Battery Pack

Abstract

The present invention relates to a battery pack. A battery pack includes a housing and an electrochemical cell disposed in the housing. The housing includes a container and a cover that closes an open end of the container. The container has a base, an outer wall surrounding the base, and a first inner wall and a second inner wall disposed inside the outer wall. The first inner wall extends between a first portion and a third portion of the outer wall and is fixed to the first portion and the third portion of the outer wall, and is spaced apart from a second portion and a fourth portion of the outer wall. The second inner wall extends between the first portion and the third portion, and is disposed between the first inner wall and the fourth portion. The second inner wall can move relative to the outer wall so that the spacing of the second inner wall from the first inner wall can be changed.

Description

Technical Field

[0001] The present invention is a divisional application of Chinese patent application No. 201780014629.3. The present invention relates to a battery pack for storing electrochemical cells, including a battery pack housing having passive cooling features and features for minimizing outer wall stress caused by growth of electrochemical cells. Background Art

[0002] Battery packs provide power for a variety of technologies ranging from portable electronic devices to renewable energy systems and environmentally friendly vehicles. For example, hybrid electric vehicles (HEVs) use battery packs and electric motors in conjunction with internal combustion engines to improve fuel efficiency. Battery packs are formed from a plurality of battery modules, each of which includes a number of electrochemical battery cells. These battery cells are arranged in a stack and are electrically connected in series or in parallel. Likewise, the battery modules within a battery pack are electrically connected in series or in parallel.

[0003] Some battery packs used with conventional hybrid vehicles are designed to provide relatively high voltages, such as 400 volts (V). To achieve the high voltage, the battery pack is relatively large and includes hundreds of electrochemical cells. In addition, to accommodate the high voltage, the components in the electrical system are relatively expensive and subject to high voltage protection requirements. It would be desirable to form a battery pack with fewer and less expensive components. Summary of the invention

[0004] In some aspects, the battery housing is configured to receive a plurality of electrochemical cells. The battery housing includes a container, and the container includes a substrate, an outer wall, a first inner wall, and a second inner wall. The substrate includes an inner surface, an outer surface opposite to the inner surface, and a peripheral edge connecting the inner surface to the outer surface. The outer wall surrounds the peripheral edge and protrudes from the substrate in a direction perpendicular to the inner surface of the substrate. The outer wall includes a first portion, a second portion adjacent to the first portion, a third portion adjacent to the second portion and opposite to the first portion, and a fourth portion opposite to the second portion. The first inner wall extends between the first portion and the third portion, and the first inner wall is fixed to each of the first portion and the third portion. The second inner wall extends between the first portion and the third portion, and is disposed between the first inner wall and the fourth portion. The second inner wall can move relative to the outer wall so that the spacing of the second inner wall from the first inner wall can be changed.

[0005] The battery pack housing may include one or more of the following features: the first inner wall is spaced apart from the second part and the fourth part, whereby a gap exists between the first inner wall and the second part. Each of the first inner wall and the second inner wall is hollow and includes an inner surface and an outer surface opposite to each other, and ribs extending between the inner surface and the outer surface opposite to each other, which define a space in each of the first inner wall and the second inner wall. The spacer is arranged between the second inner wall and the fourth part. The second inner wall has an inner surface parallel to the second part and facing the second part, and an outer surface facing the fourth part, and at least a portion of the outer surface of the second inner wall is not parallel to the fourth part. A portion of the outer surface of the outer wall is formed to have cooling ribs protruding outward. The battery pack housing is formed of a non-conductive material. The outer wall is formed by a first element, a second element formed separately from the first element and detachably connected to the first element, and a latch member. The first element includes a first part, a second part, and a third part arranged in a U shape. The inner surface of the first element includes a first surface feature configured to receive a latch member. The second element includes a fourth portion, and the inner surface of the second element includes a second surface feature, the second surface feature is configured to receive a latch member and cooperate with the first surface feature to removably connect the first element to the second element. The second element includes a second inner wall, and the second inner wall is parallel to the fourth portion and is spaced apart from the fourth portion via a spacer. The latch member is a pin, the first surface feature includes a first through opening and the second surface feature includes a second through opening, and the pin extends through both the first through opening and the second through opening. The second through opening is aligned with the first through opening along an axis perpendicular to the inner surface of the substrate.

[0006] In some aspects, a battery pack includes a battery pack housing and an electrochemical cell disposed in the housing. The housing includes a container, the container including a substrate, an outer wall, a first inner wall and a second inner wall. The substrate includes an inner surface, an outer surface opposite to the inner surface, and a peripheral edge connecting the inner surface to the outer surface. The outer wall surrounds the peripheral edge and protrudes from the substrate in a direction perpendicular to the inner surface of the substrate. The outer wall includes a first portion, a second portion adjacent to the first portion, a third portion adjacent to the second portion and opposite to the first portion, and a fourth portion opposite to the second portion. The first inner wall extends between the first portion and the third portion, and the first inner wall is fixed to each of the first portion and the third portion. The second inner wall extends between the first portion and the third portion, and is disposed between the first inner wall and the fourth portion. The second inner wall can move relative to the outer wall so that the spacing of the second inner wall from the first inner wall can be changed.

