Patent Description:
An energy storage system (ESS) battery pack is equipped with secondary battery cells to store power during a day time and can take out and use the power when needed. For example, the ESS battery pack is a form of storing electricity generated using solar panels or wind power generation in secondary battery cells and then taking out and use the electricity.

The size and weight of the ESS battery pack can be configured differently depending on its storage capacity. For example, an ESS battery pack for home use may be provided in a rectangular box shape of approximately <NUM> × <NUM> × <NUM> (height × width × thickness), and may be provided to be installed on a wall or a pole indoors or outdoors by using a bracket or the like.

When overcharging occurs in a secondary battery cell during charging/discharging or an internal short circuit occurs due to any factor in the secondary battery cell, the temperature of the secondary battery cell increases and gas is generated through a chemical reaction and may leak from the secondary battery cell. The ESS battery pack includes a venting hole to discharge the gas to the outside. The venting hole is generally provided in a lower surface or upper surface of a pack housing.

Because the ESS battery pack is a product subject to safety certification, an Ingress Protection (IP) rating equal to or greater than a certain level is required. Accordingly, a waterproof and dustproof unit is applied to the venting hole to prevent moisture or foreign substances from entering the pack housing through the venting hole in normal times.

As an example of the waterproof and dustproof unit according to the conventional art, a fiber filter is disposed between two meshes of a size corresponding to the venting hole. However, as a thick fiber filter is disposed between the two meshes to satisfy the IP rating, the thickness of the waterproof and dustproof unit increases, and it is difficult to align and assemble each of the meshes and the fiber filter to fit to the venting hole.

An example of battery pack is disclosed in <CIT> and <CIT>. <CIT> discloses a vent member attached to a housing that accommodates automobile components.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a pack housing including a waterproof and dustproof unit that can reduce man-hours and satisfy waterproof and dustproof performance when applied to a venting hole included in the pack housing, and a battery pack including the pack housing.

The technical problems to be solved in the present disclosure are not limited to the above, and other problems that are not mentioned could be clearly understood by one of ordinary skill in the art from the description of the present disclosure below.

In one aspect of the present disclosure, there is provided a pack housing including an internal space capable of accommodating battery cells. The pack housing includes a venting hole provided in at least one surface of the pack housing to communicate with the internal space; and a hole cover assembly configured to cover the venting hole, wherein the hole cover assembly includes a filter mesh including a resin filter layer formed of a resin and a mesh integrated with the resin filter layer by insert injection and placed in the venting hole; and a mounting plate provided in the form of a frame having an empty center and coupled to the at least one surface of the pack housing while pressing an edge region of the filter mesh.

The at least one surface may be at least one of a bottom plate forming a bottom surface of the pack housing and a top plate forming a top surface of the pack housing.

The mesh is formed of a metal material and includes a first mesh and a second mesh disposed to face the first mesh a predetermined distance apart from the first mesh, and the resin filter layer is located between the first mesh and the second mesh.

The mesh may further include an outer frame connected to an edge region of the first mesh and an edge region of the second mesh and surrounding the resin filter layer.

The resin filter layer includes a first filter layer and a second filter layer disposed to face the first filter layer a predetermined distance apart from the first filter layer, and the mesh is formed of a metal material, and is located between the first filter layer and the second filter layer.

An edge region of the mesh may extend in a vertical direction to surround the first filter layer and the second filter layer.

The resin filter layer may be made of at least one of a fluororesin, a polyurethane resin, and an epoxy resin.

The pack housing may include a housing main body formed in a hollow structure and having a lower end portion coupled to the bottom plate and an upper end portion provided to be coupled to the top plate.

The bottom plate or the top plate may include a recessed portion recessed along the periphery of the venting hole to be able to mount an edge region of the filter mesh. The recessed portion may include, in its corner region, a column in which a thread is formed along the inner circumferential surface of its inner diameter. The filter mesh may be provided in a form in which a corner area is cut out, and the mounting plate may have a bolt fastening hole in its corner area and may be fixed to the column by a bolt member fitted into the bolt fastening hole.

In another aspect of the present disclosure, there is provided an energy storage system (ESS) battery pack for home use including the above-described pack housing.

According to an aspect of the present disclosure, provided are a pack housing including an integrated filter mesh that can reduce man-hours and satisfy waterproof and dustproof performance when applied to a venting hole for gas discharge, and a battery pack including the pack housing.

