CN113437334B - Vanadium ion concentration monitoring method, vanadium battery SOC monitoring method, equipment and medium - Google Patents

Abstract

The present invention provides a vanadium ion concentration monitoring method, a vanadium battery SOC monitoring method, equipment and medium; wherein, the vanadium ion concentration monitoring method comprises: obtaining the total initial concentration of vanadium ions in the vanadium battery; at a monitoring moment, Collect the liquid level information, potential information and temperature information of the positive and negative electrolytes respectively; at the same time, respectively collect positive and negative electrolyte samples of the same volume in the positive and negative electrolytes for mixing, and collect and mix The potential information and temperature information of the electrolyte sample; according to the total initial concentration of the vanadium ions, and the liquid position information, potential information, and temperature information of the positive and negative electrolytes, and the potential information and temperature information of the mixed electrolyte sample , the concentration information of various valence vanadium ions at the monitoring time can be obtained by constructing a system of equations to solve, so that the concentration of various valence vanadium ions at any monitoring time can be obtained quickly and conveniently.

Description

Vanadium ion concentration monitoring method, vanadium battery SOC monitoring method, equipment and medium

technical field

The invention belongs to the field of electrochemical energy storage, and relates to a vanadium ion concentration monitoring method in a vanadium battery, a vanadium battery SOC monitoring method, an electronic device and a computer storage medium.

Background technique

The all-vanadium redox battery is a redox battery with vanadium as the active material in a circulating liquid state. It stores electrical energy in vanadium ion solutions of different valence states. The charge-discharge process on the electrode surface. The positive electrolyte is composed of tetravalent vanadium ion V(IV) and pentavalent vanadium ion V(V) solution, and the negative electrode electrolyte is composed of divalent vanadium ion V(II) and trivalent vanadium ion V(III) solution.

Since the electrolyte of the vanadium battery is stored in the storage tanks of the positive and negative electrodes, it is convenient to monitor the state parameters such as the concentration, temperature and volume of the electrolyte. By obtaining various state parameters such as the concentration and temperature of the vanadium battery electrolyte, the state of charge (SOC) and battery capacity information of the vanadium battery can be obtained, and then the boundary condition information of the valence state of the electrolyte can be obtained.

At present, the commonly used methods for obtaining the concentration of various valence vanadium ions in vanadium batteries mainly include potentiometric titration, ultraviolet spectroscopy, etc.; however, these methods often require steps such as sampling, diluting solution and concentration detection, and the whole set of steps takes 2-3 hours, which does not meet the real-time requirements. Monitoring requires detection time, so it does not have the characteristics of real-time monitoring.

Therefore, how to automatically, accurately and efficiently obtain information on the concentration of vanadium ions in vanadium batteries has become an urgent technical problem to be solved in the art.

SUMMARY OF THE INVENTION

In view of the shortcomings existing in the above prior art, the purpose of the present invention is to provide a vanadium ion concentration monitoring method, a vanadium battery SOC monitoring method, an electronic device and a computer storage medium, which are used to solve the problem that any monitoring method cannot be quickly obtained in the prior art. Information on the concentration of vanadium ions in various valence states in vanadium batteries at different times.

In order to achieve the above object and other related objects, the present invention first provides a method for monitoring vanadium ion concentration in a vanadium battery, which is used to monitor the concentration of vanadium ions in the charging and discharging process of the vanadium battery, wherein the vanadium battery includes a positive and negative electrode storage unit, The positive and negative electrode storage units are respectively stored with positive and negative electrode electrolytes; wherein, the positive electrode electrolyte contains tetravalent and pentavalent vanadium ions; the negative electrode electrolyte contains divalent and trivalent vanadium ions; The vanadium ion concentration monitoring method comprises: obtaining the total initial concentration of vanadium ions in the vanadium battery; at a monitoring moment, collecting the liquid level information, potential information and temperature information of the positive and negative electrolytes respectively; In the positive and negative electrolytes, the positive and negative electrolyte samples of the same volume are respectively collected and mixed to obtain a mixed electrolyte sample, and the potential information and temperature information of the mixed electrolyte sample are collected; The total initial concentration, and the liquid position information, potential information, and temperature information of the positive and negative electrolytes, as well as the potential information and temperature information of the mixed electrolyte sample, are obtained by constructing equations and solving them at the monitoring time. Concentration information of valence vanadium ions.

In an embodiment of the present invention, the total volume of the electrolyte samples collected from the positive and negative electrolytes is not greater than 10‰ of the total volume of the positive and negative electrolytes at the monitoring time.

In an embodiment of the present invention, according to the total initial concentration of vanadium ions, and the liquid position information, potential information, temperature information of the positive and negative electrolytes, and the potential information of the mixed electrolyte sample and temperature information, by constructing a system of equations, the solution for obtaining the concentration information of each valence vanadium ion at the monitoring time includes: based on the total initial concentration of the vanadium ion and the liquid position of the positive and negative electrolytes information, construct the concentration equation of the positive and negative electrolytes; based on the potential information and temperature information of the positive electrolyte at the monitoring time, construct the Nernst equation of the positive electrolyte, and According to the potential information and temperature information of the negative electrolyte, the Nernst equation of the negative electrolyte is constructed; according to the potential information and temperature information of the mixed electrolyte sample at the monitoring time, the energy of the mixed electrolyte sample is constructed. Sterling equation; and, based on the comprehensive valence state of vanadium ions in the mixed electrolyte sample and the comprehensive valence state of the positive and negative electrolytes are the same, construct the comprehensive valence state equation of vanadium ions; The concentration equation of the polar electrolyte, the Nernst equation of the positive electrolyte, the Nernst equation of the negative electrolyte, the Nernst equation of the mixed electrolyte sample, and the comprehensive valence equation of the vanadium ion, Obtain the concentration information of each valence vanadium ion at the monitoring time.

