阅读说明：本技术 电池组、对该电池组进行电压采集、电池能量均衡的方法 (Battery pack and method for voltage acquisition and battery energy equalization of battery pack ) 是由 丁远雷 郑洪河 于 2021-08-03 设计创作，主要内容包括：公开一种电池组、对该电池组进行电压采集、电池能量均衡的方法,该电池组包括多个串联的可充电电池,可充电电池包括：电芯、设在电芯两相对的端部上的正极耳和负极耳；其特征在于,其中至少一个可充电电池的电芯还设有辅助极耳；其中,辅助极耳被配置为其电位与正极耳和负极耳中之一的电位是相等的,且至少部分辅助极耳用于与进行电压采集和/或进行电池能量均衡的线路连接。采用该设计的电池组对方便电压的采集、电池能量均衡是有利的。(Disclosed are a battery pack and a method for performing voltage acquisition and battery energy equalization on the battery pack, wherein the battery pack comprises a plurality of rechargeable batteries connected in series, and each rechargeable battery comprises: the battery comprises a battery cell, a positive electrode lug and a negative electrode lug, wherein the positive electrode lug and the negative electrode lug are arranged on two opposite end parts of the battery cell; the rechargeable battery is characterized in that the electric core of at least one rechargeable battery is also provided with an auxiliary tab; wherein the auxiliary tab is configured to have a potential equal to the potential of one of the positive tab and the negative tab, and at least a portion of the auxiliary tab is used for connection with a line for voltage acquisition and/or battery energy equalization. The battery pack adopting the design is beneficial to facilitating voltage acquisition and battery energy balance.)

1. A battery pack comprising a plurality of rechargeable batteries connected in series, the rechargeable batteries comprising: the battery comprises a battery cell, a positive electrode lug and a negative electrode lug, wherein the positive electrode lug and the negative electrode lug are arranged on two opposite end parts of the battery cell; the rechargeable battery is characterized in that at least one battery core of the rechargeable battery is also provided with an auxiliary tab; wherein the auxiliary tab is configured to have the same potential as one of the positive tab and the negative tab, and at least part of the auxiliary tab is used for connecting with a line for voltage acquisition and/or battery energy equalization.

2. The battery pack of claim 1 wherein all of the rechargeable batteries are provided with an auxiliary tab and are connected in series in single columns and multiple rows; the auxiliary tabs of the rechargeable batteries on all the odd-numbered rows are positioned on the same first side, and the auxiliary tabs of the rechargeable batteries on all the even-numbered rows are positioned on the same second side; the first side and the second side are opposite sides.

3. The battery pack of claim 1, wherein all of the rechargeable batteries are arranged in series in a single row and multiple rows; the rechargeable batteries in all the odd rows are not provided with auxiliary lugs, and the auxiliary lugs arranged on the rechargeable batteries in all the even rows are positioned on the same side; or, the auxiliary tabs are not arranged on all the rechargeable batteries in the even rows, and the auxiliary tabs arranged on all the rechargeable batteries in the odd rows are positioned on the same side.

4. The battery pack of claim 1, wherein all of the rechargeable batteries are arranged in a series of a plurality of columns and a plurality of rows; the rechargeable batteries on the odd-numbered rows and the rechargeable batteries on the even-numbered rows and the odd-numbered rows are not provided with auxiliary lugs, and the rechargeable batteries on the odd-numbered rows and the rechargeable batteries on the even-numbered rows and the auxiliary lugs are positioned on two opposite sides;

Alternatively, the first and second electrodes may be,

the rechargeable batteries positioned on the odd-numbered rows and the rechargeable batteries positioned on the even-numbered rows are not provided with auxiliary tabs, and the rechargeable batteries positioned on the odd-numbered rows and the rechargeable batteries positioned on the even-numbered rows are provided with auxiliary tabs at two opposite sides.

5. The battery pack of claim 1, wherein the auxiliary tab is provided at least one end of the cell and is at the same potential as a tab provided at the other end of the cell.

6. The battery according to claim 1, wherein the auxiliary tab and the tab having the same potential as the auxiliary tab are welded to a non-coated exposed position of the same electrode current collector; the number of the welding points of the auxiliary lug and the current collector is less than that of the welding points of at least one lug and the current collector, and the sectional area of the auxiliary lug is less than that of the positive lug and/or the negative lug.

