CN115494395A - Lithium-ion battery cell voltage sampling system and its sampling method - Google Patents

Abstract

The invention discloses a single lithium ion storage battery voltage sampling system which comprises a single storage battery voltage sampling circuit, a temperature sampling module and a temperature compensation module, wherein the single storage battery voltage sampling circuit is used for acquiring a single storage battery voltage sampling value; the invention also discloses a lithium ion storage battery monomer voltage sampling method, which comprises the steps of firstly fitting the temperature compensation model, and then compensating the storage battery monomer voltage sampling value at the working temperature by using the fitted temperature compensation model to obtain the storage battery monomer voltage compensation value. The invention reduces the sampling error caused by temperature change and improves the reliability and temperature adaptability of the sampling system.

Description

Lithium-ion battery cell voltage sampling system and its sampling method

technical field

The invention belongs to the technical field of on-orbit management of lithium-ion storage batteries for satellites, and in particular relates to a lithium-ion storage battery monomer voltage sampling system and a sampling method thereof.

Background technique

Lithium-ion batteries have the advantages of high specific energy, long cycle life, and wide temperature range. They have gradually replaced nickel-cadmium batteries and nickel-hydrogen batteries, and are widely used in the field of satellite power supplies. A lithium-ion battery pack is composed of multiple lithium-ion battery cells connected in series and in parallel, and the voltage difference between each battery cell affects the service life of the battery pack. In order to prolong the service life of the lithium-ion battery pack, the on-rail management of the battery must be balanced and controlled based on the voltage of each cell to reduce the difference between each cell.

Battery cell voltage sampling is the basis of equalization control, and its accuracy directly affects the effect of equalization control. The voltage sampling accuracy of lithium-ion battery is affected by many factors, such as sampling circuit topology, component quality level, circuit operating temperature, etc. The existing technology mainly optimizes the topology structure of the sampling circuit and the parameters of components, while ignoring the influence of the ambient temperature on the voltage sampling of the battery cell. For example, CN104237806A discloses a single cell sampling device, system and method for a lithium-ion storage battery pack. Its main technical feature is to improve the sampling accuracy of the battery cell voltage from the topological structure, without considering the sampling accuracy of the battery cell voltage by the ambient temperature. Impact. The operating temperature range of the battery cell voltage sampling circuit of the satellite in orbit is relatively large, which can reach -25°C to 70°C. Therefore, it is necessary to reduce the influence of the operating temperature of the sampling circuit on the sampling accuracy, and the present invention is based on this.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned defects, provide a lithium-ion battery cell voltage sampling system and its sampling method, and solve the technical problem that the ambient temperature has a great influence on the battery cell voltage sampling accuracy. The invention reduces the sampling error caused by the temperature change, and improves the reliability and temperature adaptability of the sampling system.

In order to realize the foregoing invention object, the present invention provides following technical scheme:

A method for sampling the voltage of a lithium-ion battery cell, comprising:

Temperature compensation model fitting stage:

Establishing a temperature compensation model, the temperature compensation model is a fitting model expressing the relationship between the battery cell voltage sampling circuit temperature, the battery cell voltage sampling value and the battery cell voltage compensation value;

Let the temperature of the battery cell voltage sampling circuit be the test temperature T ₀ , T ₁ , T ₂ ,...,T _n ;

Use the battery cell voltage sampling circuit to obtain the battery cell voltage sampling values V ₀ , V ₁ , V ₂ ,...,V _n at each test temperature when the actual value of the battery cell voltage is V _Z ;

Based on V _Z , T ₀ , T ₁ , T ₂ ,..., T _n and V ₀ , V ₁ , V ₂ ,..., V _n determine the fitting coefficients in the temperature compensation model, and complete the fitting of the temperature compensation model; n is an integer greater than 2;

Real working stage:

Obtain the working temperature T of the battery cell voltage sampling circuit and the battery cell voltage sampling value V;

Substitute the working temperature T of the battery cell voltage sampling circuit and the battery cell voltage sampling value V into the fitted temperature compensation model to obtain the battery cell voltage compensation value at the working temperature T of the battery cell voltage sampling circuit.

Further, the temperature compensation model is V _s (T)=k(T)V+b(T), where V _s (T), k(T), and b(T) are the working temperature of the battery cell voltage sampling circuit respectively V is the battery cell voltage compensation value, the first fitting coefficient and the second fitting coefficient at T; V is the battery cell voltage sampling value when the working temperature of the battery cell voltage sampling circuit is T.

