System of measuring battery internal resistance and method thereof

Abstract

A system of measuring battery internal resistance, for measuring an internal resistance value of a battery under test, the battery under test comprising a first end portion and a second end portion, and the first end portion having an oxide layer; the system of measuring battery internal resistance comprising: a power supply device, comprising a first connection terminal and a second connection terminal, the first connection terminal and the second connection terminal for electrically connecting to the first end portion and the second end portion of the battery under test, respectively, wherein one of the first connection terminal and the second connection terminal has a probe, wherein the probe is used to contact the oxide layer of the battery under test, and to supply power to the battery under test via the probe, such that an electron passes through the oxide layer and arrives at the first end portion to generate a tunneling current; a data acquisition device, electrically connected to the battery under test and the power supply device to form a loop, wherein the data acquisition device measuring a current value of the tunneling current and a voltage value of the battery under test after the tunneling current is generated; and a calculation device, communicatively connected to the power supply device and / or the data acquisition device, the calculation device calculating the internal resistance value of the battery under test according to the voltage value and the current value.

Description

SYSTEM OF MEASURING BATTERY INTERNAL RESISTANCE AND METHOD THEREOFBACKGROUND OF THE INVENTIONFIELD OF THE INVENTION

[0001] The present invention relates to a system of measuring battery internal resistance and a method thereof, particularly to a battery internal resistance measurement system and method able to measure a battery internal resistance without first removing an oxide above an end cap of a battery, and more particularly to a battery internal resistance measurement system employing the principle of field emission (FE), also referred to as carrier tunneling and a method thereof.DESCRIPTION OF THE PRIOR ART

[0002] In a current battery having been completely assembled, an end cap of the battery is susceptible to forming an oxide. The formation of the oxide (which may be regarded as an insulating layer) hinders conduction of a contact resistor, such that it may be difficult for a user to accurately measure an internal resistance of the battery. For the issue above, a user may first remove the oxide by means of laser and etching or other means, and then measure the internal resistance of the battery. However, this approach is more complex and yields poor efficiency. In view of the above, there is a need for a system of measuring battery internal resistance with simple operations and higher implementation efficiency, and a method thereof. Preferably, there is a need for a system of measuring battery internal resistancethat able to measure an internal resistance of a battery without first removing an oxide above an end cap of the battery, and a method thereof.SUMMARY OF THE INVENTION

[0003] To overcome the issues above, it is a concept of the present invention to provide a system of measuring battery internal resistance with simple operations and higher implementation efficiency, and a method thereof. It is another concept of the present invention to provide a system of measuring battery internal resistance that able to measure an internal resistance of a battery without first removing an oxide above an end cap of the battery, and a method thereof. It is yet another concept of the present invention to provide a battery internal resistance measurement system employing the principle of field emission (FE), also referred to as carrier tunneling, and a method thereof.

[0004] A battery internal resistance measurement system, for measuring an internal resistance value of a battery under test, the battery under test comprising a first end portion and a second end portion, and the first end portion having an oxide layer; the battery internal resistance measurement system comprising: a power supply device, comprising a first connection terminal and a second connection terminal, the first connection terminal and the second connection terminal for electrically connecting to the first end portion and the second end portion of the battery under test, respectively, wherein one of the first connection terminal and the second connection terminal has a probe, wherein the probe is used to contact the oxide layer of the battery under test, and to supply power to the battery under test via the probe, such that an electron passes through the oxidelayer and arrives at the first end portion to generate a tunneling current; a data acquisition device, electrically connected to the battery under test and the power supply device to form a loop, wherein the data acquisition device measuring a current value of the tunneling current and a voltage value of the battery under test after the tunneling current is generated; and a calculation device, communicatively connected to the power supply device and / or the data acquisition device, the calculation device calculating the internal resistance value of the battery under test according to the voltage value and the current value.

[0005] In a preferred embodiment of the present invention, the probe has a blunt tip and a sharp tip, and the power supply device provides an electron flow along a direction from the blunt tip of the probe toward the sharp tip.

[0006] In a preferred embodiment of the present invention, the first end portion is a positive terminal, the second end portion is a negative terminal, and the power supply device provides an electron flow along a direction from the positive terminal of the battery under test toward the negative terminal.

[0007] In a preferred embodiment of the present invention, the power supply device provides the battery under test with a test current, the test current flows in a direction from the negative terminal of the battery under test toward the positive terminal.

[0008] In a preferred embodiment of the present invention, the probe has a blunt tip and a sharp tip, and the power supply device provides the battery under test with a test current, the test current flows in a direction from the sharp tip of the probe toward the blunt tip.

[0009] In a preferred embodiment of the present invention, the power supply device provides a voltage to the battery under test, such that a potential of the first end portion is less (smaller) than a potential of the second end portion.

[0010] In a preferred embodiment of the present invention, the power supply device applies a detection voltage to the battery under test via the probe, such that carrier tunneling occurs in the battery under test and the tunneling current is generated.

[0011] In a preferred embodiment of the present invention, the first end portion of the battery under test is a positive terminal, the second end portion of the battery under test is a negative terminal, the probe of the first connection terminal of the power supply device is connected to the positive terminal, and the second connection terminal of the power supply device is connected to the negative terminal.

