Patent Description:
In an environment with a relatively low temperature, a battery usually needs to be preheated, and a manner of preheating is usually electric heating by attaching a heating sheet to a side surface of the battery.

In the related art, if the heating sheet operates for a long time, the heating sheet may be burnt out or even cause fire.

Example of prior art is known from <CIT> and <CIT>.

A heating sheet and a battery module are provided in implementations of the present disclosure, which solves a problem that an existing heating sheet is burnt out due to long-time operation.

A battery module is provided in implementations of the present disclosure. The battery module includes multiple battery cells and a heating sheet. Two adjacent battery cells may be in contact with each other, and a gap region may be defined between side walls of the two adjacent battery cells. The heating sheet includes
multiple heating units and multiple connection units, and two adjacent heating units are coupled with each other through a connection unit. A heating unit may be attached to a side wall of a battery cell, and the connection unit corresponds to the gap region. The heating unit includes an insulating film and a heating wire laid on the insulating film, and the heating wire has an inflow end and an outflow end. The connection unit includes a first connection film and a first conductive wire laid on the first connection film, and the outflow end of the heating unit is electrically coupled with the inflow end of an adjacent heating unit through the first conductive wire. Two insulating films of the two adjacent heating units are connected with each other through the first connection film. The first conductive wire has a routing density less than the heating wire, or the first conductive wire has a cross-sectional area larger than the heating wire, such that the connection unit has a heat productivity per unit area less than the heating unit.

The outflow end of the heating unit is electrically coupled with the inflow end of the adjacent heating unit through the first conductive wire, such that heating wires of the two adjacent heating units are electrically coupled with each other. The connection unit has the heat productivity per unit area less than the heating unit, such that heat of the heating sheet corresponding to the gap region is reduced, and "dry burning" caused by the heat of the heating sheet corresponding to the gap region being unable to be transferred to a battery cell in a direct contact manner is effectively avoided, thereby avoiding a situation of damage of the heating sheet due to local overheating.

In some implementations of the present disclosure, each of the multiple connection units may be provided with first connection films at two surfaces respectively.

In some implementations of the present disclosure, the first conductive wire may be only laid on part of the first connection film.

In some implementations of the present disclosure, the first connection film may only cover part of the gap region.

The first connection film may only cover part of the gap region, such that damage of the heating sheet due to local overheating can be avoided.

In some implementations of the present disclosure, the first connection film may define at least one through hole, and the at least one through hole may communicate with the gap region between the side walls of the two adjacent battery cells.

No heat exists at a position of the at least one through hole, so no dry burning occurs at the position of the at least one through hole, which can avoid a phenomenon that a local temperature of the heating sheet is too high.

In some implementations of the present disclosure, the first connection film may include two film strips. The two film strips may be located at two ends of the insulating film in a width direction of the insulating film respectively. Each of the two film strips may have two ends connected with two insulating films respectively. The two film strips and the two insulating films cooperatively define the through hole.

The first connection film includes the two film strips, such that the two adjacent heating units can be avoided from being folded or even torn.

In some implementations of the present disclosure, the through hole may be defined in part of the first connection film where the heating wire is not laid.

In some implementations of the present disclosure, the first conductive wire may have a size larger than the heating wire in an extension direction of the gap region.

In some implementations of the present disclosure, an extension direction of the first conductive wire may be an arrangement direction of the multiple battery cells.

With this disposing manner, a length and an area of the first conductive wire corresponding to the gap between the side walls of the two adjacent battery cells can be reduced, and heat emitted by the first conductive wire can be reduced.

In some implementations of the present disclosure, the first conductive wire may have a width larger than the heating wire in a direction parallel to the side wall of the battery cell.

With this disposing manner, under a condition that resistance of the first conductive wire is reduced, a size of the heating sheet in a direction perpendicular to the side wall of the battery cell can be avoided from being increased, such that indentation, puncture, etc., in a subsequent packaging process can be avoided.

In some implementations of the present disclosure, the inflow end and the outflow end of the heating wire each may be located in the middle of the insulating film in a width direction of the insulating film.

According to the invention, the heating sheet is implemented as two heating sheets. The two heating sheets may be attached to two opposite side walls of the battery cell respectively, and the heating wires of the two heating sheets are coupled with each other through a second conductive wire.

Heating wires are coupled with each other through the second conductive wire instead of a connector, which avoids failure of coupling between the connector and the heating wires. A welding process of the connector and the heating wires is replaced, such that welding costs, wiring-harness material costs, connector costs, and wiring-harness fixing costs are reduced.

In some implementations of the present disclosure, the insulating films of the two heating sheets may be connected with each other through a second connection film, and the second conductive wire is laid on the second connection film.

