Acetylene carbon black internal resistance measuring tool

Abstract

The utility model provides an acetylene carbon black internal resistance measuring tool, which comprises an electrode assembly, an acetylene carbon black sample and a voltage and current measuring circuit, the acetylene carbon black sample is arranged in the electrode assembly, the outside of the electrode assembly is abutted against a pressure testing machine, and the pressure testing machine is electrically isolated from the electrode assembly; the electrode assembly generates internal movement under the pressure driving of the pressure testing machine and is in close contact with an acetylene carbon black sample; two electrodes of the electrode assembly are electrically connected with positive and negative electrodes of the voltage and current measuring circuit respectively. Constant current is applied to the acetylene carbon black sample in the filling cavity through the circulating constant current source, voltages at two ends of the acetylene carbon black sample are measured, the internal resistance is calculated based on the Ohm law, stable contact of the sample is ensured by adopting a detachable filling cavity and pressure testing machine pre-tightening structure, the problems of complex operation and high cost of a traditional method are solved, and the test efficiency is improved. The device is suitable for research and development of battery materials and rapid quality control of conductive fillers, and has the advantages of portability, high efficiency and non-destructive measurement.

Description

TECHNICAL FIELD

[0001] The utility model relates to the electric performance test technical field of conductive material, particularly, relate to the resistivity technical field of test battery material, conductive filler etc. BACKGROUND

[0002] The acetylene carbon black is widely used in battery negative conductive agent and rubber reinforcing agent because of high conductivity and chemical stability, and the internal resistance (i.e. resistivity) of the acetyylene carbon black directly influences the conductivity of the final product of the battery.

[0003] The traditional measurement method of the internal resistance of the acetylene carbon black relies on complex equipment, such as the direct current four electrode method, which measures the resistance by using four electrodes at the same time, and needs expensive experimental equipment and higher technical requirements, and has problems of high cost, complicated operation, sample damage, etc.

[0004] Moreover, in the existing measurement technology of the internal resistance of the acetylene carbon black, the acetylene carbon black is in the form of loose powder, and the contact resistance of the loose powder is easily affected by the filling density, resulting in unstable measurement results of the internal resistance of the acetylene carbon black. SUMMARY

[0005] Therefore, the utility model provides a kind of acetylene carbon black internal resistance measurement tool, develop and design by electrode assembly, acetylene carbon black sample and filling cavity, circulating constant current source and voltage and current measurement circuit etc. Component constitutes tool structure, use copper bar as electrode conduction current;Filling cavity is opened on copper bar to accommodate the acetylene carbon black sample to be measured, and circulating constant current source is used to provide constant current;Measurement circuit is used to measure voltage and current, and the internal resistance of acetylene carbon black is calculated according to Ohm's law (R=U / I), to realize simple and fast development, reduce cost, easy operation, improve measurement efficiency and measurement result stability, accuracy.

[0006] The utility model provides a kind of acetylene carbon black internal resistance measurement tool, including: electrode assembly, acetylene carbon black sample, voltage and current measurement circuit, the acetylene carbon black sample is installed in the inside of the electrode assembly, the outside of the electrode assembly is abutted with pressure testing machine, the pressure testing machine is electrically isolated with the electrode assembly;The electrode assembly generates internal movement under the pressure driving of the pressure testing machine, and is in close contact with the acetylene carbon black sample;The two poles of the electrode assembly are electrically connected with the positive and negative poles of the voltage and current measurement circuit.

[0007] By pressure testing machine to electrode assembly and its inside acetylene carbon black sample apply pressure (pre-tightening force), guarantee acetylene carbon black sample and electrode assembly close contact, eliminate the gap of acetyylene carbon black sample powder, solve the problem that the filling density of loose powder of existing measurement method affects the stability of contact resistance measurement result.