[0012] In a preferred embodiment of the present invention, the power supply device provides a detection current at the loop, the data acquisition device measures a cross voltage of the battery under test, and the calculation device calculates the internal resistance value of the battery under test according to the detection current and the cross voltage.

[0013] In a preferred embodiment of the present invention, the detection current increases as a thickness of the oxide layer increases.

[0014] In a preferred embodiment of the present invention, the power supply device provides a detection voltage at the loop, the data acquisition device measures a current on the loop, and the calculation device calculates the internal resistance value of the battery under test according to the detection voltage and the current.

[0015] In a preferred embodiment of the present invention, the detection voltage increases as a thickness of the oxide layer increases.

[0016] According to the objects of the present invention, the present invention further provides a battery internal resistance measurement method, for measuring an internal resistance value of a battery under test, the battery under test comprising a first end portion and a second end portion, and the first end portion having an oxide layer; the battery internal resistance measurement method comprising steps of: connecting a first connection terminal and a second connection terminal of a power supply device to the first end portion and the second end portion of the battery under test, respectively, wherein the one of the first connection terminal and the second connection terminal has a probe, and contacting the probe of the power supply device with the oxide layer of the battery under test; connecting a data acquisition device to the battery under test and the power supply device; communicatively connecting a calculation device to the power supply device and / or the data acquisition device; supplying power to the battery under test by the power supply device via the probe to enable electrons to pass through the oxide layer and arrive at the first end portion to thereby generate a tunneling current, wherein the power supply device is electrically connected to the data acquisition device and the battery under test to form a loop; measuring a current value of the tunneling current and a voltage value of the battery under test by the data acquisition device; and calculating the internal resistance value of the battery under test according to the voltage value and the current value.

[0017] In a preferred embodiment of the present invention, the probe has a blunt tip and a sharp tip, and the battery internal resistance measurement method furtherincludes a step of: providing an electron flow along a direction from the blunt tip of the probe toward the sharp tip by the power supply device.

[0018] In a preferred embodiment of the present invention, the first end portion is a positive terminal, the second end portion is a negative terminal, and the battery internal resistance measurement method further includes a step of: providing an electron flow along a direction from the positive terminal of the battery under test toward the negative terminal by the power supply device.

[0019] In a preferred embodiment of the present invention, the battery internal resistance measurement method further includes a step of: providing the battery under test with a test current along a direction from the negative terminal of the battery under test toward the positive terminal.

[0020] In a preferred embodiment of the present invention, the probe has a blunt tip and a sharp tip, and the battery internal resistance measurement method further includes a step of: providing the battery under test with a test current along a direction from the sharp tip of the probe toward the blunt tip by the power supply device.

[0021] In a preferred embodiment of the present invention, the battery internal resistance measurement method further includes a step of: providing a voltage to the battery under test by the power supply device, such that a potential of the first end portion is less than a potential of the second end portion.

[0022] In a preferred embodiment of the present invention, the battery internal resistance measurement method further includes a step of: applying a detection voltage to the battery under test by the power supply device via the probe, such that carrier tunneling occurs in the battery under test and the tunneling current is generated.

[0023] In a preferred embodiment of the present invention, the first end portion of the battery under test is a positive terminal, the second end portion of the battery under test is a negative terminal, and the battery internal resistance measurement method further includes steps of: connecting the probe of the first connection terminal of the power supply device to the positive terminal, and connecting the second connection terminal of the power supply device to the negative terminal.

[0024] In a preferred embodiment of the present invention, the battery internal resistance measurement method further includes steps of: providing a detection current at the loop by the power supply device, measuring a cross voltage on the loop by the data acquisition device, and calculating the internal resistance value of the battery under test by the calculation device according to the detection current and the cross voltage.

[0025] In a preferred embodiment of the present invention, the battery internal resistance measurement method further includes steps of: providing a detection voltage at the loop by the power supply device, measuring a current on the loop by the data acquisition device, and calculating the internal resistance value of the battery under test by the calculation device according to the detection voltage and the current.

[0026] In a preferred embodiment of the present invention, the battery internal resistance measurement method further includes a step of: the detection voltage increases as a thickness of the oxide layer increases.

[0027] To provide better understanding, the above and other aspects of the present invention are to be described with reference by way of the non-limiting embodiments and the accompanying drawings below.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a schematic diagram of a system of measuring battery internal resistance according to a specific embodiment of the present invention;

[0029] FIG. 2a is a schematic diagram of potential distribution between a probe and a battery under test and carrier tunneling taking place when an electric field in a specific direction is applied in a system of measuring battery internal resistance according to a specific embodiment of the present invention;

[0030] FIG. 2b is an equivalent circuit diagram of FIG. 2a;

[0031] FIG. 3 is a side view of a probe of a power supply device according to a specific embodiment of the present invention;

[0032] FIG. 4 is a top view of a probe of a power supply device according to a specific embodiment of the present invention;

[0033] FIG. 5 is a schematic diagram of calculating an internal resistance value of a battery under test according to a specific embodiment;

[0034] FIG. 6 is a flowchart of a method of measuring battery internal resistance according to a specific embodiment of the present invention; and