Further, the standard test temperature T ₀ is any temperature point within -25°C to 70°C, preferably room temperature.

m≥2；其中v₁，…，v_m为不同的蓄电池单体电压真实值；Furthermore, the actual value of the battery cell voltage is

m≥2; where v ₁ ,..., v _m are the real voltage values of different battery cells;

0≤i≤n，其中v_i1，…，v_im为试验温度T_i下，蓄电池单体电压真实值v₁，…，v_m分别对应的蓄电池单体电压采样值。Sampling value of battery cell voltage at each test temperature

0≤i≤n, where v _i1 , ..., v _im are the sampling values of the battery cell voltages corresponding to the actual voltage v ₁ , ..., v _m of the battery cells at the test temperature T _i .

Further, the method for determining the fitting coefficient in the temperature compensation model based on V _Z , T ₀ , T ₁ , T ₂ ,..., T _n and V ₀ , V ₁ , V ₂ ,..., V _n includes:

Substitute V ₀ into the temperature compensation model, and make V _s (T) equal to V _Z , to obtain k(T ₀ ) and b(T ₀ );

Substitute V ₁ , V ₂ ,…,V _n into the temperature compensation model respectively, and make V _s (T) equal to V _Z , to obtain k(T ₁ ), k(T ₂ ),…,k(T _n ) and b (T ₁ ),b(T ₂ ),…,b(T _n ); V _Z contains ≥2

Determine k(T) according to k(T ₀ ), T ₁ , T ₂ ,...,T _n and k(T ₁ ), k(T ₂ ),...,k(T _n );

b(T) is determined from b(T ₀ ), T ₁ , T ₂ , . . . , T _n and b(T ₁ ), b(T ₂ ), . . . , b(T _n ). Specifically, in the temperature compensation model fitting stage, firstly, the actual value of the battery cell voltage is set to ≥ 2 different values, and at a certain test temperature T _i , ≥ 2 different sampled values of the battery cell voltage are obtained , with a set of data of a battery cell voltage sampling value and a corresponding battery cell voltage real value, multiple sets of data are substituted into the temperature compensation model, and after fitting, the first fitting coefficient and the second fitting coefficient at the test temperature are obtained Two fit coefficients.

Further, _{k ( T ) = k 0 +} f _k (T), wherein, k ₀ =k (T ₀ ), f _k (T) is a function of temperature;

b _{( T ) =} b _{0 + f b (} T ), where b ₀ =b(T ₀ ), f _b (T) is a function of temperature.

Further, after sorting T ₀ , T ₁ , T ₂ ,..., T _n in order of high and low, the difference between adjacent test temperatures is 3-10°C.

A lithium-ion battery cell voltage sampling system, used to realize the above-mentioned lithium-ion battery cell voltage sampling method, comprising a battery cell voltage sampling circuit, a temperature sampling module and a temperature compensation module;

The battery cell voltage sampling circuit is used to obtain the sampling value V of the battery cell voltage at the working temperature T, and output V to the temperature compensation module;

The temperature sampling module is used to obtain the working temperature T of the battery cell voltage sampling circuit, and output the value of T to the temperature compensation module;

The temperature compensation module is used to receive the fitted temperature compensation model input from the outside, the V input from the battery cell voltage sampling circuit, and the T input from the temperature sampling module, and substitute V and T into the fitted temperature compensation model The battery cell voltage compensation value at the working temperature T of the battery cell voltage sampling circuit is obtained.

Further, the temperature sampling module includes a temperature sensor and a temperature sampling circuit;

The temperature sensor is installed on the printed circuit board where the battery cell voltage sampling circuit is located, and the temperature sampling circuit is used to collect the output signal of the temperature sensor.

Further, the temperature sensor is a thermistor.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention creatively proposes a lithium-ion battery cell voltage sampling method, which enables the temperature of the battery cell voltage sampling circuit to participate in temperature compensation, reduces sampling errors caused by temperature changes, and improves the reliability of the sampling system sex and temperature adaptability;

(2) The present invention establishes a temperature compensation model, and provides an identification method for coefficients in the model, greatly improving the accuracy of the sampling system through a simple and effective method;

(3) In the temperature compensation model of the present invention, the operating temperature range of the sampling system is fully considered, so that it can ensure higher accuracy when working in the operating temperature range;

(4) The sampling system of the present invention is provided with a temperature sensor and a temperature sampling circuit, which can collect the temperature of the battery cell voltage sampling circuit, provides a basis for realizing temperature compensation, and has far-reaching significance for the on-orbit management of the battery.

