Voltage control method of vehicle lithium ion battery series super-capacity module

Abstract

The invention discloses a voltage control method for a vehicle lithium ion battery series super-capacity module, and belongs to the technical field of battery modules. The lithium ion battery and the first switch form a main loop, and meanwhile, the first switch is connected in parallel with a circuit in which the super capacitor and the second switch are connected in series to jointly form a lithium ion battery series super-capacitance module for supplying power to a load; when the lithium ion battery works in a large-current power supply mode, the first switch is switched on, the second switch is switched off, when the output voltage of the lithium ion battery at the discharging tail end drops to a threshold value, the first switch is switched off, the second switch is switched on, and the super capacitor is connected into a main loop in series to supply power to the whole vehicle. The lithium ion battery and the supercapacitor are connected in series through the switch, the voltage of the whole lithium ion battery can be increased at the large-current discharging tail end, the voltage requirement of the whole vehicle is met, the capacity of the battery does not need to be increased, and cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery modules, and in particular to a voltage control method for a super-capacity module of lithium-ion batteries connected in series for vehicles. Background Art

[0002] Since lithium-ion batteries have a higher discharge rate and service life, 12V lithium-ion batteries are increasingly being used in automobiles. In addition to providing normal low-voltage power supply for the entire vehicle, they also provide short-term high-current power supply. However, under short-term high-current power supply conditions, the voltage of the battery at the end of discharge will drop sharply, and current lithium-ion batteries cannot meet the voltage requirements of the entire vehicle. In order to solve this problem, 12V lithium-ion batteries need to consider increasing the battery capacity during the design phase, but this will result in a higher cost for the entire battery pack, so a new solution is urgently needed to solve this problem. Summary of the invention

[0003] In view of the defects of the prior art, the present invention proposes a voltage control method for connecting a lithium-ion battery and a supercapacitor in series through a switch, which can raise the voltage of the entire lithium-ion battery at the end of high-current discharge to meet the requirements of the entire vehicle without increasing the capacity of the battery, thereby reducing the overall cost of the 12V battery pack.

[0004] In order to achieve the above object, the present invention provides a voltage control method for a super-capacity module group of lithium-ion batteries connected in series for a vehicle, comprising:

[0005] The lithium-ion battery and the first switch form a main circuit, and the first switch is connected in parallel with the circuit in series with the supercapacitor and the second switch, together forming a lithium-ion battery series supercapacitor module to supply power to the load;

[0006] When the lithium-ion battery is operating at a high current, the first switch is closed and the second switch is opened, and the lithium-ion battery supplies power to the entire vehicle; at the end of discharge, when the output voltage of the lithium-ion battery drops to a threshold, the first switch is opened and the second switch is closed, and the supercapacitor is connected in series to the main circuit to supply power to the entire vehicle.

[0007] Furthermore, the lithium-ion battery series super-capacity module comprises a battery cell group, a pressure plate, a PCBA board and an upper cover which are sequentially arranged in the U-shaped cavity of the shell from bottom to top;

[0008] The PCBA board is provided with the first switch, the second switch, the positive transfer row and the negative transfer row; the positive and negative electrodes of the battery cell group are welded to the upper surface of the PCBA board through the pressing plate and the PCBA board; the negative electrode of the supercapacitor is connected to the negative transfer row, and the positive electrode of the supercapacitor is welded on the PCBA board; the positive electrode of the battery cell group is connected to the positive transfer row, the negative electrode of the battery cell group is connected to the first switch and the second switch, the other end of the first switch is connected to the negative transfer row, and the other end of the second switch is connected to the positive electrode of the supercapacitor;

[0009] The upper cover is provided with a total positive and negative battery terminals and an interface, and the positive electrode transfer bar and the negative electrode transfer bar are respectively connected to the total positive and negative battery terminals provided on the upper cover;

[0010] The U-shaped cavity of the shell is filled with glue for curing, and cooperates with the upper cover to form the lithium-ion battery series super-capacity module.

[0011] Furthermore, the pressing plate is provided with through holes, and the total positive electrode ear, the total negative electrode ear and the middle series electrode ear of the battery cell group respectively pass through the through holes on the pressing plate and are bent;

[0012] A positive conductive bar and a negative conductive bar are fixed between the PCBA and the pressure plate; the total positive tab of the battery cell group is bent and welded to the positive conductive bar by laser, and the total negative tab of the battery cell group is bent and welded to the negative conductive bar by laser; the middle series tab is sequentially welded with the tabs of the adjacent battery cells by laser to realize the series connection of the battery cell group; PIN pins are respectively provided at the ends of the positive conductive bar and the negative conductive bar; vias are provided on the PCBA board; the PIN pins pass through the vias of the PCBA and are welded to the PCBA board by soldering to realize the connection of the positive and negative electrodes of the battery cell group to the PCBA board.

[0013] Furthermore, a collection board is fixed on the pressing plate for collecting the voltage and the temperature of the tab at each series node of the battery cell group.

