256 results about "Cell impedance" patented technology

A battery self heating system for batteries that experience battery impedance or internal battery resistance when temperature drops. The system comprises an energy storage element applied to the battery terminals to draw energy from the battery. The energy is stored in a magnetic or capacitive storage device. The system is self-resonant so that energy transfer from the storage device to the battery will occur at a frequency and load level that is compatible with the current state of the battery. Internal heating of the battery is accomplished by a cycle comprising the out flux and influx of energy through the impedance of the battery. Energy losses due to battery impedance are converted to heat thereby heating the battery internally.

The invention relates to the battery impedance spectroscopy testing technology. The invention provides a battery impedance spectroscopy testing method, which imposes the current incentive I(t) on the battery, and through synchronous measurement of current incentive I(t) and terminal voltage response U(t), calculates the amplitude spectrum I(Omegak), U(Omegak) and phase spectrum phiI(Omegak), phiU(Omegak) of current incentive I(t) and terminal voltage response U(t) under a variety of frequencies, and according to the spectrum of I and U, calculates the battery inner impedance Z0(Omegak)=U(Omegak) / I(Omegak) under a variety of frequencies, resulting in the complete spectra of battery inner impedance. The invention also provides a battery impedance spectroscopy testing system, including the control and data processing module, the high-speed synchronous sampling and measurement module, the voltage and current signal isolation and modulating module, the discharge control module, the controllable discharge module. Using the method and system in this invention, it can quickly complete the battery impedance spectrum measurement and analysis in a short time, greatly increasing the measurement efficiency.

A self-energized measuring system for determining primary and secondary battery / cell's performance, age, and health by measuring and recording battery / cell's voltage response to a specified load-changing perturbation spot-test event. The cell's voltage response is compared to a synchronously measured voltage signal of a comparator resistor. The relationship between the two voltage signals is analyzed on logarithmic time scale to determine performance parameters such as cell impedance and power and their variation in the time domain. The cell temperature is also measured for impedance and power normalization for 20 centigrade. Results are compared to a previously generated master data tabulation characteristic of a similar, new cell of perfect health condition. The time-domain performance parameters are related to the performance, age and health of the cell at any particular instant. The evaluation method can be easily adjusted to various battery chemistries, types.

A solid-state lithium battery including a lithium-containing anode and a phosphorus-containing cathode is disclosed. The cathode may include any of a number of electronically conductive allotropes of phosphorus, referred to as a group as black phosphorus. A solid discharge product of the cell acts as an electrolyte for the cell. The cathode may include an auxiliary electronic conductor phase to improve the conductivity of the cathode, improve the cathode utilization during discharge and reduce the overall cell impedance.

The invention relates to a monitoring system for the electric quantity of a lithium battery. The monitoring system comprises a state monitoring unit, an electric quantity recording unit, an impedance tracking unit, an arithmetic element and the lithium battery, wherein the state monitoring state monitors the current output voltage, the output current and the ambient temperature of the lithium battery; the electric quantity recording unit records the input electric quantity during the charging of the lithium battery and the output electric quantity during the discharging of the lithium battery; the impedance tracking unit calculates the internal impedance of the lithium battery after the charging of the lithium battery is completed every time; the arithmetic element calculates the remaining electric quantity and the remaining working hour of the lithium battery according to input data; the system monitors the whole charging / discharging process of the lithium battery, takes a complete charging and discharging time as a period, dynamically updates battery capacity based on an integral method and eliminates the influence of the variation of the battery capacity; after the battery is fully charged every time, the impedance tracking unit of the lithium battery is started so as to update the internal resistor of the lithium battery; finally, the remaining electrical quantity and the remaining working time of the lithium battery are calculated by combining the environment temperature, the loading and the like.

When impedance calculating conditions are satisfied after a system is started, the impedance of a battery is calculated using the current of the battery, a time variation in open circuit voltage thereof, a time variation in terminal voltage thereof, a time variation in current thereof, and a time variation in impedance thereof. The ratio of the calculated impedance to the initial impedance is calculated. The impedance ratio is subjected to weighting and averaging, thus obtaining a weighted average. When the system is terminated, an impedance-correction-coefficient learned value is updated using the weighted average. Thus, a change in impedance of the battery can be accurately grasped. Advantageously, parameters indicating the state of the battery, e.g., the remaining capacity thereof, reflect the change in impedance, resulting in accurate battery management.

A method for determining the state of health (SOH) of a battery is provided in which cell impedance is determined continuously, and including determining one or more confidence coefficients that depend on one or several variables selected from cell current, temperature or state of charge or their derivatives or integrals with respect to time, and continuously determining the state of health of the battery at a given point in time, using the state of health of the battery at a preceding point in time corrected as a function of cell impedance determined at the given point in time and weighted by the confidence coefficient or coefficients. The method provides a reliable way of determining the state of health of the battery with greater stability and robustness than existing methods.

