposes. Background Art

[0005] Electrochemical impedance spectroscopy (EIS) has been used for many years to test rechargeable batteries such as lithium-ion batteries. EIS is well-suited for observing reactions in electrodes and battery dynamics. In EIS, the impedance of the battery is measured over a range of frequencies. By examining the resulting frequency response curve, the energy storage and dissipation performance of the battery can be shown. For example, impedance parameters such as ohmic resistance and charge transfer resistance can be estimated from the Nyquist plot of the frequency response of the battery.

[0006] Other parameters that can be measured using EIS relate to the double-layer effect, which is the formation of two layers of opposite polarities at the interface between the electrode and the electrolyte. The charges stored on one side are equal in value but opposite in sign to the charges stored on the other side. If one of the two phases is a liquid, there is a minimum distance that solvated ions can reach. The region of this minimum distance is the so-called Helmholtz plane. The region outside the Helmholtz plane is called the outer Helmholtz layer. Ions can be located at a distance below the plane. This region is called the inner Helmholtz layer. EIS is used to characterize the double layer. The parameters extracted from this characterization are used together with a mathematical model of the phenomenon. Electrochemical insertion, intercalation, and alloying are all processes that involve the inner layer.

[0007] Another set of parameters measurable using EIS are the diffusion and reaction parameters that change during battery charging and discharging and also depend on battery life, health, and temperature. Common experimental setups for parameterizing electrochemical systems are cyclic voltammetry and galvanostatic cycling. In cyclic voltammetry, the potential difference changes continuously at a fixed slope, called the scan rate. Once the maximum or minimum potential difference is reached, the scan rate changes sign. During this process, the current intensity is recorded as a function of the potential, and typically, the shape depends on the scan rate. In a galvanostatic cycling experiment, the current intensity is applied and kept constant. The potential will be measured as a function of the total charge passing through the system. Typically, the shape of this curve is a function of the current intensity. Once the maximum or minimum potential difference is reached, the current intensity changes sign. The shape of such a curve is related to the reaction mechanism, the transport of reactants from the bulk of the phase to the interface, and the transport of products in the opposite direction.

[0008] For the entire potential range used during battery cycling, the electrode material must be stable in the battery electrolyte and vice versa. This stability is achieved due to the formation of a protective layer called the solid electrolyte interface (SEI). It can be an oxidation / reduction product, in which case it consumes a portion of the battery's charge, or a chemical product formed by bringing the particles into contact with the electrolyte. The SEI affects the kinetic behavior of the electrode, the irreversible charge consumed during cycling, and the cycle life. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Regarding the subsequent discussion, particularly the drawings, it is emphasized that the details shown represent examples for illustrative discussion purposes and are presented to provide a description of the principles and conceptual aspects of the present disclosure. In this regard, no attempt is made to show implementation details beyond what is required for a basic understanding of the present disclosure. The discussion in conjunction with the drawings enables those skilled in the art to understand how to implement embodiments in accordance with the present disclosure. Similar or identical

[0010] Reference numerals may be used to identify or otherwise refer to similar or identical elements in the various drawings and the supporting description. In the drawings:

[0011] Figure 1 A battery charging system according to an embodiment of the present disclosure is shown.

[0012] Figure 2 A variant of the battery charging system shown in Figure 1 is shown.

[0013] Figure 3 A battery charging system according to an embodiment of the present disclosure using pulse charging is shown.

[0014] Figure 4 An illustrative example of a pulse train is depicted.

[0015] Figure 5 illustrates a variation of the battery charging system shown in Figure 3 accordance with an embodiment of the present disclosure.

[0016] Figure 6 illustrates a process of pulse charging in accordance with the present disclosure using continuous EIS measurements.

[0017] Figure 7 illustrates a process of pulse charging in accordance with the present disclosure using intermittent EIS measurements.

[0018] Figure 8 illustrates a process of pulse charging in accordance with the present disclosure using pulses suitable for EIS measurements. DETAILED DESCRIPTION

[0019] The present disclosure describes techniques for charging a battery using charging parameters that can be determined in real time. In various embodiments, a pulse train can be used to generate a charging current for charging the battery. Battery parameters can be measured during charging. The pulse train can be adjusted based on the measured battery parameters and environmental conditions to optimize the pulse train for battery charging. In some embodiments, the pulse train can be adjusted during the time when battery measurements are being made to include pulses optimized for the battery measurements.