[0007] The battery pack housing may include one or more of the following features: The first inner wall is spaced apart from the second portion and the fourth portion, whereby a gap exists between the first inner wall and the second portion. Each of the first inner wall and the second inner wall is hollow and includes an opposing inner surface and an outer surface, and ribs extending between the opposing inner surface and the outer surface, which define a void within each of the first inner wall and the second inner wall. The second inner wall has an inner surface parallel to the second portion and facing the second portion, and an outer surface facing the fourth portion, and at least a portion of the outer surface of the second inner wall is not parallel to the fourth portion. A spacer is disposed between the second inner wall and the fourth portion. The battery pack includes a battery management device, the battery management device including an electronic device configured to monitor and control the function of an electrochemical cell, and the battery management device is disposed in a container between the second inner wall and the fourth portion. The outer wall is formed by a first element, a second element formed separately from the first element and detachably connected to the first element, and a latch member. The first element includes a first portion, a second portion, and a third portion arranged in a U-shape, and an inner surface of the first element includes a first surface feature configured to receive a latch member. The second element includes a fourth portion, and the inner surface of the second element includes a second surface feature, the second surface feature being configured to receive the latch member and cooperate with the first surface feature to removably connect the first element to the second element. The electrochemical cells are arranged side by side in the housing, and the insulating sheet is disposed between each electrochemical cell. The electrochemical cells are supported on the substrate so that the outer surface of the cell housing directly contacts the inner surface of the substrate.

[0008] In some aspects, a battery pack that produces a voltage less than 60 V can be used as part of a hybrid vehicle powertrain, thereby potentially reducing the cost and complexity of the powertrain. Because the voltage produced by the battery pack is less than 60 V, the components used to form the battery pack are less expensive.

[0009] The battery pack housing is configured to receive a plurality of prismatic battery cells. In some embodiments, the prismatic battery cells have a metal housing and may therefore have an electrical charge due to contact between an electrolyte disposed in the battery cell and the battery cell housing. The battery pack housing is formed of a non-conductive and thermally conductive material. This can be compared to some conventional battery pack housings, wherein the conventional battery pack housings are formed of a conductive material such as a metal, and wherein an insulating structure must be inserted between the prismatic battery cell housing and the battery pack housing and between adjacent battery cells. By forming a battery pack housing made of a non-conductive material, it is possible to place the battery cells in direct contact with the housing without the risk of forming an electrical short circuit. Since the insulating structure can be simplified, the size of the battery pack housing can be reduced and the cost of materials and assembly can be reduced.

[0010] By forming the battery housing from a thermally conductive material, passive cooling of the battery housing and the battery cells disposed therein is enhanced. Advantageously, an outer surface of the battery housing includes cooling fins that further promote heat exchange with ambient air.

[0011] The battery pack housing includes a container and a cover that closes the open end of the container. The container is formed to have a double-walled sidewall structure, wherein the inner wall portion is spaced apart from the outer wall. In the illustrated embodiment, the container includes two inner wall portions, which are arranged inside the outer wall and are arranged parallel to each other and parallel to the opposite side portions of the outer wall. The first inner wall portion is fixed in the container so as to be adjacent to and spaced apart from one side portion of the outer wall. The second inner wall portion is movable in the container and is positioned adjacent to and spaced apart from the opposite side portion of the outer wall. The electrochemical battery cells are arranged side by side in the container between the first inner wall portion and the second inner wall portion so that the stacking axis transverse to the opposite side of the battery cell passes through the one side portion and the opposite portion of the outer wall. During assembly, the second inner wall portion is moved toward the first inner wall portion as a whole, thereby placing the battery cell under a compressive load. In addition, the stacking axis is parallel to the battery cell growth direction of the prismatic battery cell, whereby any expansion of the battery cell due to battery cell growth results in a force applied to the inner wall portion along the stacking axis. The inner wall portion is configured to accommodate stresses due to the growth of the prismatic battery cells. For example, when fully grown, the inner wall portion may change shape (deform or slightly deflect) to accommodate the force. Since the inner wall portion is spaced apart from the outer wall portion and the inner wall portion accommodates the growth of the prismatic battery cells, the force is not applied to the outer wall portion. Therefore, the outer wall is dimensionally stable. By providing a dimensionally stable outer wall, a seal disposed between the outer wall of the container and the cover is more reliable than some battery pack housings in which the side walls may be affected by the growth of the battery cells. The seal prevents particles and / or moisture from entering the interior space of the battery pack housing, thereby improving the operability, reliability and life of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a top perspective view of the battery pack.

[0013] Figure 2 yes Figure 1 A top perspective view of a battery pack with the cover omitted.

[0014] Figure 3 is a schematic diagram of the arrangement of electrodes and separator strips used to form the electrode assembly of each battery cell.

[0015] Figure 4 is a cross-sectional view of the electrode assembly as seen in a direction transverse to the electrode winding axis.

[0016] Figure 5 is a perspective exploded view of a portion of a battery cell array illustrating an alternating arrangement of battery cells and insulating separators within the battery cell array.

[0017] Figure 6 It is a top perspective exploded view of the container of the battery pack housing.

[0018] Figure 7 is a top plan view of a second element of the container.

[0019] Figure 8 It is like Figure 7 A cross-sectional view of the container as seen along line 8-8.

[0020] Fig. 9 It is like Fig.10 A cross-sectional view of the container as seen along line 9-9.

[0021] Fig.10 yes Figure 6 A top plan view of one end of a container illustrating a battery management device housed in the container.

[0022] Fig.11 is a top plan view of an alternative embodiment container.

