Description:TECHNICAL FIELD
[0001]
The present subject matter relates to battery modules. More particularly, end covers of the battery modules are disclosed in the patent application number 202041013370 and the present subject matter offers an improvement over the subject matter as claimed in aforementioned patent application. 5
BACKGROUND
[0002]
Existing research in battery technology is directed to rechargeable batteries, such as sealed, starved electrolyte, lead/acid batteries, are commonly used as power sources in different applications, such as, vehicles and the like. However, the lead-10 acid batteries are heavy, bulky, and have short cycle life, short calendar life, and low turn around efficiency, resulting in limitations in applications.
[0003]
Thus, in order to overcome problems associated with conventional energy storage devices including the lead-acid batteries, a lithium ion battery provides an ideal system for high energy-density applications, improved rate capability, and 15 safety. Further, the rechargeable energy storage devices - lithium-ion batteries exhibit one or more beneficial characteristics which makes it useable on powered devices. First, for safety reasons, the lithium ion battery is constructed of all solid components while still being flexible and compact. Secondly, the energy storage device including the lithium ion battery exhibits similar conductivity characteristics 20 to primary batteries with liquid electrolytes, i.e., deliver high power and energy density with low rates of self-discharge. Thirdly, the energy storage device as the lithium ion battery is readily manufacturable in a manner that it is both reliable and cost-efficient. Finally, the energy storage device including the lithium ion battery is able to maintain a necessary minimum level of conductivity at sub-ambient 25 temperatures. By virtue of these advantages, the energy storage devices find applications in rugged environments with increased ambient temperatures. However, the energy storage devices are susceptible to vibrations during their lifetime, which may lead to functional failure and fatigue damage to the energy storage devices. The construction of the energy storage devices is critical to the 30 longevity, safety, serviceability, and maintainability of the energy storage devices.
3
BRIEF DESCRIPTION OF DRAWINGS
[0004]
The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components. 5
[0005]
Fig. 1 exemplarily illustrates an exploded perspective view of a battery module;
[0006]
Figs. 2A-2C exemplarily illustrate partially exploded perspectives view of the battery pack of the battery module exemplarily illustrated in Fig. 1; 10
[0007]
Figs. 3A-3B exemplarily illustrate a front perspective view and a front view respectively of a damper in the battery module, as per an embodiment of the present invention;
[0008]
Fig. 4 exemplarily illustrates an exploded perspective view of the damper, as per an embodiment of the present invention; 15
[0009]
Fig. 5 exemplarily illustrates a bottom perspective view of a cushioning member of the damper;
[00010]
Figs. 6A-6B exemplarily illustrate the perspective view of a solid seat member of the damper;
[00011]
Fig. 7 exemplarily illustrates a front perspective view of an 20 embodiment of the damper of the battery module;
[00012]
Figs. 8A- 8B exemplarily illustrate a rear perspective view of a front end cover and a partially exploded rear perspective view of a front end cover respectively;
[00013]
Fig. 9 exemplarily illustrates a perspective view of the rear end 25 cover;
[00014]
Figs. 10A-10B exemplarily illustrate the first sealant member;
[00015]
Figs. 11A-11B exemplarily illustrates different views of the wire clip of the battery module;
[00016]
Figs. 12A-12B exemplarily illustrate different sectional views of the 30 battery module; and
4
[00017]
Figs. 13A-13B exemplarily illustrates a method of assembly of the battery module.
DETAILED DESCRIPTION OF THE INVENTION
[00018]
An energy storage device, or otherwise referred to as battery 5 module, comprises one or more energy storage cells, such as, lithium ion battery cells enclosed within a casing. The battery module finds application in numerous domains, one such application being in driving electric vehicles or hybrid electric vehicles. On deployment of the electric or hybrid electric vehicles in rugged environment, the vehicle frame is subjected to vibrations. Such vibrations are 10 transmitted to the energy storage device in the vehicle. The casing of the energy storage device experiencing the vibrations, transmits the vibrations to the energy storage cells affecting the functionality of the energy storage device in long run.
[00019]
Also, marginal deviation in design of the casing or the design of the cell holders can result in loose packaging of the energy storage cells within the 15 casing. Such a packaging can compromise number of life cycles of the energy storage device. The vibrations may also set exothermic reactions within the energy storage cells resulting in release of smoke or toxic gases and high-pressure events leading to a catastrophic failure of the energy storage device. A reliable packaging of the energy storage device is needed for mechanical stability, durability, thermal 20 stability, vibration isolation, and impact resistance of the energy storage device.