The second connection film can transfer heat of the second conductive wire to insulating films at ends of the two heating sheets, to heat side walls of battery cells and increase a heat utilization rate.

According to the invention, the second conductive wire has a cross-sectional area larger than the heating wire.

A heating sheet is further provided in implementations of the present disclosure. The heating sheet includes multiple heating units and multiple connection units, and two adjacent heating units are coupled with each other through a connection unit. A heating unit includes an insulating film and a heating wire laid on the insulating film, and the heating wire has an inflow end and an outflow end. The connection unit includes a first connection film and a first conductive wire laid on the first connection film, and the outflow end of the heating unit is electrically coupled with the inflow end of an adjacent heating unit through the first conductive wire. Two insulating films of the two adjacent heating units are connected with each other through the first connection film. The first conductive wire has a routing density less than the heating wire, or the first conductive wire has a cross-sectional area larger than the heating wire, such that the connection unit has a heat productivity per unit area less than the each of the multiple heating units.

The connection unit has the heat productivity per unit area less than the heating unit, such that heat of the heating sheet corresponding to the gap region is reduced, and "dry burning" caused by the heat of the heating sheet corresponding to the gap region being unable to be transferred to the battery cell in a direct contact manner is effectively avoided, thereby avoiding a situation of damage of the heating sheet due to local overheating.

In order to explain technical solutions in implementations of the present disclosure more clearly, the following will give a brief introduction to accompanying drawings which are needed to be used in description of implementations. It should be understood that followings accompanying drawings only illustrate some implementations of the present disclosure and thus should not be considered as limitation to the scope. For those of ordinary skill in the art, other accompanying drawings can be obtained according to these accompanying drawings without creative efforts.

Reference signs:
<NUM>-battery module; <NUM>-first conductive wire; <NUM>-first connection film; <NUM>-through hole; <NUM>-second conductive wire; <NUM>-second connection film; <NUM>-battery cell; <NUM>-heating sheet; <NUM>-heating unit; <NUM>-insulating film; <NUM>-heating wire; <NUM>-inflow end; <NUM>-outflow end; <NUM>-connection unit.

In order to make a purpose, a technical solution, and an advantage of implementations of the present disclosure clearer, the technical solution of implementations of the present disclosure will be described clearly and completely in conjunction with accompanying drawings in implementations of the present disclosure. Obviously, described implementations are part of implementations of the present disclosure, not all of implementations. Generally, assemblies of implementations of the present disclosure, which are described and illustrated in the accompanying drawings herein, may be arranged and designed in a variety of different configurations.

Therefore, the detailed description of implementations of the present disclosure provided in the accompanying drawings is not intended to limit the claimed scope of the present disclosure, but illustrates only the selected implementations of the present disclosure.

It should be noted that similar signs and letters indicate similar items in the following accompanying drawings, and therefore, once an item is defined in an accompanying drawing, it is not necessary to further define and explain it in the subsequent accompanying drawings.

In the description of the implementations of the present disclosure, it should be understood that orientation or positional relations indicated by terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside" are orientation or positional relations based on the accompanying drawings, or orientation or positional relations in which the application product is placed conventionally in use, or orientation or positional relations commonly understood by those skilled in the art, only for facilitating description of the present disclosure and simplifying the description, rather than indicating or implying that the referred devices or elements must be in a particular orientation or constructed or operated in the particular orientation, and therefore they should not be construed as limiting the present disclosure.

In addition, terms such as "first", "second", "third", etc., are used only for distinguishing illustration, and should not be construed as indicating or implying relativity importance.

In the description of the present disclosure, it also should be noted that unless otherwise expressly specified or defined, terms such as "disposed", "arranged", "provided with", "mount", "couple", and "connect" should be understood broadly, and for example, a fixed connection, or a detachable connection, or an integrated connection; may be a mechanical connection, or an electrical coupling; and may be a direct connection, or an indirect connection via an intermediate medium, or may be an internal communication between two elements. The specific meanings of the above terms in the present disclosure could be understood by those of ordinary skill in the art according to specific situations.

Reference can be made to <FIG>, which is a schematic structural diagram of a battery module <NUM> from a first viewing angle provided in implementations of the present disclosure. A battery module <NUM> is provided in implementations. The battery module <NUM> may include multiple battery cells <NUM> and a heating sheet <NUM>. The multiple battery cells <NUM> may be arranged in sequence by being attached to each other, the heating sheet <NUM> may be attached to side walls (walls not attached to other battery cells <NUM>) of battery cells <NUM>, and a main function of the heating sheet <NUM> is to heat the battery cells <NUM>. The multiple battery cells <NUM> are arranged in sequence by being attached to each other, and a battery cell <NUM> usually has chamfered structures at edges and corners. Therefore, after the battery cells <NUM> are attached to each other, a gap is defined between side walls of two adjacent battery cells <NUM>, and a region corresponding to the gap is defined as a gap region in implementations of the present disclosure.