[0020] In the following description, for purposes of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure, as expressed in the claims, may include some or all of these features of the examples, either alone or in combination with other features described below, and may further include modifications and equivalents of the features and concepts described herein.

[0021] Figure 1 illustrates a battery charging system (circuit) 100 for charging a rechargeable battery (e.g., a lithium-ion battery cell) in accordance with the present disclosure. The battery charging system 100 can include a controller 102 and switches S1, S2, S3, S4. The controller 102 can include control logic 112 to perform battery charging in accordance with the present disclosure.

[0022] An external load can be connected to the controller 102 at its load terminals to receive power from the battery (battery discharge).

[0023] An external power supply can be connected to the controller 102 at its Vin terminals to supply power to the battery during battery charging. The controller 102 can include a voltage level shifter 114 to attenuate the voltage provided by the external power supply during battery charging. The voltage level shifter 114 can be an operational amplifier (op-amp), a DC-DC converter, or any other suitable voltage level shifting circuit.

[0024] The controller 102 may include a high-speed analog-to-digital converter (ADC) for converting signals at its inputs In1, In2, In3, In4.

[0025] The controller 102 may include a signal generator 116. Under the control of the control logic 112, the signal generator 116 may generate a sine wave signal at a given frequency. The controller 102 may connect the output of the signal generator 116 to either of its outputs Out1, Out2. In some embodiments, for example, the signal generator 116 may generate signals in the range of 0.1 Hz to 100 MHz. In some cases, the signal generator 116 may output signals at a single frequency. In other cases, the signal generator 116 may sweep through a series of frequencies. Merely for illustration, for example, the controller 102 may operate the signal generator 116 to output signals in the range of 1 Hz to 100 KHz in 10 Hz increments over a 5-second interval.

[0026] The controller 102 includes Pin1 and Pin2. When in the charging mode, the controller 102 may connect the battery to an external power source through Pin1 and Pin2 for charging by the external power source. Alternatively, when in the discharging mode, the controller 102 may connect the battery to an external load through Pin1 and Pin2 to supply power from the battery to the external load.

[0027] The controller 102 may include communication links Link1, Link2 for communicating with external devices. For example, Link1 may be used to convey aspects of the battery condition to a battery management system in an electronic device (not shown) that includes the battery charging system 100. Information related to the battery condition includes, but is not limited to, battery parameters measured in real time, calculations, overall battery health, charge state, battery parameter history, etc. In some embodiments, Link2 may be used for advanced external loads, so-called "smart" loads, to communicate the battery state and negotiate the optimal operating mode of the battery and the external load. In embodiments including multiple battery systems, both Link1 and Link2 may be used to communicate the battery condition and the optimal mode to other elements in the system, respectively.

[0028] Operating Modes

[0029] The discussion will now turn to a description of the discharging mode and the charging mode of operation of the battery charging system 100 in accordance with the present disclosure.

[0030] A. Discharging Mode

[0031] In the discharge mode, the controller 102 may turn off or otherwise silence the signal generator 116. The controller 102 may operate switches S1, S2, S3, S4 to the on state (closed position). The controller 102 may connect PIN1 to the load terminal and Pin2 to the ground (GND) terminal, thereby connecting the battery to an external load. According to some embodiments of the present disclosure, during the discharge mode, the controller 102 may interrupt power delivery to the external load for EIS measurement (described below). For example, the smart load may coordinate with the controller 102 (e.g., vial Link2) to interrupt power for a short period (e.g., around 50 μS).

[0032] B. Charge mode

[0033] In the charge mode, the controller 102 may operate the signal generator 116 to output a signal. The controller 102 may perform a calibration sequence on the signal generator 116. For example, the controller 102 may operate switches S1, S2, S3, S4 to the off state (open position). In this configuration, the output from the signal generator 116 may be provided to Out1, and calibration may be performed through In2. Similarly, the output from the signal generator 116 may be provided to Out2, and calibration may be performed through In3.

[0034] During charging, the controller 102 may alternate between a charging phase, in which energy (charging current) is provided to the battery from an external power source, and a measurement phase in which EIS measurements are performed on the battery. The alternation between the charging phase and the measurement phase may be performed intermittently, e.g., in response to a change in operating conditions (e.g., ambient temperature). The alternation may be periodic, e.g., EIS measurements may be performed at regular intervals from milliseconds to minutes.