[00020]
Existing packaging of the energy storage cells within a casing employs a packaging material that which can withstand raised temperatures and pressures. However, the packaging material needs to be uniformly distributed along the length of the casing using a fastening means. However, the packaging material 25 increases the weight, the manufacturing cost, and the assembling cost of the energy storage device. Also, while loading or unloading the assembly of the energy storage cells into the casing, the packaging material may hinder the ease in pushing in or pulling out of the energy storage cells from the casing. To address this problem, the packaging material has to be made firm and rigid to not deform, while loading and 30 unloading of the assembly of the energy storage cells.
5
[00021]
Further, based on the application of the energy storage device, the capacity of the energy storage device is varied. Based on the capacity of the energy storage device, the number of energy storage cells, the mass of the energy storage cells, and the capacity of the energy storage cells, etc., are varied. If energy storage cells with reduced size or mass are to be enclosed within an existing casing, a gap 5 may be formed between the casing and the energy storage cells. Such gaps will result in not a very tight packaging of the energy storage cells in the energy storage device. This loose gap in the configuration of packaging between the energy storage cells and the casing will not provide adequate protection to the energy storage cells from vibrations, pressure, temperature, and abuse experienced by the casing. If a 10 packaging material that is rigid and firm is used, it may not allow for the flexibility of using an existing casing for different assemblies of the energy storage cells. This may lead to manufacture of different casings for different assemblies of the energy storage cells increasing material cost and manufacture cost of entities.
[00022]
The casing may be open on either sides and the open sides may be 15 covered by end covers. As the battery module is susceptible to vibrations and temperatures, the casing may deform and gaps may be formed between the casing and end covers. Through the gaps between the casing and the end covers, water, dust and moisture ingress can occur into the battery module. This ingress is detrimental to the durability and functioning of the battery module. Thus, there is a 20 need for sealing such gaps between the casing and the end covers to improve durability of the battery module. However, there is need to ease the assembly of such sealants to seal the gaps, to improve manufacturability, the serviceability, the assembly of the battery module. Also, there is a need to prevent squeezing out or displacement of the sealants when the casing and the end cover are fastened 25 together.
[00023]
Also, there is need to limit the amount of tightening torque in the process of assembly of the end covers to the casing to prevent breakage of the end covers and aid in assembly of the battery module. Further, the durability of the battery module demands for a protection circuit for protecting the electrical 30 terminals of the cells from short circuiting. Also, the wires connecting the terminal
6
of the cells to a control board of the battery module may be slacking, entangling
with each other and can cause short circuit of the battery module accidentally. There is a need to prevent slacking of the wires and need to guide the wires from the cells to prevent catastrophes from occurring. Also, there is a need for thermal management of the battery module to prevent thermal runaway of the cells and 5 catastrophe of the battery module.
[00024]
Thus, there exists a need for an improved design of a battery module with packaging, sealants, and protection circuits, between the assembly of energy storage cells and a casing to ensure ease and safety during assembly, use, maintenance, and servicing of the energy storage device overcoming all problems 10 disclosed above as well as other problems of known art.
[00025]
The present subject matter discloses an energy storage device, that is, a battery module comprising an improved and simplified design of a packaging for impact resistance, shock isolation, and vibration dampening of a battery module. Such a battery module may be employed in powered devices, such as, vehicles, for 15 example, electric vehicle, hybrid electric vehicles, IC engine vehicles, etc.
[00026]
In an embodiment of the present invention, a battery module for a powered device is disclosed. The battery module comprises one or more cell holders, multiple cells positioned in the cell holders, and a casing enclosing the cells in the cell holders. A front end cover and a rear end cover enclose the plurality of 20 cells in the casing, in a front side and a rear side of the casing. A first sealant member is positioned between the front end cover and the front side of the casing and a second sealant member is positioned between the rear end cover and the rear side of the casing. Further, one or more dampers are positioned at predetermined locations of the cell holders for rigidity of the battery module. Each of the dampers 25 comprise a hollow cushioning member, a solid seat member, and a stem portion extending from the seat member. The hollow cushioning member is accommodated in a space between the cell holders and the casing. The hollow cushioning member comprises one or more extenders extending from underneath a first surface. The solid seat member comprises depression with one or more ribs engaging with the 30 extenders of the cushioning member. The stem portion extends from underneath the
7
depression
of the seat member and locks into an aperture at the predetermined locations of the cell holders. The position and the embodiments of the structure of the dampers and the sealant members are disclosed in the detailed description of Figs. 2-12.