Reference can be made to <FIG>, which is a schematic structural diagram of a heating sheet <NUM> provided in implementations of the present disclosure. In implementations, the heating sheet <NUM> may include multiple heating units <NUM> and multiple connection units <NUM>, and a connection unit <NUM> may have two opposite sides connected with two heating units <NUM> respectively.

One heating unit <NUM> may be attached to a side wall of one battery cell <NUM>, and the connection unit <NUM> may correspond to the gap region.

Each heating unit <NUM> includes an insulating film <NUM> and a heating wire <NUM>, and the heating wire <NUM> is laid on the insulating film <NUM>. The heating wire <NUM> includes an inflow end <NUM> and an outflow end <NUM>, and a current flows into the heating wire <NUM> through the inflow end <NUM> and then flows out through the outflow end <NUM>.

In implementations of the present disclosure, two surfaces of the heating sheet <NUM> each may be an insulating film <NUM>, and the heating wire <NUM> may be laid between insulating films <NUM> at two sides. In order to show a trend of the heating wire <NUM> in the heating sheet <NUM>, only one insulating film <NUM> at one side is illustrated in <FIG>. In implementations of the present disclosure, shapes, sizes, and, materials of the insulating films <NUM> on the two surfaces may be the same. It should be noted that in other implementations, the insulating films <NUM> on the two surfaces may be different in at least one of shape, size, or material.

Each connection unit <NUM> includes a first conductive wire <NUM> and a first connection film <NUM>. The first connection film <NUM> is connected with insulating films <NUM> of adjacent heating units <NUM>. Heating wires <NUM> of two adjacent heating units <NUM> are coupled with each other through the first conductive wire <NUM>, and an outflow end <NUM> of the heating unit <NUM> is electrically coupled with an inflow end <NUM> of an adjacent heating unit <NUM> through the first conductive wire <NUM>. The heating wire <NUM> may be located outside the side wall of the battery cell <NUM>, heat emitted by the heating wire <NUM> is transferred to the side wall of the battery cell <NUM> to heat the battery cell <NUM>, and the heating wire <NUM> may cover an entire surface of the side wall of the battery cell <NUM>. The first conductive wire <NUM> may be located at a gap between the side walls of the two adjacent battery cells <NUM>.

Two surfaces of each connection unit <NUM> each may be a first connection film <NUM>, and the first conductive wire <NUM> may be disposed between the first connection films <NUM> at two sides. In order to clearly represent arrangement of the first conductive wire <NUM>, only one first connection film <NUM> is illustrated in <FIG>.

The first conductive wire <NUM> has a routing density less than the heating wire <NUM>, or the first conductive wire <NUM> has a cross-sectional area larger than the heating wire <NUM>, such that the connection unit <NUM> has a heat productivity per unit area less than the heating unit <NUM>. In other words, an arrangement interval of the first conductive wire <NUM> at the gap region may be larger than an arrangement interval of the heating wire <NUM>, and the heat productivity per unit area of the heating sheet <NUM> corresponding to the gap region may be less than the heat productivity per unit area of the heating unit <NUM>. Alternatively, the first conductive wire <NUM> may have the cross-sectional area larger than the heating wire <NUM>, and the first conductive wire <NUM> may have resistance less than the heating wire <NUM>, such that the heat productivity per unit area of the connection unit <NUM> is less than the heat productivity per unit area of the heating unit <NUM>.

In implementations, each of the first conductive wire <NUM> and the heating wire <NUM> may be made of copper. It should be noted that in other implementations of the present disclosure, the first conductive wire <NUM> and the heating wire <NUM> may be made of other materials. Accordingly, the first conductive wire <NUM> and the heating wire <NUM> may be made of different materials.

The battery cell <NUM> can have rounded-corner structures at edges and corners. The multiple battery cells <NUM> can be arranged by being attached to each other, and after the two adjacent battery cells <NUM> are attached to each other, rounded-corner structures of the battery cells <NUM> may be unable to be attached to insulating films <NUM>. In other words, a corresponding gap region between the two adjacent battery cells <NUM> is not easy to be attached to the heating sheet <NUM>, a gap will exist between the heating sheet <NUM> and a position corresponding to a rounded-corner structure, resulting in no attachment.