[0035] For the charging phase, the controller 102 may operate switches S1, S2, S3, S4 to the on state and turn off or silence the signal generator 116 for the charging phase, thereby allowing the external power source to charge the battery.

[0036] For the measurement phase, typically, an EIS measurement is obtained by disconnecting the battery from its charging current path and coupling the battery to a signal source (driver) in the form of a band-limited white noise. The EIS measurement includes measuring the response of the battery (e.g., current response) over a given frequency range of the drive signal. Thus, the controller 102 can operate switches S1, S3 to the closed state to disconnect the external power supply from the battery and turn on the signal generator 116, thereby providing a drive signal to the battery through Output Out1 for EIS measurement. The measurement can be made by converting the signal at Input In1 using the ADC at Inl. Since the measurement duration can be relatively short (e.g., from a few tens of microseconds to several seconds), the measurement can be made without interrupting the normal operation of the battery. For example, in the case of integrating the battery into a smart phone, the main processor can choose to insert an EIS measurement at a time when it deems the smart phone to be idle or neat idle.

[0037] In some embodiments, the measurement can be continuous. The controller 102 operates switches S1, S2, S3, S4 to the open state and turns on the signal generator 116, thereby allowing power from the external power supply and the signal from the signal generator 116 to reach the battery, and the EIS measurement can be performed while charging the battery.

[0038] C. Adapting to Battery Charging

[0039] It should be understood that the EIS measurement is related to the electrochemical and even mechanical phenomena inside the battery. These electrochemical and mechanical phenomena are manifested as various parameters of the battery, including, for example, state of charge (SOC), capacitance of the double layer, thickness of the double layer, electrolyte oxidation level, corrosion of the current collector, deterioration of the active material binder, diffusion rate inside the battery, and other physical aspects of the battery. The EIS measurement can be analyzed as a sum of sine functions (Fourier series). In some embodiments, appropriate fast Fourier transform (FFT) techniques can be used for analysis.

[0040] According to the present disclosure, the controller 102 can adjust the charging of the battery based on the EIS measurement. For example, when the EIS measurement indicates a decrease in the diffusion rate in the battery, the charging current can be reduced (e.g., by reducing the gain of the level shifter 114). In some cases, this may be desirable to increase the life cycle of the battery. By inserting the EIS measurement at specific intervals, the charging process can be adjusted in real time to regulate the charging current to improve the life cycle of the battery.

[0041] Further according to the present disclosure, the controller 102 can analyze the EIS measurement to evaluate the battery condition and report the results from the analysis. In some embodiments, for example, the results can be reported (e.g., through Link1) to the battery management system.

[0042] Figure 2 FIG. 2 shows a battery charging system (circuit) 200 according to another embodiment of the present disclosure. The battery charging system 200 may include a first controller 202 and a second controller 204. The circuit components described in the controller 102 of the battery charging system 100 are allocated to the first controller and the second controller 202, 204 of the battery charging system 200. Similarly, the control logic 112 in the controller 102 of the battery charging system 100 is allocated to the control logic 1 and the control logic 2 in the battery charging system 200. The operation of the battery charging system 200 is the same as that of the battery charging system 100.

[0043] Figure 3 FIG. 6 shows a battery charging system (circuit) 300 for charging a rechargeable battery (e.g., a lithium ion battery cell) according to the present disclosure. The battery charging system 300 may include a controller 302 and switches S1, S2, S3, S4. The controller 302 may include control logic 312 to perform battery charging according to the present disclosure.

[0044] An external load may be connected to the controller 302 at its load terminals to receive power from the battery (battery discharge).

[0045] An external power supply may be connected to the controller 302 at its Vin terminal to supply power to the battery during battery charging. The controller 302 may include a level shifter 314 to attenuate the voltage provided by the external power supply during battery charging. The level shifter 314 may be an operational amplifier-based design, a DC-DC converter, or any other suitable level shifting circuit.

[0046] The controller 302 may include a high-speed analog-to-digital converter (ADC) for converting signals at its inputs In1, In2, In3, In4.

[0047] The controller 302 may include a pulse train generator 316. Under the control of the control logic 312, the pulse train generator 316 may generate a series of pulses. The controller 302 may connect the output of the pulse train generator 316 to either of its outputs Out1, Out2.