In an embodiment of the present invention, the concentration equation of the positive and negative electrolytes is:

和

分别为所述监测时刻下所述二价钒离子、所述三价钒离子、所述四价钒离子和所述五价钒离子的浓度信息，D_p、D_n分别对应为所述监测时刻下正极和负极电解液的液位，

为所述钒电池中钒离子的总初始浓度；in,

and

are respectively the concentration information of the divalent vanadium ion, the trivalent vanadium ion, the tetravalent vanadium ion and the pentavalent vanadium ion at the monitoring time, and D _p and D _n are respectively the monitoring time Lower the level of the positive and negative electrolytes,

is the total initial concentration of vanadium ions in the vanadium battery;

The Nernst equation of the positive electrolyte is:

Wherein, E ⁺ is the potential of the positive electrode electrolyte at the described monitoring time; E ^θ(+) is the standard potential of the positive electrode electrolyte; T ⁺ is the temperature of the positive electrode electrolyte at the described monitoring time; R is the gas constant, 8.314J/(mol*K); F is Faraday's constant, 96485C/mol;

The Nernst equation of the negative electrolyte is:

Wherein, E ^- is the potential of the negative electrode electrolyte under the described monitoring moment; E ^{θ (-)} is the standard potential of the negative electrode electrolyte; T ^- is the temperature of the negative electrode electrolyte under the described monitoring moment;

The Nernst equation of the mixed electrolyte sample is:

为所述监测时刻下所述混合电解液中四价钒离子的浓度；

所述监测时刻下所述混合电解液中三价钒离子的浓度；Wherein, E' is the potential of the mixed electrolyte at the monitoring time; E ^θ(') is the standard potential of the mixed electrolyte at the monitoring time; T' is the standard potential of the mixed electrolyte at the monitoring time The temperature of the mixed electrolyte;

be the concentration of tetravalent vanadium ions in the mixed electrolyte under the monitoring time;

The concentration of trivalent vanadium ions in the mixed electrolyte at the monitoring time;

The comprehensive valence equation of the vanadium ion is:

Wherein, V _III ' is the concentration of trivalent vanadium ions in the mixed electrolyte at the monitoring time.

The present invention secondly provides a vanadium battery SOC monitoring method for obtaining the vanadium battery SOC value corresponding to the monitoring time in the vanadium ion concentration monitoring method; the vanadium battery SOC monitoring method comprises: using the vanadium ion concentration The monitoring method obtains the concentration of the vanadium ions in each valence state and the liquid level information of the positive and negative electrode electrolytes; obtain the relative amount of vanadium ions in each valence state; compare the relative amounts of the vanadium ions corresponding to the corresponding pairs of vanadium ions in the positive and negative electrolytes, and determine the calculation method of SOC based on the comparison results to obtain all the The SOC value of the vanadium battery at the monitoring time.

In an embodiment of the present invention, the relative amount of vanadium ions in each valence state is obtained based on the concentration of vanadium ions in each valence state and the liquid level information of the positive/negative electrode electrolyte containing the vanadium ions in each valence state The realization method includes: obtaining the relative amount of trivalent vanadium ions based on the concentration of the trivalent vanadium ions and the liquid level information of the positive electrode electrolyte; based on the concentration of the divalent vanadium ions and the liquid level of the positive electrode electrolyte information, obtain the relative amount of divalent vanadium ions; based on the tetravalent vanadium ion concentration and the liquid level information of the negative electrolyte, obtain the relative amount of tetravalent vanadium ions; and, based on the pentavalent vanadium ion concentration and the The liquid level information of the negative electrolyte is obtained to obtain the relative amount of pentavalent vanadium ions.

In an embodiment of the present invention, the comparison of the relative amounts of the vanadium ions corresponding to the vanadium ions in the positive and negative electrolytes, and determining the implementation of the SOC calculation method based on the comparison results, includes: comparing The relative amount of the trivalent vanadium ion and the relative amount of the tetravalent vanadium ion, and comparing the relative amount of the divalent vanadium ion and the relative amount of the pentavalent vanadium ion; when the relative amount of the trivalent vanadium ion is greater than The relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is greater than the relative amount of the pentavalent vanadium ion, the calculation method of SOC is:

When the relative amount of the trivalent vanadium ion is greater than the relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is not greater than the relative amount of the pentavalent vanadium ion, the calculation method of SOC is:

When the relative amount of the trivalent vanadium ion is not greater than the relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is greater than the relative amount of the pentavalent vanadium ion, the calculation method of SOC is:

When the relative amount of the trivalent vanadium ion is not greater than the relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is not greater than the relative amount of the pentavalent vanadium ion, the calculation method of SOC is:

Among them, K is the capacity conversion coefficient; S is the bottom area of the positive and negative electrode storage tanks, and the bottom area of the positive and negative electrode storage tanks is the same; D _p , D _n correspond to the liquid level of the positive electrode and the negative electrode electrolyte at the monitoring time, respectively bit; _CR is the actual electric capacity of the vanadium battery at the monitoring time; _CT is the theoretical electric capacity of the vanadium battery.