Since the battery cells <NUM> are unable to be attached to the insulating film <NUM> at gap between the side walls of battery cells <NUM>, if the heating sheet <NUM> is used for a long time, the heating sheet <NUM> corresponding to the gap region will be locally overheated, resulting in damage. If the gap between the side walls of the battery cells <NUM> is filled with a thermally conductive adhesive, a weight of the battery module <NUM> will be increased, which is not beneficial to improving an energy density. In addition, an operation process of the thermally conductive adhesive is relatively complex, such that the heating sheet <NUM> is unable to be reworked.

In implementations, a heat productivity per unit area of the heating sheet <NUM> corresponding to the gap region is less than a heat productivity per unit area of the heating unit <NUM>. Since heat of the heating sheet <NUM> corresponding to the gap region is reduced, and a heat productivity of part of the heating sheet <NUM> which is unable to be attached to the battery cells <NUM> is reduced, damage of the heating wire <NUM> caused by local overheating can be avoided.

<FIG> is a schematic structural diagram of a first conductive wire <NUM> provided in implementations of the present disclosure.

Reference can be made to <FIG>, the outflow end <NUM> of the heating unit <NUM> may be electrically coupled with the inflow end <NUM> of an adjacent heating unit <NUM> through the first conductive wire <NUM>. The first conductive wire <NUM> may only cover part of the first connection film <NUM>.

The first conductive wire <NUM> only needs to electrically couple the outflow end <NUM> of the heating unit <NUM> with the inflow end <NUM> of the adjacent heating unit <NUM>, and the first conductive wire <NUM> is disposed corresponding to part of the gap between the side walls of the two adjacent battery cells <NUM>. The first conductive wire <NUM> itself will emit part of heat, but the first conductive wire <NUM> only covers part of the first connection film <NUM>, the first conductive wire <NUM> has the routing density less than the heating wire <NUM>, therefore heat emitted by the first conductive wire <NUM> is limited, such that the heat productivity per unit area of the heating sheet <NUM> corresponding to the gap region is far less than the heat productivity per unit area of the heating unit <NUM>, which can greatly alleviate a problem of local overheating.

Reference can be made to <FIG> and <FIG>, where <FIG> is a partial schematic diagram of a heating sheet <NUM> provided in an implementation of the present disclosure. In implementations, the insulating film <NUM> of the heating unit <NUM> may be connected with an insulating film <NUM> of the adjacent heating unit <NUM> through the first connection film <NUM>, and the first conductive wire <NUM> may be laid on the first connection film <NUM>. In other words, the first connection film <NUM> can be disposed at the gap between the side walls of the two adjacent battery cells <NUM>, two opposite ends of the first connection film <NUM> are connected with insulating films <NUM> at two sides of the first connection film <NUM>, and the first conductive wire <NUM> is laid on the first connection film <NUM>.

A main function of the first connection film <NUM> is to connect the insulating films <NUM> at the two sides of the first connection film <NUM>, to avoid short circuit and other phenomena caused by direct contract between the first conductive wire <NUM> and the battery cell <NUM>. In addition, the main function of the first connection film <NUM> is further to carry and support the first conductive wire <NUM> to avoid the first conductive wire <NUM> from being broken off.

In implementations of the present disclosure, the first conductive wire <NUM> may only meet requirements of coupling the outflow end <NUM> of the heating unit <NUM> with the inflow end <NUM> of the adjacent heating unit <NUM>, and the first conductive wire <NUM> is laid on the first connection film <NUM>.

The first connection film <NUM> and the first conductive wire <NUM> can be implemented in various ways, for example, one implementation in <FIG>. In one implementation, the first conductive wire <NUM> is only laid on part of the first connection film <NUM>, and does not cover an entire first connection film <NUM>. This arrangement is beneficial to reducing a heat productivity of the connection unit <NUM>.

Reference can be made to <FIG> again. In implementations of <FIG>, the first connection film <NUM> may define a through hole <NUM>. The first connection film <NUM> may include two film strips, the two film strips are located at two ends of the insulating film <NUM> in a width direction of the insulating film <NUM> respectively, and each of the two film strips has two ends connected with two insulating films <NUM> respectively. The two film strips and the two insulating films <NUM> cooperatively define a long stirp-shaped through hole <NUM>. The through hole <NUM> may correspond to the gap region between the two adjacent battery cells <NUM>. It can be understood that in other implementations, the through hole <NUM> may be a circular hole or other irregularly-shaped holes.

In implementations, the first connection film <NUM> may include the two film strips, such that the two adjacent heating units <NUM> can be avoided from being folded or even torn. It can be understood that in other implementations, the first connection film <NUM> may include a greater number of film strips.