Description of drawings

Fig. 1 is the schematic diagram of the voltage sampling system of the lithium-ion battery cell of the present invention;

Fig. 2 is the sampling circuit diagram of the battery cell selected in the embodiment of the present invention;

Fig. 3 is the selected temperature sampling circuit diagram in the embodiment of the present invention;

Fig. 4 is a flow chart of the voltage sampling method of a lithium-ion battery cell of the present invention.

detailed description

The following describes the present invention in detail, and the features and advantages of the present invention will become more clear and definite along with these descriptions.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments. While various aspects of the embodiments are shown in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The invention provides a single voltage sampling system of a lithium-ion storage battery. The sampling system has high sampling precision, strong temperature adaptability and high reliability, and is suitable for sampling the voltage of a single lithium-ion storage battery in the field of satellite power supplies. The sampling system of the present invention includes a battery cell voltage sampling circuit, a temperature sampling module and a temperature compensation module, wherein the temperature sampling module includes a temperature sensor and a temperature sampling circuit.

The battery cell voltage sampling circuit is connected to the positive and negative poles of the battery cell to collect the voltage of a cell in the battery pack;

The temperature sensor is installed on the printed circuit board where the battery cell voltage sampling circuit is located, and is used to convert the temperature signal into an electrical signal;

The temperature sampling circuit is connected with the temperature sensor for collecting the output signal of the temperature sensor;

The input of the temperature compensation module is the output value of the battery cell voltage sampling circuit and the collected temperature of the battery cell voltage sampling circuit, and the output is the compensation value of the battery cell voltage.

The present invention also provides a battery cell voltage sampling method, which is realized by the above-mentioned lithium-ion battery cell voltage sampling system, including the following steps:

A1, establish the temperature compensation model: V _s (T)=k (T) V+b (T), wherein V is the output voltage of the battery cell voltage sampling circuit, the present invention is also called the battery cell voltage sampling value, V _s (T) is the compensation value of the battery cell voltage, k(T) and b(T) are the coefficients of the temperature compensation model, when the battery cell voltage sampling circuit works at T ₀ =20°C, the battery cell voltage sampling The circuit obtains the battery cell voltage sampling value V ₀ , and obtains the sampling model coefficients k ₀ =k(T ₀ ), b ₀ =b(T ₀ ) at 20°C through linear fitting;

A2. Operate the battery cell voltage sampling circuit at different temperatures T ₁ ; T ₂ ;...; T _n , the above temperatures are collected by the temperature sensor and the temperature sampling circuit, and use linear fitting to respectively fit the sampling mathematics at different temperatures Coefficients of the model k ₁ , b ₁ ; k ₂ , b ₂ ; . . . ; k _n , b _n ;

A3. According to {T ₁ ; T ₂ ;...; T _n } and {k ₁ ; k ₂ ;...; k _n } in A2, establish the relationship between k coefficient and temperature k(T)=k ₀ +f _k ( T), where k ₀ is the k coefficient at 20°C, f _k (T) is a function of temperature, and k(T) is the k coefficient under the condition of temperature T;

A4. According to {T ₁ ; T ₂ ;...; T _n } and {b ₁ ; b ₂ ;...; b _n } in A2, establish the relationship between b coefficient and temperature b(T)=b ₀ +f _b ( T), where b ₀ is the b coefficient at 20°C, f _b (T) is a function of temperature, and b(T) is the b coefficient under the condition of temperature T;

A5. When k(T) and b(T) are determined, the temperature compensation model V _s (T)=k(T)V+b(T) is determined, where V _s (T) is the battery cell voltage Compensation value, k(T) is the k coefficient under the temperature T condition, b(T) is the b coefficient under the temperature T condition, V is the output voltage of the battery cell voltage sampling circuit;

A6. Use software to implement the temperature compensation model in A5. According to the sampling value of the battery cell voltage and the working temperature of the sampling circuit, the temperature compensation model can output the compensation value of the battery cell voltage.

Example:

The lithium-ion battery cell voltage sampling system and sampling method of the present invention will be further described in detail with reference to FIGS. 1 to 4 .