The invention relates to a low-temperature rapid self-heating method for a lithium-ion battery. The method comprises the following steps: (S1) determining a polarization voltage amplitude range which does not have influence on the service lifetime of the lithium-ion battery and is safely used, and selecting a sine AC voltage amplitude according to the range; (S2) calculating the relationship between heat production power and frequency and obtaining a frequency point, namely the optimal heat production frequency point, with the maximum heat production power according to the relationship between battery impedance and frequency under the selected sine AC voltage amplitude; and (S3) carrying out heating free of lifetime loss on the battery by a sine AC signal according to the amplitude determined in the step (S1) and the frequency determined in the step (S2). The low-temperature rapid self-heating method for the lithium-ion battery has the effects of being high in heating rate, obvious in low-temperature performance improvement, free of an influence on the service lifetime of the lithium-ion battery, good in heating temperature uniformity and the like; and the target of reducing the influence on the service lifetime of the lithium-ion battery to the maximal extent is achieved.

A method and system for determining the temperature of cells in a battery pack, without using temperature sensors, by measuring the impedance of the cells and using the impedance to determine the temperature. An AC voltage signal is applied to the battery pack, and a time sample of voltage and current data is obtained. The voltage and current data is narrowed down to a simultaneous time window of interest, and a fast fourier transformation is performed on the windowed voltage and current data to identify voltage and current magnitudes at one or more specific frequencies. The voltage and current magnitudes are used to determine the impedance at the one or more frequencies. Finally, the impedance is used to determine the temperature of the cell or cells using a look-up table, where the impedance, the frequency, and a state of charge are used as input parameters for the look-up.

The invention discloses a modeling method of a liquid state or semi-liquid state metal battery. The modeling method comprises the following steps: according to a battery impedance spectrum, carrying out fitting, constructing a battery impedance spectrum fitting circuit, and constructing the equivalent circuit model of the battery according to the battery impedance spectrum fitting circuit; adopting symmetrical impulse to carry out a hybrid impulse power performance test on the battery, and obtaining test data used for distinguishing the open-circuit voltage, the resistance and the capacitance parameters of the battery; according to the test data, fitting a function relationship between SOC (State of Charge) and the electrodynamic force, the Ohmic internal resistance, the polarization resistance, the polarization capacitance, the diffusion equivalent resistance and the diffusion equivalent capacitance of the battery, and distinguishing the parameters of the equivalent circuit model; adopting an ampere-hour method to calculate the SOC of the battery; correcting the SOC to obtain a corrected SOC; according to the corrected SOC, correcting the parameters of the equivalent circuit model; and finishing modeling. The modeling method can accurately simulate the external characteristics of the liquid state or semi-liquid state metal battery, and lays a foundation for the charging and discharging management and the subsequent application of the type of novel power grid type energy storage battery including the liquid state or semi-liquid state metal battery.

The invention relates to a variable-frequency and variable-amplitude AC low-temperature self-heating method of a lithium ion battery. The variable-frequency and variable-amplitude AC low-temperature self-heating method comprises the steps of determining a polarization voltage amplitude range having no influence on lifetime of a lithium ion battery, selecting sine AC polarization voltage amplitudeaccording to the range, and determining sine AC current amplitude according to the sine AC polarization voltage amplitude and battery internal resistance under a current temperature; calculating to obtain a frequency at which heating power is maximum under the current temperature according to a relation between the heating power and the frequency and a relation between battery impedance and the frequency under the selected sine AC polarization voltage amplitude; performing low-temperature self-heating on the battery by a sine AC current signal according to the determined amplitude and the frequency; compensating the sine AC current amplitude per certain temperature in real time under the condition that constant polarization voltage amplitude is ensured, finding out optimal heating frequency under the current temperature, and changing the amplitude and the frequency of the applied sine AC current signal. The variable-frequency and variable-amplitude AC low-temperature self-heating method has the advantages of good self-heating rate, no influence on service lifetime of the battery and good heating temperature uniformity.

Battery impedance testing devices, circuits, systems, and related methods are disclosed. An impedance measurement device includes a current driver configured to generate an excitation current signal to be applied to a test battery responsive to a control signal, and a processor operably coupled with the current driver. The processor is configured to generate the control signal during an auto-ranging mode and a measuring mode. The auto-ranging mode applies the excitation current signal to the test battery over a plurality of different amplitudes to measure a response to the excitation current signal at each amplitude. The measuring mode applies the excitation current signal to the test battery for an amplitude responsive to the results of the auto-ranging mode. Improved sensitivity and resolution may be achieved for low impedance batteries with a rapid measurement time.