[0023] Fig.12 yes Fig.11 A top plan view of one end of a container illustrating a battery management device housed in the container.

[0024] Fig.13 is a perspective view of another alternative embodiment container. DETAILED DESCRIPTION

[0025] refer to Figure 1 to Figure 2 , the battery 1 is a power generation and storage device including electrochemical cells 2, which are electrically interconnected and stored in an organized manner within a battery housing 40. The battery housing 40 includes a container 60 and a cover 50 that closes the open end of the container 60. Within the battery housing 40, an array of battery cells 2 is electrically connected in series or in parallel to battery terminals 54, 55 protruding from the cover 50. The battery housing 40 including the cover 50 and the container 60 is formed of a non-conductive material. In addition, the container 60 has a passive cooling feature and a feature that minimizes the outer wall stress due to the growth of the electrochemical cells, as will be described below.

[0026] refer to Figures 3 to 5The battery cell 2 is a lithium-ion battery cell including a battery cell housing 20, which encloses an electrode assembly 4 and an electrolyte to form a power generation and storage unit. The electrode assembly 4 includes at least one positive electrode 6, at least one negative electrode 8, a first electrically insulating separator 10 disposed between the positive electrode 6 and the negative electrode 8, and a second electrically insulating separator 12 disposed on the other side of one of the positive electrode 6 and the negative electrode 8.

[0027] Each of the positive electrode 6 and the negative electrode 8 has a layered structure to facilitate the insertion and / or movement of lithium ions. In the illustrated embodiment, the positive electrode 6 is formed of copper with a graphite coating, and the negative electrode 8 is formed of aluminum with a lithiated metal oxide coating. The separators 10, 12 are formed of an electrically insulating material such as a three-layer polypropylene-polyethylene-polypropylene film.

[0028] The electrodes 6, 8 and separators 10, 12 are elongated strips of material that are stacked and then wound around an elliptical mandrel to form an elliptical or racetrack-shaped jelly roll assembly 4. As used herein, the term "strip" refers to a material comprising a plurality of strips of material having a height h. e A larger (e.g., about 1000x) length l e and relative to the thickness t e A larger (e.g., about 1000x) height h e For example, in some applications, the electrodes 26, 28 may have a thickness t of 0.03 mm. e , height h 60 mm e and a length of 45 m e .

[0029] The battery cell housing 20 has a rectangular prism shape (e.g., a prism shape), and includes a first side 22, and a second side 24 opposite to the first side 22, a third side 26 adjacent to the first side 22 and the second side 24, and a fourth side 28 opposite to the third side 26 and adjacent to the first side 22 and the second side 24. The first side 22 and the second side 24 have the same height as the third side 26 and the fourth side 28, but have a greater width. For example, in the illustrated embodiment, the width of the first side 22 and the second side 24 is about twice the height, while the width of the third side 26 and the fourth side 28 is about one-quarter the height. In addition, the battery cell housing 20 includes a first end 30, through which a positive terminal 34 and a negative terminal 36 protrude; and a second end 32, which is opposite to the first end. The electrode assembly 4 is disposed in the battery cell housing 20 so that the winding axis (e.g., the axis around which the electrode and the separator are wound) 14 extends through the first end 30 and the second end 32.

[0030] The electrode assembly 4 undergoes dimensional changes during charging and discharging of the battery. This is due, at least in part, to the expansion of the layered structures of the positive and negative electrodes in the direction of the electrode thickness due to the expansion of the active materials during cycling. The expansion of the jellyroll electrode assembly 4 within the cell housing 20 results in "cell growth," which corresponds to the outward bending of the first side 22 and the second side 24 of the cell housing 20 in a direction transverse to the winding axis and perpendicular to the outer surfaces of the first side 22 and the second side 24. The battery pack housing includes features to accommodate the growth of the battery cells 2 disposed therein, as discussed further below.

[0031] refer to Figure 2 and Figure 5 , an array of battery cells 2 is disposed in a container 60 of a battery pack housing 40. For example, in the illustrated embodiment, the array includes a single row of 12 battery cells arranged side by side such that the second side 24a of one battery cell 2a faces the first side 22b of an adjacent battery cell 2b, and such that the first end 30 of each battery faces the cover 50. A stacking axis 16 corresponding to the stacking direction of the battery cell array is transverse to the facing surfaces (e.g., the first side 22 and the second side 24) of the battery cells 2. An insulating partition 18 is disposed between the facing surfaces of adjacent battery cells 2. The array is arranged in the battery pack housing 40 such that the first side 22 of the outermost battery cell 2(1) at one end of the array faces and abuts the first inner wall 101 of the container 60, and the second side 24 of the outermost battery cell 2(12) at the opposite end of the array faces and abuts the second inner wall 121 of the container 60.

[0032] refer to Figure 2 and Figure 6 , the container 60 is a box-like structure, which includes a base 61, an outer wall 70 surrounding the base 61, and inner walls 101, 121 disposed between multiple portions of the outer wall 70 and the battery cells 2. The base 61 is rectangular and has a length dimension greater than its width dimension. The base 61 includes an inner surface 62 and an outer surface 63 opposite to the inner surface 62. The outer wall 70 surrounds the peripheral edge of the base 61 and protrudes from the base 61 in a direction perpendicular to the base inner surface 62.

