Carbon cloth texture method for improving electrical performance of carbon cloth

Abstract

The present application relates to carbon cloth texture technical field, specifically discloses a kind of carbon cloth texture method for improving the electrical performance of carbon cloth, by simulating related structure phase and organizational structure, to improve the electrical performance of carbon cloth in iron-chromium flow battery as purpose, by designing organizational structure, change structure phase to obtain preferred organizational scheme, and produce the carbon cloth organization used for iron-chromium flow battery performance verification.The organizational structure obtained by simulation in the present application, the groove between warp and weft yarn interlacing point and float long line increases, so that the contact area of electrolyte and carbon cloth increases, reduces the charge transfer resistance of carbon cloth defect site, improves the electronic conductivity of electrolyte in flow battery, improves the mechanical properties of carbon cloth in electrolyte, reduces fluid resistance.The present application limits the organizational structure of carbon cloth, warp and weft yarn, weaving parameter variable and other factors by simulation law, verifies the carbon cloth configured by the present application, and it is found that the carbon cloth can effectively improve the electrical performance in battery after verification.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon cloth texture, and particularly relates to a carbon cloth texture method for improving the electrical performance of carbon cloth. BACKGROUND

[0002] Iron-chromium flow battery has good industrialization and market application prospects in the emerging field of flow battery energy storage due to its lower cost and better environmental friendliness. The research of iron-chromium flow battery mainly focuses on three key materials, including electrode material, electrolyte and ion exchange membrane.

[0003] The mainstream electrode material is carbon-based material, such as carbon fiber felt, carbon cloth, carbon paper, etc. Compared with carbon paper and carbon fiber felt, carbon cloth has relatively ordered fiber arrangement, extensive pore distribution, larger pore size, lower bending degree, higher permeability, lower flow resistance and lower pumping loss, so carbon cloth is a more widely used electrode material. At present, the research on electrode material is mainly the modification of electrode material, such as oxidation modification and catalyst modification, aiming to improve the hydrophilicity and electrochemical activity of the electrode to improve the performance of the battery. However, there is less research on the structure of carbon cloth. According to the structural characteristics of the carbon cloth electrode, the arrangement and number of interlacing points between the warp and weft yarns will affect the charge transfer resistance and electron conductivity of the carbonized carbon cloth. The porosity, pore size and permeability of the carbon cloth also affect the performance of the battery. Therefore, studying the influence factors of the structure of carbon cloth on the performance of the battery has profound significance for in-depth exploration of electrode materials and acceleration of the industrialization development of iron-chromium flow battery. SUMMARY

[0004] To solve the problems in the prior art, the present application provides a carbon cloth texture method for improving the electrical performance of carbon cloth. The simulation of related structure phase and organization structure is used to improve the electrical performance of carbon cloth in iron-chromium flow battery. The optimal organization scheme is obtained by designing the organization structure and changing the structure phase, and the carbon cloth organization is produced for performance verification of iron-chromium flow battery. In the present application, the number of grooves between the interlacing points of warp and weft yarns and the floating threads is increased by simulation, thereby increasing the contact area between the electrolyte and the carbon cloth, reducing the charge transfer resistance of the defect site of the carbon cloth, improving the electron conductivity of the electrolyte in the flow battery, improving the mechanical properties of the carbon cloth in the electrolyte, reducing the fluid resistance, and finally improving the electrical performance of the carbon cloth in the battery. The present application limits the organization structure, weaving parameters and other aspects of the organization. The change factors of the fabric organization structure include the fineness of warp and weft yarns, the twist of warp and weft yarns, and the tightness of weaving, etc. The problems mentioned in the background technology are solved.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a carbon cloth texture method for improving the electrical performance of carbon cloth, comprising the following steps:

[0006] S1, simulation is carried out with the performance of carbon cloth as the target;

[0007] S2, the structure is designed according to the simulation simulation rule result, and the organization design is drawn;

[0008] S3, based on the organization design, the carbon cloth structure is completed by the loom using warp and weft yarns and weaving parameters.

[0009] Preferably, in step S1, the performance of the carbon cloth includes the electronic conductivity, charge transfer resistance, liquid flow resistance and surface area of the carbon cloth.