Referring to Fig. 1, the lithium-ion battery cell voltage sampling system of this embodiment includes a battery cell voltage sampling circuit, a temperature sampling module and a temperature compensation module, wherein the temperature sampling module includes a temperature sensor and a temperature sampling circuit;

The battery cell voltage sampling circuit adopts the circuit structure shown in Figure 2. The positive pole of the battery cell is connected to the negative pole of the battery pack through two series resistors R2 and R4, and the connection point of resistors R2 and R4 is connected to pin 3 of AD620 through resistor R6. The negative pole of the monomer is connected to the negative pole of the battery pack through two series resistors R1 and R3, the connection point of resistors R1 and R3 is connected to pin 2 of AD620 through resistor R5, the pin 4 of AD620 is connected to -12V telemetry power supply through resistor R7, the 5 pin of AD620 Pin 6 of AD620 is connected to telemetry ground via resistor R10, pin 7 of AD620 is connected to +12V telemetry power supply via resistor R9, pin 7 of AD620 is connected to + telemetry ground via two series capacitors C3 and C4, Pin 1 and pin 8 of AD620 are connected through resistor R8, -12V telemetry power supply is connected to telemetry ground through two series capacitors C1 and C2, the cathode of diode D1 is connected to pin 6 of AD620 through resistor R11, and the anode of diode D1 is connected to telemetry ground, the capacitor C5 is connected in parallel between the cathode and the anode of the diode D1, and the cathode voltage of the diode D1 is the output value of the battery cell voltage sampling circuit;

The temperature sensor is installed on the printed circuit board where the battery cell voltage sampling circuit is located, and is used to convert the temperature signal into an electrical signal. In this embodiment, the temperature sensor is a thermistor;

The temperature sampling circuit is connected with the temperature sensor to collect the output signal of the temperature sensor, and the working temperature of the battery cell voltage sampling circuit is collected through the temperature sensor and the temperature sampling circuit. In this embodiment, the temperature sampling circuit adopts the structure shown in Fig. After the voltage Vref is divided by resistors R3, R9 and thermistor Rtemp, it is sent to the voltage follower circuit, and the output value of the voltage follower circuit is sent to the proportional amplifier circuit to finally output the voltage value corresponding to the temperature;

The input of the temperature compensation module is the output value of the battery cell voltage sampling circuit and the collected temperature of the battery cell voltage sampling circuit, and the output is the compensation value of the battery cell voltage. The temperature compensation module is implemented by software. The output of the sampling circuit and the output of the temperature sampling circuit are used to calculate the accurate voltage compensation value of the battery cell by using the temperature compensation model.

The lithium-ion battery cell voltage sampling method of this embodiment, as shown in Figure 4, adopts the above-mentioned lithium-ion battery cell voltage sampling system, including the following steps:

A1, establish the temperature compensation model: V _s (T)=k (T) V+b (T), wherein V is the output voltage of the battery cell voltage sampling circuit, the present invention is also called the battery cell voltage sampling value, V _s (T) is the compensation value of the battery cell voltage, k(T) and b(T) are the coefficients of the temperature compensation model, when the battery cell voltage sampling circuit works at T ₀ =20°C, the battery cell voltage sampling The circuit obtains the battery cell voltage sampling value V ₀ , and obtains the sampling model coefficients k ₀ =k(T ₀ ), b ₀ =b(T ₀ ) at 20°C through linear fitting;

The coefficients k ₀ and b ₀ in step A1 are obtained through actual circuit testing and fitting to k ₀ =1.0024 and b ₀ =0.0036.

A2. Operate the battery cell voltage sampling circuit at different temperatures T ₁ ; T ₂ ;...; T _n , the above temperatures are collected by the temperature sensor and the temperature sampling circuit, and use linear fitting to respectively fit the sampling mathematics at different temperatures Coefficients of the model k ₁ , b ₁ ; k ₂ , b ₂ ; . . . ; k _n , b _n ;