[0048] The controller 302 may control the pulse amplitude, pulse length (duration, period), and pulse width of each pulse. In one aspect, for example, the controller 302 may generate a series of pulses with a constant duty cycle. On the other hand, the controller 302 may generate a pulse train with pulses of different pulse amplitudes, pulse lengths, and pulses. For example, Figure 4Shows a portion of a pulse train including pulses P1, P2, P3, P4, P5. Pulses P1 - P3 have different pulse amplitudes (a1 ≠ a2 ≠ a3), pulse lengths (11 ≠ 12 ≠ 13), and different pulse widths (w1 ≠ w2 ≠ w3). The pulse train can include pulse repetitions having the same pulse period and pulse width; for example, pulses P3, P4, and P5 show an example of repetitive pulses. Generally, the pulse train can include pulses having any combination of the same or different amplitudes, lengths, and widths. In some embodiments, the pulses can be rectangular. In other embodiments, the pulses can have other shapes.

[0049] Controller 302 includes Pin1 and Pin2. When in the charging mode, controller 302 can connect the battery to an external power source through Pin1 and Pin2 for charging by the external power source. Alternatively, when in the discharging mode, controller 302 can connect the battery to an external load through Pin1 and Pin2 to supply power from the battery to the external load.

[0050] Controller 302 can include the same communication links Link1, Link2 for communicating with an external device that is controller 102.

[0051] Figure 5 Shows a battery charging system (circuit) 500 according to another embodiment of the present disclosure. The battery charging system 500 can include a first controller 502 and a second controller 504. The circuit components described in controller 302 of battery charging system 300 are assigned to the first controller and the second controller 502, 504 of battery charging system 500. Similarly, the control logic 312 in controller 302 of battery charging system 100 is assigned to control logic 1 and control logic 2 in battery charging system 500. The operation of battery charging system 500 is the same as that of battery charging system 300.

[0052] Reference Figure 6 And reference Figure 3 , now the discussion will turn to a high - level description of the process for pulse - charging a battery according to the present disclosure by control logic 312.

[0053] At block 602, control logic 312 can configure the connectors in controller 302 to connect an external power source to the battery. For example, control logic 312 can connect Pin1 and Pin2 to the Vin and GND terminals respectively, and operate switches S1, S2, S3, S4 to the on state.

[0054] At block 604, control logic 312 may operate a pulse train generator 318 to generate a pulse train. The control logic 312 may select initial settings for the pulse amplitude, pulse length, and pulse duration of the pulses comprising the pulse train based on previously stored measured battery parameters.

[0055] At block 606, the control logic 312 may operate switch S2 in accordance with the pulse train to generate a pulsed charging current by modulating the output of an external power source, thereby initiating pulsed charging of the battery. The pulse amplitude, pulse length, and pulse width of the pulsed charging current are determined by the pulse amplitude, pulse length, and pulse width of the pulses in the pulse train. In some embodiments, the pulse amplitude in the pulse train may be used to set the gain of the level shifter 314 and thus set the amplitude of the pulsed charging current.

[0056] At block 608, while the battery is receiving the pulsed charging current, the control logic 312 may perform EIS measurements on the battery, including one or more measurements of the current flowing into the battery and / or one or more measurements of the voltage across the battery. For example, the control logic 312 may operate the ADCs corresponding to inputs In1 and In4 to make the measurements without disconnecting the pulsed charging current from the battery. In effect, the pulsed charging current serves as a drive signal for the battery while performing the EIS measurements.

[0057] At block 610, the control logic 312 may accumulate the EIS measurements using the previously performed EIS measurements. As described above, the control logic 312 may analyze the accumulated EIS measurement results to evaluate the parameters of the battery. Based on the evaluated battery parameters, the control logic 312 may change any one or more of the pulse amplitude, pulse length, and pulse width of the pulses comprising the pulse train, which in turn affects the pulsed charging current generated at block 606. For example, the pulse amplitude may be adjusted according to the SOC of the battery. Similarly, the pulse length may be adjusted when the ion diffusion level reaches a predetermined threshold, etc. In this way, the pulsed charging of the battery can be optimized in real time using the EIS measurements of the battery that are performed concurrently with the battery charging to extend the cycle life of the battery.