[0010] Preferably, in step S1, the simulation includes the following:

[0011] S11, a geometric model is established based on the base structure, and a grid is divided to form a calculation model;

[0012] The base structure is plain weave, twill weave, satin weave; a geometric model is established according to the structure phase and warp and weft yarn interlacing characteristics of the three base structures respectively, and a grid is divided to form a simulation calculation model;

[0013] S12, define the physical field and material properties, set the boundary conditions, simulation parameters and the size of the working space;

[0014] The set physical field is the multi-physical field coupling field of fluid, structure and current, and the set boundary conditions and simulation parameters include but are not limited to fluid resistance, pressure drop, current density and liquid flow mode;

[0015] S13, change the structure phase condition, solve the model and obtain the simulation rule;

[0016] The changed structure phase condition refers to changing the arrangement and number of interlacing points under the condition of warp and weft yarn interlacing of the base structure; through comparison of multiple simulation data, the rule of the change of the structure phase, warp and weft yarn interlacing point arrangement and number is obtained.

[0017] Preferably, in step S2, the simulation simulation rule is: 1) the more the warp and weft yarn interlacing points, the more the parallel formed by the potential points on the carbon cloth, the smaller the charge transfer resistance, the greater the electronic conductivity, and the better the electrical performance of the carbon cloth; 2) the more the gullies / grooves between the interlacing points and the floating lines, the greater the contact area between the electrolyte and the carbon cloth, the lower the fluid resistance of the electrolyte, the greater the surface area of the carbon cloth, and the electrolyte reaction sites will be randomly increased after carbonization and activation, improving the electrical performance of the carbon cloth in the battery.

[0018] Through simulation and analog computation on the basic structure and the change of the related structure, it is concluded that the more the interlacing points increase, the more the parallel formed by the potential points on the carbon cloth, the smaller the charge transfer resistance, the greater the electron conductivity, and the better the electrical performance of the carbon cloth. Meanwhile, the more the interlacing points increase, the more the force acting on the inside of the carbon cloth, and the mechanical performance of the carbon cloth against the outside increases. Therefore, the designed structure increases the number of interlacing points by 40-150 structure points in a single structure cycle compared with the basic structure.

[0019] Through simulation and analog computation on the basic structure and the change of the related structure, it is concluded that the more the grooves between the interlacing points and the floating long lines, the greater the contact area of the electrolyte and the carbon cloth, and the better the electrical performance of the carbon cloth. When the carbon cloth is used in the iron-chromium flow battery, the carbonization stage will randomly give the carbon cloth different reaction sites. The greater the contact area of the electrolyte and the carbon cloth, the more the contact reaction sites, and the better the battery performance.

[0020] Preferably, in step S2, through simulation and analog computation on the basic structure and the change of the related structure, it is concluded that the increase of the interlacing points and the increase of the grooves in the structure will both improve the battery performance, but the factors will restrict each other. The increase of the grooves in a single structure will lead to the decrease of the interlacing points. Therefore, the designed structure is formed by two parts of the ground structure and the pattern structure. The ground structure is the plain weave structure, and the pattern structure is the jacquard structure, which adopts the knotless weaving method. The structure increases the interlacing points of the warp and weft yarns through the ground structure, and increases the grooves in the structure through the pattern structure. Different from the basic structures such as the plain weave and the twill in the market, the structure of the application has the innovation of the structure and the ability to improve the battery performance.

[0021] Preferably, in step S3, the parameters of the warp and weft yarns include the fineness, the twist, the number of the plied yarns and the double-twisted twist of the yarns; and the weaving parameters include the spring position affecting the tension on the loom, the shedding time and the beating-up time.

[0022] Preferably, the fineness of the warp and weft yarns ranges from 23.6 tex to 39.4 tex.

[0023] Preferably, the twist of the yarns ranges from 430 T / m to 617 T / m. The smaller the twist of the single yarn, the looser the yarn, and the smaller the hardness. At this time, the grooves formed by the warp and weft yarns in the fabric are obvious, and the permeability of the treated carbon cloth to the electrolyte is also higher.

[0024] Preferably, the number of the plied yarns ranges from 2 to 4.

[0025] Preferably, the double-twisted twist ranges from 140 T / m to 280 T / m. The smaller the double-twisted twist of the plied yarns in this range, the more dispersed the inlaying between the single yarns, the higher the weaving efficiency under the same weaving parameters, and the higher the permeability and flowability of the electrolyte.

