Patent Description:
A battery module includes a plurality of battery cells. To monitor parameters such as a voltage and a temperature of each battery cell, a cell management unit is usually disposed in the battery module. In the prior art, the cell management unit is usually disposed on an end plate of the battery module, or is disposed together with a busbar on a harness separator above the battery cells.

The battery cells press against the end plate when swelling. Therefore, if the cell management unit is disposed on the end plate, there is a risk of the cell management unit being deformed and failing under pressure. In addition, the battery cells and the busbar produce much heat during operating. Therefore, if the cell management unit is disposed on the harness separator, there is a technical problem that the cell management unit is heated, resulting in a high temperature.

<CIT> describes an electrical energy store for a vehicle with a housing in which a number of individual cells connected in series and / or in parallel are arranged. A cell monitoring unit is arranged in a further housing which is positioned between individual cells in the housing and forms a force absorption element.

<CIT> describes a power supply device comprising a battery accommodating base and a circuit board, wherein the battery accommodating base comprises two casing frames arranged oppositely. A plurality of accommodating grooves recessed inwards are formed at one end of the two casing frames away from each other so as to load batteries. The circuit board is arranged between the two casing supports and provided with two circuit surfaces, one of the circuit surfaces is opposite to one casing frame, and the other circuit surface is opposite to the other casing frame. The two circuit surfaces are provided with conducting connection pieces respectively corresponding to the accommodating grooves of the two casing frames, the conducting connection pieces can be electrically connected with conducting connection portions of batteries when the batteries are loaded in the accommodating grooves.

<CIT> describes a rechargeable battery module. The rechargeable battery module includes unit cells including rechargeable batteries, a bus bar holder covering the unit cells, a bus bar that is disposed in a bus bar holder and is electrically connected to unit cells, and an end plate and a side plate supporting and accommodating the unit cells.

Therefore, a novel battery module and a manufacturing method thereof need to be provided to resolve the foregoing prior-art technical problem that a cell management unit is vulnerable to a failure under pressure.

To achieve the foregoing objective, the present invention provides a battery module as specified in any one of claims <NUM> to <NUM>. The present invention prevents the cell management unit from failing under swelling pressure of the battery cells. In addition, the present invention prevents over-temperature caused by heating of the battery cells and the busbar, thereby greatly improving reliability of the cell management unit.

Reference numerals in the accompanying drawings are described as follows:.

The accompanying drawings herein are incorporated into and constitute a part of the specification. They show embodiments that conform to this application, and are used in combination with the specification to explain rationale of this application.

To describe in detail the technical content, structural features, and intended objectives and effects of the technical solutions, the following provides detailed descriptions with reference to specific embodiments and accompanying drawings.

Referring to <FIG>, an embodiment provides a battery module.

As shown in <FIG> and <FIG>, the battery module includes a module frame <NUM>, two or more battery groups <NUM>, a middle plate <NUM>, and a cell management unit <NUM>.

The battery group <NUM> includes two or more battery cells <NUM> arranged in order, and two adjacent battery cells <NUM> are disposed with large faces of their housings facing each other. The battery cells <NUM> are energy storage units of the battery module, and are configured to store electrical energy and provide electrical energy to the outside. The battery cells <NUM> in the battery group <NUM> may be connected in series or parallel, and each battery group <NUM> may be provided with a positive output electrode and a negative output electrode. When the battery group <NUM> includes a plurality of battery cells <NUM>, the battery group <NUM> may form a cuboid structure in which large faces of the housings of the battery cells <NUM> face both ends. In a coordinate system in <FIG>, Z1 is an X-axis, that is, a length direction; Z2 is a Y-axis, that is, a width direction; and Z3 is a Z-axis, that is, a height direction.

The module frame <NUM> includes two oppositely disposed end plates <NUM> and two oppositely disposed side plates <NUM>. The end plates <NUM> and the side plates <NUM> are connected to each other end to end to enclose an accommodating cavity for accommodating the battery groups <NUM> (that is, a position at which the battery groups <NUM> are placed). The module frame <NUM> can serve a purpose of fixing and protecting the battery groups <NUM> to prevent the battery groups <NUM> and the battery cells <NUM> from being displaced or being hit or scratched by an external object. The module frame <NUM> may be formed by connecting metal sheets such as aluminum alloy or steel sheets. As shown in <FIG> and <FIG>, the module frame <NUM> may further include cover plates <NUM>. The cover plates <NUM> are disposed above the battery groups <NUM> and serve a purpose of protection at the top.