In an embodiment of the present invention, the vanadium battery SOC monitoring method further includes: obtaining a mixing time t required for mixing the positive and negative electrolyte samples into the mixed electrolyte sample; The charging and discharging power of the vanadium battery; the calculation method of the SOC is corrected based on the charging power.

The present invention further provides an electronic device, comprising: a memory for storing a computer program; a processor, connected in communication with the memory, and executing the vanadium ion concentration monitoring method when the computer program is invoked, and/or the Vanadium battery SOC monitoring method.

The present invention also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the vanadium ion concentration monitoring method and/or the vanadium battery SOC monitoring method.

As mentioned above, the vanadium ion concentration monitoring method, vanadium battery SOC monitoring method, electronic equipment and computer storage medium provided by the present invention, by collecting the potential information, temperature information and liquid level information of the positive and negative electrolytes at the monitoring time, During the collection, the positive and negative electrolytes are sampled and mixed respectively, and the potential information and temperature information of the mixed electrolyte samples are collected, so as to obtain the concentration of each valent vanadium ion at the monitoring time by constructing a plurality of equations. Compared with the existing method for obtaining the vanadium ion concentration in the charging and discharging process, the method of the present invention can conveniently and quickly obtain the concentration information of each valence vanadium ion at a certain monitoring time, which provides a basis and a method for monitoring the instantaneous state of the vanadium battery. convenient.

Description of drawings

FIG. 1 is a schematic diagram showing the structure of the vanadium battery in the present invention.

2 shows a schematic flow chart of the vanadium ion concentration monitoring method according to the present invention in one embodiment;

FIG. 3 is a schematic flowchart of the vanadium battery SOC monitoring method according to an embodiment of the present invention.

FIG. 4 shows a comparison result of the online and offline SOC values of the vanadium battery in one embodiment.

Detailed ways

The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments may be combined with each other under the condition of no conflict.

It should be noted that the drawings provided in the following embodiments are only used to illustrate the basic concept of the present invention in a schematic way, so the drawings only show the components related to the present invention rather than the number, shape and number of components in actual implementation. For dimension drawing, the type, quantity and proportion of each component can be changed at will in actual implementation, and the component layout may also be more complicated.

Example 1

In order to solve the technical problems existing in the prior art, the present invention provides a vanadium ion concentration monitoring method in Embodiment 1, which is used to monitor the vanadium ion concentration of each valence during the charging and discharging process of a vanadium battery.

In this embodiment, as shown in FIG. 1 , the vanadium battery includes a stack, a positive electrode storage unit, a negative electrode storage unit and a battery management unit; the battery stack is respectively connected to the positive electrode storage unit and the negative electrode storage unit; The positive and negative storage units are both connected to the battery management unit; and, the positive and negative storage units have the same shape, and store a positive electrolyte and a negative electrolyte respectively; wherein, the positive electrolyte contains four Valence and pentavalent vanadium ions; the negative electrolyte contains divalent and trivalent vanadium ions.

Please refer to FIG. 2 , which is a schematic flowchart of the vanadium ion concentration monitoring method in Example 1.

As shown in Figure 2, the vanadium ion concentration monitoring method comprises the following steps:

S11, obtaining the total initial concentration of vanadium ions in the vanadium battery;

即获取所述正极存储单元中所述四价钒离子和五价钒离子的总浓度，或者获取负极存储单元中所述二价钒离子和所述三价钒离子的总浓度。Specifically, before the vanadium battery is charged and discharged, the initial concentration of vanadium ions in the positive electrode or negative electrode storage unit is obtained

That is, the total concentration of the tetravalent vanadium ions and the pentavalent vanadium ions in the positive electrode storage unit is obtained, or the total concentration of the divalent vanadium ions and the trivalent vanadium ions in the negative electrode storage unit is obtained.

S12, at a monitoring moment, collect the liquid level information, potential information, and temperature information of the positive and negative electrolytes respectively;

Specifically, at a monitoring moment, the liquid level information D _p , the temperature information T ⁺ and the potential information E ⁺ of the positive electrode electrolyte are collected; and the liquid level information D _n and the temperature information T ⁻ of the negative electrode electrolyte are collected at the same time. and potential information E ^- .

S13, at the monitoring moment, collect and mix positive and negative electrolyte samples of the same volume in the positive and negative electrolytes, respectively, to obtain a mixed electrolyte sample, and collect potential information of the mixed electrolyte sample and temperature information;

Specifically, a positive electrolyte sample of a certain volume is collected from the positive electrolyte, and a negative electrolyte sample of the same volume is collected from the negative electrolyte, and the negative electrolyte sample and the positive electrolyte sample are collected. Mixing is performed to obtain a mixed electrolyte sample; and after the mixed electrolyte sample is obtained, the potential information E' and the temperature information T' of the mixed electrolyte sample are collected.

Optionally, in order to avoid the influence on the potential information, temperature information and liquid level information of the positive and negative electrolytes after sampling, the total volume of the electrolyte samples collected corresponding to the positive and negative electrolytes not greater than 10‰ of the total volume of the positive electrolyte and the negative electrolyte at the monitoring time; that is, the total volume of the positive electrolyte sample and the negative electrolyte sample collected is not greater than the monitoring time 10‰ of the total volume of the positive electrode electrolyte and the negative electrode electrolyte.