7. The battery pack of claim 1, wherein the battery pack comprises a plurality of battery cells arranged in series, each of the battery cells comprising at least two rechargeable batteries connected in parallel; wherein at least one rechargeable battery contained in at least one battery unit is provided with the auxiliary tab.

8. The battery pack of claim 1, wherein the rechargeable battery comprises at least one of:

lithium ion batteries and sodium ion batteries.

9. A method of voltage harvesting a battery pack according to any of claims 1 to 8, comprising: and a voltage acquisition line is led out from the auxiliary lug and is connected to a voltage detection device so as to acquire the voltage of the corresponding rechargeable battery based on the voltage detection device.

10. A method of cell energy equalization of a battery according to any of claims 1 to 8, comprising: and a battery energy balancing line is led out from the auxiliary lug and is connected to a balancing circuit so as to balance the energy of the corresponding rechargeable battery based on the balancing circuit.

Technical Field

The invention relates to the field of new energy batteries, in particular to a battery pack and a method for voltage acquisition and battery energy balance of the battery pack.

Background

With the development of productivity, technological progress and people's attention to natural environment and energy efficiency. The energy storage device is widely applied to the fields of digital codes, electric energy storage and new energy automobiles. With the rapid development of new energy automobiles, the usage amount of rechargeable batteries such as lithium ion batteries and sodium ion batteries is rapidly increasing.

The rechargeable battery may be classified into a cylindrical rechargeable battery, a prismatic rechargeable battery, and a pouch rechargeable battery according to the packaging manner. Taking a soft package lithium ion battery as an example, the soft package lithium ion battery is the most widely applied battery type in the digital field due to the advantages of high energy density, relative safety and the like, and is also widely used in the field of new energy automobiles.

In order to be integrated with a vehicle body conveniently, rechargeable batteries such as soft package lithium ion batteries and the like are generally designed to be long and narrow, namely, the battery core is longer and narrower. The positive and negative electrodes of the battery are output from two ends, namely the positive and negative electrode lugs are arranged on two sides of the battery.

The voltage of a power system designed for the new energy automobile is generally larger than 300V, and the voltage of a single body of rechargeable batteries such as lithium ion batteries is generally only 2.0-4.3V. Therefore, tens or even hundreds of unit cells need to be connected in series to obtain a target high voltage. In order to prevent the battery life from being influenced by the over/under voltage of a single battery and bring about potential safety hazards, voltage monitoring needs to be carried out on each battery. Further, in order to prevent the SOC difference of each series battery from affecting the battery life and reducing the electric energy storage capacity of the battery pack, it is necessary to equalize the energy of the batteries.

The positive and negative electrodes of the rechargeable battery monomers are positioned at two sides of the battery, and each battery connected in series needs a lead with the length larger than the length of the battery core of the monomer for connection so as to finish voltage acquisition and battery energy balance management. This situation leads to a complex circuit, increases the difficulty of the assembly process, and brings about a potential safety hazard.

Disclosure of Invention

In view of the above, the present invention provides a battery pack and a method for performing voltage acquisition and battery energy equalization on the battery pack.

A battery pack comprising a plurality of rechargeable batteries connected in series, the rechargeable batteries comprising: the battery comprises a battery cell, a positive electrode lug and a negative electrode lug, wherein the positive electrode lug and the negative electrode lug are arranged on two opposite end parts of the battery cell; the rechargeable battery is characterized in that at least one battery core of the rechargeable battery is also provided with an auxiliary tab; wherein the auxiliary tab is configured to have the same potential as one of the positive tab and the negative tab, and at least part of the auxiliary tab is used for connecting with a line for voltage acquisition and/or battery energy equalization.

Optionally, all the rechargeable batteries are provided with an auxiliary tab, and all the rechargeable batteries are connected in series in a single row and multiple rows; the auxiliary tabs of the rechargeable batteries on all the odd-numbered rows are positioned on the same first side, and the auxiliary tabs of the rechargeable batteries on all the even-numbered rows are positioned on the same second side; the first side and the second side are opposite sides.