[0035] FIG. 7 is a schematic diagram of potential distribution between a probe and a battery under test when an electric field in a specific direction is applied in a system of measuring battery internal resistance according to a specific embodiment of the present invention.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] Refer to FIG. 1 showing a schematic diagram of an example of a system of measuring battery internal resistance according to a specific embodiment of thepresent invention. As the embodiment shown in FIG. 1 , the system 100 of measuring battery internal resistance may be used to measure an internal resistance value of a battery under test 900. The battery under test 900 includes a first end portion 910 and a second end portion 920. In one specific embodiment, the first end portion 910 of the battery under test 900 has an oxide layer, which may be formed due to, for example but not limited to, oxidation of the first end portion 910. The system 100 of measuring battery internal resistance may include a power supply device 110, a data acquisition device 120 and a calculation device 130.

[0037] The power supply device 110 includes a first connection terminal 112 and a second connection terminal 114, and at least one of the first connection terminal 112 and the second connection terminal 114 has a probe. In a specific embodiment, the first connection terminal 112 has a probe 116. During measurement, the first connection terminal 112 and the second connection terminal 114 may be electrically connected to the first end portion 910 and the second end portion 920 of the battery under test 900, respectively. In a specific embodiment, the probe 116 of the first connection terminal 112 is electrically connected to the first end portion 910, and the second connection terminal 114 is electrically connected to the second end portion 920, as shown in FIG. 1 .

[0038] The data acquisition device 120 may be electrically connected to the battery under test 900 and the power supply device 110 to form a loop (that is, the power supply device 110, the data acquisition device 120 and the battery under test 900 form a loop). In a specific embodiment, as shown in FIG. 1 , the power supply device 110 and the battery under test 900 are connected in parallel, and the data acquisition device 120 and the battery under test 900 are connected in series. It should be understood that, being connected in series herein does not mean thatthe data acquisition device 120 and the battery under test 900 are necessarily connected directly. In practice, if the data acquisition device 120 and the battery under test 900 are connected otherwise by another electronic element (for example but not limited to, a resistor or other measurement devices) in between, the data acquisition device 120 and the battery under test 900 are then indirectly connected in series, which also accounts for a form of being connected in series. It should be understood that, the system 100 of measuring battery internal resistance may measure the internal resistance value of the battery under test 900 by utilizing, for example but not limited to, a two-terminal method or four-terminal method according to requirements.

[0039] The probe 116 of the power supply device 110 may contact the oxide layer of the battery under test 900, and the power supply device 110 may supply power to the battery under test 900 via the probe 116. It should be understood that, the probe 116 is formed of a metal material, and preferably, the probe 116 has a sharp appearance. In a specific embodiment, the probe 116 of the power supply device 110 is at least partially formed of copper (for example, the probe 116 of the power supply device 110 may be formed of copper, a part of the probe 116 contacting the oxide layer may be formed of copper, or the probe 116 of the power supply device 110 may include copper). In a specific embodiment, the probe 116 may have a sharp tip 116a and a blunt tip 116b, as shown in FIG. 1 , and the probe 116 contacts the oxide layer of the battery under test 900 by its sharp tip 116a. The sharp appearance of the probe 116 has a huge influence on field emission. When a surface of metal has a sharp tip or a minute protrusion, the strength of electric field at the sharp tip 116a is significantly enhanced, and this is referred to as a tip effect or a field enhancement effect. Thus, at the sharp tip of the probe 116, by applyinga voltage in a specific direction, and even by applying a low voltage, the electric field is locally concentrated to trigger carrier tunneling or field emission.

[0040] One of the first end portion and the second end portion of the battery under test is a positive terminal of the battery and the other is a negative terminal of the battery. In a specific embodiment, the first end portion 910 of the battery under test 900 is a positive terminal, and the second end portion 920 is a negative terminal of the battery under test 900. In a specific embodiment, the first end portion 910 and the second end portion 920 are opposite to each other. It should be understood that, when the positive terminal of the battery under test 900 cannot be conducted due to an oxide layer, an electric field in a specific direction may be externally applied via the probe 116 of the power supply device to promote the occurrence of carrier tunneling and hence successful conduction. Specifically, the sharp tip 116a of the probe 116 may contact the oxide layer of the positive terminal, and a voltage, current or electron flow in a specific direction may be provided to the battery under test 900, such that electrons are allowed to depart from the sharp tip of the probe, pass through the oxide layer and arrive at a battery end portion below the oxide layer to generate a tunneling current. The battery under test 900, the power supply device 110 and the data acquisition device 120 become electrically connected to one another to form a loop.

[0041] A specific embodiment is as disclosed above. However, it should be understood that, in the present invention, by contacting the probe of the power supply device with the oxide layer of the battery under test and supplying power to the power supply device via the probe, electrons are allowed to pass through the oxide layer and arrive at the battery end portion below the oxide layer, hence generating a tunneling current. In this case, if an oxide layer is present at thenegative terminal (that is, the second end portion 920) of the battery undertest 900), the probe 116 of the power supply device 110 may be made to contact the negative terminal of the battery under test 900, and an external electric field in a specific direction is applied (including applying a voltage or providing a current or an electron flow) to cause carrier tunneling in the battery under test 900.