[0058] When the charging current is very high (either globally or locally in some regions of the battery), the rate of transport of lithium ions (Li+) to the anode may exceed the rate at which Li+ can be inserted (intercalated). Under these conditions, Li+ may deposit as metallic Li, which can lead to the growth of dendrites. Dendrites can create a short circuit, which reduces the life and durability of the battery and, in the worst case, can cause a fire. The EIS measurements performed in accordance with the present disclosure can also be used to detect the development of metallic plating formation, even at a very early stage of development.

[0059] Thus, according to some embodiments, the control logic 312 can include an analysis to detect the occurrence of a metal plating, such as dendrite formation, and in response, can change the pulse parameters to reduce the charging current or completely interrupt the charging process. In some embodiments, the control logic 312 can reduce the available capacity of the battery and allow charging to continue only until the reduced capacity. The battery remains usable although the capacity is reduced.

[0060] In some embodiments, the control logic 312 can initiate a discharge sequence to discharge the battery in a controlled manner, thereby reducing the charge level in the battery (or completely depleting the battery) to minimize the fire hazard. In some cases, the control logic 312 can completely disable the use of the battery. In some cases, the control logic 312 can also communicate the detection of the metal plating to the battery management system (e.g., via Link1), which can alert the user or provide other indications.

[0061] Figure 6 Illustrated is that in some embodiments, the control logic 312 can continuously perform EIS measurements during the time that the battery charging is in progress. For example, for each iteration, one or more current and / or voltage measurements can be made. The EIS measurements can be combined with and analyzed against previous EIS measurements (e.g., Fourier analysis). The battery parameters discussed above can be evaluated from the analysis results and then used to change the parameters of the pulses in the pulse train (e.g., amplitude, length, and width) for the next iteration. The next iteration can be performed without delay (continuously).

[0062] Figure 7 Illustrated is that in some embodiments, the control logic 312 can perform intermittent EIS measurements. Figure 7 The processing in Figure 6 is the same as the processing in

[0063] including a delay at block 702 to provide a delay between performing EIS measurements (block 608). In some embodiments, for example, the delay can be a predetermined fixed time value. The delay can vary from one iteration to the next. In other embodiments, the EIS measurements can be triggered by the occurrence of one or more predetermined events (e.g., a change in operating conditions such as ambient temperature); the delay occurring from the time between these events.

[0064] Referring toFigure 8 And refer to Figure 3 The discussion will now turn to a high-level description of the process used by the control logic 312 to pulse charge a battery in accordance with the present disclosure.

[0065] At block 802, the control logic 312 may configure the connections in the controller 302 to connect the external power source to the battery. For example, the control logic 312 may connect Pin 1 and Pin 2 to the Vin and GND terminals, respectively, and operate switches S1, S2, S3, and S4 to an open state.

[0066] At block 804, the control logic 312 may operate the pulse train generator 318 to generate a pulse train. The control logic 312 may select initial settings for pulse amplitude, pulse length, and pulse duration for the pulses comprising the pulse train based on previously stored measured battery parameters. Thus, the pulse train initially includes a first type of pulse to optimize battery charging.

[0067] At block 806, control logic 312 may operate switch S2 according to the pulse train to generate a pulse charging current by modulating the output of the external power supply, thereby initiating pulse charging of the battery. The pulse amplitude, pulse length, and pulse width of the pulse charging current are determined by the pulse amplitude, pulse length, and pulse width of the pulses in the pulse train. In some embodiments, the pulse amplitude in the pulse train may be used to set the gain of level shifter 314 and, therefore, the amplitude of the pulse charging current.

[0068] At block 808, the control logic 312 may provide a delay before proceeding to the next block. In some embodiments, for example, the delay may be a predetermined fixed time value. The delay may vary from one iteration to the next. In other embodiments, the EIS measurement may be triggered by the occurrence of one or more predetermined events (e.g., a change in an operating condition such as ambient temperature); the delay may occur from the time between these events.

[0069] At block 810, the control logic 312 may configure the pulse train generator 316 to generate a second type of pulse that is more suitable for performing EIS measurements. In some embodiments, for example, the pulse train may be a pseudo-random binary pulse sequence that approximates a band-limited white noise pattern and generates a pulse charging current with a pulse amplitude in the range of 0.1C to 20C and a pulse duration in the range of 1mS to 5000mS. Thus, while the generated pulse charging current continues to charge the battery, it will no longer

[0070] It is optimized for battery charging but is used to perform EIS measurements. However, instantaneous changes in pulse parameters should not be detrimental to the battery charging process, as EIS measurements take a few seconds or less.