[0008] The voltage and current measuring circuit is based on the principle of Ohm's law (R=U / I), first measures the voltage and current between the two poles of the electrode assembly, and then calculates the resistivity between the two poles (i.e. the internal resistance of the acetylene carbon black sample) according to Ohm's law (R=U / I). The voltage and current measuring circuit only needs two electrode connection points, compared with existing experimental equipment such as direct current four electrode method, it is simple to develop, low in cost, easy to operate and high in efficiency.

[0009] Further, the electrode assembly comprises a thick copper rod and a thin copper rod, the thin copper rod and the thick copper rod are respectively a first pole and a second pole of the electrode assembly, the upper part of the thick copper rod is provided with a filling cavity, the upper part of the filling cavity is provided with an opening, the inside of the filling cavity is filled with an acetylene carbon black sample, the thin copper rod is inserted into the inside of the filling cavity from the opening, the thin copper rod 1 is electrically isolated between the outer diameter and the inner wall of the filling cavity, and the acetylene carbon black sample is compressed below the thin copper rod.

[0010] Specifically, as shown in Figure 1 The electrode assembly adopts a split structure, the thick copper rod and the thin copper rod are respectively two electrodes of the electrode assembly, and the relative positions of the thick copper rod and the thin copper rod change with the pressing or lifting of the pressure testing machine, so that the height of the filling cavity changes, and the acetylene carbon black sample in the inside of the filling cavity is tightly attached to the thick copper rod and the thin copper rod (two poles of the electrode assembly) respectively. The thick copper rod and the thin copper rod are in a stepped matching relationship, the thick copper rod with a large diameter is located at the lower part, and the thin copper rod with a small diameter is located at the upper part, so that the structural stability is high and the experimental operation is facilitated.

[0011] Preferably, the thick copper rod and the thin copper rod are both high-purity copper rods, so as to reduce the influence of the resistance of the copper rods (electrodes) themselves on the measurement results.

[0012] Preferably, the filling cavity is a standardized cylindrical cavity with a diameter of φ20 mm and a depth of 50 mm, the outer diameter of the thin copper rod is matched with the size of the inner wall of the filling cavity (although the size is matched, the thin copper rod is electrically isolated, and the method of electrical isolation can be an insulating oxidation treatment of a specific surface), the thin copper rod is inserted from the upper part of the filling cavity and compresses the acetylene carbon black sample downward.

[0013] Further, the acetylene carbon black internal resistance measuring tool further comprises a circulating constant current source connected in series with the thick copper rod and the thin copper rod.

[0014] Specifically, the circulating constant current source provides an adjustable constant current of 0.5-5 A, a discharge time of 1-5 minutes, and an accuracy of ±0.5%; the circulating constant current source supports multiple current switching;

[0015] Preferably, the cyclic constant current source discharges for 3 minutes, the stable voltage value U and current value I of the electrode assembly are recorded, the internal resistance of the acetylene carbon black sample in the electrode assembly is calculated according to the Ohm's law formula R=U / I, and the resistivity p=R×S / L is further calculated in combination with the cross-sectional area S and length L of the filling cavity.

[0016] Further, the voltage and current measurement circuit comprises a voltage detection module connected in series with the thick copper rod and the thin copper rod.

[0017] Specifically, the voltage detection module has an accuracy of ±0.1 mV, displays the voltage detection data in real time, and stores the voltage detection data.

[0018] Preferably, the voltage detection module can adopt a voltmeter.

[0019] Further, the voltage and current measurement circuit further comprises a data acquisition unit connected in signal connection with the voltage detection module.

[0020] The data acquisition unit collects the voltage detection data of the voltage detection module and transmits the voltage detection data to relevant instruments for processing and analysis.

[0021] Preferably, the data acquisition unit and the voltage detection module are integrated into one component.

[0022] Preferably, the data acquisition unit can adopt a recorder.

[0023] Further, the voltage detection module is connected to the end faces of the thick copper rod and the thin copper rod.

[0024] The voltage detection module is directly connected to the end faces of the copper rods, so that the voltage detection line (wire) is away from the outer cylindrical surface of the copper rods, the interference of the wire on the measurement of the internal resistance of acetylene carbon black can be eliminated, and the measurement accuracy is further improved.