[0033] When viewed in a top plan view, the outer wall 70 forms a rectangular closed section and therefore includes four orthogonal outer wall portions. Specifically, the outer wall 70 includes a first portion 71, which extends along the length of the base 61; a second portion 72, which is adjacent to the first portion 71 and extends along the width of the base 61. The outer wall 70 includes a third portion 73, which is adjacent to the second portion 72 and opposite to the first portion 71; and a fourth portion 74, which is opposite to the second portion 72 and adjacent to the first portion 71 and the third portion 73. The first portion 71 and the third portion 73 have a larger area than the second portion 72 and the fourth portion 74, and are parallel to the stacking axis 16 of the battery cell 2. The outer surface 76 of the outer wall 70 includes surface features that enhance the cooling of the battery pack. Specifically, the outer surfaces of the first portion 71 and the third portion 73 include cooling ribs 78 protruding outward. The cooling ribs 78 extend between the base 61 and the free edge 79 of the outer wall 70, and cover an area corresponding to the position of the battery cell 2 disposed in the battery pack 1.

[0034] The first inner wall 101 is disposed inside the outer wall 70 and extends in the width direction. More specifically, the first inner wall 101 is parallel to and spaced apart from both the second portion 72 and the fourth portion 74, and is disposed between the center 64 of the container 60 and the second portion 72, so that the first gap g 1 The first gap g exists between the first inner wall 101 and the second portion 72. 1 Relative to the total length l of the container 60 o (as measured between the outer surfaces of the second portion 72 and the fourth portion 74) and the dimension d of the battery cell 2 along the stacking direction is small. For example, in some embodiments, the first gap g 1 At total length l o Similarly, in some embodiments, the first gap g 1 It is in the range of 5% to 30% of the dimension d of the battery cell 2 in the stacking direction.

[0035] The first inner wall 101 includes a pair of parallel, spaced-apart plates 102, 103 that are parallel to the second portion 72 and the fourth portion 74. Angled ribs 106 extend between the inner surfaces of the plates 102, 103, resulting in voids 107 formed in the first inner wall 101 that facilitate the ability of the first inner wall 101 to deform under loads applied in a direction perpendicular to the surfaces of the plates 102, 103, such as occurs during cell growth.

[0036] The first inner wall 101 extends between the first portion 71 and the third portion 73. Specifically, the first inner wall 101 abuts and is fixed to each of the first portion 71, the base 61, and the third portion 73. For example, in some embodiments, the inner wall 101 is integrally formed with the outer wall 70 and the base 61. In other embodiments, the inner wall 101 is fixed to the outer wall 70 and the base 61 during manufacturing.

[0037] The second inner wall 121 is disposed inside the outer wall 70 and extends in the width direction. The second inner wall 121 is parallel to and spaced apart from the second portion 72 and the fourth portion 74. In addition, the second inner wall 121 is disposed between the center 64 of the container 60 and the fourth portion 74 so as to be disposed between the first inner wall 101 and the fourth portion 74. The second gap g 2 Exists between the second inner wall 121 and the fourth portion 74. The second gap g 2 Relative to the total length l of the first portion 71 o The second gap g is small in terms of the dimension d of the battery cell 2 along the stacking direction. For example, in some embodiments, the second gap g is 2 At total length l o However, in some embodiments, the second gap g 2 It is in the range of 100% to 300% of the dimension d of the battery cell 2 in the stacking direction.

[0038] Like the first inner wall 101, the second inner wall 121 includes a pair of parallel, spaced-apart plates 122, 123 that are parallel to the fourth portion 74. Angled structural ribs 126 extend between the inner surfaces of the plates 122, 123, resulting in voids 127 formed in the second inner wall 121 that facilitate the ability of the second inner wall 121 to deform under loads applied in a direction perpendicular to the surfaces of the plates 122, 123, such as occurs during cell growth.

[0039] refer to Figures 6 to 8 , the second inner wall 121 extends between the first portion 71 and the third portion 73, but is not fixed to the first portion 71 and the third portion 73. Instead, the second inner wall 121 is fixed to the fourth portion 74 via two pairs of arms 132, 142, which extend inwardly from the inner surface of the fourth portion 74 and serve to maintain the gap g between the second inner wall 121 and the fourth portion 74. 2A rigid spacer structure. The first pair of arms 132 is disposed along one side edge of the fourth portion 74 so as to be adjacent to the first portion 71, and the second pair of arms 142 is disposed along the opposite side edge of the fourth portion 74 so as to be adjacent to the third portion 73. The first clip plate 88 is disposed between the arms 133, 134 of the first pair of arms 132, and the second clip plate 89 is disposed between the arms 143, 144 of the second pair of arms 142. The first clip plate 88 and the second clip plate 89 are parallel to the base 61 and have clip plate openings 88a, 89a disposed between the second inner wall 121 and the fourth portion 74. The clip plates 88, 89 are part of a latch structure that is used to hold the fourth portion 74 in an assembled configuration with the remainder of the outer wall 70, as discussed further below.

[0040] exist Figures 1 to 8 In the embodiment illustrated in , the outer wall 70 is formed as two separate elements 66, 68, which are configured to be detachably engaged with each other to form the rectangular closed section described above. The first element 66 of the outer wall 70 includes a first portion 71, a second portion 72, and a third portion 73, which are integrally formed with the base 61 and arranged in a U-shaped configuration when viewed in a top plan view. The second element 68 of the outer wall 70 includes a fourth portion 74, which closes the open end 90 (hereinafter referred to as the U-shaped open end 90) of the U-shaped first element 66 when assembled with the first element 66. The second element 68 corresponding to the fourth portion 74 is formed separately from the first element 66 and is detachably connected to the first element 66 via a latch structure.