[0071] At block 812, when the battery is receiving a pulsed charging current, the control logic 312 can perform an EIS measurement on the battery, including one or more measurements of the current flowing into the battery and / or one or more measurements of the voltage across the battery. For example, the control logic 312 can operate the ADCs corresponding to inputs In1 and In4 to make the measurements without disconnecting the pulsed charging current from the battery. In fact, the pulsed charging current serves as a drive signal for the battery during the EIS measurement.

[0072] At block 814, the control logic 312 can adjust the pulse parameters for charging the battery, as described above. For example, it is connected to block 610 in Figure 6 .

[0073] At block 816, the control logic 312 can set the pulse train generator 316 to generate a first type of pulse to resume battery charging using a pulse train optimized for battery charging. Then, the control logic 312 can return to block 808 to repeat the process.

[0074] The EIS measurement can be performed using any of several possible implementations. In one such implementation, for example, a programmable current source is controlled by an integrated circuit, and the EIS measurement is performed continuously. In another embodiment where cost control is a factor, a conventional charger for the battery can be used instead of a separate current source, and its current output can be controlled to generate a suitable pulse train having parameters selected based on the results of the EIS measurement. For example, a laptop computer or a smart phone already includes a charging integrated circuit responsible for charging the battery. The charging integrated circuit can be directly controlled via the I 2 C or communication bus.

[0075] According to an embodiment of the present disclosure, a circuit coupled to a battery cell can be employed. The monitoring circuit in the controller (e.g., 302) can be implemented on an ASIC or an FPGA, where the monitoring circuit monitors, senses, detects, and / or samples the characteristics of the battery on an intermittent, continuous, and / or periodic basis, including, for example, the impedance, terminal voltage, and temperature of the battery. The control logic (e.g., 312) can obtain data from the monitoring circuit and calculate one or more charging signal characteristics (e.g., charging current), and if appropriate (e.g., mitigate, minimize, and / or reduce the adverse impact of the charging process on the health state of the battery), adjust the charging process, for example, by controlling the pulse parameters.

[0076] The circuits for the adaptive charging techniques of the present disclosure may employ any monitoring circuits and techniques, whether described herein, now known, or later developed, to obtain the EIS measurements employed by the control circuit to adapt to the charging curve of the battery; all such monitoring circuits and techniques are intended to fall within the scope of the present invention.

[0077] Similarly, embodiments of the present disclosure may employ any control circuits and charging circuits, whether described herein, now known, or later developed, to charge a battery pack (or its cells), and to adapt the charging process to, for example, mitigate, minimize, and / or reduce the adverse effects of the charging operation on the state of health of the battery.

[0078] It is noted that "circuit" particularly refers to a single component (e.g., an integrated circuit or ASIC) or multiple components, whether in the form of integrated circuits, discrete forms, or other forms, which are active and / or passive and are coupled together to provide or perform the desired operation. Additionally, "circuit" particularly refers to a circuit (whether integrated or otherwise), a group of such circuits, one or more processors, one or more state machines, one or more processor-implemented software, one or more gate arrays, programmable gate arrays, and / or field programmable gate arrays, or a combination of one or more circuits (whether integrated or otherwise), one or more state machines, one or more processors, one or more processor-implemented software, one or more gate arrays, programmable gate arrays, and / or field programmable gate arrays. The term "data" particularly refers to current or voltage signals (plural or singular), whether in analog or digital form, which may be one bit (etc.) or multiple bits (etc.).

[0079] The above description illustrates various embodiments of the present disclosure and examples of how aspects of a particular embodiment may be implemented. The above embodiments should not be regarded as the only embodiments, and are used to illustrate the flexibility and advantages of the particular embodiments defined by the appended claims. Based on the above disclosure and the following claims, other arrangements, embodiments, implementations, and equivalents may be employed without departing from the scope of the present disclosure as defined by the claims.

