CN-122000508-A - Water system battery full life cycle safety management method and system

CN122000508ACN 122000508 ACN122000508 ACN 122000508ACN-122000508-A

Abstract

The application relates to the field of battery safety management, and particularly discloses a full life cycle safety management method and system of a water system battery, which abandon the traditional mode depending on single macroscopic parameters or global fuzzy analysis, and accurately extract a plurality of core precursor features respectively representing electrode interface degradation, dangerous side reaction germination and thermodynamic instability trend of the system through deep analysis of electrochemical impedance spectroscopy and temperature dynamics. By fusing these multi-dimensional microscopic features into a comprehensive risk score, accurate quantitative assessment of the security state is achieved. Furthermore, an active decision is made based on the risk score, and after the risk is identified, an electric field pulse can be actively applied to trigger a self-repairing mechanism in the electrolyte, and a protective layer is formed in situ at the risk source, so that the safety management after-engaged alarm is converted into the prior intervention, and the running reliability of the whole life cycle of the water system battery is fundamentally improved.

Inventors

SHI ZHIWEI
HU CHENGZHE
LV HAOJIE
WU ZHINING
XU ZHILIANG
LI XIANGYANG
WANG LI

Assignees

永康市光明送变电工程有限公司
国网浙江省电力有限公司永康市供电公司

Dates

Publication Date: 20260508
Application Date: 20260305

Claims (9)

1. A full life cycle safety management method for a water system battery, comprising the steps of: acquiring an electrochemical impedance spectrum and a battery surface temperature sequence; Extracting thermal runaway precursor characteristics of an electrochemical impedance spectrum and a battery surface temperature sequence to obtain normalized charge transfer resistance, abnormal impedance characteristics and normalized temperature rise rate; Determining a thermal runaway risk score based on the normalized charge transfer resistance, the abnormal impedance characteristics, and the normalized temperature rise rate; performing a regulatory decision based on the thermal runaway risk score to obtain a regulatory signal; And responding to the regulation signal to be non-empty, applying electric field pulses to two ends of the battery, wherein dormant functional molecules in the electrolyte form an activated protective layer on the surface of the negative electrode in situ under the excitation of the electric field pulses.
2. The method of claim 1, wherein performing thermal runaway precursor signature extraction on the electrochemical impedance spectrum and the battery surface temperature sequence to obtain normalized charge transfer resistance, abnormal impedance signature, and normalized temperature rise rate comprises: Performing nonlinear least square fitting on the electrochemical impedance spectrum and the baseline impedance spectrum to reach the current charge transfer resistance and the baseline charge transfer resistance; A normalized charge transfer resistance is determined based on the current charge transfer resistance and the baseline charge transfer resistance.
3. The method of claim 2, wherein determining the normalized charge transfer resistance based on the current charge transfer resistance and the baseline charge transfer resistance comprises calculating the normalized charge transfer resistance according to the formula: ; Wherein, the As the current charge transfer resistance is, As a function of the baseline charge transfer resistance, And Respectively controlling the slope and the center point according to the hyper-parameters calibrated by experimental data, To normalize the charge transfer resistance.
4. The method of claim 2, wherein performing thermal runaway precursor signature extraction on the electrochemical impedance spectrum and the battery surface temperature sequence to obtain normalized charge transfer resistance, abnormal impedance signature, and normalized temperature rise rate comprises: Inputting the electrochemical impedance spectrum into an ECM model to obtain an equivalent circuit fitting impedance spectrum; calculating a frequency resolution residual vector between the electrochemical impedance spectrum and the equivalent circuit fitting impedance spectrum; carrying out weighted anomaly scoring on the frequency resolution residual vector to obtain a frequency weighted residual difference; and carrying out self-adaptive threshold judgment on the frequency weighted residual difference to obtain abnormal impedance characteristics.
5. The method of claim 4, wherein the adaptive threshold determination of the frequency weighted residual difference to obtain the abnormal impedance feature comprises: determining an adaptive threshold based on the battery state of health indicator; and determining an abnormal impedance characteristic based on a comparison between the frequency weighted residual and the adaptive threshold, wherein the abnormal impedance characteristic is determined to be abnormal when the frequency weighted residual is greater than the adaptive threshold.
6. The method of claim 5, wherein determining the adaptive threshold based on the battery state of health indicator comprises determining the adaptive threshold according to the following formula: ; Wherein, the Is an adaptive threshold; Is a reference threshold value of the battery in a brand new state; is an indicator of the state of health of the battery; then it is a normal number control factor for adjusting the sensitivity of the threshold to SoH changes.
7. The method of claim 1, wherein determining a thermal runaway risk score based on the normalized charge transfer resistance, the abnormal impedance characteristic, and the normalized temperature rise rate comprises calculating a weighted sum of the normalized charge transfer resistance, the abnormal impedance characteristic, and the normalized temperature rise rate as the thermal runaway risk score.
8. The method of claim 1, wherein performing a regulatory decision based on a thermal runaway risk score to obtain a regulatory signal comprises: If the thermal runaway risk score is less than the alarm threshold, the regulatory signal is null; if the thermal runaway risk score is between the alarm threshold and the regulation threshold, the regulation signal is a warning signal; if the thermal runaway risk score is greater than the regulatory threshold, the regulatory signal is a status regulatory action.
9. A full life cycle safety management system for a water-based battery, comprising: the battery data acquisition module is used for acquiring an electrochemical impedance spectrum and a battery surface temperature sequence; The thermal runaway precursor characteristic extraction module is used for carrying out thermal runaway precursor characteristic extraction on the electrochemical impedance spectrum and the battery surface temperature sequence to obtain a normalized charge transfer resistance, an abnormal impedance characteristic and a normalized temperature rise rate; A thermal runaway risk scoring module for determining a thermal runaway risk score based on the normalized charge transfer resistance, the abnormal impedance characteristics, and the normalized temperature rise rate; the regulation and control decision module is used for carrying out regulation and control decision based on the thermal runaway risk score so as to obtain a regulation and control signal; And the regulation response module is used for responding to the condition that the regulation signal is non-empty and applying electric field pulses to the two ends of the battery, wherein the dormant functional molecules in the electrolyte form an activated protective layer on the surface of the negative electrode in situ under the excitation of the electric field pulses.