[0025] Further, a variable resistor is connected in series between the cyclic constant current source and the thick copper rod or the thin copper rod.

[0026] The variable resistor can adjust the resistance of the cyclic constant current source circuit, and can adjust the size of the current in the cyclic constant current source circuit to realize the selection and use of multiple test currents.

[0027] Preferably, the variable resistor can adopt a device for adjusting resistance by changing contact points.

[0028] Further, insulating gaskets are respectively arranged between the pressure testing machine and the thick copper rod and the thin copper rod.

[0029] The pressure testing machine applies pre-tightening force to the thick copper rod and the thin copper rod through the insulating pad, guarantees the close contact of the acetylene carbon black sample, and does not affect the measurement of the current and voltage based on the electrical insulation isolation, thereby guaranteeing the accuracy of the measurement result.

[0030] Further, the upper side of the thin copper rod is provided with a first pole threaded interface, and the first pole threaded interface is screwed with a first pole lead wire through a screw; the lower side of the thick copper rod is provided with a second pole threaded interface, and the second pole threaded interface is screwed with a second pole lead wire through a screw.

[0031] The threaded interface is used for lead wire connection, improves the firmness of the lead wire connection, guarantees the stability of the measurement, and is convenient to assemble and disassemble, easy to operate, and easy to maintain.

[0032] Further, the acetylene carbon black sample is filled in the inside of the filling cavity through the funnel.

[0033] The use of the funnel can avoid the leakage of the acetylene carbon black sample during the filling process, reduce the loss and waste of raw materials, and save the cost of raw materials.

[0034] Preferably, after the acetylene carbon black sample is filled into the inside of the filling cavity, the acetylene carbon black sample is vibrated for 30 seconds to eliminate the gap between the acetylene carbon black powder.

[0035] The utility model discloses a standardized filling cavity and pressure pre-tightening structure, and combines a circulating constant current source to directly measure the acetylene carbon black sample, realizes rapid, low-cost and non-destructive detection.

[0036] Compared with the prior art, the utility model has the beneficial effects that:

[0037] The acetylene carbon black internal resistance measurement tool structure provided by the utility model is simple and reasonable, has high integrity, applies a constant current to the acetylene carbon black sample in the filling cavity through a circulating constant current source, measures the voltage at both ends of the acetylene carbon black sample and calculates the internal resistance based on Ohm's law, adopts a detachable filling cavity and pressure testing machine pre-tightening structure to guarantee stable sample contact, solves the problems of complex operation and high cost of the traditional method, is suitable for battery material research and development and rapid quality control of conductive fillers, has the advantages of portability, high efficiency and non-destructive measurement, and has wide popularization and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustration only and are not considered a limitation of the present utility model. Moreover, like reference numerals are used to designate identical parts throughout the specification and drawings. In the drawings:

[0039] Figure 1 It is the structure section view schematic diagram of the thin copper bar and the thick copper bar of the utility model embodiment;

[0040] Figure 2 It is the section view of the filling cavity in the utility model embodiment;

[0041] Figure 3 It is the connection schematic diagram of the measuring circuit in the utility model embodiment.

[0042] The mark in the drawing indicates that:

[0043] 1, thin copper bar, 2, thick copper bar, 3, acetylene black sample, 4, screw, 5, insulating gasket, 6, pressure testing machine, 7, voltage detection module, 8, circulating constant current source, 9, variable resistor. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood, and the scope of the present disclosure can be accurately conveyed to those skilled in the art. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0045] In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "inner", "outer" and the like are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0046] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly, for example, it can be fixedly connected, or integrally connected, or mechanically connected, or electrically connected, or directly connected, or indirectly connected through an intermediate medium, or the connection between two elements inside. For those skilled in the art, the specific meaning of the above-mentioned term in the present application can be understood according to the specific circumstances.