S14, based on the total initial concentration of the vanadium ions, the liquid level information, potential information and temperature information of the positive and negative electrolytes, and the potential information and temperature information of the mixed electrolyte sample, solve by constructing a system of equations Obtaining the vanadium ion concentration of each valence state in the vanadium battery at the monitoring time;

Specifically, according to the total concentration of vanadium ions at any time, the total concentration of vanadium ions is unchanged. Therefore, based on the total initial concentration of vanadium ions and the liquid level information of the positive and negative electrolytes at the monitoring time, the positive and negative electrolytes are constructed. The concentration equation of the liquid is:

和

分别为所述监测时刻下二价钒离子浓度、三价钒离子浓度、四价钒离子浓度和五价钒离子浓度，D_p、D_n分别对应为所述监测时刻下正极电解液液位和负极电解液液位，

为所述钒离子的总初始浓度；in,

and

are respectively the divalent vanadium ion concentration, the trivalent vanadium ion concentration, the tetravalent vanadium ion concentration and the pentavalent vanadium ion concentration at the monitoring time, and _Dp and _Dn are respectively corresponding to the positive electrolyte liquid level and Negative Electrolyte Level,

is the total initial concentration of the vanadium ion;

According to the potential information and temperature information of the positive electrolyte at the monitoring time, construct the Nernst equation of the positive electrolyte, and based on the potential information and temperature information of the negative electrolyte at the monitoring time, construct The Nernst equation of the negative electrolyte is:

Wherein, E ⁺ and E ^- are the potentials of the positive and negative electrolytes at the monitoring time, respectively; E ^θ(+) and E ^θ(-) are the standard potentials of the positive and negative electrolytes at the monitoring time, respectively , which can be obtained by querying the thermodynamic standard parameter table; T ⁺ , T ^- are the temperatures of the positive and negative electrolytes at the monitoring time; R is the gas constant, 8.314J/(mol*K); F is the Faraday constant, 96485C/ mol.

According to the potential information and temperature information of the mixed electrolyte sample at the monitoring time, the Nernst equation of the mixed electrolyte sample is constructed as:

为所述监测时刻下所述混合电解液中四价钒离子的浓度；

所述监测时刻下所述混合电解液中三价钒离子的浓度。Wherein, E' is the potential of the mixed electrolyte at the monitoring time; E ^θ(') is the standard potential of the mixed electrolyte at the monitoring time; T' is the standard potential of the mixed electrolyte at the monitoring time The temperature of the mixed electrolyte;

be the concentration of tetravalent vanadium ions in the mixed electrolyte under the monitoring time;

The concentration of trivalent vanadium ions in the mixed electrolyte at the monitoring time.

And, since the valence state of the mixed electrolyte after mixing is equal to the comprehensive valence state of the positive and negative electrode electrolytes before mixing, based on the comprehensive valence state of vanadium ions in the mixed electrolyte sample and the positive and negative electrode The comprehensive valence state of the electrolyte is the same, and the comprehensive valence state equation of vanadium ions is constructed as:

For ease of calculation, let:

From formula 2 and formula 3, it can be known that the values of k ₁ and k ₂ can be directly obtained by obtaining E ⁺ and E ⁻ ;

Similarly, let:

It can be seen from formula 4 that the value of k ₃ can be directly obtained by obtaining E′;

Substitute k ₁ , k ₂ and k ₃ , namely, the above formulas 6 to 8 into formula 5, then the above formula 5 is converted into the following formula, which is:

make:

Simplify Equation 5 as:

Substituting k ₁ and k ₂ into the first formula, converting Equation 1 to Equation 11, is:

Combined solution formula 10 and formula 11, obtained at the monitoring time, the concentration of divalent vanadium ions and the concentration of tetravalent vanadium ions are:

And, according to the concentration of described divalent vanadium ion and formula 7, obtain the concentration of described trivalent vanadium ion; And according to the concentration formula 8 of described tetravalent vanadium ion, obtain the concentration of described pentavalent vanadium ion, namely:

Thus, at the monitoring time, the concentration information of each valent vanadium ion in the vanadium battery, that is, the divalent vanadium ion concentration, the trivalent vanadium ion concentration, the tetravalent vanadium ion concentration and the pentavalent vanadium ion concentration are obtained.

In this embodiment, by collecting the potential information, temperature information and liquid level information of the positive and negative electrolytes at the monitoring time, the positive and negative electrolytes are sampled and mixed respectively during the collection, and the potentials of the mixed electrolyte samples are collected. information and temperature information, so as to obtain the concentration of each valent vanadium ion at the monitoring time by constructing a plurality of equations, compared with the existing method for obtaining the vanadium ion concentration in the charging and discharging process, the method of the present invention can be convenient, Quickly obtain the information on the concentration of vanadium ions of various valences at a certain monitoring time, which provides the basis and convenience for monitoring the instantaneous state of vanadium batteries; in addition, by obtaining the information on the concentration of vanadium ions, the comprehensive valence state of vanadium batteries at the monitoring time can be obtained , and then the deployment strategy of the electrolyte can be determined based on the comprehensive price attitude, so that the rapid recovery of the capacity of the vanadium battery can be achieved.