The inflow end <NUM> and the outflow end <NUM> of the heating wire <NUM> may be located at the two ends of the insulating film <NUM> in the width direction of the insulating film <NUM> respectively, the two film strips may also be located at the two ends of the insulating film <NUM> of the insulating film <NUM> in the width direction of the insulating film <NUM> respectively, and the first conductive wire <NUM> may be laid on the first connection film <NUM>.

With aid of the through hole <NUM>, "dry burning" of the first connection film <NUM> due to heat of the insulating films <NUM> at two sides being transferred to a position of a gap between the side walls of the battery cells <NUM> through the first connection film <NUM> can be avoided.

In implementations, the first connection film <NUM> and the insulating film <NUM> have the same materials and thicknesses, the first connection film <NUM> and the insulating film <NUM> are integrally molded, and the first connection film <NUM> and the insulating film <NUM> each are made of polyimide films. It should be noted that in other implementations of the present disclosure, the first connection film <NUM> and the insulating film <NUM> may be different in at least one of material or thicknesses, and the first connection film <NUM> and the insulating film <NUM> may be made of other materials.

Optionally, in implementations illustrated in <FIG>, one heating wire <NUM> may have one inflow end <NUM> and one outflow end <NUM>. Accordingly, two adjacent heating wires <NUM> may be coupled with each other through only one first conductive wire <NUM>, and the first conductive wire <NUM> may be laid on one film strip. Optionally, in implementations, in order to reduce a length of the first conductive wire <NUM>, an extension direction of the first conductive wire <NUM> may be an arrangement direction of the multiple battery cells <NUM>. With this disposing manner, a length and an area of the first conductive wire <NUM> corresponding to the gap between the side walls of the two adjacent battery cells <NUM> can be reduced, and heat emitted by the first conductive wire <NUM> can be reduced. In implementations, one inflow end <NUM> may include two parallel lines. Accordingly, the outflow end <NUM> may include two parallel lines, and the first conductive wire <NUM> may also include two parallel lines. It should be noted that in implementations of the present disclosure, the number of lines included in the output end <NUM> is not limited.

Reference can be made to <FIG> again. In implementations of <FIG>, the cross-sectional area of the first conductive wire <NUM> may be larger than the cross-sectional area of the heating wire <NUM>. The cross-sectional area of the first conductive wire <NUM> is larger than the cross-sectional area of the heating wire <NUM>, which is beneficial to reducing resistance of the first conductive wire <NUM> and further reducing a heat productivity of the first conductive wire <NUM> when a current passes through the first conductive wire <NUM>.

Optionally, in implementations illustrated in <FIG>, the first conductive wire <NUM> may have a width larger than the heating wire <NUM> in a direction parallel to the side wall of the battery cell <NUM>. In other words, the first conductive wire <NUM> and the heating wire <NUM> may have the same thicknesses (a size in a direction perpendicular to the side wall of the battery cell <NUM>), such that a purpose that the cross-sectional area of the first conductive wire <NUM> is larger than the cross-sectional area of the heating wire <NUM> can be realized only by increasing the width of the width of the first conductive wire <NUM>. With this disposing manner, under a condition that resistance of the first conductive wire <NUM> is reduced, a size of the heating sheet <NUM> in the direction perpendicular to the side wall of the battery cell <NUM> can be avoided from being increased, such that indentation, puncture, etc., in a subsequent packaging process can be avoided.

It should be noted that in other implementations of the present disclosure, the first conductive wire <NUM> may have the width the same as or slightly smaller than the heating wire <NUM>.

<FIG> is a partial schematic diagram of a heating sheet provided in another implementation of the present disclosure.

Reference can be made to <FIG> together, in implementations illustrated in <FIG>, the first connection film <NUM> defines no through hole <NUM>. In other words, two opposite sides of the first connection film <NUM> may be connected with insulating films <NUM> of heating units <NUM> respectively, and the first connection film <NUM> can cover the gap between the two adjacent battery cells <NUM>.

In implementations illustrated in <FIG>, each of the inflow end <NUM> and the outflow end <NUM> of the heating wire <NUM> is located in the middle of the insulating film <NUM> in a width direction of the insulating film <NUM>. Accordingly, two opposite ends of the first conductive wire <NUM> may be electrically coupled with the outflow end <NUM> of a heating unit <NUM> and an inflow end <NUM> of an adjacent heating unit <NUM> respectively. The inflow end <NUM> may include two lines. Accordingly, the outflow end <NUM> may include only one line. The cross-sectional area of the first conductive wire <NUM> may be larger than the cross-sectional area of the heating wire <NUM>.

It should be noted that the width direction of the insulating film <NUM> refers to a direction parallel to a height direction of the battery cell <NUM>, and the middle of the insulating film <NUM> in the width direction of the insulating film <NUM> refers to a position which is not located at two ends of the insulating film <NUM>, where the middle here is not limited to a middle in size.