The effects of the present disclosure are not limited to the aforementioned effects, and effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the present specification and the accompanying drawings.

The description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the present disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the present disclosure.

Since embodiments of the present disclosure are provided to more completely explain the present disclosure to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer description. Thus, the size or proportion of each component do not fully reflect an actual size or proportion thereof.

<FIG> is a perspective view of the exterior of a battery pack according to an embodiment of the present disclosure, <FIG> is a perspective view of a bottom plate of a pack housing of <FIG>, and <FIG> is an exploded perspective view of a hole cover assembly according to an embodiment of the present disclosure.

Referring to <FIG>, an energy storage system (ESS) battery pack for home use according to an embodiment of the present disclosure includes battery cells (not shown), a pack housing <NUM> accommodating the battery cells, a venting hole <NUM> provided in at least one surface of the pack housing <NUM>, and a hole cover assembly <NUM> installed in the venting hole <NUM>.

A lithium ion secondary battery may be employed as each of the battery cells (not shown), and includes an electrode assembly, an electrolyte, and an outer casing that seals the electrode assembly and the electrolyte. Battery cells may be classified into a pouch type, a cylindrical type, and a prismatic type according to the shapes of outer casings, and do not need to be limited to a specific shape.

The electrode assembly is an assembly of an electrode and a separator, and may be configured such that one or more positive electrode plates and one or more negative electrode plates are disposed with a separator interposed therebetween. An electrode tab may be included in each electrode plate of the electrode assembly and may be connected to an electrode lead. For example, in the case of a pouch-type secondary battery, one or more electrode tabs may be connected to an electrode lead. The electrode lead may have one end exposed to the outside by being interposed between pouch outer casings, and thus may function as an electrode terminal.

The configuration of such a pouch-type secondary battery is obvious to those skilled in the art to which the present disclosure pertains, and thus a more detailed description thereof will be omitted. In an ESS battery pack for home use according to the present disclosure, various secondary batteries known at the time of filing of the present disclosure may be employed.

The pack housing <NUM> may include a bottom plate <NUM> forming a bottom surface, a top plate <NUM> forming a top surface, and a housing main body <NUM> having a hollow structure. The housing main body <NUM> may be manufactured by extrusion molding, and forms front, rear, and both side surfaces of the pack housing <NUM>.

Although the housing main body <NUM> is not shown in detail in the drawings, the housing main body <NUM> may be provided such that a lower end portion of the housing main body <NUM> may be coupled to the bottom plate <NUM> by bolting or hooking and an upper end portion of the housing main body <NUM> may be coupled to the top plate <NUM> by bolting or hooking.

The pack housing <NUM> may include an internal space surrounded by the bottom plate <NUM>, the top plate <NUM>, and the housing main body <NUM>, and may protect battery cells and other embedded component parts from external impacts or vibrations by being formed of a metal material having high mechanical rigidity.

The venting hole <NUM> is a unit for discharging a gas generable by battery cells from the pack housing <NUM>, and one or more venting holes <NUM> may be provided in at least one surface of the pack housing <NUM>.

According to the present embodiment, the venting hole <NUM> may be provided in the bottom plate <NUM>. In other words, when the venting hole <NUM> is provided in the top plate <NUM> or the housing main body <NUM>, rainwater may flow into the pack housing <NUM> through the venting hole <NUM> in rainy weather, and foreign substances or dust may fall and are prone to be accumulated around the venting hole <NUM>.

However, when the venting hole <NUM> is provided in the bottom plate <NUM>, there is no room for rainwater to flow in through the venting hole <NUM>, and foreign substances or dust do not fall and accumulate around the venting hole <NUM>.

According to the present embodiment, the venting hole <NUM> is implemented to have a rectangular shape. However, the venting hole <NUM> does not necessarily have a rectangular shape. If necessary, the venting hole <NUM> may be configured in various shapes, such as a circle, an ellipse, and a polygon, and various sizes.

The hole cover assembly <NUM> covers the venting hole <NUM> to satisfy waterproofing and dustproofing of an ESS battery pack, and is configured to be fixedly coupled to the bottom plate <NUM>.

As shown in <FIG> and <FIG>, the hole cover assembly <NUM> according to the present embodiment may include a filter mesh <NUM>, a mounting plate <NUM>, and a bolt member <NUM>.