[0042] In a specific embodiment, the probe 116 has a blunt tip 116b and a sharp tip 116a. The power supply device 110 may provide the battery under test 900 with an electron flow along a direction from the blunt tip 116b of the probe 116 toward the sharp tip 116a. In a specific embodiment, the first end portion 910 of the battery under test 900 is a positive terminal, and the second end portion 920 of the battery under test 900 is a negative terminal. The power supply device 110 may provide the electron flow along a direction from the positive terminal of the battery under test 900 toward the negative terminal.

[0043] In a specific embodiment, the first end portion 910 of the battery under test 900 is a positive terminal, and the second end portion 920 of the battery under test 900 is a negative terminal. The power supply device 110 may provide the battery under test 900 and / or the loop formed by the battery under test 900, the power supply device 110 and the data acquisition device 120 a test current in a specific direction, wherein the test current flows in a direction from the negative terminal of the battery under test 900 toward the positive terminal.

[0044] In a specific embodiment, the probe 116 has a blunt tip 116b and a sharp tip 116a. The power supply device 110 may provide the battery under test 900 and / or the loop formed by the battery under test 900, the power supply device 110 and the data acquisition device 120 a test current, wherein the test current flows ina direction from the sharp tip 116a of the probe 116 toward the blunt tip 116b of the probe 116.

[0045] In a specific embodiment, the power supply device 110 may provide a voltage at the battery under test 900, wherein a potential of the first end portion 910 is less than a potential of the second end portion 920. In a specific embodiment, the power supply device 110 may apply a detection voltage to the battery under test 900 via the probe 116, such that the potential of the first end portion 910 of the battery under test is less than the potential of the second end portion 920. By applying a voltage in a specific direction, an electron flow in a specific direction can be generated. For example, an electric field formed at the sharp tip 116a of the probe 116 can promote electrons to be rearranged and accumulated at the sharp tip of the probe, then depart from the surface of the sharp tip and pass through the oxide layer, hence causing carrier tunneling and generate a tunneling current.

[0046] In a specific embodiment, the system 100 of measuring battery internal resistance may include a carrier device for carrying the battery under test 900. When an electric field in a specific direction is to be applied, a placement direction of a battery under test in the carrier device may also be selectively changed; for example, inverting vertically or placing oppositely left and right. Alternatively, a connection direction of the battery under test and the power supply device may also be changed; for example, the first end portion of the battery under test originally connected to the first connection terminal of the power supply device is changed to be connected to the second connection terminal of the power supply device. Under the premise that the remaining connections and power supply settings remain unchanged, with the approach above, the object of forming an electric field, voltage, current or electron flow in a specific direction can be achieved. In a specificembodiment, the battery under test 900 is placed in the carrier device, such that the probe 116 of the first connection terminal 112 of the power supply device 110 is connected to, abuts against or contacts the positive terminal of the battery under test 900 (in FIG. 1 , the positive terminal may be the first end portion 910), and the second connection terminal 114 of the power supply device 110 is connected to, abuts against or contacts the negative terminal of the battery under test 900 (in FIG. 1 , the negative terminal may be the second end portion 920). When the carrier tunneling takes place, the tunneling current flows in a direction from the positive terminal of the battery under test (in FIG. 1 , the positive terminal may be the first end portion 910) toward the probe 116 of the power supply device 110, or moves from the negative terminal of the battery under test toward the positive terminal, and the electron flow moves along a direction from the probe toward the positive terminal of the battery under test.

[0047] Refer to both FIG. 2a and FIG. 2b. FIG. 2a shows a schematic diagram of potential distribution between a probe and a battery under test and carrier tunneling taking place when an electric field of a specific direction is applied in a system of measuring battery internal resistance according to a specific embodiment of the present invention. FIG. 2b shows an equivalent circuit diagram of FIG. 2a. In the embodiments shown in FIG. 2a and FIG. 2b, when a probe 216 of a power supply device is made to contact the oxide layer 912 of the first end portion 910 of the battery under test 900 and an electric field in a specific direction is applied to the battery under test 900, the specific approach includes the following: when a current (or the detection current above), an electron flow or a voltage(or the detection voltage above) in a specific direction is applied, or the battery under test is placed in a specific direction into the carrier device, the electric field promotes charges ona surface of a sharp tip 216a to be rearranged and accumulated at the tip, and electrons 800 are assisted to depart from the surface of the sharp tip 216a, pass through an oxide layer 912 of the first end portion 910 originally cannot be passed through and arrive at the first end portion 910 of the battery under test, hence causing carrier tunneling. FIG. 2b shows an equivalent circuit diagram of FIG. 2a after carrier tunneling (or field emission) has taken place. Once carrier tunneling has taken place, the battery under test and the system of measuring battery internal resistance form a loop, d is a cross voltage of the battery under test 900, Id is a current generated after carrier tunneling has taken place, Rin is an internal resistance of the battery under test 900, RL is a load in the loop (including the power supply device and the data acquisition device, which are collectively referred to as a load for brevity), and an electron flow direction 250 may be a direction from the blunt tip 216b toward the sharp tip 216a, a direction from the positive terminal of the battery under test 900 toward the negative terminal, or a direction from the first end portion 910 of the battery under test toward the second end portion 920. A current direction 260 may be a direction from the sharp tip 216a of the probe toward the blunt tip 216b, a direction from the negative terminal of the battery under test 900 toward the positive terminal, or a direction from the second end portion 920 of the battery under test toward the first end portion 910.