In implementations illustrated in <FIG>, the first conductive wire <NUM> may only partially cover the first connection film <NUM>, which can also greatly reduce the heat productivity of the heating sheet <NUM> corresponding to the gap region to avoid dry burning of the heating sheet <NUM> corresponding to the gap region, thereby avoiding damage to the heating sheet <NUM>.

It can be understood that in implementations, the first connection film <NUM> may also define a through hole <NUM>. The through hole <NUM> may be defined in part of the first connection film <NUM> where the heating wire <NUM> is not laid. For example, a hole, such as a U-shaped hole, etc., may be defined above or below the heating wire <NUM>. The connection film <NUM> defines the U-shaped hole, such that damage of the heating sheet <NUM> due to excessive temperature at this position caused by local overheating of the connection unit <NUM> can be avoided.

<FIG> is a partial schematic diagram of a heating sheet <NUM> provided in yet another implementation of the present disclosure.

Reference can be made to <FIG>. In implementations illustrated in <FIG>, the heating wire <NUM> disposed on the insulating film <NUM> may have two inflow ends <NUM> and two outflow ends <NUM>. The two inflow ends <NUM> on the same insulating film <NUM> may be disposed independently, and the two outflow ends <NUM> on the same insulating film <NUM> may be disposed independently. Accordingly, one connection unit <NUM> may be configured with two first conductive wires <NUM>. Two opposite ends of the first conductive wire <NUM> may be electrically coupled with an outflow end <NUM> of a heating unit <NUM> and an inflow end <NUM> of an adjacent heating unit <NUM> respectively.

The first conductive film <NUM> may include two film strips. One first conductive wire <NUM> may be laid on one film strip, and the through hole <NUM> may be defined between two adjacent film strips. It can be understood that the first connection film <NUM> may define no through hole <NUM>. In other words, no gap may exist between the above two film stirps.

Optionally, in implementations, the cross-sectional area of the first conductive wire <NUM> may be larger than the cross-section area of the heating wire <NUM>.

It should be noted that in other implementations, the heating wire <NUM> disposed on the insulating film <NUM> may have three, four, or more independent inflow ends <NUM>. Heating wires <NUM> of two adjacent heating units <NUM> may be coupled with each other through the same number of first conductive wires <NUM> as inflow ends <NUM>.

In implementations illustrated in <FIG>, the first conductive wires <NUM> of the connection unit <NUM> may only cover part of the first connection film <NUM>, which can also greatly reduce a heat productivity of the connection unit <NUM> to avoid dry burning of the connection unit <NUM>, thereby avoiding damage to the heating sheet <NUM> due to the dry burning.

Alternatively, in other implementations of the present disclosure, the heating wire <NUM> disposed on the insulating film <NUM> may have one inflow end <NUM> and one outflow end <NUM>. An outflow end <NUM> of one heating unit <NUM> may be located at an upper end of the insulating film <NUM>, and an inflow end <NUM> of an adjacent heating unit <NUM> may be located at a lower end of the insulating film <NUM>. Two opposite ends of the first conductive wire <NUM> may be electrically coupled with the outflow end <NUM> of the heating <NUM> and the inflow end <NUM> of the adjacent heating unit <NUM> respectively.

In other words, the outflow end <NUM> and the inflow end <NUM> which are coupled with each other through the first conductive wire <NUM> are not located at the same side of the heating sheet <NUM>, but located at two opposite sides of the heating sheet <NUM>. The gap between the two adjacent battery cells <NUM> may be in a shape of a rectangle, and the first conductive wire <NUM> may be located at a diagonal of the rectangle.

In implementations, a shape of the first connection film <NUM> may correspond to a shape of the first conductive wire <NUM>. It can be understood that in other implementations of the present disclosure, the first connection film <NUM> may cover an entire gap between two battery cells <NUM>.

In implementations illustrated in <FIG>, the first conductive wires <NUM> only partially covers the gap between the side walls of the two adjacent battery cells <NUM>, which can greatly reduce the heat productivity of the connection unit <NUM> and avoid damage to the heating sheet <NUM> caused by the connection unit <NUM>.

It should be noted that in implementations of the present disclosure, the first conductive wire <NUM> and the first connection film <NUM> may also be disposed in other ways, which are not limited to implementations illustrated in <FIG>. For example, in implementations illustrated in <FIG>, the first conductive wire <NUM> may have a substantially straight line, but in other implementations, the first conductive wire <NUM> may have a curved path, etc..