The invention discloses a multi-scale integrated cell impedance sensor for detecting the behavior of single cells and cell groups. Four interdigital electrode arrays are symmetrically distributed on an insulated substrate, and the edge parts of the insulated substrate are distributed with connection pads; a bus of each interdigital electrode array is respectively connected with the corresponding connection pad through a lead; microelectrodes are correspondingly distributed on at least an opening of the bus of each interdigital electrode array, and each microelectrode is connected with the corresponding connection pad through a lead; a culture container is provided with four culture cavities respectively matched with the areas where the four interdigital electrode arrays are positioned; a top cover is provided with four cavity covers respectively matched with the four culture cavities; the connection pads on the insulated substrate are connected with a PCB board; the four culture cavities of the culture container are respectively and correspondingly fixed on the areas where the four interdigital electrode arrays are positioned; and the four cavity covers are respectively and correspondingly arranged in the four culture cavities. The sensor not only improves the integration degree, but also can simultaneously detect the behavior of the single cells and the cell groups.

The invention discloses an on-line secondary battery simplified impedance spectroscopy model parameter estimating method based on fractional order united Kalman filtering, relates to an on-line estimation method of battery parameters, and aims to improve the accuracy, the estimation speed and the working condition adaptability of secondary battery parameter estimation. The method is based on a simplified battery impedance spectroscopy equivalent circuit model, a state equation and an observation equation required by an algorithm are established, the diffusion polarization end voltage (UW), the open-circuit voltage (OCVe), the internal ohm resistance (Ro) and the diffusion parameter (XW) of a battery are taken as the estimators by using a fractional order united Kalman filter, the end voltage (UL), the load current (IL) and the sampling time interval Ts being 1s which are measured in real time are taken as known amount, noise covariance is excited and measured according to the sensor precision selection process, and the estimation values of the open-circuit voltage (OCVe), the internal ohm resistance (Ro) and the diffusion parameter (XW) of a battery model are obtained. The on-line secondary battery simplified impedance spectroscopy model parameter estimating method is applicable to on-line estimation of secondary battery parameters.

Energy storage cell impedance testing devices, circuits, and related methods are disclosed. An energy storage cell impedance measuring device includes a sum of sinusoids (SOS) current excitation circuit including differential current sources configured to isolate a ground terminal of the differential current sources from a positive terminal and a negative terminal of an energy storage cell. A method includes applying an SOS signal comprising a sum of sinusoidal current signals to the energy storage cell with the SOS current excitation circuit, each of the sinusoidal current signals oscillating at a different one of a plurality of different frequencies. The method also includes measuring an electrical signal at a positive terminal and a negative terminal of the energy storage cell, and computing an impedance of the energy storage cell at each of the plurality of different frequencies using the measured electrical signal.

The invention discloses a method for preparing positive and negative plates of a lithium battery by a dry method, and the method comprises the following steps: mixing an active substance, a conductiveagent, a binder and solid electrolyte powder according to a certain proportion and a certain sequence in a solvent-free manner, uniformly mixing by using a stirrer, and performing mechanical mixing by using a jet mill; extruding the uniform dry powder into continuous sheets by using a screw extruder, and finally rolling the continuous sheets on a current collector at high temperature for multipletimes to form the dry electrode. The invention solves the problems of high cost, difficult recovery and heavy pollution of the solvent used in the existing lithium battery production; meanwhile, thesolid electrolyte powder is added into the positive electrode and the negative electrode, so that the polarization of the battery can be reduced, the battery impedance is reduced, the battery performance is improved, electrolyte is reduced or even not added, and the safety problem caused by using organic electrolyte by the lithium battery is solved.

A battery operable electrical device, such as a mobile telephone or a laptop computer, with a clock frequency generator operable to generate electrical clock frequency signals, and a first electrical circuit adapted to perform a first or main function of the device, utilising the clock frequency signals generated by the clock generator. The device further includes a second electrical or auxiliary circuit adapted to generate an electrical excitation signal with an excitation frequency derived from the clock frequency signals. The excitation signal is fed to battery terminals of the device, and the second electrical circuit receives, from a battery connected to the battery terminals, an electrical signal in response to the excitation signal, and to analyse the received signal for the battery impedance at the excitation frequency and, based on the battery impedance, the state-of-charge of the battery is estimated.

The invention discloses a method for detecting consistency of single batteries. The method comprises the steps that the qualified single batteries are discharged, the actual battery capacity of the single batteries is detected, and the single batteries are graded according to the capacity difference standard; ohmic resistance testing and polarization resistance testing in high-temperature and low-temperature work areas are carried out on the single batteries of the same grade, and the single batteries are graded according to the difference standard of the tested battery resistance values; a battery unit is formed by selecting the single batteries of the same grade. The work characteristics of lithium ion batteries in the high-temperature area and the low-temperature area are considered comprehensively, the consistency of the batteries can be distinguished more directly, and therefore damage caused by inconsistency of the batteries to the battery set is reduced, and the service life of the battery set is prolonged.