[0048] Regarding carrier tunneling (or field emission), because field emission is primarily produced by a high-intensity electric field on a cathode, field emission usually happens when charges are concentrated at a negative terminal (the cathode). Such strong electric field is able to produce local enhancement of the electric field at a tip or a protrusion of a surface of the cathode, enabling electrons to pass through a barrier layer. While the electric field is enhanced, a barrier layer(for example, an oxide layer) near the cathode is compressed (that is, the thickness or height of the barrier layer is reduced by the effect of the electric field). Such occurrence of compression enable electrons to more easily pass through the barrier layer at a local electric field.

[0049] FIG. 3 shows a side view of a probe of a power supply device according to a specific embodiment of the present invention. FIG. 4 shows a top view of a probe of a power supply device according to a specific embodiment of the present invention. Refer to FIG. 3 and FIG. 4, a probe 340 of the power supply device may have a center portion 342 and an edge portion 344. The center portion 342 includes multiple needle-like objects, each of which includes a sharp tip 340a and a blunt tip 340b, wherein the sharp tip 340a is a free end for contacting a surface of an object under test. The edge portion 344 includes multiple needle-like objects, each of which includes the sharp tip 340a and the blunt tip 340b, wherein the sharp tip 340a is a free end for contacting a surface of an object under test. Preferably, the power supply device may provide the battery under test with a voltage and a current via the center portion 342 and the edge portion 344 of the probe 340, respectively. The probe of the power supply device may be, for example but not limited to, a probe of a four-point probe or a four-end fixture, or the probe of the power supply device may be similar to, for example but not limit to, a four-end fixture.

[0050] After the tunneling current is generated, the data acquisition device 120 may measure a current value of the tunneling current or a voltage value of the battery under test 900. The calculation device 130 may be communicatively connected to the power supply device 110 and / or the data acquisition device 120, and may calculate the internal resistance value of the battery under test 900 according to the voltage value and the current value measured by the dataacquisition device 120. In a specific embodiment, the power supply device 110 may provide a detection current at the loop formed by the power supply device 110, the data acquisition device 120 and the battery under test 900 (providing the detection current at battery under test 900 by the power supply device 110 may also be regarded as an implementation mode of providing the detection current at the loop formed by the power supply device 110, the data acquisition device 120 and the battery under test 900 by the power supply device 110). The data acquisition device 120 may measure a cross voltage (the cross voltage is, for example, a cross voltage of the battery under test 900) on the loop, and the calculation device 130 may calculate the internal resistance value of the battery under test 900 according to the detection current and the cross voltage measured by the data acquisition device 120.

[0051] Refer to FIG. 5 showing a schematic diagram of calculating an internal resistance value of a battery under test according to a specific embodiment. In the embodiment shown in FIG. 5, once carrier tunneling takes place in the battery under test 900 after the power supply device supplies power to the battery under test 900, the battery under test has a cross voltage V, and a current I flows through the battery under test 900. At this point, the calculation device of the system of measuring battery internal resistance may calculate the internal resistance value Rin of the battery under test 900 according to the cross voltage and the current I. The cross voltage is equal to the positive potential V+ of the battery under test 900 subtracted by the negative potential V- of the battery under test 900. The internal resistance value Rin of the battery under test 900 is equal to the cross voltage divided by the current I. The calculation method is as follows (Ri is the resistance of the positive terminal, and R2 is the resistance of the negative terminal):V = V+ - V- = | * (Ri + Rin - R2)V / I = Rin

[0052] The detection current applied by the power supply device 110 may be an alternating current or a direct current. In a specific embodiment, the power supply device 110 provides a direct current, and once the tunneling current is generated, the tunneling current generated is a direct current. Thus, a user may calculate the internal resistance value of the battery under test 900 according to the current value of the detection current applied and the value of the cross voltage (or referred to as a voltage value) measured by the data acquisition device 12. For example, a user may divide the voltage value of the cross voltage measured by the data acquisition device 120 by the current value of the detection current to calculate the internal resistance value of the battery under test 900.

[0053] In a specific embodiment, the power supply device 110 may provide a detection voltage at the loop formed by the power supply device 110, the data acquisition device 120 and the battery under test 900 (providing the detection voltage at battery under test 900 by the power supply device 110 may also be regarded as an implementation mode of providing the detection voltage at the loop formed by the power supply device 110, the data acquisition device 120 and the battery under test 900 by the power supply device 110), thereby generating the tunneling current. The data acquisition device 120 may measure a current (the current is, for example, a current flowing through the battery under test 900, or a current flowing through the data acquisition device 120) on the loop, and the calculation device 130 may calculate the internal resistance value of the battery under test 900 according to the detection voltage and the current measured by the data acquisition device 120.