[0041] The latch structure is disposed on the inner surface 75 of the outer wall 70 and includes a first pair of eyes 80, 81 protruding from the inner surface of the first portion 71 at a position adjacent to the U-shaped open end 90. The first pair of eyes 80, 81 include openings 80a, 81a aligned along a first axis 86 perpendicular to the base inner surface 62. The latch structure includes a second pair of eyes 82, 83 (eyes 83 are not visible) protruding from the inner surface of the third portion 73 at a position adjacent to the U-shaped open end 90. The second pair of eyes 82, 83 include openings 82a, 83a aligned along a second axis 88 perpendicular to the base inner surface 62. The latch structure also includes a first catch plate 88, which protrudes from the inner surface of the fourth portion 74 at a position adjacent to the first portion 71; and a second catch plate 89, which protrudes from the inner surface of the fourth portion 74 at a position adjacent to the third portion 73. When the second element 68 or the fourth portion 74 is assembled with the first element 66, the first clip plate 88 is inserted between the first pair of eyes 80, 81, so that the first clip plate opening 88a is aligned with the openings 80a, 81a of the first pair of eyes along the first axis 86. In addition, the second clip plate 89 is inserted between the second pair of eyes 82, 83, so that the second clip plate opening 89a is aligned with the openings 82a, 83a of the second pair of eyes along the second axis 87. The latch structure includes a first pin 84, which is aligned with the first axis 86 and passes through the openings 80a, 88a, 81a of the first pair of eyes and the first clip plate 88; and a second pin 85, which is aligned with the second axis 87 and passes through the openings 82a, 89a, 83a of the second pair of eyes and the second clip plate 89. Specifically, the first pin 84 and the second pin 85 cooperate with the corresponding eyes and clip plates formed on the inner surface 75 of the outer wall to detachably connect the first element 66 to the second element 68.

[0042] refer to Figure 1 and Fig. 9 The cover 50 of the battery case 40 is shaped and sized to close the open end of the container 60. The periphery of the container-facing surface 52 of the cover 50 includes openings (not shown) that receive and engage upstanding latches 77 disposed on the container outer wall 70. These openings and the upstanding latches cooperate to maintain the cover 50 in a closed configuration relative to the container open end. The positive terminal 54 and the negative terminal 55 protrude from the outer-facing surface 51 of the cover 50.

[0043] The battery pack housing 60 is formed of a material that is both electrically non-conductive and thermally conductive. For example, the battery pack housing 60 may be formed of a molded high-strength plastic with additives that improve thermal conductivity and provide electrical isolation. When used in conjunction with the cooling ribs 78, the thermally conductive battery pack housing 60 provides passive cooling of the battery cells 2 during operation, thereby improving battery cell operating efficiency and preventing damage to heat-sensitive components of the battery cells 2.

[0044] The seal 56 is disposed between the perimeter of the container-facing surface 52 of the lid 50 and the free edge 79 of the container outer wall 70. The seal may be a gasket or a sealing adhesive, or may be implemented by other conventional techniques. In some embodiments using a sealing adhesive, the sealing adhesive permits the lid 50 to be removed from the container 60, while in other embodiments, the sealing adhesive provides a permanent bond of the lid 50 to the container 60.

[0045] refer to Figure 6 , Figure 7 and Fig.10 The second element 68 includes a second inner wall 121, which is parallel to the fourth portion 74 and is separated from the fourth portion 74 by two pairs of arms 132, 142. The gap g between the second inner wall 121 and the fourth portion 74 2 Used to receive a battery management device 53. The battery management device 53 is electrically connected to each battery cell 2 disposed in the battery pack housing 40, and includes electronic devices configured to monitor and control the functions of the electrochemical battery cells. For example, the battery management device 53 can regulate the battery pack 1 by actively affecting the flow of current. The electronic devices may include a printed circuit board, a resistor bus, a relay, a fuse, etc. In some embodiments, the battery management device 53 is incorporated into the cover structure and protrudes from the container-facing surface 52 of the cover and protrudes into the space between the second inner wall 121 and the fourth portion of the outer wall 70. In other embodiments, the battery management device 53 is separately arranged from the cover 50 and is disposed in the space between the second inner wall 121 and the fourth portion of the outer wall 70.

[0046] The battery pack 1 is assembled as follows. The first element 66 is separated from the second element 68, and the battery cells 2 are placed in the first element 66 while the second element 68 is detached from the first element 66. The battery cells 2 are arranged side by side in a 1x (number of battery cells) array, and wherein the electrically insulating partition 18 is disposed between adjacent battery cells 2. The number of battery cells 2 placed in the battery pack 1 and the size of the battery cells 2 are set so that the total length of the battery cell array in the stacking direction is greater than the distance d between the facing surfaces of the first inner wall 101 and the second inner wall 121. 2. The second element 68 is partially assembled with the first element 66, and wherein the second inner wall 121 abuts the outermost battery cell 2 (12) of the battery cell array. In this initial position, due to the total length of the battery cell array, the fourth portion 74 does not abut the first portion 71 and the third portion 73. Then, the second element 68 including the second inner wall 121 is pushed toward the first inner wall 101 until the fourth portion 74 abuts the first portion 71 and the third portion 73. In this abutting position, the openings 80a, 81a, 82a, 83a, 88a, 89a of the latch structure are aligned along the corresponding axes 86, 87. At this time, the pins 84, 85 are inserted through the corresponding openings, thereby fixing the second element 68 to the first element 66 and completing the container, and thereby placing the battery cell 2 in the container 60 under compression in the direction of the stacking axis 16. In some embodiments, a second seal (not shown) may be provided between the abutting surfaces of the first element 66 and the second element 68. This assembly method is possible because the second element 68 including the second inner wall 121 is movable relative to the first element 66 including the first portion 71, the base 61 and the third portion 73. As used herein, the term "movable" refers to the movement of the second inner wall 121 as a whole relative to the first portion 71 and the third portion 73, and is considered to be different from the terms "deformation" and "deflection" used to refer to changes in the shapes of the first inner wall 101 and the second inner wall 121.