Optionally, all the rechargeable batteries are arranged in series in a single row and multiple rows; the rechargeable batteries in all the odd rows are not provided with auxiliary lugs, and the auxiliary lugs arranged on the rechargeable batteries in all the even rows are positioned on the same side; or, the auxiliary tabs are not arranged on all the rechargeable batteries in the even rows, and the auxiliary tabs arranged on all the rechargeable batteries in the odd rows are positioned on the same side.

Optionally, all the rechargeable batteries are arranged in a series connection mode of a plurality of columns and a plurality of rows; the rechargeable batteries on the odd-numbered rows and the rechargeable batteries on the even-numbered rows and the odd-numbered rows are not provided with auxiliary lugs, and the rechargeable batteries on the odd-numbered rows and the rechargeable batteries on the even-numbered rows and the auxiliary lugs are positioned on two opposite sides;

alternatively, the first and second electrodes may be,

the rechargeable batteries positioned on the odd-numbered rows and the rechargeable batteries positioned on the even-numbered rows are not provided with auxiliary tabs, and the rechargeable batteries positioned on the odd-numbered rows and the rechargeable batteries positioned on the even-numbered rows are provided with auxiliary tabs at two opposite sides.

Optionally, the auxiliary tab is disposed at least one end of the battery cell, and is equal to a tab disposed at the other end of the battery cell in potential.

Optionally, the battery pack includes a plurality of battery units arranged in series, each battery unit includes at least two rechargeable batteries connected in parallel; wherein at least one rechargeable battery contained in at least one battery unit is provided with the auxiliary tab.

Optionally, all the rechargeable batteries contained in each battery unit are provided with auxiliary tabs; the auxiliary tabs arranged on the rechargeable batteries contained in the two adjacent battery units are positioned on two opposite sides.

Optionally, the positive tab is disposed at the first end of the battery cell, and the auxiliary tab and the negative tab are disposed at the second end of the battery cell; or the auxiliary lug and the positive lug are arranged at the first end of the battery cell, and the negative lug is arranged at the second end of the battery cell.

Optionally, the auxiliary tab and the tab with the same potential as the auxiliary tab are welded at the non-coating exposed position of the same electrode current collector; the number of the welding points of the auxiliary lug and the current collector is less than that of the welding points of at least one lug and the current collector, and the sectional area of the auxiliary lug is less than that of the positive lug and/or the negative lug.

Optionally, the rechargeable battery comprises at least one of:

Lithium ion batteries and sodium ion batteries.

A method for collecting voltage of a battery pack according to any one of the above embodiments, comprising: and a voltage acquisition line is led out from the auxiliary lug and is connected to a voltage detection device so as to acquire the voltage of the corresponding rechargeable battery based on the voltage detection device.

A method for equalizing battery energy of a battery pack according to any one of the above embodiments, comprising: and a battery energy balancing line is led out from the auxiliary lug and is connected to a balancing circuit so as to balance the energy of the corresponding rechargeable battery based on the balancing circuit.

The invention adopts the design of the auxiliary tab, and can at least obtain the following beneficial effects:

1. the lengths of the wires of the voltage acquisition circuit and the battery energy balance circuit are shortened, and the material cost is saved.

2. The integration of the BMS system is spatially facilitated, which facilitates optimization of the battery structure.

3. In safety, the low-voltage system and the high-voltage system are separated in space, so that the interference of a high-voltage circuit to the low-voltage system is reduced, the stability of the system is improved, and the safety of the system is also improved.

The improvement of the invention greatly optimizes the voltage acquisition and battery management of the battery pack suitable for the large array, which is extremely beneficial to the application and popularization of the battery pack of the large array to the current popular fields such as new energy automobiles.

Drawings

Fig. 1 is a schematic structural view of a rechargeable battery according to the prior art;

fig. 2 is a schematic structural view of a battery pack constructed using the rechargeable battery shown in fig. 1;

FIG. 3 is a schematic structural diagram of a rechargeable battery according to the present invention;

fig. 4 to 8 are schematic structural views of a battery pack constructed using the rechargeable battery shown in fig. 3.