[0054] The detection voltage applied by the power supply device 110 may be an alternating-current (AC) voltage or a direct-current (DC) voltage. In a specific embodiment, the detection voltage applied by the power supply device 110 is a DC voltage, and once the carrier tunneling takes place, the tunneling current generated is a direct current. Thus, a user may calculate the internal resistance value of the battery under test 900 according to the voltage value of the detection voltage applied and the value of the current value measured by the data acquisition device 120. For example, a user may divide the voltage value of the detection voltage by the current value measured by the data acquisition device 120 to calculate the internal resistance value of the battery under test 900.

[0055] Preferably, the voltage value of the detection voltage and the current value of the detection current may be determined according to requirements. In a specific embodiment, the detection current increases as the thickness of the oxide layer increases so as to be sufficient to promote the occurrence of carrier tunneling. In a specific embodiment, the detection voltage increases as the thickness of the oxide layer increases, or the magnitude of the voltage value of the detection voltage may be adjusted according to the level of oxidation of the battery under test 900 or the thickness of the oxide layer (that is, the thickness of the oxide layer 912 of the first end portion 910 of the battery under test 900), so as to ensure that a voltage value with a magnitude sufficient for triggering the occurrence of the carrier tunneling is provided. The reference formula is E=V / d, where E represents an electric field, represent a potential difference, and d represents a distance along a direction of the electric field. For example, as the level of oxidation of the battery gets higher, the thickness of the oxide layer on the surface on the electrode of the battery under test gets thicker, and this means that the distance (d) along the direction of theelectric field also increases. At this point, a greater voltage (V) needs to be provided in order to form a greater electric field (E), which causes charges on the surface of the probe 116 to be rearranged and stacked at the sharp tip of the probe, so as to assist electrons to depart from the sharp tip of the probe, pass through the oxide layer (or referred to as an insulating layer) and arrive at the surface of the electrode of the battery under test.

[0056] It should be noted that, when an electric field in a specific direction is applied, the potential energy of a material may change, and this may directly affect the ionization energy of electrons (that is, energy needed for electrons to depart from the surface of the material) and may also indirectly change a potential energy difference between of a material and a material, hence increasing or reducing difficulties for conduction of electrons between the material and the material. FIG. 7 shows a schematic diagram of potential distribution between a probe and a battery under test when an electric field of a specific direction is applied in a system of measuring battery internal resistance according to a specific embodiment of the present invention. Referring to FIG. 7, when the battery internal resistance system applies an electric field in an opposite direction, the potential energy of a sharp tip 16a of a probe is lower and the ionization energy of electrons is large. At this point, it is more difficult for an electron 8 to depart from the surface of the sharp tip 16a of the probe. Moreover, the potential energy difference between the sharp tip 16a of the probe and the potential energy of an oxide layer 12 is also larger. In sum, it is not easy for the electron 8 to depart from the surface of the sharp tip 16a of the probe, and also difficult to exceed the potential energy difference between the sharp tip 16a of the probe and the oxide layer 12. As a result, carrier tunneling of the electron is less likely to occur, and has a success rate of only about 11.1%. Incomparison, by applying an electric field in a specific direction as shown in FIG. 2a and FIG. 2b, under the effect of the electric field, the potential energy of the sharp tip 216a of the probe is increased and the potential energy difference from the oxide layer 912 is reduced. The electric field promotes the electron 800 at the probe sharp tip 216a to be rearranged and stacked at the sharp tip and eventually depart from the surface of the sharp tip 216a of the probe, and inevitably becomes capable of passing through the oxide layer 912 to arrive at the first tip portion 910 of the battery under test. Thus, carrier tunneling of the electron is likely to occur, and has a success rate of about 88.8%.

[0057] Refer to FIG. 6 showing a flowchart of a method of measuring battery internal resistance according to a specific embodiment of the present invention. In the embodiment shown in FIG. 6, the method 600 of measuring battery internal resistance is for measuring an internal resistance value of a battery under test. The battery under test includes a first end portion and a second end portion, and the first end portion of the battery under test has an oxide layer. The method 600 of measuring battery internal resistance begins at step 610 to connect a first connection terminal and a second connection terminal of a power supply device to the first end portion and the second end portion of the battery under test, respectively (wherein the one of the first connection terminal and the second connection terminal has a probe), and contact a probe of the power supply device with the oxide layer of the battery under test.

[0058] Next, step 620 is performed to connect a data acquisition device to the battery under test and the power supply device. Next, step 630 is performed to communicatively connect a calculation device to the power supply device and / or the data acquisition device. Next, step 640 is performed to supply power to thebattery under test by the power supply device via the probe to enable electrons to pass through the oxide layer and arrive at the first end portion to thereby generate a tunneling current. Wherein, the power supply device is electrically connected to the data acquisition device and the battery under test to form a loop. Next, step 650 is performed to measure a current value of the tunneling current and a voltage value of the battery under test by the data acquisition device. Next, step 660 is performed to calculate the internal resistance value of the battery under test by the calculation device according to the voltage value and the current value measured by the data acquisition device.