Example 2

Based on the description of the vanadium ion concentration monitoring method in Embodiment 1, the present invention provides a vanadium battery SOC monitoring method in this embodiment, based on the monitoring time obtained by the vanadium ion concentration monitoring method provided in Embodiment 1 and the liquid level information of the positive and negative electrolytes to obtain the SOC value of the vanadium battery at the monitoring time.

Wherein, the vanadium battery is the same as the vanadium battery described in Example 1, and details are not repeated here.

Please refer to FIG. 3 , which is a schematic flowchart of the vanadium battery SOC monitoring method in this embodiment.

As shown in Figure 3, the vanadium battery SOC monitoring method includes the following steps:

S21, utilize the vanadium ion concentration monitoring method of the present invention to obtain the vanadium ion concentration of each valence state and the liquid level information of the positive and negative electrolytes;

Wherein, the vanadium ion concentration monitoring method is the same as that in Example 1, and is not repeated here.

S22, based on the concentration of vanadium ions in each valence state and the liquid level information of the positive/negative electrode electrolyte containing the vanadium ions in each valence state, obtain the relative amounts of vanadium ions in each valence state;

In this embodiment, since the shape of the positive electrode storage unit and the negative electrode storage unit are the same, based on the vanadium ion concentration and the liquid level information of the positive electrode or negative electrode electrolyte containing the vanadium ion, the relative value of the vanadium ion is obtained. The amount of vanadium ions contained in the electrolyte per unit area of the positive electrode storage unit or the negative electrode storage unit.

Specifically, based on the trivalent vanadium ion concentration and the liquid level information of the positive electrode electrolyte, obtain the relative amount of trivalent vanadium ions; based on the divalent vanadium ion concentration and the liquid level information of the positive electrode electrolyte, obtain The relative amount of divalent vanadium ions; based on the concentration of tetravalent vanadium ions and the liquid level information of the negative electrolyte, the relative amount of tetravalent vanadium ions is obtained; based on the concentration of pentavalent vanadium ions and the liquid level of the negative electrolyte bit information to obtain the relative amount of pentavalent vanadium ions.

S23, compare the magnitude of the relative amount of the vanadium ions corresponding to the vanadium ions in the positive and negative electrolytes, and determine the vanadium ion pairing state of the vanadium battery based on the comparison result; based on the different vanadium ion pairing states, Determine the SOC calculation method to obtain the SOC value of the vanadium battery at the monitoring time.

In this embodiment, the tetravalent vanadium ions in the positive electrode electrolyte and the trivalent vanadium ions in the negative electrode electrolyte are matched to determine the discharge state of the vanadium battery, and the The pentavalent vanadium ions in the anode are paired with the divalent vanadium ions in the negative electrolyte to determine the state of charge of the vanadium battery. That is, when the vanadium battery is discharged, the amount of electricity that can be released depends on the molar amount of the divalent vanadium ion and the pentavalent vanadium ion, whichever is smaller. When the vanadium battery is charged, the amount of electricity that can be stored depends on the trivalent vanadium ion. The molar amount of vanadium ion and tetravalent vanadium ion is smaller.

Comparing the relative amount of the trivalent vanadium ion and the relative amount of the tetravalent vanadium ion, and comparing the relative amount of the divalent vanadium ion greater than the relative amount of the pentavalent vanadium ion, a comparison result is obtained.

When the relative amount of trivalent vanadium ions is greater than the relative amount of tetravalent vanadium ions, and when the relative amount of divalent vanadium ions is greater than the relative amount of pentavalent vanadium ions, the calculation method for determining SOC is:

When the relative amount of the trivalent vanadium ion is greater than the relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is not greater than the relative amount of the pentavalent vanadium ion, the calculation method for determining the SOC is:

When the relative amount of the trivalent vanadium ion is not greater than the relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is greater than the relative amount of the pentavalent vanadium ion, the calculation method for determining the SOC is:

When the relative amount of the trivalent vanadium ion is not greater than the relative amount of the tetravalent vanadium ion, and when the relative amount of the divalent vanadium ion is not greater than the relative amount of the pentavalent vanadium ion, the calculation method for determining the SOC is:

Among them, K is the capacity conversion coefficient; S is the bottom area of the positive and negative electrode storage tanks, and the bottom area of the positive and negative electrode storage tanks is the same; D _p , D _n correspond to the liquid level of the positive electrode and the negative electrode electrolyte at the monitoring time, respectively bit; _CR is the actual electric capacity of the vanadium battery at the monitoring time; _CT is the theoretical electric capacity of the vanadium battery.

It should be noted that when performing the monitoring of the vanadium ion concentration, it takes a certain time for the positive and negative electrolytes to be sampled and mixed, and a certain amount of electricity will change due to charging and discharging during this time, which will affect the vanadium battery. The calculation accuracy of SOC has a certain influence; therefore, in order to improve the accuracy of the SOC calculation of the vanadium battery, further, the vanadium battery SOC monitoring method further includes:

Obtain the mixing time t required to mix the positive and negative electrolyte samples into the mixed electrolyte sample; obtain the charge and discharge capacity of the vanadium battery within the mixing time; calculate the SOC based on the charge capacity way to correct.

Specifically, the SOC is corrected as follows:

Wherein, v is the charge and discharge capacity of the vanadium battery during the mixing time.