Detailed Description

As shown in fig. 1, a conventional rechargeable battery 100 includes a battery cell 101, and a positive electrode tab 102 and a negative electrode tab 103 provided on opposite ends of the battery cell 101.

As shown in fig. 2, when voltage acquisition and/or battery energy equalization needs to be performed on each rechargeable battery 100 in a battery pack formed by connecting the rechargeable batteries 100 in series as shown in fig. 1, for example, when voltage acquisition and/or battery energy equalization is performed on the uppermost rechargeable battery 100 in fig. 2, a line having a length greater than that of the battery 100 crosses the length direction of the battery 100 to the left and right ends thereof. In the case that the entire battery pack is formed by connecting dozens or even hundreds of batteries 100 in series, it is obvious that the above scheme causes a problem that the acquisition line and/or the battery energy balancing line are complicated.

As shown in fig. 3, the rechargeable battery 200 of the present invention includes a cell 201, a positive tab 202, and a negative tab 203, which are the same as or similar to the above-described structure, except that an auxiliary tab 204 is added, and the auxiliary tab 204 is configured to have a potential equal to that of one of the positive tab 202 and the negative tab 203.

Specifically, the auxiliary lug and the lug with the same potential as the auxiliary lug are welded at the non-coating exposed position of the same electrode current collector, so that the auxiliary lug and the corresponding lug are at the same potential.

In a specific embodiment, the rechargeable battery includes at least one of:

lithium ion batteries and sodium ion batteries.

Optionally, the rechargeable battery mainly comprises a positive electrode, a negative electrode, a diaphragm, electrolyte and a packaging material.

In a specific embodiment, taking a rechargeable battery as a soft package lithium ion battery in a lithium ion battery as an example, the positive electrode mainly comprises a positive current collector (generally, an aluminum foil), a positive active material, a conductive agent and an adhesive, wherein the positive active material may be lithium cobaltate, lithium iron phosphate, lithium manganate or a ternary positive material, the positive active material is mixed with the conductive agent and the adhesive and then coated on the positive current collector, and a positive tab (generally, an aluminum metal material) is welded at a non-coated exposed position of the positive current collector.

Similarly, the negative electrode is mainly composed of a negative electrode current collector (typically, copper foil), a negative electrode active material, a conductive agent, and a binder. The negative active material can be graphite, hard carbon, lithium titanate or silicon, etc., the negative active material is mixed with a conductive agent and a binder and then coated on a negative current collector, and a negative pole lug (generally a copper, nickel or copper-nickel alloy material) is welded at a non-coating exposed position of the negative current collector.

Specifically, the auxiliary tab is disposed at least at one end of the battery cell and has the same potential as the tab disposed at the other end of the battery cell.

Optionally, the cell conforms to the characteristics of the elongated structure design, for example, the cell thickness is between 5 and 40mm, and further preferably between 8 and 20 mm. The width is 40 to 200mm, and more preferably 70 to 150 mm. The length is between 100 and 1700mm, and more preferably between 300 and 1200 mm. Thus, the cell has two opposite ends along the length direction: a first end and a second end. The positive electrode tab and the negative electrode tab are respectively provided at the two end portions.

In an alternative embodiment, the positive tab is disposed at the first end of the cell, and the auxiliary tab and the negative tab are disposed at the second end of the cell. Specifically, the auxiliary tab may be welded to the positive current collector, and the auxiliary tab serves as an auxiliary positive tab.

In another alternative embodiment, the auxiliary tab and the positive tab are disposed at the first end of the battery cell, and the negative tab is disposed at the second end of the battery cell. Specifically, the auxiliary tab may be welded to the negative current collector, and the auxiliary tab serves as an auxiliary negative tab.

On the basis of the above structure, it is optimal or preferable that the number of the auxiliary tabs is configured to be one. The reason is that the cost is maximally reduced in the case of satisfying the demand.

In the present invention, the rechargeable battery may be assembled by a lamination or winding process, preferably a lamination production process. Because the auxiliary lug is only used for voltage acquisition or battery capacity equalization, the passing current is very small. Therefore, in an alternative embodiment, the sectional area of the auxiliary tab may be reduced, and accordingly, the sectional area of the auxiliary tab is smaller than that of the positive tab and/or the negative tab; in addition, the number of welding points with the current collector can be reduced properly.