Description

Water system battery full life cycle safety management method and system Technical Field The application relates to the field of battery safety management, in particular to a full life cycle safety management method and system for a water system battery. Background The water system battery is regarded as a technical route with great potential in the field of large-scale energy storage systems (such as power grid peak shaving and renewable energy grid connection) by virtue of the outstanding advantages of intrinsically safe electrolyte, abundant resources, low cost, environmental friendliness and the like. However, although the safety of the aqueous battery is far higher than that of the traditional organic electrolyte lithium ion battery, under the abuse conditions of overcharge, overdischarge, rapid charge and discharge or internal short circuit, severe chemical side reactions such as hydrogen evolution, electrode material dissolution, dendrite growth and the like can still occur in the aqueous battery, and the reactions can release a large amount of heat, and when the heat generation rate exceeds the heat dissipation rate, thermal runaway can be triggered as well, so that safety accidents such as battery swelling, electrolyte leakage and even combustion explosion can be caused. Currently, for safety management of batteries, the prior art mainly relies on monitoring macroscopic parameters such as voltage, current, and battery surface temperature by a battery management system. When these parameters exceed a preset static threshold, the system will perform protective actions such as warning or cut-off loops. However, the nature of such methods is a passive response mechanism whose monitored macroscopic parameter is often a hysteresis characterization of the thermal runaway process. That is, when the battery management system detects a significant temperature surge or voltage jump, the chain exothermic reaction inside the battery is usually already initiated, and the intervention is often too late to effectively prevent thermal runaway from occurring. In order to achieve earlier warning, some schemes introduce electrochemical impedance spectroscopy as a probe for internal states. However, these schemes typically employ global, non-differential anomaly determination logic in analyzing the impedance spectrum data, e.g., by accumulating the fitting errors for all frequency bins into a total residual and comparing to a fixed global threshold. The fundamental disadvantage of this approach is that it ignores the strong correspondence between different frequency bands in the impedance spectrum and different physicochemical processes inside the battery. For example, early, weak signals associated with high risk events such as dendrite growth are predominantly represented in the low frequency region, whose contribution in the global residual is highly overwhelmed by measurement noise or relatively benign high frequency region errors, resulting in insufficient sensitivity of critical early fault features, thereby missing the best opportunity for preventive intervention. In summary, the prior art generally has the technical problems of insensitivity to thermal runaway precursor signal perception, single risk assessment dimension, lack of effective distinction of fault properties and the like. Therefore, an optimized aqueous battery full life cycle safety management scheme is desired. Disclosure of Invention The present application has been made to solve the above-mentioned technical problems. The embodiment of the application provides a full life cycle safety management method and system for a water system battery. According to one aspect of the present application, there is provided a full life cycle safety management method of an aqueous battery, comprising: acquiring an electrochemical impedance spectrum and a battery surface temperature sequence; Extracting thermal runaway precursor characteristics of an electrochemical impedance spectrum and a battery surface temperature sequence to obtain normalized charge transfer resistance, abnormal impedance characteristics and normalized temperature rise rate; Determining a thermal runaway risk score based on the normalized charge transfer resistance, the abnormal impedance characteristics, and the normalized temperature rise rate; performing a regulatory decision based on the thermal runaway risk score to obtain a regulatory signal; And responding to the regulation signal to be non-empty, applying electric field pulses to two ends of the battery, wherein dormant functional molecules in the electrolyte form an activated protective layer on the surface of the negative electrode in situ under the excitation of the electric field pulses. According to another aspect of the present application, there is provided a full life cycle safety management system for an aqueous battery, comprising: the battery data acquisition module is used for acquiring an electrochemical impedance spec