In implementations of <FIG>, heating wires <NUM> of two adjacent heating units <NUM> may be laid in the same way. Multiple heating wires <NUM> may be sequentially coupled through first conductive wires <NUM> to form an S-shaped path. It can be understood that in other implementations of the present disclosure, the heating wires <NUM> on the two adjacent heating units <NUM> may be laid in different ways, as long as the heating wires <NUM> of the two adjacent heating units <NUM> are electrically coupled with each other through the first conductive wire <NUM>.

Optionally, in implementations of <FIG>, the first conductive wire <NUM> of the connection unit <NUM> may only cover part of the first connection film <NUM>. It can be understood that in other implementations of the present disclosure, the first conductive wire <NUM> of the connection unit <NUM> may be laid on an entire first connection film <NUM> to increase the cross-sectional area of the first conductive wire <NUM>, such that the cross-sectional area of the first conductive wire <NUM> is larger than the cross-sectional area of the heating wire <NUM>. Therefore, a purpose that the heat productivity per unit area of the connection unit <NUM> is less than the heat productivity per unit area of the heating unit <NUM> is realized.

It should be noted that an arrangement manner and a laid manner of the heating wire <NUM> are not limited in the present disclosure. For example, the heating wire <NUM> may be laid in multiple directions, such as a transverse direction, a longitudinal direction, an included direction, etc..

It should be noted that for implementations where the first connection film <NUM> includes multiple film strips, the number of film stirps may correspond to the number of first conductive wires <NUM>, and the number of film strips may also be greater than the number of first conductive wires <NUM>. Accordingly, a shape of a film strip may or may not be adapted to a shape laid by the first conductive wire <NUM>, as long as the first conductive wire <NUM> is attached to the film strip.

Reference can be made to <FIG> again, according to the invention, the battery module <NUM> includes two heating sheets <NUM>, and the two heating sheets <NUM> are coupled with each other through a second conductive wire <NUM>. In detail, the two heating sheets <NUM> may be attached to two opposite side walls of the battery cell <NUM> respectively, and heating wires <NUM> of the two heating sheets <NUM> may be coupled with each other through the second conductive wire <NUM>.

The two heating sheets <NUM> each have an end, where a heating wire <NUM> of a heating unit <NUM> at the end of one heating sheet <NUM> may be coupled with a heating wire <NUM> of a heating unit <NUM> at the end of another heating sheet <NUM> through the second conductive wire <NUM>. In detail, an outflow end <NUM> of one heating wire <NUM> may be electrically coupled with an inflow end <NUM> of another heating wire <NUM> through the second conductive wire <NUM>.

The two heating sheets <NUM> are coupled with each other through the second conductive wire <NUM> instead of a connector, such that a problem of coupling failure caused by damage at connection positions of the two heating sheets <NUM> and the connector can be avoided. In addition, a welding process between the connector and the heating wire <NUM> is replaced by adapting the second conductive wire <NUM>, such that welding costs, wiring-harness material costs, connector costs, wiring-harness fixing costs, etc., can be avoided, and manufacturing costs of the heating sheet <NUM> can be reduced.

According to the invention, the cross-sectional area of the second conductive wire <NUM> is larger than the cross-sectional area of the heating wire <NUM>. For example, in a height direction of the battery cell <NUM>, a width of the second conductive wire <NUM> may be larger than a width of the heating wire <NUM>. The cross-sectional area of the second conductive wire <NUM> is relatively large, such that resistance of the second conductive wire <NUM> can be reduced, and the heat productivity emitted by the second conductive wire <NUM> can be reduced.

Optionally, in implementations of the present disclosure, insulating films <NUM> of the two heating sheets <NUM> may be connected with each other through a second connection film <NUM>, and the second conductive wire <NUM> may be laid on the second connection film <NUM>.

In other words, two opposite ends of the second connection film <NUM> may be coupled with insulating films <NUM> at ends of the two heating sheets <NUM> respectively. A main function of the second connection film <NUM> is to carry the second conductive wire <NUM>. In addition, the second connection film <NUM> can also transfer heat of the second conductive wire <NUM> to the insulating films <NUM> at the ends of the two heating sheets <NUM>, to heat side walls of battery cells <NUM> and increase a heat utilization rate.

In implementations, the second connection film <NUM> may be integrated with insulating films <NUM> of the two heating sheets <NUM>, and the second connection film <NUM> and the insulating films <NUM> of the two heating sheets <NUM> may be made of the same materials. It should be noted that in other implementations of the present disclosure, the second connection film <NUM> may be connected with the insulating films <NUM> of the two heating sheets <NUM> in other ways, and the second connection film <NUM> and the insulating films <NUM> of the two heating sheets <NUM> may be made of different materials.

Advantages of the battery module <NUM> provided in implementations of the present disclosure include, for example, the following.