[0047] refer to Figure 11 to Figure 12 , alternative embodiment container 260 can be used with cover 50 to form a battery pack. Container 260 is similar to the above with respect to Figures 1 to 10 The container 60 described herein is a box-like structure that includes a base 61, an outer wall 270 surrounding the base 61, and inner walls 101, 221 disposed between portions of the outer wall 270 and the battery cells 2. The outer wall 270 and the second inner wall 221 of the container 260 are different from the outer wall 70 and the second inner wall 121 described previously, as now described.

[0048] In the container 260, the outer wall 270 and the base 61 are a unitary structure, which includes four orthogonal outer wall portions 271, 272, 273, 274, which together surround the peripheral edge of the base 61 and protrude from the base 61 in a direction perpendicular to the base inner surface 62. In some embodiments, the outer wall portions 271, 272, 273, 274 are integrally formed with each other and with the base 61 (e.g., as a monolithic structure), such as using a molding process. In other embodiments, the outer wall portions 271, 272, 273, 274 are fixed to each other and the base 61 during manufacturing.

[0049] As in the previously described embodiment, the second inner wall 221 is disposed inside the outer wall 270 and extends in the width direction. The second inner wall 221 is parallel to and spaced apart from the second portion 272 and the fourth portion 274. In addition, the second inner wall 221 is disposed between the first inner wall 101 and the fourth portion 274.

[0050] The second inner wall 221 includes a pair of parallel, spaced-apart plates 122, 123 that are parallel to the fourth portion 274. Angled structural ribs 126 extend between the inner surfaces of the plates 122, 123, resulting in voids 127 formed within the second inner wall 221 that facilitate the ability of the second inner wall 221 to deform under loads applied in a direction perpendicular to the surfaces of the plates 122, 123, such as occurs during cell growth.

[0051] The second inner wall 221 extends between the first portion 271 and the third portion 273, but is not fixed to the outer wall 270 or the base 61. Therefore, the second inner wall 221 can move relative to the outer wall 170, so that the spacing of the second inner wall 221 from both the first inner wall 101 and the fourth portion 274 can be changed. For example, the second inner wall 221 is free-floating relative to the outer wall 270 and the base 61. Because the second inner wall 221 is free-floating, it is possible to achieve assembly of the battery cell 2 in the container 260 under a compressive load in the stacking direction while providing an integral, four-sided outer wall structure. The integral, four-sided outer wall structure is dimensionally stable due to its integral structure combined with the use of the inner walls 101, 221, and can therefore be reliably sealed.

[0052] When the battery pack 100 is assembled, the second inner wall 221 is disposed between the array of battery cells 2 and the fourth portion 274 so that the second gap g 2 Exists between the second inner wall 221 and the fourth portion 274. The gap g 2 This is achieved by providing a first spacer 232 and a second spacer 242 between the second inner wall 221 and the fourth portion 274. The first spacer 232 is provided along one side edge of the fourth portion 274 so as to be adjacent to the first portion 271, and the second spacer 242 is provided along the opposite side edge of the fourth portion 274 so as to be adjacent to the third portion 273. In the illustrated embodiment, the first spacer 232 and the second spacer 242 are rectangular tubes whose size is suitable for providing the desired gap g. 2In some embodiments, the first spacer 232 and the second spacer 242 taper along an axis perpendicular to the base inner surface 62, whereby the first spacer 232 and the second spacer 242 are used to drive the second inner wall 221 and the battery cell array toward the first inner wall 101 during assembly, and thus apply a compressive force to the battery cell array in the stacking direction. In addition, the first spacer 232 and the second spacer 242 maintain a gap g between the second inner wall 221 and the fourth portion 274 during assembly. 2 .

[0053] refer to Fig.13 Another alternative embodiment container 360 can be used with cover 50 to form a battery pack. Container 360 is similar to the above-mentioned Figure 11 to Figure 12 The container 260 described above will be described in detail, and common reference numerals will be used to refer to common elements. The container 360 is a box-like structure that includes a base 61, an outer wall 270 surrounding the base 61, and inner walls 101, 321 disposed between portions of the outer wall 270 and the battery cells 2. The second inner wall 321 of the container 360 is different from Figure 11 to Figure 12 The second inner wall 221 is as described in detail below.