The filter mesh <NUM> is formed by integrating a resin filter layer <NUM> formed of a resin with a mesh <NUM> made of a metal material by insert injection molding. In other words, the filter mesh <NUM> may be formed by putting a pre-fabricated metal mesh <NUM> in an injection mold and molding a filter layer with a resin. That is, the filter mesh <NUM> may be a result of taking unique advantages of conventional several waterproof and dustproof units including a mesh <NUM> and a filter by closely adhering the conventional several waterproof and dustproof units into a single product.

Compared with manufacturing a fiber filter and a mesh separately, laminating and aligning them, and installing a result of the lamination and alignment in the venting hole <NUM>, as the waterproof and dustproof unit mentioned in the last paragraph of the Background Art section, the filter mesh <NUM> according to the present disclosure is a single product, and thus may be directly installed in the venting hole <NUM> without stacking and aligning the resin filter layer <NUM> and the mesh network <NUM>.

Moreover, because the filter mesh <NUM> is obtained by closely adhering the resin filter layer <NUM> having low rigidity and the mesh <NUM> having a somewhat insufficient waterproof function each other, the disadvantage of the resin filter layer <NUM> and the disadvantage of the mesh <NUM> may be complemented each other, and thus the filter mesh <NUM> may have both waterproof and dustproof performance and excellent durability.

The resin filter layer <NUM> may have a porous structure capable of filtering out micro-sized foreign substances. Resins having excellent heat resistance, such as a fluororesin, a polyurethane resin, and an epoxy resin, may be used as a resin used for molding the resin filter layer <NUM>.

For example, the fluororesin has very excellent properties such as heat resistance, chemical resistance, low temperature resistance, electrical insulation, and high frequency characteristics compared to general plastics. However, the scope of the present disclosure is not limited to the specific types of resin. Resins having various chemical properties, such as resins for suppressing occurrence of fire, may be applied as the resin used for molding the resin filter layer <NUM>.

The mesh <NUM> interrupts introduction of foreign substances and supports the resin filter layer <NUM>. The mesh <NUM> may be provided with a hole size less than or equal to <NUM> horizontal × <NUM> vertical. The mesh <NUM> may be made of a material with good rigidity, such as stainless steel. However, the mesh <NUM> is not necessarily made of stainless steel, and any material with good heat resistance and good durability may be used.

<FIG> is a perspective view of the filter mesh of <FIG>, and <FIG> is a cross-sectional view taken along line I-I' of <FIG>.

Describing the structure of the filter mesh <NUM> according to the present embodiment in detail with reference to <FIG>, the mesh <NUM> includes a first mesh 33a, a second mesh 33b, and an outer frame 33c, and the resin filter layer <NUM> is located between the first mesh 33a and the second mesh 33b.

The first mesh 33a and the second mesh 33b may be provided in the same shape and the same size, and may be configured to face each other at a predetermined distance apart from each other. Respective edge regions of the first mesh 33a and the second mesh 33b may be connected to the outer frame 33c, and thus the first mesh 33a and the second mesh 33b may keep a constant distance therebetween. The resin filter layer <NUM> may be located between the first mesh 33a and the second mesh 33b and may be surrounded by the outer frame 33c.

According to this structure, the resin filter layer <NUM> is not easily distorted by strong impacts or heat by being interposed in a space surrounded by the first mesh 33a, the second mesh 33b, and the outer frame 33c.

<FIG> is a drawing corresponding to <FIG> and is a cross-sectional view of a modification of the filter mesh <NUM>.

In a filter mesh <NUM> according to a modification of the present embodiment, a resin filter layer is divided into a first filter layer 32a and a second filter layer 32b, and the mesh <NUM> is located between the first filter layer 32a and the second filter layer 32b.

For example, as shown in <FIG>, the first filter layer 32a may be located above the mesh <NUM>, and the second filter layer 32b may be located below the mesh <NUM> to be apart from the first filter layer 32a. The mesh <NUM> may be configured in an approximately "H" shape such that its edge region 33d extends in a vertical direction to surround the first filter layer 32a and the second filter layer 32b.

According to this structure, the mesh <NUM> that is relatively rigid acts as a skeleton inside the resin filter layer <NUM> to prevent deformation of the resin filter layer <NUM>. In addition, a contact surface between the mesh network <NUM> and the resin filter layer <NUM> spans a wide area in all directions during insert injection molding, and thus a bonding strength between the two materials may be improved.