[0026] Preferably, the spring position in the weaving parameter variable affecting the machine tension is 1-5 points, and the machine tension increases in turn.

[0027] Preferably, the opening time and beating-up time in the weaving parameter variable are changed according to the increase of the interlacing points of the weave, and the change range is 5°-25° of the conjugate camshaft. Specifically, the opening time is 305°-325°, and the beating-up time is 315°-355°.

[0028] The beneficial effects of the present application are:

[0029] 1) The present application provides a carbon cloth weaving method for improving the electrical performance of carbon cloth, specifically proposes the arrangement of the interlacing points of warp and weft yarns, the specifications of warp and weft yarns, and the weaving parameter variables for forming the weave, which can reduce the fluid resistance of the electrolyte in the flow battery, improve the permeability of the carbon cloth electrode, reduce the charge transfer resistance between the interlacing points in the carbon cloth, improve the electronic conductivity, and improve the electrical performance of the carbon cloth electrode.

[0030] 2) The present application enriches the carbon cloth weave structure and weaving method in the current market, optimizes the physical and electrical performance of carbon cloth in the flow battery, makes up for the short board of the current research on battery materials in the field of iron-chromium flow battery, increases the research on carbon cloth structure in this field, and helps to promote the development process of iron-chromium flow battery and accelerate the industrialization development of iron-chromium flow battery. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Part of the schematic diagram of the simulation model in the embodiment of the present application;

[0032] Figure 2 The schematic diagram of 20 times electron microscope observation of the weave of embodiment 3 of the present application;

[0033] Figure 3 The schematic diagram of 50 times electron microscope observation of the weave of embodiment 3 of the present application;

[0034] Figure 4 The schematic diagram of 50 times electron microscope observation of the weave of embodiment 4 of the present application;

[0035] Figure 5 The weave schematic diagram of comparative example 1 of the present application. DETAILED DESCRIPTION

[0036] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0037] Embodiment 1

[0038] Simulation is performed with the performance of carbon cloth as a target;

[0039] The simulation includes the following:

[0040] 1. A geometric model is established based on a basic weave, and a mesh is divided to form a calculation model, as shown in FIG. 1. Figure 1

[0041] The basic weave is a plain weave, a twill weave or a satin weave; a geometric model is established according to the structure phase and the interweaving characteristics of warp and weft yarns of the three basic weaves respectively, and a mesh is divided to form a simulation calculation model;

[0042] In this embodiment, a geometric model is established based on the plain weave in the basic weave.

[0043] 2. Physical fields and material properties are defined, and boundary conditions, simulation parameters and the size of a working space are set.

[0044] The physical fields set are the multi-physical field coupling fields of fluid, structure and current, and the boundary conditions and simulation parameters set include but are not limited to fluid resistance, pressure drop, current density and liquid flow mode.

[0045] 3. The structure phase condition is changed, the model is solved and a simulation rule is obtained;

[0046] The changed structure phase condition refers to changing the arrangement and number of interweaving points under the interweaving condition of warp and weft yarns of the basic weave; through comparison of multiple sets of simulation data, the rule of the change of the structure phase, the arrangement and number of interweaving points of warp and weft yarns is obtained.

[0047] In this embodiment, 20, 40 and 60 interweaving points of warp and weft yarns are randomly added to the model respectively, and 20, 40 and 60 interweaving points of warp and weft yarns are reduced respectively, the above steps are repeated, and the simulation rule is obtained through data comparison and statistics, as shown in Table 1.

[0048] Table 1: Data of various simulation changes in Embodiment 1

[0049] Interleaving point change +20 +40 +60 -20 -40 -60 Charge transfer resistance (Ω) -36.8％ -50.1％ -70.5％ +11.1％ +26.7％ +31.2％ Electrical conductivity (S / m) +89.5 +100.4％ +293％ -9.9％ -21.1％ -23.8％ Energy efficiency (%) +3.8％ +5.1％ +7.6％ -1.3％ -2.5％ -5.2％

[0050] Embodiment 2

[0051] Simulation is performed with the performance of carbon cloth as a target;​

[0052] The simulation includes the following:

[0053] 1. Establish a geometric model based on the base weave, and mesh division to form a calculation model;

[0054] The base weave is plain weave, twill weave, and satin weave; geometric models are established according to the structure phase and the interweaving characteristics of warp and weft yarns of the three base weaves, respectively, and mesh division is performed to form a simulation calculation model;

[0055] In this embodiment, a geometric model is established based on the base weave 2 / 1 twill weave.