[00027]
Fig. 1 exemplarily illustrates an exploded perspective view of a 5 battery module 100. The battery module 100 comprises a front end cover 101, a rear end cover 104, a casing 103, and a battery pack 102. The casing 103 comprises four walls 103a, 103b, 103c, 103d for enclosing the battery pack 102 on four sides. The front end cover 101 and the rear end cover 104 encloses the battery pack 102 in the casing 103, in a front side 103e and a rear side 103f of the casing 103. The 10 dovetail pattern (not labelled) of the external casing 103 facilitates easy mounting and unmounting of the battery module 100 in a designated space in a powered device. The external casing 103 with the four walls 103a, 103b, 103c, 103d encloses the battery pack 102 from top, bottom, and sides. The rear end cover 104 and the front end cover 101 enclose the battery pack 102 from rear and front 15 respectively. The battery pack 104 comprises a plurality of cells arranged in a particular sequence between one or more cell holders 105. The cells are electrically connected in series and/or parallel configuration to form an array of cells. Such arrays of cells are electrically connected to a control board, i.e. a battery management system (BMS) 106 within the battery module 100. The BMS 106 is a 20 printed circuit board with one or more integrated circuits integrally built on it as exemplarily illustrated in Fig. 2. The external casing 103 has mounting provisions 103g for the rear end cover 104 and the front end cover 101. The rear end cover 104 and the front end cover 101 are fastened to the external casing 103 using a plurality of attachment means 101c. The external casing 101 with a dovetail pattern 25 that allows easy insertion and removal of the battery module 100 into a battery mounting bracket (not shown). The dovetail pattern is also formed on the interior side of the casing 103. The dovetail pattern on the interior side allows easy sliding of the battery pack 104 into the casing 103.
[00028]
As per a preferred embodiment, the attachment means 101c can be 30 fasteners. The battery pack 102 has mounting provisions (not shown) for the BMS
8
board
106. The BMS board 106 is screwably attached to the cell holders 105 of the battery pack 102. The BMS board 106 is located between the battery pack 102 and the first end cover 101. One or more dampers, such as, 107a are positioned at predetermined locations on the cell holders 105 for rigidity of the battery module 100. 5
[00029]
A front surface 101a of the front end cover 101 comprises an opening with a cover 110 for pouring a thermally conductive material into the casing 103 which enables extracting heat dissipated by the cells. The thermally conductive material may be a thermal foam, phase change material, etc. The front surface 101a further comprises an external connector 108 protruding inwards from 10 a recessed flat section of the front surface 101a for electrically connecting the battery module 100 in a powered device. The external electrical connector 108 with integrated pins caters to both control signals and power signals of the battery module 100. The front surface 101a further comprises of an external wire guide 108 configured proximal to the electrical connector 108 for guiding an external 15 cable of the battery module 100 originating from the external connector 108. The front end cover 101 and the rear end cover 104 may be made of any electrically and thermally insulating material, such as, plastic, resin, silicone, etc.
[00030]
Figs. 2A-2C exemplarily illustrate partially exploded perspective view of the battery pack 102 of the battery module 100 exemplarily illustrated in 20 Fig. 1. As exemplarily illustrated, the battery pack 102 comprises of the cell holders 105 and the BMS board 106 removably attached to the cell holders 105. The cell holders 105 comprises of a first cell holder 105a and a second cell holder 105b. The cell holders 105 comprise placeholders, each placeholder capable of holding a cell, such as, 201. Each of the cell holders 105 comprises a planar surface, such as, 105c 25 with the placeholders and raised edges, such as, 105d at the sides of the planar surface 105c. One of the cell holders 105b is positioned at a first end of the cells 201 and another cell holder 105a is positioned at second end of the cells 201 where the first end and second end have electrical contact of the cell. The cell holders 105a, 105b are fixed together using a plurality of fasteners to tightly hold the cells 30 201 in the placeholders. The raised edges, such as, 105d of the cell holders 105a
9
and
105b come in contact with each other, when the cell holders 105a and 105b are fixed together. To fasten the cell holders 105a and 105b together, recesses such as, 203 are provided to position the fasteners in the cell holders 105a and 105b. The cells 201 in the cell holders 105a, 105b are electrically connected to each other using multiple interconnect sheets 210 where the interconnect sheets 210 are 5 disposed substantially parallel to the planar surface 105c of the cell holder 105.
[00031]
As an embodiment, the cell holders 105a and 105b may be rectangular in shape and holding cylindrical cells in the placeholders. As exemplarily illustrated, the dampers 107a, 107b, …, 107f, 107g, 107h (not shown) are positioned at predetermined recess locations, such as, 204a of the cell holders 10 105. The dampers 107a, 107b, …, 107g, 107h may be positioned on the sides of the cell holders 105a and 105b that come in contact with the casing 103 of the battery module 100. In total for the rectangular cell holders 105a and 105b, there are 8 dampers, 4 at the shorter edges of each of the cell holders 105a and 105b. The dampers 107c, 107d, 107e, and 107f are positioned on the raised edges of the top 15 cell holder 105a. The dampers 107a, 107b, 107g, and another damper (not visible but referred to as 107h) are positioned on the raised edges of the bottom cell holder 105b. In an embodiment, the dampers 107a, 107b, …, 107h may be positioned at shorter raised edges 105f of the cell holders 105a and 105b that come in contact with sides of the casing 103. On the longer raised edges 105e of the cell holders 20 105a and 105b, the BMS board 106 is mounted as shown. The predetermined recess locations, such as, 204a may be at center of the edges 105f or proximal to vertices 205 of the cell holders 105a and 105b. At the predetermined recess locations, such as, 204a depressions or recesses are formed on the cell holders 105a and 105b or a part of the cell holder 105a or 105b is excavated. The damper, such as, 107c sits in 25 the depressions and may bulge away from the cell holders 105a and 105b. When the battery pack 102 is positioned in the casing 103, the bulge in the damper, such as, 107c may occupy the space between the battery pack 102 and the casing 103. At the depressions, an aperture, such as, 204b is provided to insert an complimentary engaging portion of the damper, such as, 107d into the cell holders 30
10
105a
and 105b. As exemplarily illustrated, the dampers 107a, 107b, …, 107h are located on top and bottom short edges, such as, 105f of the battery pack 102.