The mounting plate <NUM> is a mediation unit for attaching the filter mesh <NUM> to the bottom plate <NUM>, and is provided in the form of a frame having an empty center. According to the present embodiment, the mounting plate <NUM> is provided in the form of a quadrangular frame corresponding to four sides corresponding to the edges of the filter mesh <NUM> and thus presses the four sides of the filter mesh <NUM> and is fastened to the bottom plate <NUM> by bolts.

Referring back to <FIG>, an assembly of the hole cover assembly <NUM> and the bottom plate <NUM> will now be described.

The bottom plate <NUM> includes a recessed portion 11a recessed along the outer periphery of the venting hole <NUM> so as to be able to mount the edges of the filter mesh <NUM>. For example, as shown in <FIG>, the recessed portion 11a may be formed by a predetermined depth from an upper surface of the bottom plate <NUM> to form a step with the upper surface. The filter mesh <NUM> is seated on an edge region of the recessed portion 11a and accordingly does not enter the venting hole <NUM>.

The recessed portion 11a includes, in its corner region, a column 11b in which a thread is formed along the inner circumferential surface of its inner diameter. The column 11b is provided such that its height substantially coincides with a thickness of the filter mesh <NUM>. According to the present embodiment, four columns 11b are provided in four places, considering that the mounting plate <NUM> has a quadrangular frame shape. However, the number of columns 11b and locations of the columns 11b may vary.

The filter mesh <NUM> is provided in a form in which four corner areas are cut out or indented inwards in order to avoid interference with the four columns 11b. The mounting plate <NUM> includes, its four corner areas, bolt fastening holes 34a through which bolts may be inserted.

According to this structure, the filter mesh <NUM> is seated on the recessed portion 11a of the bottom plate <NUM>, and the mounting plate <NUM> is disposed above the filter mesh <NUM>. At this time, the columns 11b are positioned at the four corner areas of the filter mesh <NUM>, and the bolt fastening holes 34a of the mounting plate <NUM> coincide with the inner diameters of the columns 11b.

Then, the mounting plate <NUM> is fixed to the columns 11b by using bolt members <NUM>. At this time, the four sides of the filter mesh <NUM> are pressed between the recessed portion 11a and the mounting plate <NUM>, and thus the filter mesh <NUM> may be firmly fixed.

In the assembly structure and the components of the hole cover assembly <NUM> according to an embodiment of the present disclosure, in an emergency, the gas generated inside the pack housing <NUM> may be discharged to the outside through the venting hole <NUM> and the filter mesh <NUM>, and, in normal times, the filter mesh <NUM> may prevent introduction of moisture or foreign substances into the pack housing <NUM> through the venting hole <NUM>.

In particular, because the filter mesh <NUM> is formed by integrating the resin filter layer <NUM> and the metal mesh <NUM> into one product by insert injection, the filter mesh <NUM> is easily assembled when applied to the venting hole <NUM> and has a reduced thickness required for waterproofing and dustproofing compared with conventional ones.

An ESS battery pack according to the present disclosure may further include various devices for controlling charging and discharging of battery cells, such as a battery management system (BMS), a relay, a current sensor, and a fuse that may be built in the pack housing, in addition to the above-described components.

Claim 1:
A pack housing (<NUM>) including an internal space capable of accommodating battery cells, the pack housing (<NUM>) comprising:
a venting hole (<NUM>) provided in at least one surface of the pack housing (<NUM>) to communicate with the internal space; and
a hole cover assembly (<NUM>) configured to cover the venting hole (<NUM>),
wherein the hole cover assembly (<NUM>) comprises:
a filter mesh (<NUM>) comprising a resin filter layer (<NUM>) formed of a resin and a mesh (<NUM>) integrated with the resin filter layer (<NUM>) by insert injection, and placed in the venting hole (<NUM>); and
a mounting plate (<NUM>) provided in a form of a frame having an empty center and coupled to the at least one surface of the pack housing (<NUM>) while pressing an edge region of the filter mesh (<NUM>),
wherein
the mesh (<NUM>) is formed of a metal material, and comprises a first mesh (33a) and a second mesh (33b) disposed to face the first mesh (33a) a predetermined distance apart from the first mesh (33a), and
the resin filter layer (<NUM>) is located between the first mesh (33a) and the second mesh (33b),
or
the resin filter layer (<NUM>) comprises a first filter layer (32a) and a second filter layer (32b) disposed to face the first filter layer (32a) a predetermined distance apart from the first filter layer (32a), and
the mesh (<NUM>) is formed of a metal material, and is located between the first filter layer (32a) and the second filter layer (32b).