[0047] The embodiments of the present application will be described in detail below with reference to the accompanying drawings:

[0048] EMBODIMENT

[0049] The embodiment of the present application provides a kind of acetylene carbon black internal resistance measurement tool, comprising: electrode assembly, acetylene carbon black sample, voltage current measurement circuit, acetylene carbon black sample is installed in the inside of electrode assembly, the outside of electrode assembly is abutted with pressure testing machine 6 (such as Figure 3 As shown), pressure testing machine 6 is electrically isolated with electrode assembly;Electrode assembly generates internal movement under the pressure driving of pressure testing machine 6, and is closely contacted with acetylene carbon black sample;Two poles of electrode assembly are electrically connected with positive and negative poles of voltage current measurement circuit respectively.Referring to Figure 1 、 Figure 2 As shown, electrode assembly includes thick copper bar 2, thin copper bar 1, and thin copper bar 1 and thick copper bar 2 are first pole and second pole of electrode assembly respectively, and thick copper bar 2 and thin copper bar 1 are high-purity copper bars, which reduces the influence of resistance of copper bar itself on measurement result.The upper part of thick copper bar 2 is provided with filling cavity, and the filling cavity is a standardized cylindrical cavity with diameter φ20mm and depth 50mm.The upper part of filling cavity is provided with opening, and acetylene carbon black sample 3 is contained in the inside of filling cavity, and acetylene carbon black sample 3 is filled in the inside of filling cavity through funnel.Using funnel avoids the phenomenon that acetylene carbon black sample 3 leaks during filling process, reduces raw material loss and waste, and saves raw material cost.After acetylene carbon black sample 3 is filled into the inside of filling cavity, it is vibrated for 30 seconds to eliminate the gap between acetylene carbon black powder.

[0050] Thin copper bar 1 is inserted into the inside of filling cavity from opening, and the outer diameter of thin copper bar 1 matches the size of inner wall of filling cavity, although the size matches, but the outer diameter of thin copper bar 1 is electrically isolated with the inner wall of filling cavity, and the electrically isolated mode is realized by insulating oxidation treatment of the inner wall of filling cavity, and thin copper bar 1 is inserted from the upper part of filling cavity, and acetylene carbon black sample 3 is pressed tightly downward, so that acetylene carbon black sample 3 is pressed tightly below thin copper bar 1.Electrode assembly adopts split structure, and thick copper bar 2 and thin copper bar 1 are two electrodes of electrode assembly, and the relative position of thick copper bar 2 and thin copper bar 1 changes with the pressing or lifting of pressure testing machine 6, so that the height of filling cavity changes, so that acetylene carbon black sample 3 in the inside of filling cavity is closely combined with thick copper bar 2 and thin copper bar 1 (two poles of electrode assembly) respectively.Pretightening force is applied to electrode assembly and acetylene carbon black sample 3 in the inside of electrode assembly by pressure testing machine 6, so as to ensure that acetylene carbon black sample 3 is closely contacted with electrode assembly, eliminate the gap of acetylene carbon black sample 3 powder, and avoid the problem that the filling density of loose powder affects the stability of contact resistance measurement result in the prior measurement mode.Moreover, thick copper bar 2 and thin copper bar 1 adopt stepped matching, thick copper bar 2 with large diameter is located at lower part, and thin copper bar 1 with small diameter is located at upper part, and the structure stability is high, and it is convenient for experimental operation.