[0059] In a specific embodiment, the method 600 of measuring battery internal resistance may further include a step of: connecting the power supply device to the battery under test in parallel. In a specific embodiment, the method 600 of measuring battery internal resistance may further include a step of: connecting the data acquisition device to the battery under test in series. In a specific embodiment, the method 600 of measuring battery internal resistance may further include a step of: forming a loop by the power supply device, the data acquisition device and the battery under test.

[0060] In a specific embodiment, the probe may have a blunt tip and a sharp tip. The method 600 of measuring battery internal resistance may further include a step of: providing an electron flow along a direction from the blunt tip of the probe toward the sharp tip by the power supply device. In a specific embodiment, the first end portion of the battery under test is a positive terminal, and the second end portion of the battery under test is a negative terminal. The method 600 of measuring battery internal resistance may further include a step of: providing an electron flowalong a direction from a positive terminal of the battery under test toward a negative terminal of the battery under test by the power supply device.

[0061] In a specific embodiment, the method 600 of measuring battery internal resistance may further include a step of: providing the battery under test with a test current along a direction from the negative terminal of the battery under test toward the positive terminal by the power supply device. In a specific embodiment, the probe may have a blunt tip and a sharp tip. The method 600 of measuring battery internal resistance may further include a step of: providing the battery under test with a test current along a direction from the sharp tip of the probe toward the blunt tip by the power supply device. In a specific embodiment, the method 600 of measuring battery internal resistance may further include a step of: providing a voltage at the battery under test by the power supply device, such that a potential of the first end portion is less than a potential of the second end portion.

[0062] In a specific embodiment, the method 600 of measuring battery internal resistance may further include a step of: applying a detection voltage to the battery under test by the power supply device via the probe, such that carrier tunneling occurs in the battery under test and a tunneling current is generated. In a specific embodiment, the first end portion of the battery under test is a positive terminal, and the second end portion of the battery under test is a negative terminal. The method 600 of measuring battery internal resistance may further include a step of: connecting the probe of the first connection terminal of the power supply device to the positive terminal, and connecting the second connection terminal of the power supply device to the negative terminal.

[0063] In a specific embodiment, the method 600 of measuring battery internal resistance may further include steps of: providing a detection current at the loop bythe power supply device, measuring a cross voltage on the loop by the data acquisition device, and calculating the internal resistance value of the battery under test by the calculation device according to the detection current and the cross voltage measured by the data acquisition device. In a specific embodiment, the method 600 of measuring battery internal resistance may further include steps of: providing a detection voltage at the loop by the power supply device, measuring a current on the loop by the data acquisition device, and calculating the internal resistance value of the battery under test by the calculation device according to the detection voltage and the current measured by the data acquisition device. In a specific embodiment, the detection voltage increases as a thickness of the oxide layer increases.

[0064] Up to this point, the system of measuring battery internal resistance and the method thereof of the present invention have been described in detail by way of the above description and drawings. It should be understood that, with the system of measuring battery internal resistance and the method thereof of the present invention, without needing a user to first remove an oxide layer on a first end portion of a battery under test, the internal resistance value of the battery under test 900 can be measured by employing the principle of field emission (EM), or referred to as carrier tunneling. It should be understood that, in addition to being performed separately, one or more of the various embodiments described above may be selectively combined with one another and be performed in parallel. Moreover, it should be understood that, the specific embodiments of the present invention are for illustration purposes, and various modifications that may be made without departing from the scope of claims and spirit of the present invention are to be encompassed within the scope of the appended claims. Therefore, the specificembodiments given in the description of the present disclosure are not to be construed as limitations to the present invention, and the essential scope and spirit of the present invention are as disclosed in the appended claims.

Claims

CLAIMS:What is claimed is:

1. A system of measuring battery internal resistance, for measuring an internal resistance value of a battery under test, the battery under test comprising a first end portion and a second end portion, and the first end portion having an oxide layer; the system of measuring battery internal resistance comprising: a power supply device, comprising a first connection terminal and a second connection terminal, the first connection terminal and the second connection terminal for electrically connecting to the first end portion and the second end portion of the battery under test, respectively, wherein one of the first connection terminal and the second connection terminal has a probe, wherein the probe is used to contact the oxide layer of the battery under test, and to supply power to the battery under test via the probe, such that an electron passes through the oxide layer and arrives at the first end portion to generate a tunneling current; a data acquisition device, electrically connected to the battery under test and the power supply device to form a loop, wherein the data acquisition device measuring a current value of the tunneling current and a voltage value of the battery under test after the tunneling current is generated; and a calculation device, communicatively connected to the power supply device and / or the data acquisition device, the calculation device calculating the internal resistance value of the battery under test according to the voltage value and the current value.

2. The system of measuring battery internal resistance according to claim 1 , wherein the probe has a blunt tip and a sharp tip, and the power supply deviceprovides an electron flow along a direction from the blunt tip of the probe toward the sharp tip.

3. The system of measuring battery internal resistance according to claim 1 , wherein the first end portion is a positive terminal, the second end portion is a negative terminal, and the power supply device provides an electron flow along a direction from the positive terminal of the battery under test toward the negative terminal.

4. The system of measuring battery internal resistance according to claim 3, wherein the power supply device provides the battery under test with a test current, the test current flows in a direction from the negative terminal of the battery under test toward the positive terminal.