[0054] In the container 360, the outer wall 270 and the base 61 are a unitary structure that includes four orthogonal outer wall portions 271, 272, 273, 274 that together surround the peripheral edge of the base 61 and protrude from the base 61 in a direction perpendicular to the base inner surface 62. In some embodiments, the outer wall portions 271, 272, 273, 274 are integrally formed (e.g., as a monolithic structure) with each other and with the base 61, such as using a molding process. In other embodiments, the outer wall portions 271, 272, 273, 274 are fixed to each other and the base 61 during manufacturing.

[0055] As in the previously described embodiment, the second inner wall 321 is disposed inside the outer wall 270 and extends in the width direction. The second inner wall 321 is parallel to and spaced apart from the second portion 272 and the fourth portion 274. In addition, the second inner wall 321 is disposed between the first inner wall 101 and the fourth portion 274.

[0056] The second inner wall 321 is formed to have an open cell structure including angled structural ribs 326 extending in a direction perpendicular to the second inner wall inner face 322, parallel to the first outer wall portion 271 and the third outer wall portion 273, and defining rectangular open cells or voids 327. The voids 327 formed in the second inner wall 321 facilitate the ability of the second inner wall 321 to deform under loads applied in a direction perpendicular to the second inner wall 321, such as occurs during cell growth. While the second inner wall inner face 322 is parallel to the second portion 272 and the fourth portion 274, the opposing second inner wall outer face 323 may not be parallel to the second portion 272 and the fourth portion 274 in order to provide a wall geometry that optimizes wall strength. The illustrated embodiment shows one possible second inner wall 321 configuration in which the outer face 323 is curved, as seen in a top plan view of the container 360. In this example, the second inner wall outer face 323 is convex so as to protrude toward the second portion, whereby the central portion of the second inner wall 321 has a greater thickness than portions of the second inner wall 321 adjacent to the first portion 271 and the third portion 273 .

[0057] The second inner wall 321 extends between the first portion 271 and the third portion 273, but is not fixed to the outer wall 270 or the base 61. Therefore, the second inner wall 321 can move relative to the outer wall 270, so that the spacing of the second inner wall 321 from both the first inner wall 101 and the fourth portion 274 can be changed. For example, the second inner wall 321 is free-floating relative to the outer wall 270 and the base 61. Since the second inner wall 321 is free-floating, it is possible to achieve assembly of the battery cell 2 in the container 260 under a compressive load in the stacking direction while providing an integral, four-sided outer wall structure. The integral, four-sided outer wall structure is dimensionally stable due to its integral structure in combination with the use of the inner walls 101, 321, and can therefore be reliably sealed.

[0058] When the battery pack 100 is assembled, the second inner wall 321 is disposed between the array of battery cells 2 and the fourth portion 274 so that the second gap g 2 Exists between the second inner wall 321 and the fourth portion 274. Gap g 2 This is achieved by providing a first spacer 332 and a second spacer 342 between the second inner wall 321 and the fourth portion 274. The first spacer 332 is provided along one side edge of the fourth portion 274 so as to be adjacent to the first portion 271, and the second spacer 342 is provided along the opposite side edge of the fourth portion 274 so as to be adjacent to the third portion 273. In the illustrated embodiment, the first spacer 332 and the second spacer 342 are rigid members whose dimensions are suitable for providing the desired gap g. 2, and the shape corresponds to and cooperates with the shape of the outer side 323 of the second inner wall. Specifically, the shapes of the first spacer 332 and the second spacer 342 are optimized together with the shape of the second inner wall 321 to provide the best strength of the second inner wall 321. In some embodiments, the first spacer 332 and the second spacer 342 may taper along an axis perpendicular to the inner surface 62 of the base, whereby the first spacer 332 and the second spacer 342 are used to drive the second inner wall 321 and the battery cell array toward the first inner wall 101 during assembly, and thus apply a compressive force to the battery cell array in the stacking direction. In addition, the first spacer 332 and the second spacer 342 maintain the gap g between the second inner wall 321 and the fourth portion 274 during assembly. 2 .

[0059] Although each of the containers 60, 260, 360 described herein includes a first gap g 1 A fixed first inner wall 101 separated from the outer wall 70, 270, but it is contemplated that in some embodiments, the gap g may be eliminated. 1 , whereby the inner wall 101 will become the second portion 72 , 272 of the outer wall 70 , 720 and will have properties that will permit some deformation of its facing inner surface 122 .

[0060] Although the battery cell 2 is described as housing an electrode assembly 4 having a jelly-roll electrode configuration, the electrode assembly 4 is not limited to such an electrode configuration. For example, the electrode assembly 4 may include a stacked or folded arrangement of electrode plates, or other suitable electrode arrangements.

[0061] Although the battery cell 2 is described as a lithium-ion battery cell, the battery cell 2 is not limited to this type of battery cell. For example, the battery cell 2 may include different combinations of electrode materials and electrolytes including lead acid, nickel cadmium (NiCd), nickel metal hydride (NiMH), and lithium ion polymer.

[0062] Although the illustrated embodiment includes 12 battery cells 2 in the battery cell array, the battery pack 1 is not limited to having 12 battery cells 2. The number of battery cells used may be greater or less than 12 and is determined by the requirements of the specific application.

[0063] Selective illustrative embodiments of battery packs and battery pack housings are described in some detail above. It should be understood that only structures that are considered necessary for clarifying these devices are described herein. It is assumed that other conventional structures and those structures of the auxiliary and auxiliary components of the battery pack system are known and understood by those skilled in the art. In addition, although working examples of battery packs and battery pack housings are described above, the battery packs and / or battery pack housings are not limited to the working examples described above, but various design changes can be implemented without departing from the devices as set forth in the claims.