[0051] The circulating constant current source 8 is connected in series with the thick copper rod 2 and the thin copper rod 1. The voltage detection module 7 is connected in series with the thick copper rod and the thin copper rod, and the data acquisition unit is connected in signal connection with the voltage detection module, and the data acquisition unit and the voltage detection module are integrated into one component. The circulating constant current source 8 is connected in series with the thick copper rod 2 or the thin copper rod 1, and a variable resistor 9 is arranged between the circulating constant current source 8 and the thick copper rod 2 or the thin copper rod 1. The variable resistor 9 can adjust the resistance of the circuit of the circulating constant current source 8, thereby being capable of adjusting the size of the current in the circuit of the circulating constant current source 8, and realizing the selection and use of various test currents. The variable resistor 9 adopts a device for adjusting resistance by changing a contact point. The voltage detection module 7 is connected to the end faces of the thick copper rod 2 and the thin copper rod 1. The voltage detection module 7 is directly connected to the end faces of the copper rods, so that the voltage detection line (wire) is away from the outer cylindrical surface of the copper rod, the interference of the wire on the measurement of the internal resistance of the acetylene carbon black is eliminated, and the measurement accuracy is improved.

[0052] The circulating constant current source 8 provides an adjustable constant current of 0.5-5A, and the discharge time is 3 minutes. The accuracy of the circulating constant current source 8 is ±0.5%. The circulating constant current source 8 supports multi-grade current switching. The accuracy of the voltage detection module is ±0.1mV. The voltage detection data is displayed in real time, and the voltage detection data is stored. In this embodiment, the voltage detection module adopts a voltmeter. The data acquisition unit collects the voltage detection data of the voltage detection module, and transmits the voltage detection data to a related instrument for processing and analysis. In this embodiment, the data acquisition unit adopts a recorder.

[0053] Based on the Ohm's law (R=U / I), the voltage detection module 7 measures the voltage and current between the two poles of the electrode assembly, records the stable voltage value U and the current value I of the electrode assembly, calculates the resistivity between the two poles according to the Ohm's law formula R=U / I, obtains the internal resistance of the acetylene carbon black sample 3 in the electrode assembly, and further calculates the resistivity p of the acetylene carbon black sample 3 in combination with the cross-sectional area S and the length L of the filling cavity:

[0054] p=R×S / L.

[0055] The voltage and current measurement circuit of this embodiment only needs two electrode connection points, compared with the existing direct current four-electrode method and other experimental equipment, and has the advantages of simple development, reduced cost, easy operation and improved efficiency.

[0056] The pressure testing machine 6 is respectively arranged with the insulating gaskets 5 between the thick copper rod 2 and the thin copper rod 1. The pressure testing machine 6 applies a pre-tightening force to the thick copper rod 2 and the thin copper rod 1 through the insulating gaskets 5, so as to ensure the close contact of the acetylene carbon black sample 3, and based on the electrical insulation isolation, the measurement of the current and voltage is not affected, and the accuracy of the measurement result is ensured.

[0057] The upper side of the thin copper rod 1 is provided with a first pole threaded interface, and the first pole threaded interface is screwed with a first pole conductor wire through a screw 4; the lower side of the thick copper rod 2 is provided with a second pole threaded interface, and the second pole threaded interface is screwed with a second pole conductor wire through the screw 4. In the embodiment, the threaded interface is used for conductor wire connection, the firmness of the conductor wire connection is improved, the stability of measurement is ensured, and the threaded interface is convenient to assemble and disassemble, convenient to operate, and easy to maintain.

[0058] The operation process of the embodiment in actual application mainly has the following steps:

[0059] Sample filling: the acetylene black powder is uniformly filled into the filling cavity of the thick copper rod 2 by using a funnel, and vibration is performed for 30 seconds to eliminate the gap of the acetylene black powder.

[0060] Pre-tightening and fixing: the thin copper rod 1 is inserted into the filling cavity from top to bottom, a pre-tightening force is applied through the pressure testing machine 6, and the acetylene black sample 3 is ensured to be in close contact with the thick copper rod 2 and the thin copper rod 1.

[0061] Circuit connection: the cyclic constant current source 6 is connected in series with the thin copper rod 1 and the thick copper rod 2, and the voltage detection module 7 is connected to the end surface of the thin copper rod 1 and the thick copper rod 2 by using a voltage detection line.

[0062] Data acquisition: the cyclic constant current source 6 is discharged for 3 minutes, the stable voltage U and the current value I are recorded, the internal resistance is calculated according to the formula R=U / I, and the resistivity p=RxS / L is further calculated in combination with the cross-sectional area S and the length L of the filling cavity.