As shown in <FIG>, at least two battery groups <NUM> can be accommodated in the accommodating cavity for the battery groups <NUM>, and the two battery groups <NUM> are disposed in order along the length direction. The middle plate <NUM> is disposed between the two battery groups <NUM>. Two large faces of the middle plate <NUM> each are opposite to an end face of each of the two battery groups <NUM>. The other end face of each of the two battery groups <NUM> is opposite to one of the two end plates <NUM>. The end plates <NUM> on the one hand can limit positions of the battery groups <NUM> and the battery cells <NUM>, and on the other hand can absorb stress produced when the battery cells <NUM> swell, to prevent the battery cells <NUM> from breaking due to swelling. Here, an end of the module frame is an end in a length direction of the module frame. The middle plate <NUM> is disposed between the two end plates <NUM> and in parallel to the end plates <NUM>, and the middle plate <NUM> is provided with an accommodating groove <NUM> inside. The middle plate <NUM> may be disposed at a middle position between the two end plates <NUM>, or at a non-middle position between the two end plates <NUM>, that is, distances between the middle plate <NUM> and the two end plates <NUM> may be unequal. The middle plate <NUM> may be made of a metal material or another hard material. The cell management unit <NUM> is disposed in the accommodating groove <NUM> of the middle plate <NUM>, and the cell management unit <NUM> is connected to a sampling line <NUM> of the battery cells <NUM> to collect data such as temperature and voltage of the battery cells <NUM>.

The cell management unit <NUM> is configured to collect the data such as voltage and temperature of the battery cells <NUM>, and send the collected data to a cell management system outside the battery module. The cell management unit <NUM> is disposed in the accommodating groove <NUM> of the middle plate <NUM>, and the cell management unit <NUM> is connected to the sampling line <NUM> of the battery cells <NUM>. The sampling line <NUM> may be electrically connected to poles of the battery cells <NUM> to collect the voltage data of the battery cells. Further, the sampling line <NUM> may be connected to a temperature sensor, and the temperature sensor may be in contact with the housings or the poles of the battery cells <NUM> to collect the temperature data of the battery cells <NUM>.

The accommodating groove <NUM> inside the middle plate <NUM> is a slot or a cavity that is able to accommodate the cell management unit <NUM> and that is formed by partially hollowing out the middle plate <NUM>. The accommodating groove <NUM> only needs to be able to accommodate the cell management unit <NUM> and make surfaces of the cell management unit <NUM> not exceed front and rear large faces of the middle plate <NUM>.

The accommodating groove <NUM> is provided inside the middle plate <NUM>, and the surfaces of the cell management unit <NUM> do not exceed the front and rear large faces of the middle plate <NUM>, so that the cell management unit <NUM> is not in contact with end faces of the battery groups <NUM>. Therefore, pressure produced when the battery cells <NUM> swell directly acts on the middle plate <NUM> without acting on the cell management unit <NUM>, thereby preventing the cell management unit <NUM> from being deformed and failing under the swelling pressure of the battery cells <NUM>. Because the middle plate <NUM> is located between two battery groups <NUM>, its temperature is lower than that above the battery cells <NUM>, avoiding over-temperature of the cell management unit <NUM>.

As shown in <FIG>, a separator <NUM> is be disposed at the top of the battery groups <NUM>, and the sampling line <NUM> of the battery cells <NUM> is a flexible circuit board, and disposed on an upper surface of the separator <NUM> at the top of the battery groups <NUM>. The flexible circuit board is also referred to as an FPC, and has advantages such as being thin and bendable. Therefore, it essentially does not occupy space at the top of the battery module, facilitating an energy density of the battery module. In addition, the flexible circuit board being bendable also facilitates wiring of the sampling line <NUM>.

As shown in <FIG> and <FIG>, the accommodating groove <NUM> inside the middle plate <NUM> is recessed from the top to the bottom of the middle plate <NUM>, that is, an opening of the accommodating groove <NUM> is provided at the top of the middle plate <NUM>, and the cell management unit <NUM> is inserted into the accommodating groove <NUM> from the top of the middle plate <NUM>. In addition, a socket between the cell management unit <NUM> and the sampling line <NUM> may also be provided at the top of the cell management unit <NUM>. Such a structure of the accommodating groove <NUM> on the one hand facilitates installation and uninstallation of the cell management unit <NUM>, and also facilitates connection between the sampling line <NUM> and the cell management unit <NUM>; and on the other hand separates the cell management unit <NUM> from the end faces of the battery groups <NUM>, so that swelling pressure and temperature of the battery groups <NUM> do not directly act on the cell management unit <NUM> (this achieves better heat insulation and anti-swelling performance compared with a case in which the opening of the accommodating groove <NUM> is provided on a side face of the middle plate <NUM>).