[0014] Furthermore, the positive electrode and negative electrode of the supercapacitor are respectively laser welded to the supercapacitor positive electrode conductive bar and the supercapacitor negative electrode conductive bar; the end of the supercapacitor negative electrode conductive bar is provided with a through hole and connected to the negative electrode adapter bar arranged on the PCBA board through screws; the end of the supercapacitor positive electrode conductive bar is provided with a PIN pin, which is soldered to the PCBA board through a through hole arranged on the PCBA board.

[0015] The effective effects of the present invention are:

[0016] The present invention realizes the series connection of the lithium-ion battery and the supercapacitor through a switch, and can raise the voltage of the entire lithium-ion battery at the end of a large current discharge to meet the voltage requirements of the entire vehicle without increasing the capacity of the battery, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a circuit diagram of a voltage control method for a super-capacity module group of lithium-ion batteries for vehicles connected in series according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the overall structure of a super-capacity module of lithium-ion batteries connected in series according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the exploded structure of a super-capacity module of lithium-ion batteries connected in series according to an embodiment of the present invention.

[0020] Figure 4 Schematic diagram of the cover plate structure according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the PCBA board structure of the super-capacity module part of an embodiment of the present invention.

[0022] Figure 6 It is a schematic diagram of the upper cover structure of an embodiment of the present invention.

[0023] Wherein: 10, shell, 20, battery cell group, 21, total positive ear of battery cell group, 22, total negative ear of battery cell group, 23, middle series ear of battery cell group, 30, pressure plate, 40, positive conductive bar of battery cell, 41, PIN pin of positive conductive bar of battery cell, 50, negative conductive bar of battery cell, 51, PIN pin of negative conductive bar of battery cell, 60, acquisition board, 70, supercapacitor, 80, supercapacitor negative conductive bar, 90, supercapacitor positive conductive bar, 91, PIN pin of supercapacitor negative conductive bar, 100, PCBA, 101, first switch, 102, second switch, 103, positive transfer bar, 104, negative transfer bar, 110, transfer bar, 120, upper cover, 121, total positive of battery on upper cover, 122, total negative of battery on upper cover. DETAILED DESCRIPTION

[0024] The present invention will be further explained below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, the embodiment of the present invention provides a voltage control method for a super-capacity module group of lithium-ion batteries connected in series for a vehicle, comprising:

[0026] The lithium-ion battery and the first switch are connected in series to form a main circuit; at the same time, the first switch is connected in parallel with the circuit in which the supercapacitor and the second switch are connected in series, together forming a lithium-ion battery series supercapacitor module to supply power to the load.

[0027] When the lithium-ion battery works normally, the first switch is closed, the second switch is opened, the main circuit is connected, and the lithium-ion battery outputs voltage to power the entire vehicle.

[0028] When the lithium-ion battery is operating at a high current, the first switch is closed and the second switch is opened. At the end of discharge, when the output voltage of the lithium-ion battery drops to a threshold, the first switch is opened and the second switch is closed, and the supercapacitor is connected in series to the main circuit to power the entire vehicle.

[0029] Since supercapacitors have the ability to discharge large currents in a short period of time, they can raise the voltage of the entire battery pack at the end of the large current discharge to meet the voltage requirements of the entire vehicle; this eliminates the need to increase the capacity of the battery and reduces the overall cost of the 12V battery pack.

[0030] like Figure 2 , Figure 3 As shown, the lithium-ion battery series super-capacity module includes a battery cell group, a pressure plate, a PCBA board and an upper cover which are arranged in sequence from bottom to top in a U-shaped cavity of a shell.

[0031] like Figure 4 As shown, a through hole is provided on the pressing plate, and the total positive electrode ear, the total negative electrode ear and the middle series electrode ear of the battery cell group pass through the through holes on the pressing plate respectively and are bent; the positive electrode conductive bar and the negative electrode conductive bar of the battery cell are fixed between the PCBA and the pressing plate; the total positive electrode ear of the battery cell group is bent and welded to the positive electrode conductive bar of the battery cell by laser, and the total negative electrode ear of the battery cell group is bent and welded to the negative electrode conductive bar of the battery cell by laser; the middle series electrode ear is sequentially laser welded with the electrode ears of the adjacent battery cells to realize the series connection of the battery cell group.

[0032] like Figure 5 As shown, PIN pins are respectively provided at the ends of the positive conductive bar of the battery cell and the negative conductive bar of the battery cell; via holes are provided on the PCBA board; the PIN pins pass through the via holes of the PCBA and are soldered to the PCBA board by tin soldering, so that the positive and negative electrodes of the battery cell group are connected to the PCBA board.

[0033] A collection board is also fixed on the pressure plate to collect the voltage at each series node of the battery cell group and the temperature of some tabs.

[0034] The collection board, the positive electrode conductive bar of the battery cell and the negative electrode conductive bar of the battery cell can be fixed on the pressing plate by screws, and can also be fixed on the pressing plate by a hot riveting process.