The battery pack provided by the invention comprises a plurality of rechargeable batteries connected in series. The rechargeable battery is characterized in that at least one rechargeable battery accords with the structural design of the added auxiliary lug, and specifically, at least part of the auxiliary lug is used for being connected with a line for voltage acquisition and/or battery energy balance.

Optionally, the line for performing voltage acquisition and the line for performing battery energy balancing may be the same line. Optionally, voltage acquisition and battery energy equalization may be performed simultaneously based on the line; alternatively, only voltage acquisition or only battery energy equalization may be performed.

It is noted that, by the design of the auxiliary tab, the voltage collection and energy equalization circuit of the battery can be completed on the same side of the rechargeable battery, which is extremely beneficial to the optimization of the circuit.

In particular, space constraints are important considerations in a suitable scenario where rechargeable batteries are connected in series to form a battery pack. In the conventional known approach of two-terminal harvesting, the longer size of the battery would greatly grow and complicate the harvesting line. This is disadvantageous for the structure and the design of the BMS (Battery Management System) wiring.

In the embodiment illustrated in fig. 3, the auxiliary tab 204 is disposed at the same end of the cell 201 as the negative tab 203, and the positive tab 202 is disposed at the opposite end of the cell 201. As can be seen from the above description, the auxiliary tab 204 is welded to the positive electrode collector at this time, and thus maintains the same potential as the positive tab 202.

Of course, the auxiliary tab 204 may be disposed at the same end of the battery cell 201 as the positive tab 202, and the negative tab 203 may be disposed at the opposite end of the battery cell 201.

By means of the design, the auxiliary tab 204 is communicated with the corresponding tab through a wire, and the potential of the auxiliary tab is equal to that of the corresponding tab.

Fig. 4 to 8 are battery packs according to different embodiments constructed on the basis of the above-described rechargeable battery 200. In these battery pack embodiments, at least a portion of the auxiliary tabs 204 are used for connection to the circuitry for voltage harvesting and/or battery energy equalization.Because the voltage acquisition circuit is similar to the battery energy balance circuit in structure, the voltage acquisition circuit is taken as the voltage acquisition circuit Example introduction。

As shown in fig. 4, in constructing the first embodiment of the formed battery pack, all the rechargeable batteries 200 are provided with one auxiliary tab 204, and all the rechargeable batteries 200 are arranged in series in a single row and multiple rows.

Wherein the auxiliary tabs 204 of the rechargeable cells 200 on all odd rows are on the same first side and the auxiliary tabs 204 of the rechargeable cells 200 on all even rows are on the same second side. The first side and the second side are opposite sides.

For ease of understanding, rechargeable battery 200 is numbered 1, 2, 3, and 4 … in the top-down direction. The auxiliary tabs 204 of the 1 st and 3 rd rechargeable batteries 200 are located on the right side, and the auxiliary tabs 204 of the 2 nd and 4 th rechargeable batteries 200 are located on the left side.

Taking the voltage collection of the 1 st rechargeable battery 200 as an example, the voltage collection line is connected to the positive electrode of the 1 st rechargeable battery 200 and the auxiliary tab 204 of the 2 nd rechargeable battery 200, and the voltage detection device V1 is disposed on the voltage collection line.

Since the positive tab 202 of the 2 nd rechargeable battery 200 is connected to the negative tab of the first rechargeable battery 200, the positive tab 202 and the auxiliary tab of the 2 nd rechargeable battery 200 are at equal potentials. Therefore, the auxiliary tab of the 2 nd rechargeable battery 200 and the negative electrode of the first rechargeable battery 200 have the same potential. Thus, both ends of the voltage detection device V1 are substantially connected to the positive and negative electrode tabs of the 1 st rechargeable battery 200. Therefore, the connection of the voltage detection device V1 is arranged on one side of the whole battery pack, and the circuit is greatly simplified.

It is noted that the battery pack shown in fig. 4 is such that the auxiliary tabs 204 of all the rechargeable batteries 200 in the odd-numbered rows are left empty and are not wired. Therefore, it is necessary to selectively insulate the auxiliary tabs 204 of the rechargeable batteries 200.