Claims

1. A method for determining the condition of a battery, the method comprising: Connecting a power source to the battery (802); Generating a pulse train (804) comprising a plurality of charge-optimized pulses; Generating a pulsed charging current from the power source by modulating the power source with the pulse train, whereby the battery is charged by the pulsed charging current (806); Providing a delay for a certain period of time (808); After the delay, generating measurement-optimized pulses (810), wherein generating the measurement-optimized pulses (810) comprises generating a pseudo-random binary pulse sequence, and wherein the pulsed charging current generated using the pseudo-random binary pulse sequence is characterized in the form of band-limited white noise; While charging the battery with the pulsed charging current generated using the pseudo-random binary pulse sequence, performing a plurality of electrochemical impedance spectroscopy (EIS) measurements on the battery (812), wherein performing the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) comprises performing the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) based on the pulsed charging current generated using the pseudo-random binary pulse sequence; Analyzing the plurality of electrochemical impedance spectroscopy (EIS) measurements to evaluate the condition of the battery; and Restoring battery charging with the charge-optimized pulses.

2. The method according to claim 1, further comprising: Reporting the results of the analysis from the plurality of electrochemical impedance spectroscopy (EIS) measurements to a battery management system.

3. The method according to claim 1, further comprising: Based on the analysis of the plurality of electrochemical impedance spectroscopy (EIS) measurements: Changing the charging process of the battery, or Initiating a discharge sequence to reduce the charge level in the battery.

4. The method according to claim 1, wherein Performing the plurality of electrochemical impedance spectroscopy (EIS) measurements without disconnecting the pulsed charging current from the battery.

5. The method according to claim 1, further comprising continuously performing the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) while the battery is receiving the pulsed charging current.

6. The method according to claim 1, wherein, Performing the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) comprises intermittently performing the plurality of electrochemical impedance spectroscopy (EIS) measurements in response to changes in operating conditions.

7. The method according to claim 1, wherein, Integrating the battery into a smart phone, and wherein performing the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) comprises performing the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) when the smart phone is in an idle or near-idle state.

8. A method for negotiating an optimal operating mode between a battery and an external load, comprising the method according to any one of the preceding claims, and communicating information regarding the condition of the battery to an external intelligent load.

9. A circuit (100) configured for determining the condition of a battery, comprising: Terminals for connecting to an external power source; Terminals for connecting to the battery; A pulse train generator (318) configured to generate a pulse train (804) comprising a plurality of charge-optimized pulses; And Control logic (804) operative to: Generating a pulsed charging current (806) from the external power source by modulating the power source with the pulse train, thereby charging the battery with the pulsed charging current; Providing a delay (808) for a certain period of time; After the delay, generating measurement-optimized pulses (810), wherein generating the measurement-optimized pulses includes generating a pseudo-random binary pulse sequence, and wherein the pulsed charging current generated using the pseudo-random binary pulse sequence is characterized in the form of band-limited white noise; While charging the battery with the pulsed charging current generated using the pseudo-random binary pulse sequence, performing a plurality of electrochemical impedance spectroscopy (EIS) measurements (812) on the battery, wherein the plurality of electrochemical impedance spectroscopy (EIS) measurements are based on the pulsed charging current generated using the pseudo-random binary pulse sequence; Analyzing the plurality of electrochemical impedance spectroscopy (EIS) measurements to evaluate the state of the battery; and Restoring battery charging with the charge-optimized pulses.

10. The circuit of claim 9, wherein the control logic (112) is further operable to: Report the results of the analysis from the plurality of electrochemical impedance spectroscopy (EIS) measurements to a battery management system.

11. The circuit of claim 9, wherein the control logic is further operable to: Based on the analysis of the plurality of electrochemical impedance spectroscopy (EIS) measurements: Change the charging process of the battery, or Initiate a discharge sequence to reduce the charge level in the battery.

12. The circuit of claim 9, wherein the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) are performed without disconnecting the pulsed charging current from the battery.

13. The circuit of claim 9, wherein the control logic (112) is operable to continuously perform the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) while the battery is receiving the pulsed charging current.

14. The circuit of claim 9, wherein the control logic (112) is operable to intermittently perform the plurality of electrochemical impedance spectroscopy (EIS) measurements in response to a change in operating conditions.

15. The circuit according to claim 9, wherein, Integrating the battery into a smart phone, and wherein the control logic is operable to perform the plurality of electrochemical impedance spectroscopy (EIS) measurements (812) when the smart phone is at an idle or near-idle moment.

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