Electrolytes for use in commercially viable, rechargeable lithium metal batteries are described. The electrolytes contain one or more lithium salts, one or more organic solvents, and one or more additives. The electrolytes allow for reversible deposition and dissolution of lithium metal. Specific additives or additive combinations dramatically improved cycle life, decrease cell swelling, and / or lower cell impedance.

Methods and systems for tracking aging effect on battery impedance are provided. A first voltage associated with a first state of a battery, a second voltage associated with a second state of the battery, and an impedance of the battery are determined. A battery impedance table that is used for calculating a state of charge of the battery is updated using the determined impedance. Methods and systems for tracking state of health of a battery are also provided. Partial charge cycles of a received battery are counted between a first charge event and a second charge event of the battery. State of health data of the batter is tracked, and a new state of health estimation is calculated based on the state of health data if the counted partial charge cycles of the battery has a count value that has a predetermined relationship with a predetermined count threshold.

A method and apparatus for adjusting transmission power in a portable two-way radio device allows the device to determine an expected battery voltage drop for a subsequent transmit event, based on present transmit power settings and battery impedance, and change the power setting for the subsequent transmit event if the battery voltage is likely to drop below a shutdown threshold at the present power setting or if the expected battery voltage drop will cause the battery voltage to be substantially above the shutdown voltage level and the present power setting is below an optimal level.

There is provided a device for calculating impedances of a battery cell for respective frequency domains. The device includes: a Fourier transformation calculator configured to perform Fourier transformation on voltage waveform data and current waveform data, which are output from the battery cell, and calculate an impedance of the battery cell by dividing a Fourier transformation data of the voltage waveform data by a Fourier transformation data of the current waveform data; a circuit constant estimator configured to estimate circuit constants of a predetermined equivalent circuit model of the battery cell, based on the impedance calculated by the Fourier transformation calculator; and an impedance estimator configured to estimate impedances of the battery cell for respective frequency domains, based on the estimated circuit constants and the equivalent circuit mode.

The present invention relates to a charger capable of diagnosing a lifespan of a battery when the battery is being charged, and a control method thereof. The charger includes a converter applying one of a perturbation voltage and a perturbation current to a battery, and a digital signal processor transmitting a perturbation signal in which an AC signal is added to a DC signal via the converter, measuring an output response of the battery, calculating an impedance spectrum according to the output response of the battery, calculating an impedance parameter by selecting an equivalent circuit according to the impedance spectrum, and estimating a lifespan of the battery by comparing the calculated impedance parameter of the battery with a predetermined impedance parameter of a reference battery.

Various aspects of the present invention are directed to monitoring battery cells. In accordance with various embodiments, an energy storage cell apparatus includes a current injection circuit that separately inject current into individual ones of a plurality of battery cells that store energy, and an impedance-detection circuit detects an impedance characteristic of each of the plurality of battery cells in response to the injected current. A filter circuit receives impedance data regarding the detected impedance characteristic and separates low-frequency components of the impedance data from high-frequency components of the impedance data. A memory circuit stores data corresponding to high-bandwidth data including both the low-frequency components and the high-frequency components, and an access circuit provides the low-frequency components for the plurality of battery cells to a battery pack controller. The access circuit further accesses and provides the stored high-bandwidth data for a subset of the individual battery cells to the battery pack controller based upon available bandwidth for communicating the high-bandwidth data.

The invention relates to a composite electrolyte and an electrochemical device using the composite electrolyte and an electronic device, and particularly provides a composite electrolyte comprising aninorganic solid electrolyte; an organic solid electrolyte; an organic additive; and a lithium salt, wherein the organic additive has a boiling point within the range of 150-350 DEG C, and the contentof the lithium salt is within the range of about 12wt%-50wt% based on the total weight of the composite electrolyte. The composite electrolyte has good conductivity. The lithium ion battery preparedby the composite electrolyte can realize operation at room temperature and low temperature and has low battery impedance and high battery capacity.

The invention belongs to the technical field of lithium ion battery materials, and discloses a lithium ion battery electrolyte and a lithium ion battery containing the electrolyte. The electrolyte comprises organic solvents, conductive lithium salts, additives and phenylpyridine compounds. According to the invention, a solid electrolyte protective film formed by the phenylpyridine compounds can inhibit decomposition of the electrolyte, reduce the battery impedance, and slow down the battery gas expansion speed under the condition of high temperature and high pressure, and further can inhibit the dissolution of transition metals, prevent the transition metals from being embedded into cathodes and protect battery anode and cathode materials to greatly improve cycle performances and safety performances of electrodes.