The outflow end <NUM> of the heating unit <NUM> may be electrically coupled with the inflow end <NUM> of the adjacent heating unit <NUM> through the first conductive wire <NUM>, such that the heating wires <NUM> of the two adjacent heating units <NUM> are electrically coupled with each other. The connection unit <NUM> has the heat productivity per unit area less than the heating unit <NUM>, such that heat emission of the connection unit <NUM> can be reduced, and "drying burning" caused by the heat of the connection unit <NUM> being unable to be transferred to the battery cell <NUM> in the direct contact manner is effectively avoided, thereby avoiding the situation of damage of the heating sheet due to local overheating.

For implementations where the first conductive wire <NUM> covers the part of the first connection film <NUM>, the heat productivity of the connection unit <NUM> can be greatly reduced, and the situation of damage to the heating sheet <NUM> caused by local overheating is avoided. For implementations where the first connection film <NUM> defines the through hole <NUM>, the through hole <NUM> can solve the problem that the heating sheet <NUM> is damaged due to local overheating caused by a poor thermal conductive property of the heating sheet <NUM> as a result of the heating sheet <NUM> at the gap position being unable to be attached to the battery cell <NUM>.

For implementations where the first conductive wire <NUM> has the relatively large cross-sectional area, the first conductive wire <NUM> has the relatively small resistance, and the first conductive wire <NUM> generates the relatively low heat productivity, which can also avoid the problem that the heating sheet <NUM> is damaged due to local overheating caused by excessive heat emitted by the first conductive wire <NUM>.

The heating sheet <NUM> is further provided in implementations of the present disclosure. For the structure and size of the heating sheet <NUM>, reference can be made to the heating sheet <NUM> in the battery module <NUM> of the above implementations.

The heating sheet <NUM> provided in implementations of the present disclosure, can greatly solve the problem that the heating sheet <NUM> is damaged due to local overheating caused by "dry heating".

The above descriptions are only preferred implementations of the present disclosure, and are not used to limit the present disclosure. For those skilled in the art, the present disclosure may have various changes and variations.

A heating sheet and a battery module are provided in the present disclosure. The battery module includes multiple battery cells and a heating sheet. The heating sheet includes multiple heating units and multiple connection units, and two heating units are coupled with each other through a connection unit. One heating unit is attached to a side wall of one battery cell, and the connection unit corresponds to a gap region. The connection unit has a heat productivity per unit area less than the heating unit, such that heat of the heating sheet corresponding to the gap region is reduced, and "dry burning" caused by the heat of the heating sheet corresponding to the gap region being unable to be transferred to the battery cell in a direct contact manner is effectively avoided, thereby avoiding a situation that the heating sheet is damaged due to local overheating.

Claim 1:
A battery module (<NUM>), comprising:
a plurality of battery cells (<NUM>); and
a heating sheet (<NUM>), wherein,
two adjacent battery cells (<NUM>) are in contact with each other, and a gap region is defined between side walls of the two adjacent battery cells (<NUM>);
the heating sheet (<NUM>) comprises a plurality of heating units (<NUM>) and a plurality of connection units (<NUM>), two adjacent heating units (<NUM>) are coupled with each other through a connection unit (<NUM>), a heating unit (<NUM>) is attached to a side wall of a battery cell (<NUM>), and the connection unit (<NUM>) corresponds to the gap region;
the heating unit (<NUM>) comprises an insulating film (<NUM>) and a heating wire (<NUM>) laid on the insulating film (<NUM>), and the heating wire (<NUM>) has an inflow end (<NUM>) and an outflow end (<NUM>);
the connection unit (<NUM>) comprises a first connection film (<NUM>) and a first conductive wire (<NUM>) laid on the first connection film (<NUM>), the outflow end (<NUM>) of the heating unit (<NUM>) is electrically coupled with the inflow end (<NUM>) of an adjacent heating unit (<NUM>) through the first conductive wire (<NUM>), and two insulating films (<NUM>) of the two adjacent heating units (<NUM>) are connected with each other through the first connection film (<NUM>); and
the first conductive wire (<NUM>) has a routing density less than the heating wire (<NUM>), or the first conductive wire (<NUM>) has a cross-sectional area larger than the heating wire (<NUM>), such that the connection unit (<NUM>) has a heat productivity per unit area less than the heating unit (<NUM>); wherein
the heating sheet (<NUM>) is implemented as two heating sheets (<NUM>); and
the two heating sheets (<NUM>) are attached to two opposite side walls of the battery cell (<NUM>) respectively, and the heating wires (<NUM>) of the two heating sheets (<NUM>) are coupled with each other through a second conductive wire (<NUM>); and
wherein the second conductive wire (<NUM>) has a cross-sectional area larger than the heating wire (<NUM>).