Optionally, the method for obtaining the charge and discharge power of the vanadium battery within the mixing time includes: obtaining the mixing time t required for mixing the positive and negative electrolyte samples into the mixed electrolyte sample; obtaining the The charging and discharging current of the vanadium battery within the mixing time t and the number of cells in the stack in the vanadium battery; based on the mixing time t, the charging and discharging current and the number of cells in the stack, calculate the The charge and discharge capacity of the vanadium battery within the mixing time is:

Wherein, N is the number of cells of the stack in the vanadium battery; I is the charging and discharging current of the vanadium battery, charging is positive and discharging is negative; t is the mixing time.

In order to verify the beneficial effects of the vanadium ion concentration monitoring and the vanadium battery SOC monitoring method provided by the present invention, comparative experiments were carried out. The experiment is as follows: a vanadium battery is used, and the vanadium battery is charged with a constant current of 80A. Among them, the vanadium battery includes 20 stack cells, the cell discharge midpoint voltage is 1.25V, the rated current is 80A, and the rated power is 2kW; both positive and negative storage units use storage tanks with a volume of about 110L and a storage tank size of φ450×h700; the initial state of the electrolyte is: the volume of the positive and negative electrolytes is 85L, the initial concentration of the positive electrolyte [V ⁴⁺ ]=1.7mol/L, and the initial temperature is 23°C.

This vanadium battery adopts the vanadium ion concentration monitoring method of the present invention (hereinafter referred to as online monitoring) and the offline monitoring method (hereinafter referred to as offline monitoring) to monitor the concentration of vanadium ions, so as to obtain the online value and offline value of each valence vanadium ion concentration respectively. value, and the SOC value is calculated by the vanadium battery SOC monitoring method and the potentiometric titration method according to the present invention based on the online value and the offline value, respectively.

Wherein, the off-line method is to collect samples correspondingly in the positive and negative electrolytes according to the traditional method at the monitoring time, and use a chemical experimental device to monitor the concentration of vanadium ions in each valence state respectively.

In order to facilitate the test, the vanadium battery was charged and discharged with a constant current, and the on-line values (E+(V), E-(V), E'(V) were obtained by online monitoring of the electrolyte at different time points based on the concentration monitoring device. ), T+(℃), T-(℃), T'(℃), Dp(m) and Dn(m)), and the positive and negative electrolytes were sampled at the corresponding time, and the samples were monitored offline to obtain Offline value: Calculate the on-line value and off-line value of SOC based on the on-line value and off-line value respectively, and compare the degree of agreement between the SOC on-line value and the SOC off-line value to judge the accuracy of the method described in the patent of the present invention.

It should be noted that the vanadium ion concentration monitoring method and the vanadium battery SOC monitoring method of the present invention are not only applicable to the charge-discharge process of the vanadium battery under the constant current mode, but also to the charge-discharge process under the non-constant current mode.

Wherein, the online data and soc calculation results collected by the online monitoring method are as shown in Table 1,

Table 1 Online monitoring parameters and SOC calculation results

The offline data collected by the offline monitoring method is extremely soc calculation results, as shown in Table 2.

Table 2 Vanadium ion concentration offline analysis value and SOC calculation value

Acquisition time [V²⁺] [V³⁺] [V⁴⁺] [V⁵⁺] SOC (offline value) 10min 0.106 1.599 1.595 0.104 6.2% 20min 0.203 1.504 1.490 0.212 12.3% 30min 0.327 1.388 1.383 0.342 19.6% 40min 0.455 1.273 1.279 0.457 26.0% 50min 0.591 1.133 1.136 0.598 33.9% 60min 0.705 1.031 1.024 0.693 39.3% 70min 0.821 0.924 0.897 0.830 46.2% 80min 0.945 0.786 0.786 0.934 53.0% 90min 1.085 0.630 0.627 1.083 61.8% 100min 1.203 0.511 0.502 1.221 69.1% 110min 1.290 0.417 0.425 1.313 74.6% 120min 1.410 0.318 0.301 1.423 80.6% 130min 1.292 0.419 0.423 1.297 74.3% 140min 1.211 0.525 0.507 1.218 68.6% 150min 1.081 0.640 0.629 1.086 61.6% 160min 0.937 0.776 0.776 0.940 53.6% 170min 0.808 0.908 0.895 0.814 46.3% 180min 0.700 1.017 1.020 0.699 40.0% 190min 0.580 1.124 1.123 0.591 34.0% 200min 0.451 1.269 1.275 0.454 26.1% 210min 0.328 1.392 1.387 0.328 19.0% 220min 0.218 1.500 1.492 0.231 13.5% 230min 0.105 1.593 1.620 0.107 6.5% 240min 0.065 1.644 1.644 0.065 4.0%

The online value of SOC and the offline value of SOC are compared, and the results are shown in Figure 4. It can be seen from Figure 4 that the online value of SOC and the offline value of SOC are basically consistent, indicating that the online monitoring value of SOC is reliable. reliable data.

Example 3

The present invention provides an electronic device in this embodiment, and the electronic device includes: a processor, a memory, and a display. Wherein, the memory stores a computer program; the processor is connected in communication with the memory, and when the computer program is invoked, the method for monitoring the SOC of the vanadium battery of the present invention is executed, and/or the method for monitoring the SOC of the vanadium battery of the present invention .