As shown in <FIG> and <FIG>, output electrodes of the battery module may be disposed on an upper surface of the middle plate <NUM>. A positive output electrode <NUM> and a negative output electrode <NUM> are disposed on both sides at the top of the middle plate <NUM>. The positive output electrode <NUM> and the negative output electrode <NUM> on either side of the middle plate <NUM> are output electrodes of a battery group <NUM> on the corresponding side. The positive output electrode <NUM> and the negative output electrode <NUM> are correspondingly connected to a positive output pole and a negative output pole of the battery group <NUM>. Disposing the output electrodes at the top of the middle plate <NUM> can make full use of space in the middle of the battery module, save room at both ends of the battery module, and help improve the energy density of the battery module.

As shown in <FIG>, positioning structures <NUM> are provided on both sides of the accommodating groove <NUM>. The positioning structures <NUM> are in contact with both sides of the cell management unit <NUM>, to fix a position of the cell management unit <NUM> in the accommodating groove <NUM>, so that the cell management unit <NUM> does not shake in the accommodating groove <NUM>. In particular, the cell management unit <NUM> is restricted from shaking in a thickness direction of the accommodating groove <NUM> (that is, the direction of the Z1-axis in the figure), so that gaps are left between front and rear surfaces of the cell management unit <NUM> and inner walls of the accommodating groove <NUM>.

In different embodiments, the positioning structures <NUM> have different structural forms. As shown in <FIG>, the positioning structures <NUM> are groove-shaped structures. To be specific, other grooves are provided on left and right sides of the accommodating groove <NUM> (that is, positions indicated by <NUM>), and widths of the grooves are equivalent to a thickness of the cell management unit <NUM>, so that both sides of the cell management unit <NUM> can be stably stuck in the grooves without shaking. In addition, the widths of the grooves are less than a width of the accommodating groove <NUM>, so that gaps are left between the front and rear surfaces of the cell management unit <NUM> and the inner walls of the accommodating groove <NUM>. The gap is at least <NUM>.

The positioning structures <NUM> are provided in the accommodating groove <NUM>, so that gaps are left between the front and rear surfaces of the cell management unit <NUM> and the inner walls of the accommodating groove <NUM>. This reserves space for deformation of the middle plate <NUM> caused by swelling of the battery cells <NUM>, so that the middle plate <NUM> does not press against the cell management unit <NUM>. In addition, the positioning structures <NUM> also serve a guiding purpose. During installation of the cell management unit <NUM>, the cell management unit <NUM> may be inserted into the accommodating groove <NUM> along the positioning structures <NUM>, and a position of the cell management unit <NUM> does not need to be adjusted after the insertion.

In another embodiment, the positioning structures <NUM> may be structures such as positioning posts or positioning blocks. The positioning posts or positioning blocks may be provided in pairs on the left and right sides of the accommodating groove <NUM>, and a spacing between the positioning posts or positioning blocks provided in pairs is equivalent to the thickness of the cell management unit <NUM>, so that ends of the positioning posts or the positioning blocks exactly press against two large faces of the cell management unit <NUM>, fixing the cell management unit <NUM> in the accommodating groove <NUM>.

As shown in <FIG>, the cell management unit <NUM> may include a cell management circuit board <NUM> and a housing <NUM>, and the cell management circuit board <NUM> is disposed in the housing <NUM>. The housing <NUM> includes a front cover and a rear cover, and the front cover and the rear cover jointly form a cavity for accommodating the cell management circuit board <NUM>. The cell management circuit board <NUM> is disposed in the cavity formed by the front cover and the rear cover. The housing <NUM> can protect the cell management circuit board <NUM>, and can prevent the cell management circuit board <NUM> from getting in contact with the middle plate <NUM> to cause a failure such as a short circuit.

The housing <NUM> is further provided with fixing lugs <NUM>, and the fixing lugs <NUM> are fixed to the top of the middle plate <NUM> by using fasteners such as bolts <NUM>. The fixing lugs <NUM> can fix the cell management unit <NUM> to the middle plate <NUM> to prevent the cell management unit <NUM> from moving up and down in the accommodating groove <NUM> in a vertical direction.

In an embodiment shown in <FIG>, there are four fixing lugs <NUM>, and the four fixing lugs <NUM> are disposed on the upper middle of two large faces of the housing <NUM>, and protrude from surfaces of the two large faces of the housing <NUM>. Certainly, in other embodiments, there may be two or three, or other quantities of fixing lugs <NUM>, and the fixing lugs <NUM> may be directly disposed on a top face of the housing <NUM> and protrude towards a side face.