Claims

1. A battery housing configured to receive an array of electrochemical cells, the cells of the array being arranged side by side along a stacking axis, the battery housing comprising a container, the container comprising: a substrate comprising an inner surface, an outer surface opposite the inner surface, and a peripheral edge joining the inner surface to the outer surface, an outer wall surrounding the peripheral edge and protruding from the base in a direction perpendicular to the inner surface of the base, the outer wall comprising a first portion, a second portion adjacent to the first portion, a third portion adjacent to the second portion and opposite to the first portion, and a fourth portion opposite to the second portion, an inner wall extending between the first portion and the third portion and disposed between and parallel to the second portion and the fourth portion; as well as a rigid spacer adjacent the inner wall, the spacer tapering along an axis perpendicular to the base such that the spacer and the inner wall cooperate to apply a compressive force to the battery cell array in a direction parallel to the stacking axis; The inner wall is freely floating relative to the outer wall, so that the distance between the inner wall and the fourth part can be changed.

2. The battery pack housing according to claim 1, wherein: The spacer is disposed between the inner wall and the fourth portion, and is configured to maintain a gap between the inner wall and the fourth portion.

3. The battery pack housing according to claim 2, wherein: The gap has a gap size corresponding to the distance between the inner wall and the fourth portion; The spacer includes a first surface facing the inner wall without an intervening structure, and a second surface opposite to the first surface, the second surface facing the fourth portion without an intervening structure, and a distance between the first surface and the second surface corresponds to the gap size.

4. The battery pack housing according to claim 2, wherein: The gap is shaped and sized to receive a battery management device configured to monitor and control the electrochemical cell.

5. The battery pack housing according to claim 1, wherein The spacer includes a first surface facing the inner wall, and a second surface opposite to the first surface, and one of the first surface and the second surface is tapered along an axis perpendicular to the base.

6. The battery pack housing according to claim 1, wherein: The spacer includes a first spacer and a second spacer separated from the first spacer, and the first spacer and the second spacer each have a polygonal shape.

7. The battery pack housing according to claim 6, wherein: The first spacer is disposed along a side edge of the inner wall so as to be adjacent to the first portion. the second spacer is disposed along a side edge of the inner wall opposite to the one side edge, such that the second spacer is disposed adjacent to the third portion, A gap is disposed between the first spacer and the second spacer, and The gap is shaped and sized to receive a battery management device therein.

8. The battery pack housing according to claim 1, wherein: The inner wall has an inner surface parallel to the second portion and facing the second portion, The inner wall has an outer surface opposite to the inner surface, The outer surface faces the fourth portion, and At least a portion of the outer surface is non-parallel to the fourth portion.

9. A battery pack comprising: Battery pack housing; and an array of electrochemical cells disposed in the battery housing, the cells of the array being arranged side by side along a stacking axis, The battery pack housing includes a container and a cover closing an open end of the container, wherein the container includes: a substrate comprising an inner surface, an outer surface opposite the inner surface, and a peripheral edge joining the inner surface to the outer surface, an outer wall surrounding the peripheral edge and protruding from the base in a direction perpendicular to the inner surface of the base, the outer wall comprising a first portion, a second portion adjacent to the first portion, a third portion adjacent to the second portion and opposite to the first portion, and a fourth portion opposite to the second portion, an inner wall extending between the first portion and the third portion and disposed between and parallel to the second portion and the fourth portion; and a rigid spacer adjacent the inner wall, the spacer tapering along an axis perpendicular to the base such that the spacer and the inner wall cooperate to apply a compressive force to the battery cell array in a direction parallel to the stacking axis; The inner wall is freely floating relative to the outer wall, so that the distance between the inner wall and the fourth part can be changed.

10. The battery pack according to claim 9, wherein: The spacer is disposed between the inner wall and the fourth portion, and is configured to maintain a gap between the inner wall and the fourth portion.

11. The battery pack according to claim 10, wherein: The gap has a gap size corresponding to the distance between the inner wall and the fourth portion; The spacer includes a first surface facing the inner wall without an intervening structure, and a second surface opposite to the first surface, the second surface facing the fourth portion without an intervening structure, and a distance between the first surface and the second surface corresponds to the gap size.

12. The battery pack according to claim 10, wherein: The gap is shaped and sized to receive a battery management device configured to monitor and control the electrochemical cell.

13. The battery pack according to claim 9, wherein The spacer includes a first surface facing the inner wall, and a second surface opposite to the first surface, and one of the first surface and the second surface is tapered along an axis perpendicular to the base.

14. The battery pack according to claim 9, wherein: The spacer includes a first spacer and a second spacer separated from the first spacer, and the first spacer and the second spacer each have a polygonal shape.

15. The battery pack according to claim 14, wherein: The first spacer is arranged along a side edge of the inner wall so as to be adjacent to the first portion, the second spacer is disposed along a side edge of the inner wall opposite to the one side edge, such that the second spacer is disposed adjacent to the third portion, A gap is disposed between the first spacer and the second spacer, and The gap is shaped and sized to receive a battery management device therein.

16. The battery pack according to claim 9, wherein: The inner wall has an inner surface parallel to the second portion and facing the second portion, The inner wall has an outer surface opposite to the inner surface, The outer surface faces the fourth portion, and At least a portion of the outer surface is non-parallel to the fourth portion.

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