The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU for short), a network processor (NP for short), etc.; it may also be a digital signal processor (Digital Signal Processing, DSP for short) , Application Specific Integrated Circuit (ASIC for short), Field Programmable Gate Array (FPGA for short) or other programmable logic devices, discrete gate or transistor logic devices, and discrete hardware components.

Example 4

The present invention also provides a computer-readable storage medium on which a computer program is stored, and when the program is called by a processor, the method for monitoring the SOC of the vanadium battery of the present invention and/or the SOC of the vanadium battery of the present invention is implemented. Ion concentration monitoring method. The computer-readable storage medium may include random access memory (Random Access Memory, RAM for short), and may also include non-volatile memory (non-volatile memory), such as at least one disk storage.

To sum up, the vanadium ion concentration monitoring method, vanadium battery SOC monitoring method, electronic device and medium provided by the present invention collect the potential information, temperature information and liquid level information of the positive and negative electrolytes, and simultaneously monitor the positive and negative electrolytes. The electrolyte is sampled and mixed separately, and the potential information and temperature information of the mixed electrolyte sample are collected, so that the obtained concentration of vanadium ions can be calculated by constructing multiple equations. Compared with the concentration of vanadium ions in the existing charging and discharging process According to the acquisition method, the concentration information of various valence vanadium ions at the monitoring time can be obtained conveniently and quickly; Relative quantity, determine the vanadium ion pairing state of the vanadium battery at the monitoring time, and determine the corresponding SOC calculation method based on the pairing state, so as to obtain the SOC value of the vanadium battery at the monitoring time, which can conveniently and quickly obtain the SOC value at the monitoring time. Therefore, the SOC obtained based on the existing current integration method can be corrected, so that the accuracy of the SOC of the vanadium battery can be improved.

The above-mentioned embodiments merely illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can make modifications or changes to the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed in the present invention should still be covered by the claims of the present invention.

Claims (9)

1. The vanadium ion concentration monitoring method is characterized by being used for monitoring the concentration of each vanadium ion in the charging and discharging process of a vanadium battery, wherein the vanadium battery comprises positive and negative electrode storage units, the positive and negative electrode storage units are identical in shape and respectively store positive and negative electrolyte correspondingly; wherein the positive electrolyte contains tetravalent and pentavalent vanadium ions; the cathode electrolyte contains divalent and trivalent vanadium ions; the vanadium ion concentration monitoring method comprises the following steps:

acquiring the total initial concentration of vanadium ions in the vanadium redox battery;

respectively acquiring liquid level information, potential information and temperature information of the positive and negative electrolytes at a monitoring moment; meanwhile, collecting positive and negative electrolyte samples with the same volume in the positive and negative electrolytes respectively and correspondingly, mixing to obtain a mixed electrolyte sample, and collecting potential information and temperature information of the mixed electrolyte sample;

obtaining concentration information of each valence vanadium ion at the monitoring moment by constructing equation group calculation according to the total initial concentration of the vanadium ions, the liquid position information, the potential information and the temperature information of the positive and negative electrolytes, and the potential information and the temperature information of the mixed electrolyte sample, wherein the concentration information comprises;

constructing a concentration equation of the positive electrolyte and the negative electrolyte based on the total initial concentration of the vanadium ions and the liquid level position information of the positive electrolyte and the negative electrolyte;

constructing a Nernst equation of the positive electrolyte based on the potential information and the temperature information of the positive electrolyte at the monitoring moment, and constructing a Nernst equation of the negative electrolyte based on the potential information and the temperature information of the negative electrolyte at the monitoring moment;

constructing a Nernst equation of the mixed electrolyte sample according to the potential information and the temperature information of the mixed electrolyte sample at the monitoring moment; and the number of the first and second groups,

constructing a vanadium ion comprehensive valence equation based on that the comprehensive valence of vanadium ions in the mixed electrolyte sample is the same as the comprehensive valence of the positive and negative electrolytes;

and obtaining the concentration information of each valence of vanadium ions at the monitoring moment by combining and calculating the concentration equation of the positive electrolyte and the negative electrolyte, the Nernst equation of the positive electrolyte, the Nernst equation of the negative electrolyte, the Nernst equation of the mixed electrolyte sample and the vanadium ion comprehensive valence equation.

2. The method for monitoring the concentration of vanadium ions according to claim 1, wherein the total volume of the electrolyte samples collected from the positive and negative electrolytes is not more than 10% o of the total volume of the positive and negative electrolytes at the monitoring time.

3. The method for monitoring the concentration of vanadium ions according to claim 1, wherein the concentration equation of the positive and negative electrolytes is as follows:

wherein,

and

the concentrations of the divalent vanadium ion, the trivalent vanadium ion, the tetravalent vanadium ion and the pentavalent vanadium ion at the time of the monitoring are respectivelyInformation, D_p、D_nRespectively corresponding to the liquid levels of the positive electrolyte and the negative electrolyte at the monitoring moment,

is the total initial concentration of vanadium ions in the vanadium battery;

the nernst equation of the positive electrode electrolyte is as follows:

wherein E is⁺The potential of the positive electrode electrolyte at the monitoring moment; e^θ(+)Is the standard potential of the positive electrolyte; t is a unit of⁺The temperature of the positive electrolyte at the monitoring moment is used as the temperature of the positive electrolyte; r is the gas constant, 8.314J/(mol × K); f is Faraday constant, 96485C/mol;