[0056] 2. Define the physical field and material properties, set the boundary conditions, simulation parameters, and the size of the working space.

[0057] The physical field set is the multi-physical field coupling field of fluid, structure, and current, and the boundary conditions and simulation parameters set include but are not limited to fluid resistance, pressure drop, current density, and liquid flow pattern.

[0058] 3. Change the structure phase conditions, solve the model, and obtain the simulation law;

[0059] The changed structure phase conditions refer to changing the arrangement and number of interweaving points under the interweaving conditions of warp and weft yarns of the base weave; through comparison of multiple sets of simulation data, the law of the change of the structure phase, the arrangement of the interweaving points of warp and weft yarns, and the number of the interweaving points is obtained.

[0060] In this embodiment, 5, 10, and 15 ditches are randomly added to the model, and 5, 10, and 15 ditches are randomly reduced. The model size is centimeter level, and the ditch size is millimeter level. Repeat the above steps, and obtain the simulation law through data comparison and statistics, as shown in Table 2.

[0061] Table 2 Data of various simulation changes in Example 2

[0062] Gully number change +5 +10 +15 -5 -10 -15 Fluid resistance (F) -10.0％ -18.1％ -40.4％ +8.2％ +20.6％ +38.5％ Reaction area (mm 2 )]]> +0.75％ +1.5％ +2.25％ -0.75％ -1.5％ -2.25％ Energy efficiency (%) +1.3％ +3.6％ +5.6％ -2.2％ -4.5％ -7.9％

[0063] According to the analysis of Table 1 and Table 2, the increase of the interweaving points of warp and weft yarns and the increase of the number of ditches can improve the battery performance, the increase of the interweaving points can improve the electronic conductivity of the carbon cloth, the increase of the number of ditches can reduce the fluid resistance of the electrolyte, increase the surface area of the carbon cloth, and randomly increase the electrolyte reaction sites after carbonization and activation. Therefore, the organization design idea of the present application is to increase the interweaving points of warp and weft yarns through the ground weave and increase the ditches between the interweaving points and the floats through the pattern weave.

[0064] Example 3

[0065] The fabric of the present application is designed according to the rules obtained from the simulation. Preferably, the specifications of the warp and weft yarns are as follows: single yarn fineness 36.9 tex, single yarn twist 461 T / m, number of threads in the ply 4, and double-twisted twist 270 T / m. The fabric is woven according to the weave and production method of the present application, and the parameters during weaving are as follows: spring position 2 of the machine tension, shedding time 305°-320°, and beating-up time 315°-350°. The weave is shown in Fig. Figure 2 and Figure 3 The performance data of the carbon cloth produced in Example 3 after treatment in the test cell are shown in Table 3.

[0066] Table 3: Performance data of the cells of each example and the comparative example

[0067]

[0068] Example 4

[0069] The fabric of the present application is designed according to the rules obtained from the simulation. Preferably, the specifications of the warp and weft yarns are as follows: single yarn fineness 28.1 tex, single yarn twist 566 T / m, number of threads in the ply 4, and double-twisted twist 330 T / m. The fabric is woven according to the weave and production method of the present application, and the parameters during weaving are as follows: spring position 2 of the machine tension, shedding time 310°-325°, and beating-up time 320°-355°. The weave is shown in Fig. Figure 4 The performance data of the carbon cloth produced in Example 4 after treatment in the test cell are shown in Table 3.

[0070] Comparative Example 1

[0071] The plain weave in the basic weave is selected for production. Preferably, the specifications of the warp and weft yarns are as follows: single yarn fineness 59 tex, single yarn twist 365 T / m, number of threads in the ply 2, and double-twisted twist 290 T / m. The parameters during weaving are as follows: spring position 1 of the machine tension, shedding time 290°-305°, and beating-up time 300°-335°. The weave is shown in Fig. Figure 5 The performance data of the carbon cloth produced in Comparative Example 1 after treatment in the test cell are shown in Table 3.

[0072] The simulation process is a relatively ideal test condition, and the actual verification effect of the weave designed according to the simulation rules is shown in the performance data of Example 3 and Example 4 and Comparative Example 1 in Table 3.