5. The system of measuring battery internal resistance according to claim 1 , wherein the probe has a blunt tip and a sharp tip, the power supply device provides the battery under test with a test current, the test current flows in a direction from the sharp tip of the probe toward the blunt tip.

6. The system of measuring battery internal resistance according to claim 1 , wherein the power supply device provides a voltage to the battery under test, such that a potential of the first end portion is less than a potential of the second end portion.

7. The system of measuring battery internal resistance according to claim 1 , wherein the power supply device applies a detection voltage to the battery under test via the probe, such that carrier tunneling occurs in the battery under test and the tunneling current is generated.

8. The system of measuring battery internal resistance according to claim 1 , wherein the first end portion of the battery under test is a positive terminal, thesecond end portion of the battery under test is a negative terminal, the probe of the first connection terminal of the power supply device is connected to the positive terminal, and the second connection terminal of the power supply device is connected to the negative terminal.

9. The system of measuring battery internal resistance according to claim 1 , wherein the power supply device provides a detection current at the loop, and the data acquisition device measures a cross voltage of the battery under test; wherein the calculation device calculates the internal resistance value of the battery under test according to the detection current and the cross voltage.

10. The system of measuring battery internal resistance according to claim 9, wherein the detection current increases as a thickness of the oxide layer increases.

11. The system of measuring battery internal resistance according to claim 1 , wherein the power supply device provides a detection voltage at the loop, and the data acquisition device measures a current on the loop; wherein the calculation device calculates the internal resistance value of the battery under test according to the detection voltage and the current.

12. The system of measuring battery internal resistance according to claim 11 , wherein the detection voltage increases as a thickness of the oxide layer increases.

13. A method of measuring battery internal resistance, for measuring an internal resistance value of a battery under test, the battery under test comprising a first end portion and a second end portion, and the first end portion having an oxide layer; the method of measuring battery internal resistance comprising steps of: connecting a first connection terminal and a second connection terminal of a power supply device to the first end portion and the second end portion of the battery under test, respectively, wherein the one of the first connection terminal andthe second connection terminal has a probe, and contacting the probe of the power supply device with the oxide layer of the battery under test; connecting a data acquisition device to the battery under test and the power supply device; communicatively connecting a calculation device to the power supply device and / or the data acquisition device; supplying power to the battery under test by the power supply device via the probe to enable electrons to pass through the oxide layer and arrive at the first end portion to thereby generate a tunneling current, wherein the power supply device is electrically connected to the data acquisition device and the battery under test to form a loop; measuring a current value of the tunneling current and a voltage value of the battery under test by the data acquisition device; and calculating the internal resistance value of the battery under test according to the voltage value and the current value.

14. The method of measuring battery internal resistance according to claim 13, wherein the probe has a blunt tip and a sharp tip; the method of measuring battery internal resistance further comprising a step of: providing an electron flow along a direction from the blunt tip of the probe toward the sharp tip by the power supply device.

15. The method of measuring battery internal resistance according to claim 13, wherein the first end portion is a positive terminal, and the second end portion is a negative terminal; the method of measuring battery internal resistance further comprising a step of:providing an electron flow along a direction from the positive terminal of the battery under test toward the negative terminal by the power supply device.

16. The method of measuring battery internal resistance according to claim 15, further comprising a step of: providing the battery under test with a test current along a direction from the negative terminal of the battery under test toward the positive terminal by the power supply device.

17. The method of measuring battery internal resistance according to claim 13, wherein the probe has a blunt tip and a sharp tip; wherein the method of measuring battery internal resistance further comprising a step of: providing the battery under test with a test current along a direction from the sharp tip of the probe toward the blunt tip by the power supply device.

18. The method of measuring battery internal resistance according to claim 13, further comprising a step of: providing a voltage to the battery under test by the power supply device, such that a potential of the first end portion is less than a potential of the second end portion.

19. The method of measuring battery internal resistance according to claim 13, further comprising a step of: applying a detection voltage to the battery under test by the power supply device via the probe, such that carrier tunneling occurs in the battery under test and the tunneling current is generated.

20. The method of measuring battery internal resistance according to claim 13, wherein the first end portion of the battery under test is a positive terminal, and the second end portion of the battery under test is a negative terminal; the method of measuring battery internal resistance further comprising a step of:connecting the probe of the first connection terminal of the power supply device to the positive terminal, and connecting the second connection terminal of the power supply device to the negative terminal.

21. The method of measuring battery internal resistance according to claim 13, further comprising steps of: providing a detection current at the loop by the power supply device; measuring a cross voltage on the loop by the data acquisition device; and calculating the internal resistance value of the battery under test by the calculation device according to the detection current and the cross voltage.

22. The method of measuring battery internal resistance according to claim 13, further comprising steps of: providing a detection voltage at the loop by the power supply device; measuring a current on the loop by the data acquisition device; and calculating the internal resistance value of the battery under test by the calculation device according to the detection voltage and the current.

23. The method of measuring battery internal resistance according to claim 22, further comprising a step of: the detection voltage increases as a thickness of the oxide layer increases.

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