Optimized battery health status detection device

Abstract

An optimized battery health status detection device includes a detection unit, a bidirectional conversion unit, a temperature sensing unit, and a control unit. The control unit analyzes the temperature sensing signal from the temperature sensing unit and the first voltage and first current signals from the detection unit to obtain the actual output energy per unit temperature change of the battery cell, and calculates the battery health status according to a battery health status equation. This battery health status equation is related to the actual DC resistance, actual charge transfer resistance, actual mass transfer impedance, actual electrical double-layer capacitance value, and actual output energy per unit temperature change. Through this design, considering the impact of the actual electrical double-layer capacitance value and the actual output energy per unit temperature change on the battery cell helps improve the accuracy of battery health status assessment.

Claims

1. An optimized battery health status detection device, suitable for detecting the health status of a battery cell, comprising: a detection unit for electrically connecting to the battery cell and for measuring the battery cell to generate a first voltage signal and a first current signal; a capacitor; a bidirectional conversion unit having a first conversion side and a second conversion side, the first conversion side being electrically connected to the detection unit and for electrically connecting to the battery cell, the second conversion side being electrically connected to the capacitor, the bidirectional conversion unit being controllable to discharge or charge the battery cell; A temperature sensing unit is used to sense the temperature of the battery cell and generate a temperature sensing signal; and a control unit is electrically connected to the sensing unit, the bidirectional conversion unit, and the temperature sensing unit, and includes a DC resistance analysis module, an AC impedance analysis module, an output energy and temperature analysis module, and a battery health status analysis module. The DC resistance analysis module can analyze the actual DC resistance of the battery cell, and the AC impedance analysis module can analyze the actual charge transfer resistance, actual mass transfer impedance, and actual double-layer capacitance of the battery cell. The output energy and temperature analysis module will analyze the temperature sensing signal, the first voltage signal, and the first current signal. The analysis module obtains the actual output energy per unit temperature change of the battery cell. The battery health status analysis module has parameter data corresponding to the initial state of the battery cell. The parameter data includes an initial DC resistance, an initial charge transfer resistance, an initial mass transfer impedance, an initial double-layer capacitance value, and an initial output energy per unit temperature change. The battery health status analysis module calculates the battery health status of the battery cell according to a battery health status equation. The battery health status equation is related to the actual DC resistance, the actual charge transfer resistance, the actual mass transfer impedance, the actual double-layer capacitance value, the actual output energy per unit temperature change, and the parameter data.

2. The optimized battery health status detection device as described in claim 1, wherein, The battery health status equation is as follows: Where SOH represents the battery health status, RS0 represents the initial DC resistance, RCT0 represents the initial charge transfer resistance, ZW0 represents the initial mass transfer impedance, CDL0 represents the initial electric double-layer capacitance value, ΔC0 represents the initial output unit energy change with temperature, RS represents the actual DC resistance, RCT represents the actual charge transfer resistance, ZW represents the actual mass transfer impedance, CDL represents the actual electric double-layer capacitance value, ΔC represents the actual output unit energy change with temperature, and k1, k2, k3, k4, and k5 represent weighted values.

3. The optimized battery health status detection device as described in claim 1 or 2, wherein, The DC resistance analysis module controls the conduction direction of the bidirectional conversion unit to discharge the battery cell, and analyzes the actual DC resistance based on the first voltage signal and the first current signal.

4. The optimized battery health status detection device as described in claim 1 or 2, wherein, The AC impedance analysis module controls the conduction direction of the bidirectional conversion unit, so that the DC voltage of the capacitor is converted into AC voltage, and then a sweep frequency AC signal is input to the battery cell. Based on the first voltage signal and the first current signal, the actual charge transfer resistance, the actual mass transfer impedance and the actual double-layer capacitance value are obtained.

5. The optimized battery health status detection device as described in claim 1 or 2, wherein the battery cell has a positive terminal and a negative terminal, wherein, The bidirectional conversion unit includes a first positive conversion terminal and a first negative conversion terminal located on the first conversion side. The detection unit includes a voltage detection module electrically connected between the positive terminal and the negative terminal of the battery, and a current detection module electrically connected between the negative terminal of the battery and the first negative conversion terminal. The voltage detection module is used to generate the first voltage signal, and the current detection module is used to generate the first current signal.

6. The optimized battery health status detection device as described in claim 1 or 2, wherein, The bidirectional conversion unit includes a second positive conversion terminal and a second negative conversion terminal located on the second conversion side. The capacitor has a first terminal electrically connected to the second positive conversion terminal and a second terminal electrically connected to the second negative conversion terminal. The optimized battery health status detection device also includes a voltage detection unit electrically connected between the first terminal and the second terminal. The voltage detection unit is signal-connected to the control unit and is used to generate a second voltage signal. The control unit also includes a capacitor voltage holding module. When the second voltage signal is analyzed to be lower than a predetermined capacitor voltage, the capacitor voltage holding module controls the bidirectional conversion unit to discharge the battery cell so that the capacitor stores energy.

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