As shown in fig. 5, a second embodiment of an optimized battery pack structural design is provided on the basis of the example of fig. 4. In this embodiment, all the rechargeable batteries 100, 200 are arranged in series in a single row and multiple rows.

All the rechargeable batteries 100 in the odd rows are not provided with auxiliary tabs, that is, the existing rechargeable batteries 100 shown in fig. 1 are used in the odd rows. Auxiliary tabs 204 are disposed on all the even rows of the rechargeable batteries 200, and the auxiliary tabs 204 are located on the same side. That is, the rechargeable battery 200 shown in fig. 3 is used in the even-numbered rows.

Alternatively, all the even-numbered rows of the rechargeable batteries are not provided with the auxiliary tabs, that is, the even-numbered rows adopt the rechargeable battery 100 as shown in fig. 1. All the rechargeable batteries in the odd rows are provided with the auxiliary tabs 204, and the auxiliary tabs 204 are positioned on the same side. That is, the odd rows employ the rechargeable batteries 200 as shown in fig. 3.

In this embodiment, the existing rechargeable battery 100 is used in combination with the rechargeable battery 200 provided by the present invention, and the auxiliary tab 204 does not need to be provided for the battery at some specific positions, but the existing battery is adopted, which is advantageous for reducing the cost.

In the embodiment illustrated in fig. 5, all of the cells are in a single column configuration. Further, as shown in fig. 6, in the third embodiment of the battery pack constructed by using the conventional rechargeable battery 100 in combination with the rechargeable battery 200 of the present invention, all the rechargeable batteries 100 and 200 are arranged in series in a plurality of rows and columns.

The rechargeable batteries 100 on the even rows of the odd columns and the rechargeable batteries 100 on the odd rows of the even columns are not provided with the auxiliary tabs 204, namely, the rechargeable batteries on the even rows of the odd columns and the rechargeable batteries on the odd rows of the even columns adopt the conventional battery structure shown in fig. 1. The rechargeable batteries on the odd rows of the odd columns and the lithium ion batteries on the even rows of the even columns are provided with auxiliary tabs 204, and the auxiliary tabs 204 are positioned on the middle sides of the left and right columns.

In the embodiment illustrated in fig. 6, two columns are taken as an example. The rechargeable batteries 100 in the first even row (1.2, 1.4) on the left side are not provided with the auxiliary tab 204, and the rechargeable batteries 200 in the odd row (1.1, 1.3) are provided with the auxiliary tab 204.

Similarly, the rechargeable batteries 100 in the second odd row (2.1, 2.3) on the right side are not provided with the auxiliary tab 204, and the rechargeable batteries 200 in the even row (2.2, 2.4) are provided with the auxiliary tab 204.

Wherein the auxiliary tab 204 of the rechargeable batteries 200 in the first odd row (1.1, 1.3) is located on the side opposite to the second row, i.e. the right side, and the auxiliary tab 204 of the rechargeable batteries 200 in the second even row (2.2, 2.4) is located on the side opposite to the first row, i.e. the left side.

Optionally, the rechargeable batteries located in odd-numbered rows and the rechargeable batteries located in even-numbered rows and the rechargeable batteries located in odd-numbered rows are not provided with auxiliary tabs, and the rechargeable batteries located in odd-numbered rows and the rechargeable batteries located in even-numbered rows and the auxiliary tabs located in even-numbered rows and the rechargeable batteries located in odd-numbered rows are located at two opposite sides.

It should be noted that in all the above embodiments, the lines connecting the positive and negative electrode tabs of the two adjacent rechargeable batteries 100 and 200 are power lines, which are shown by thick solid lines in the figures. All lines connected to the auxiliary tab 204 are voltage acquisition lines or lines for battery energy equalization, and only a small current needs to be passed, which is shown by a thin solid line in the figure.

In fig. 6, an auxiliary tab of a cell provided with an auxiliary tab is used as a positive electrode auxiliary tab. Arranged according to the above principle, the last left-hand row of rechargeable batteries (1.4) in series has no auxiliary tab, so a wire is required to connect the negative poles of the rechargeable batteries across the rechargeable batteries. To optimize the structure, a rechargeable battery (denoted 1.4') with an auxiliary negative electrode can be selected to achieve the optimum state. Of course, it is also possible to reduce one series unit, i.e. to eliminate the 1.4 position rechargeable battery and the 2.4 position rechargeable battery is the total negative pole of the series system, under the condition that the overall voltage of the system is satisfied.