The different test temperatures in step A2 are T ₁ =-25°C; T ₂ =-20°C; T ₃ =-15°C; T ₄ =-10°C; T ₅ =-5°C; T ₆ =0°C; ₇ =5°C; T ₈ =10°C; T ₉ =15°C; T ₁₀ =25°C; T ₁₁ =30°C; T ₁₂ =35°C; T ₁₃ =40°C; T ₁₄ =45°C; T ₁₅ = 50°C; T ₁₆ = 55°C; T ₁₇ = 60°C; T ₁₈ = 65°C; T ₁₉ = 70°C, the fitting k coefficients are as follows: k ₁ =1.0022; k ₂ =1.0022; k ₃ =1.0022; k ₄ = 1.0022; k ₅ = 1.0023; k ₆ = _1.0023 ; k ₇ = _1.0023 ; k ₈ = _1.0023 ; k ₉ = _1.0023 ; ₁₄ = 1.0025; k ₁₅ = 1.0025; k ₁₆ = 1.0025; k _{17 =} 1.0025; _{k 18 = 1.0026} ; b ₄ = _0.0138 ; b ₅ = _0.0121 ; b ₆ = _0.0104 ; b ₇ =0.0087; b ₈ = _0.0070 ; b ₉ =0.0053; -0.0031; b ₁₄ =-0.0048; b ₁₅ =-0.0065; b ₁₆ =-0.0082; b ₁₇ =-0.0099; b ₁₈ =-0.0116; b ₁₉ =-0.0133.

A3. According to {T ₁ ; T ₂ ;...; T _n } and {k ₁ ; k ₂ ;...; k _n } in A2, establish the relationship between k coefficient and temperature k(T)=k ₀ +f _k ( T), where k ₀ is the k coefficient at 20°C, f _k (T) is a function of temperature, and k(T) is the k coefficient under the condition of temperature T;

The relational expression of k coefficient and temperature in described step A3 is as follows:

k(T)＝1.0024+0.000004T-0.000121 (1)

A4. According to {T ₁ ; T ₂ ;...; T _n } and {b ₁ ; b ₂ ;...; b _n } in A2, establish the relationship between b coefficient and temperature b(T)=b ₀ +f _b ( T), where b ₀ is the b coefficient at 20°C, f _b (T) is a function of temperature, and b(T) is the b coefficient under the condition of temperature T;

The relational expression of b coefficient and temperature in described step A4 is as follows:

b(T)＝0.0036-0.000339T+0.006819 (2)

A5. When k(T) and b(T) are determined, the temperature compensation model V _s (T)=k(T)V+b(T) is determined, where V _s (T) is the battery cell voltage Sampling compensation value, k(T) is the k coefficient under the condition of temperature T, that is, the first fitting coefficient, b(T) is the b coefficient under the condition of temperature T, that is, the second fitting coefficient, and V is the battery cell voltage The sampling circuit samples the value (that is, the output value of the sampling circuit).

The temperature compensation model after fitting in step A5 is as follows:

V _s =[1.0024+0.000004T-0.000121]V _o +[0.0036-0.000339T+0.006819] (3)

A6. Use software to implement the temperature compensation model in A5. According to the output V of the battery cell voltage sampling circuit and the output value T of the temperature acquisition circuit, the accurate battery cell voltage compensation value can be output by the temperature compensation model formula (3).

The above k(T) and b(T) are related to the specific component settings of the battery cell voltage sampling circuit.

The sampling system has good temperature adaptability, can ensure the sampling accuracy of battery cell voltage in a relatively large temperature range, and overcomes the problem that the sampling accuracy of lithium-ion battery cell voltage for satellites is greatly affected by temperature.

The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent replacements, modifications or improvements can be made to the technical solutions and implementations of the present invention, all of which fall within the scope of the present invention. The protection scope of the present invention shall be determined by the appended claims.

The content that is not described in detail in the description of the present invention belongs to the well-known technology of those skilled in the art.

Claims (10)