[0073] According to the analysis in Table 1, the battery performance of the carbon cloth fabric woven according to the weave and production method of the present application in Examples 3-4 is better than that of the plain weave of Comparative Example 1 after treatment in the test cell.

[0074] In combination with the drawings and Tables 1-3, the tissue of the present application increases the grooves between the interlacing points and the float lines of the basic tissue, so that the contact area of the electrolyte and the carbon cloth is increased; the present application has more convex points, and the more parallel potential formed on the carbon cloth, the smaller the charge transfer resistance, and the greater the electronic conductivity of the carbon cloth; the more convex points of the present application, the more the mechanical force reaction component of the electrolyte acting on the carbon cloth, and the greater the impact resistance of the carbon cloth; the carbon cloth formed by the tissue of the present application can improve the battery performance.

[0075] In summary, the tissue and the texturing method of the present application can improve the electrical performance of the carbon cloth in the battery. The factors affecting the design of the tissue of the present application include the specifications of the yarns and the design of the tissue draft, etc. The factors affecting the texturing method of the present application include the design of the tissue and the weaving parameters, etc.

[0076] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made shall be included in the protection scope of the present application.

Claims

1. A carbon cloth texture method for improving the electrical performance of carbon cloth, characterized by, The method comprises the following steps: S1, simulation is performed with the performance of carbon cloth as the target; S2, the structure is designed according to the simulation law, and a weave design is drawn; S3, the carbon cloth structure is completed by a loom based on the weave design, warp and weft yarns and weaving parameters; In step S1, the performance of the carbon cloth includes the electronic conductivity, charge transfer resistance, liquid flow resistance and surface area of the carbon cloth; In step S1, the simulation includes the following: S11, a geometric model is established based on a base weave, and a grid is divided to form a calculation model; The base weave is plain weave, twill weave or satin weave; a geometric model is established based on the structure and warp-weft yarn interlacing characteristics of the three base weaves, and a grid is divided to form a simulation calculation model; S12, physical fields and material properties are defined, and boundary conditions, simulation parameters and the size of the working space are set; The physical fields are set as fluid, structure and current multi-physical field coupling fields, and the boundary conditions and simulation parameters include fluid resistance, pressure drop, current density and liquid flow mode; S13, the model is solved under the condition of changing the weave structure phase, and simulation laws are obtained; The changed weave structure phase refers to changing the arrangement and number of interlacing points under the condition of warp-weft yarn interlacing of the base weave; through comparison of multiple simulation data, the laws of the change of the weave structure phase, the arrangement and number of the warp-weft yarn interlacing points are obtained; In step S2, the simulation laws are as follows: 1) the more the warp-weft yarn interlacing points, the more the parallel formed by the potential points on the carbon cloth, the smaller the charge transfer resistance, the greater the electronic conductivity, and the better the electrical performance of the carbon cloth; 2) the more the grooves / grooves between the interlacing points and the float lines, the greater the contact area between the electrolyte and the carbon cloth, the lower the fluid resistance of the electrolyte, the greater the surface area of the carbon cloth, and the more the electrolyte reaction sites randomly increased after carbonization and activation, thereby improving the electrical performance of the carbon cloth in the battery; In step S2, the weave structure is formed by ground weave and pattern weave, the ground weave is plain weave, the pattern weave is jacquard weave, and a knot-free weaving method is adopted; the weave structure increases the warp-weft yarn interlacing points through the ground weave, and increases the grooves in the weave through the pattern weave; In step S3, the warp-weft yarn parameters include warp-weft yarn fineness, yarn twist, number of threads and double-twisted twist; the weaving parameters include spring position affecting the machine tension, shedding time and beating-up time.

2. The carbon cloth texture method for improving the electrical performance of carbon cloth according to claim 1, characterized by: The fineness of the warp-weft yarn ranges from 23.6 tex to 39.4 tex; the yarn twist ranges from 430 T / m to 617 T / m; the number of threads ranges from 2 to 4; and the double-twisted twist ranges from 140 T / m to 280 T / m.

3. The carbon cloth texture method for improving the electrical performance of carbon cloth according to claim 1, characterized by: The spring position affecting the machine tension is 1-5 points; the shedding time is 305°-325°; and the beating-up time is 315°-355°.

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