[0063] The embodiment directly measures the acetylene black sample 3 by using the standardized filling cavity and the pressure pre-tightening structure in combination with the cyclic constant current source 6, and realizes rapid, low-cost and non-destructive detection.

[0064] The acetylene black internal resistance measurement tool of the embodiment applies a constant current to the acetylene black sample in the filling cavity by using the cyclic constant current source, measures the voltage of the acetylene black sample, calculates the internal resistance based on the Ohm's law, adopts the detachable filling cavity and the pressure testing machine pre-tightening structure, ensures stable sample contact, solves the problems of complex operation and high cost in the traditional method, is suitable for rapid quality control of battery material research and development and conductive filler, has the advantages of portability, high efficiency and non-destructive measurement, and has the advantages of simple and reasonable structure, high integrity, simple development, easy operation and high efficiency.

[0065] Thus far, the technical scheme of the present application has been described in connection with the preferred embodiments shown in the drawings, but it is readily understood by those skilled in the art that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the relevant technical features without deviating from the principles of the present application, and the technical schemes after these changes or replacements will all fall within the protection scope of the present application.

[0066] The above description is merely preferred embodiments of the present application and is not intended to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An acetylene carbon black internal resistance measuring tool, characterized by, The electrode assembly, acetylene carbon black sample, voltage current measurement circuit, the acetyylene carbon black sample is installed in the inside of the electrode assembly, the outside of the electrode assembly abuts with the pressure testing machine, the pressure testing machine is electrically isolated with the electrode assembly;The electrode assembly generates internal movement under the pressure driving of the pressure testing machine, and is in close contact with the acetylene carbon black sample;Two poles of the electrode assembly are electrically connected with the positive and negative poles of the voltage current measurement circuit. The electrode assembly includes a thick copper rod and a thin copper rod, the thin copper rod and the thick copper rod are the first pole and the second pole of the electrode assembly respectively, the upper part of the thick copper rod is provided with a filling cavity, the upper part of the filling cavity is provided with an opening, the inside of the filling cavity is filled with an acetylene carbon black sample, the thin copper rod is inserted into the inside of the filling cavity from the opening, the outer diameter of the thin copper rod is electrically isolated with the inner wall of the filling cavity, and the acetyylene carbon black sample is pressed below the thin copper rod.

2. The acetylene carbon black internal resistance measuring tool according to claim 1, wherein The acetylene carbon black internal resistance measurement tool further includes a circulating constant current source connected in series with the thick copper rod and the thin copper rod.

3. The acetylene carbon black internal resistance measuring tool according to claim 2, wherein The voltage current measurement circuit includes a voltage detection module connected in series with the thick copper rod and the thin copper rod.

4. The acetylene carbon black internal resistance measuring tool according to claim 3, wherein The voltage current measurement circuit further includes a data acquisition unit connected with the voltage detection module.

5. The acetylene carbon black internal resistance measuring tool according to claim 4, wherein The voltage detection module is connected with the end face of the thick copper rod and the thin copper rod.

6. The acetylene carbon black internal resistance measuring tool according to claim 4, wherein A variable resistor is further connected in series between the circulating constant current source and the thick copper rod or the thin copper rod.

7. The acetylene carbon black internal resistance measuring tool according to claim 4, wherein Insulating spacers are respectively arranged between the pressure testing machine and the thick copper rod and the thin copper rod.

8. The acetylene carbon black internal resistance measuring tool according to claim 2, wherein A first pole threaded interface is arranged on the upper side of the thin copper rod, and a first pole lead is screwed with the first pole threaded interface by a screw.

9. The acetylene carbon black internal resistance measuring tool according to claim 2, wherein The acetylene carbon black sample is filled in the inside of the filling cavity through a funnel.

10. The acetylene carbon black internal resistance measuring tool according to claim 2, wherein ​

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