As shown in fig. 7 and 8, in other modified embodiments, the battery pack includes a plurality of battery cells arranged in series, each battery cell including at least two rechargeable batteries arranged in parallel.

In the embodiment illustrated in fig. 7, two battery cells are schematically illustrated, but not limited thereto. In practice, the line leading from the left side of the lower cell may continue to connect to other cells.

In the exemplary embodiment, each battery cell contains two rechargeable batteries 100/200. Wherein the lower cell contains a rechargeable battery 200 with an auxiliary tab 204.

Since the voltage of the rechargeable battery 100/200 is indicative of the voltage of the cell in which it is located, the auxiliary tab 204 can facilitate voltage collection for two adjacent cells at the same time.

Therefore, in a battery pack constructed by connecting a plurality of battery cells in series, one auxiliary tab 204 can radiate the voltage collection of two battery cells. Therefore, from the viewpoint of structural integration, one auxiliary tab 204 is provided every other group of battery cells. The position of the auxiliary tab 204 may not be limited.

That is, the number of the auxiliary tabs 204 is n/2, and n is the number of the battery cells. When n is an odd number, the number of the auxiliary tabs 204 is rounded, and may be (n-1)/2 or (n + 1)/2.

Of course, in the embodiment illustrated in fig. 8, all of the rechargeable batteries 200 included in each battery cell are provided with the auxiliary tabs 204. The auxiliary tabs 204 provided on the rechargeable batteries 200 included in two adjacent battery units are located at two opposite sides.

In this embodiment, the auxiliary tabs of the odd-numbered rows of cells serve only to connect the unit cells in parallel, and are not used for voltage collection or battery energy equalization.

The invention also provides a method for collecting the voltage of the battery pack of the embodiment, which comprises the step of leading out a voltage collecting line from the auxiliary lug 204, wherein the voltage collecting line is connected to a voltage detection device so as to collect the voltage of the corresponding rechargeable battery based on the voltage detection device.

The invention also provides a method for balancing battery energy of the battery pack of the embodiment, which comprises the step of leading out a battery energy balancing line from the auxiliary lug 204, wherein the battery energy balancing line is connected to a balancing circuit so as to balance the energy of the corresponding rechargeable battery based on the balancing circuit.

It is noted that the connection locations of the other ends of the voltage harvesting lines and/or the battery energy equalization lines leading from the auxiliary tabs 204 are different in different battery pack embodiments. However, the rechargeable battery 200 with the voltage value to be measured can be named as a target battery based on the fact that the auxiliary tab 204 is equal in potential to the positive tab 202 or the negative tab 203 from the same battery cell 201. One of the positive tab 202 or the negative tab 203 of the target battery is equal in potential to the auxiliary tab 204, and the other is connected to the other end of the voltage acquisition line and/or the battery energy equalization line.

For example, taking the battery pack illustrated in fig. 5 as an example, the auxiliary tab 204 provided on the left side of the 2 nd rechargeable battery 200 may be used for voltage collection of the 1 st and 2 nd rechargeable batteries 200. In the case that the 1 st rechargeable battery 100 is the target battery, the potential of the auxiliary tab 204 is equal to that of the negative tab thereof, and the two ends of the voltage collecting line are respectively connected with the auxiliary tab 204 and the positive tab of the 1 st rechargeable battery 100.

Similarly, in the case where the 2 nd rechargeable battery 200 is the target battery, the auxiliary tab 204 and the positive tab thereof have the same potential, and both ends of the voltage collecting line are connected to the auxiliary tab 204 and the negative tab of the 2 nd rechargeable battery 100, respectively.

In the battery pack of other embodiments, the voltage collecting circuit or the battery energy balancing circuit may be connected according to the above-mentioned principles and examples, which are not described herein again.

The above description is only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention based on the disclosure of the invention document without departing from the spirit and scope of the present invention.