1. A lithium-ion battery cell voltage sampling method, characterized in that, comprising: Temperature compensation model fitting stage: Establishing a temperature compensation model, the temperature compensation model is a fitting model expressing the relationship between the battery cell voltage sampling circuit temperature, the battery cell voltage sampling value and the battery cell voltage compensation value; Let the temperature of the battery cell voltage sampling circuit be the test temperature T ₀ , T ₁ , T ₂ ,...,T _n ; Use the battery cell voltage sampling circuit to obtain the battery cell voltage sampling values V ₀ , V ₁ , V ₂ ,...,V _n at each test temperature when the actual value of the battery cell voltage is V _Z ; Based on V _Z , T ₀ , T ₁ , T ₂ ,..., T _n and V ₀ , V ₁ , V ₂ ,..., V _n determine the fitting coefficients in the temperature compensation model, and complete the fitting of the temperature compensation model; n is an integer greater than 2; Real working stage: Obtain the working temperature T of the battery cell voltage sampling circuit and the battery cell voltage sampling value V; Substitute the working temperature T of the battery cell voltage sampling circuit and the battery cell voltage sampling value V into the fitted temperature compensation model to obtain the battery cell voltage compensation value at the working temperature T of the battery cell voltage sampling circuit. 2. a kind of lithium-ion battery cell voltage sampling method according to claim 1, is characterized in that, temperature compensation model is V _s (T)=k (T) V+b (T), wherein V _s (T ), k(T), b(T) are the battery cell voltage compensation value, the first fitting coefficient and the second fitting coefficient when the working temperature of the battery cell voltage sampling circuit is T, respectively. 3. A method for sampling the voltage of a lithium-ion battery cell according to claim 2, wherein the standard test temperature _T0 is any temperature point within the range of -25°C to 70°C. 4. a kind of lithium-ion battery cell voltage sampling method according to claim 1, is characterized in that, the true value of battery cell voltage is

m≥2; where v ₁ ,..., v _m are the real voltage values of different battery cells; Sampling value of battery cell voltage at each test temperature

0≤i≤n, where v _i1 , ..., v _im are the sampling values of the battery cell voltage corresponding to the actual voltage v ₁ , ..., v _m of the battery cell at the test temperature T _i . 5. A lithium-ion battery cell voltage sampling method according to claim 1, characterized in that based on V _Z , T ₀ , T ₁ , T ₂ ,..., T _n and V ₀ , V ₁ , V ₂ ,...,V _n Methods to determine the fitting coefficients in the temperature compensation model include: Substitute V ₀ into the temperature compensation model, and make V _s (T) equal to V _Z , to obtain k(T ₀ ) and b(T ₀ ); Substitute V ₁ , V ₂ ,…,V _n into the temperature compensation model respectively, and make V _s (T) equal to V _Z , to obtain k(T ₁ ), k(T ₂ ),…,k(T _n ) and b (T ₁ ),b(T ₂ ),…,b(T _n ); Determine k(T) according to k(T ₀ ), T ₁ , T ₂ ,...,T _n and k(T ₁ ), k(T ₂ ),...,k(T _n ); b(T) is determined from b(T ₀ ), T ₁ , T ₂ , . . . , T _n and b(T ₁ ), b(T ₂ ), . . . , b(T _n ). 6. The voltage sampling method of a lithium-ion battery cell according to claim 5, wherein, according to k(T ₀ ), T ₁ , T ₂ ,..., T _n and k(T ₁ ), k( T ₂ ),..., k(T _n ) determined k(T)=k ₀ +f _k (T), wherein, k ₀ =k(T ₀ ), f _k (T) is a function of temperature; b _{( T ) =} b _{0 + f b (} T ), where b ₀ =b(T ₀ ), f _b (T) is a function of temperature. 7. The voltage sampling method of a lithium-ion battery cell according to claim 1, wherein after sorting T ₀ , T ₁ , T ₂ ,..., T _n according to the order of high and low, between adjacent test temperatures The difference is 3 ~ 10 ℃. 8. A lithium-ion battery cell voltage sampling system, characterized in that, it is used to realize the lithium-ion battery cell voltage sampling method described in any one of claims 1-7, comprising a battery cell voltage sampling circuit, a temperature sampling module and temperature compensation module; The battery cell voltage sampling circuit is used to obtain the sampling value V of the battery cell voltage at the working temperature T, and output V to the temperature compensation module; The temperature sampling module is used to obtain the working temperature T of the battery cell voltage sampling circuit, and output the value of T to the temperature compensation module; The temperature compensation module is used to receive the fitted temperature compensation model input from the outside, the V input from the battery cell voltage sampling circuit, and the T input from the temperature sampling module, and substitute V and T into the fitted temperature compensation model The battery cell voltage compensation value at the working temperature T of the battery cell voltage sampling circuit is obtained. 9. The voltage sampling system of a lithium-ion battery cell according to claim 8, wherein the temperature sampling module comprises a temperature sensor and a temperature sampling circuit; The temperature sensor is installed on the printed circuit board where the battery cell voltage sampling circuit is located, and the temperature sampling circuit is used to collect the output signal of the temperature sensor. 10 . The voltage sampling system for a lithium-ion battery cell according to claim 9 , wherein the temperature sensor is a thermistor. 11 .

Images