the nernst equation of the negative electrode electrolyte is as follows:

wherein E is^-The potential of the negative electrode electrolyte at the monitoring moment is obtained; e^θ(-)Is the standard potential of the negative electrolyte; t is^-The temperature of the negative electrode electrolyte at the monitoring moment is obtained;

the nernst equation of the mixed electrolyte sample is as follows:

wherein E' is the potential of the mixed electrolyte at the monitoring time; e^θ(′)The standard potential of the mixed electrolyte at the monitoring moment; t' the temperature of the mixed electrolyte at the monitoring moment;

the concentration of tetravalent vanadium ions in the mixed electrolyte at the monitoring moment is obtained;

the concentration of trivalent vanadium ions in the mixed electrolyte is monitored at the moment;

the vanadium ion comprehensive valence equation is as follows:

wherein, V_III' the concentration of trivalent vanadium ions in the mixed electrolyte at the time of the monitoring.

4. A vanadium battery SOC monitoring method, characterized by being used for obtaining a vanadium battery SOC value corresponding to the monitoring time in the vanadium ion concentration monitoring method according to any one of claims 1 to 3; the method for monitoring the SOC of the vanadium redox battery comprises the following steps:

acquiring the concentration of vanadium ions in each valence state and the liquid level information of the positive and negative electrolytes by using the vanadium ion concentration monitoring method in any one of claims 1 to 3;

obtaining the relative amount of each valence state vanadium ion based on the concentration of each valence state vanadium ion and the liquid level information of the positive/negative electrode electrolyte containing each valence state vanadium ion;

and comparing the relative quantity of the vanadium ions corresponding to the paired vanadium ions in the positive and negative electrolytes, and determining an SOC calculation method based on the comparison result to obtain the SOC value of the vanadium battery at the monitoring moment.

5. The method for monitoring the SOC of the vanadium redox battery as claimed in claim 4, wherein the obtaining of the relative amount of the vanadium ions in each valence state based on the concentration of the vanadium ions in each valence state and the liquid level information of the positive/negative electrode electrolyte containing the vanadium ions in each valence state comprises:

obtaining the relative amount of the trivalent vanadium ions based on the concentration of the trivalent vanadium ions and the liquid level information of the anode electrolyte;

obtaining the relative amount of divalent vanadium ions based on the divalent vanadium ion concentration and the liquid level information of the anode electrolyte;

obtaining the relative amount of the tetravalent vanadium ions based on the concentration of the tetravalent vanadium ions and the liquid level information of the cathode electrolyte; and the number of the first and second groups,

and obtaining the relative amount of the pentavalent vanadium ions based on the pentavalent vanadium ion concentration and the liquid level information of the cathode electrolyte.

6. The method for monitoring the SOC of the vanadium redox battery according to claim 5, wherein the implementation of the calculation method for determining the SOC based on the comparison result by comparing the relative amounts of the vanadium ions corresponding to the paired vanadium ions in the positive and negative electrolytes comprises:

comparing the relative amount of trivalent vanadium ions with the relative amount of tetravalent vanadium ions, and comparing the relative amount of divalent vanadium ions with the relative amount of pentavalent vanadium ions;

when the relative amount of the trivalent vanadium ions is larger than the relative amount of the tetravalent vanadium ions and when the relative amount of the divalent vanadium ions is larger than the relative amount of the pentavalent vanadium ions, the SOC is calculated as follows:

when the relative amount of the trivalent vanadium ions is larger than the relative amount of the tetravalent vanadium ions and when the relative amount of the divalent vanadium ions is not larger than the relative amount of the pentavalent vanadium ions, the SOC is calculated as follows:

when the relative amount of the trivalent vanadium ions is not more than the relative amount of the tetravalent vanadium ions and when the relative amount of the divalent vanadium ions is more than the relative amount of the pentavalent vanadium ions, the SOC is calculated by:

when the relative amount of the trivalent vanadium ions is not more than the relative amount of the tetravalent vanadium ions and when the relative amount of the divalent vanadium ions is not more than the relative amount of the pentavalent vanadium ions, the SOC is calculated by:

wherein K is a capacity conversion coefficient; s is the bottom areas of the positive and negative storage tanks, and the bottom areas of the positive and negative storage tanks are the same; d_p、D_nRespectively corresponding to the liquid levels of the positive electrolyte and the negative electrolyte at the monitoring moment; c_RThe actual capacitance of the vanadium redox battery at the monitoring moment is obtained; c_TIs the theoretical capacity of the vanadium battery.

7. The vanadium battery SOC monitoring method according to claim 6, further comprising: obtaining the mixing time t required for mixing the positive electrolyte sample and the negative electrolyte sample into the mixed electrolyte sample; acquiring the charge and discharge electric quantity of the vanadium battery within the mixing time; and correcting the calculation mode of the SOC based on the charging electric quantity.

8. An electronic device, comprising:

a memory for storing a computer program;

a processor, communicatively connected to the memory, for executing the vanadium ion concentration monitoring method according to any one of claims 1 to 3 and/or the vanadium battery SOC monitoring method according to any one of claims 4 to 7 when the computer program is invoked.

9. A computer readable storage medium having stored thereon a computer program, wherein the computer program, when executed by a processor, implements the vanadium ion concentration monitoring method according to any one of claims 1 to 3 and/or the vanadium battery SOC monitoring method according to any one of claims 4 to 7.

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