As shown in <FIG>, elastic pads <NUM> are disposed at the bottom of the middle plate <NUM>, and the elastic pads <NUM> may be made of an elastic material such as rubber or silicone. There may be two elastic pads <NUM>, which are separately disposed on two sides at the bottom of the housing <NUM>. The cell management unit <NUM> is in contact with the bottom of the battery module through the elastic pads <NUM>. When the bolts <NUM> lock the cell management unit <NUM>, the cell management unit <NUM> moves down to make the elastic pads <NUM> press against the bottom of the battery module. Thereby, an installation error of the cell management unit <NUM> in the vertical direction can be eliminated.

To facilitate installation of the elastic pads <NUM>, grooves <NUM> are provided on both sides at the bottom of the housing <NUM>, and the top of the elastic pads <NUM> is fixed in the grooves <NUM>, so that the elastic pads <NUM> are fixed to the bottom of the housing <NUM>. The grooves <NUM> can ensure connection strength of the elastic pads <NUM> to prevent them from falling off. Certainly, in other embodiments, there may be more than three elastic pads <NUM>, and the elastic pads <NUM> may be further fixed to the bottom of the housing <NUM> in another manner such as gluing or bolting.

As shown in <FIG>, in an embodiment, the bottom of the side plates <NUM> is provided with L-shaped flanges <NUM>, and the L-shaped flanges <NUM> may be formed by bending the bottom of the side plates <NUM> in an inward direction (that is, a direction in which the battery cells <NUM> are located). The L-shaped flanges <NUM> are bent inward, so that the bottom of the battery cells <NUM> and the middle plate <NUM> may be located on an upper surface of the L-shaped flanges <NUM>, thereby limiting a position of the bottom of the battery cells <NUM> and the middle plate <NUM>.

An embodiment of this application further provides a battery module manufacturing method, including:.

Further, the manufacturing method further includes:
connecting the cell management unit <NUM> to a sampling line <NUM> of battery cells <NUM>.

Further, the manufacturing method further includes:
disposing the battery groups <NUM> in an accommodating cavity of a module frame <NUM>.

The disposing a cell management unit <NUM> in the accommodating groove <NUM> of the middle plate <NUM> includes:
disposing a cell management circuit board <NUM> and a housing <NUM> in the accommodating groove <NUM> of the middle plate <NUM>, and disposing the cell management circuit board <NUM> in the housing <NUM>.

Further, the housing <NUM> is provided with fixing lugs <NUM>, and the manufacturing method further includes:
fixing the fixing lugs <NUM> to the top of the middle plate <NUM>.

It should be noted that, in the descriptions of this application, unless otherwise specified and defined explicitly, the terms "first" and "second" are merely intended for a purpose of description, and should not be understood as an indication or implication of relative importance, and the terms "connection" and "fixing" should be understood in their general senses. For example, the "connection" may be a fixed connection, a detachable connection, an integrated connection, or an electrical connection; or may be a direct connection, or an indirect connection through an intermediate medium. A person of ordinary skill in the art can understand specific meanings of the foregoing terms in this application according to a specific situation.

Claim 1:
A battery module, comprising:
two or more battery groups (<NUM>), wherein each battery group (<NUM>) comprises two or more battery cells (<NUM>);
a module frame (<NUM>), comprising end plates (<NUM>) and side plates (<NUM>), wherein the end plates (<NUM>) and the side plates (<NUM>) enclose an accommodating cavity for fixing the battery groups (<NUM>);
a middle plate (<NUM>), wherein the middle plate (<NUM>) is disposed between two of the battery groups (<NUM>), and is provided with an accommodating groove (<NUM>) inside, wherein the accommodating groove (<NUM>) is recessed from a top to a bottom of the middle plate (<NUM>); and
a cell management unit (<NUM>), disposed in the accommodating groove (<NUM>) of the middle plate (<NUM>) and connected to a sampling line (<NUM>) of the battery cells (<NUM>) to collect data of the battery cells (<NUM>), wherein the sampling line (<NUM>) of the battery cells (<NUM>) is connected to a top of the cell management unit (<NUM>);characterized in that
the battery module further comprises a separator (<NUM>), wherein the separator (<NUM>) is disposed at a top of the battery groups (<NUM>), and wherein the sampling line (<NUM>) of the battery cells (<NUM>) is a flexible circuit board, and disposed on an upper surface of the separator (<NUM>) at the top of the battery groups (<NUM>).