[0035] The positive and negative electrodes of the supercapacitor are laser welded to the supercapacitor positive conductive bar and the supercapacitor negative conductive bar respectively; a through hole is provided at the end of the supercapacitor negative conductive bar and connected to the negative electrode transfer bar arranged on the PCBA board through screws; a PIN foot is provided at the end of the supercapacitor positive conductive bar, which passes through the via hole of the PCBA board and is soldered to the PCBA board.

[0036] The PCBA board is provided with a first switch, a second switch, a positive electrode transfer row and a negative electrode transfer row; the positive and negative electrodes of the battery cell group are welded to the upper surface of the PCBA board through a pressing plate and a PCBA board; the negative electrode of the supercapacitor is connected to the negative electrode transfer row, and the positive electrode of the supercapacitor is welded on the PCBA board; the positive electrode of the battery cell group is connected to the positive electrode transfer row, the negative electrode of the battery cell group is connected to the first switch and the second switch, the other end of the first switch is connected to the negative electrode transfer row, and the other end of the second switch is connected to the positive electrode of the supercapacitor.

[0037] like Figure 6 As shown, the upper cover is provided with a total battery positive and a total battery negative interface, and the positive electrode adapter bar and the negative electrode adapter bar are respectively connected to the total battery positive and the total battery negative provided on the upper cover, and all circuit connections in the above module are completed.

[0038] The U-shaped cavity of the shell is filled with glue for curing, and together with the upper cover, a lithium-ion battery series super-capacity module is formed.

[0039] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A voltage control method for a super-capacity module group of lithium-ion batteries for vehicles, characterized in that: The lithium-ion battery and the first switch form a main circuit, and the first switch is connected in parallel with the circuit in series with the supercapacitor and the second switch, together forming a lithium-ion battery series supercapacitor module to supply power to the load; When the lithium-ion battery is operating at a high current, the first switch is closed and the second switch is opened, and the lithium-ion battery supplies power to the entire vehicle; at the end of discharge, when the output voltage of the lithium-ion battery drops to a threshold, the first switch is opened and the second switch is closed, and the supercapacitor is connected in series to the main circuit to supply power to the entire vehicle.

2. The voltage control method of the automotive lithium-ion battery series super-capacity module according to claim 1, characterized in that: The lithium-ion battery series super-capacity module comprises a battery cell group, a pressure plate, a PCBA board and an upper cover which are sequentially arranged in a U-shaped cavity of the shell from bottom to top; the first switch, the second switch setting, the positive electrode transfer row and the negative electrode transfer row are arranged on the PCBA board; the positive and negative electrodes of the battery cell group pass through the pressure plate and the PCBA board and are welded to the upper surface of the PCBA board; the negative electrode of the supercapacitor is connected to the negative electrode transfer row, and the positive electrode of the supercapacitor is welded on the PCBA board; the positive electrode of the battery cell group is connected to the positive electrode transfer row, the negative electrode of the battery cell group is connected to the first switch and the second switch, the other end of the first switch is connected to the negative electrode transfer row, and the other end of the second switch is connected to the positive electrode of the supercapacitor; The upper cover is provided with a total positive and negative battery terminals and an interface, and the positive electrode transfer bar and the negative electrode transfer bar are respectively connected to the total positive and negative battery terminals provided on the upper cover; The U-shaped cavity of the shell is filled with glue for curing, and cooperates with the upper cover to form the lithium-ion battery series super-capacity module.

3. The voltage control method of the automotive lithium-ion battery series super-capacity module according to claim 2, characterized in that: The pressing plate is provided with through holes, and the total positive electrode ear, the total negative electrode ear and the middle series electrode ear of the battery cell group pass through the through holes on the pressing plate and are bent respectively; A positive conductive bar and a negative conductive bar are fixed between the PCBA and the pressure plate; the total positive tab of the battery cell group is bent and welded to the positive conductive bar by laser, and the total negative tab of the battery cell group is bent and welded to the negative conductive bar by laser; the middle series tab is sequentially welded with the tabs of the adjacent battery cells by laser to realize the series connection of the battery cell group; PIN pins are respectively provided at the ends of the positive conductive bar and the negative conductive bar; vias are provided on the PCBA board; the PIN pins pass through the vias of the PCBA and are welded to the PCBA board by soldering to realize the connection of the positive and negative electrodes of the battery cell group to the PCBA board.

4. The voltage control method of the automotive lithium-ion battery series super-capacity module according to claim 2, characterized in that: A collection board is also fixed on the pressing plate to collect the voltage at each series node of the battery cell group and the temperature of the tab.

5. The voltage control method of the automotive lithium-ion battery series super-capacity module according to claim 2, characterized in that: The positive electrode and negative electrode of the supercapacitor are respectively laser welded to the supercapacitor positive electrode conductive bar and the supercapacitor negative electrode conductive bar; the end of the supercapacitor negative electrode conductive bar is provided with a through hole connected to the negative electrode adapter bar arranged on the PCBA board through screws; the end of the supercapacitor positive electrode conductive bar is provided with a PIN pin, which is soldered to the PCBA board through the through hole arranged on the PCBA board.

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