[00032]
The interconnect sheets 210 and the BMS board 106 are connected and mounted to the cell holders 105a, 105b at mounting locations, such as, 211 on the longer edges 105e of the cell holders using floating nuts 213. The battery pack 5 102 further comprises a safety plate 202 positioned over the interconnect sheets 210 of the battery pack 102. The safety plate 202 is disposed between each cell holder 105a and 105b and an adjacent wall of the casing 103b and 103d, one safety plate 202 each at the top and the bottom of the battery pack 102. The safety plate 202 protects the interconnect sheets 210 where the terminals of the cells 201 are 10 interconnected, from being exposed, to avoid a potential risk of tampering of the terminals and also a short circuit. The BMS board 106 is disposed between the cell holders 105a and 105b and the front end cover 101. At least one heat sink 206 is mounted on the BMS board 106 for cooling of the electronic components on the board 106. Further, the BMS board 106 has an aperture 212 through which a wire 15 clip 209 is mounted to one of the cell holders 105b for routing the wires originating from the cells 201 as well as wires originating from the control board 106 to connect the cells 201 and the control board 106 to the external connector 108. The BMS board 106 further comprises of a protection circuit 207 of the battery module 100 and a wire guide 208 for guiding wires originating from the BMS board 106 to the 20 wire clip 209. The protection circuit 207 comprises of a fuse connected between terminals of the cells 201 and the external connector 108.
[00033]
Figs. 3A-3B exemplarily illustrate a front perspective view and a front view respectively of the damper, such as, 107a in the battery module 100, as per an embodiment of the present invention. As exemplarily illustrated, the damper 25 107a comprises a hollow cushioning member 301, a solid seat member 302, and a stem portion 303. The hollow cushioning member 301 is accommodated in the space between each cell holder 105a and 105b and the casing 103. The hollow cushioning member 301 forms the bulge portion of the damper 107a. The hollow cushioning member 301 is attached with the solid seat member 302. The solid seat 30 member 302 rests at the predetermined recess locations, such as, 204a of the cell
11
holders
105a and 105b. A bottom profile of the solid seat member 302 comprises a groove 302a that is aligned along the short edges 105f of the cell holders 105a and 105b. The groove 302a facilitates resting of the solid seat member 302 in the depressions in the cell holders 105a and 105b. The stem portion 303 of the damper 107a extends from underneath the depressions in the seat member 302, locking into 5 the aperture 204b at the predetermined location 204a of the cell holders 105a and 105b.
[00034]
The stem portion 303 is inserted into the aperture 204b at the predetermined location 204a of the cell holders 105a and 105b. As exemplarily illustrated in Fig. 3B, the stem portion 303 comprises at least two parallel half 10 locking portions, such as, 303a with locking ridges 303b at a distal end. As exemplarily illustrated, two parallel locking portions, such as, 303a constitute the stem portion 303. In an embodiment, three or more parallel locking portions, such as, 303a constitute the stem portion 303 of the damper 107a. Each of the locking portion 303a comprises a locking ridge 303b at a distal end. The two parallel half 15 locking portions 303a are pressed towards each other and the stem portion 303 is inserted into the aperture 204b of the predetermined location 204a of the cell holders 105a and 105b. Once the stem portion 303 is inserted into the aperture 204b, the locking portions 303a move to their original position. In the inserted position, the locking ridge 303b of the stem portion 303 arrests uprooting of the 20 damper 107a from the predetermined location 204a of the cell holders 105a and 105b.
[00035]
Fig. 4 exemplarily illustrates an exploded perspective view of the damper 107a, as per an embodiment of the present invention. As exemplarily illustrated, the damper 107a comprises the hollow cushioning member 301, the 25 solid seat member 302, having the stem portion 303. The cushioning member 301 comprises one or more extenders 301b extending from underneath the first surface 301a which isthe first surface 301a of the hollow cushioning member 301 which forms the bulge portion. The extenders, such as, 301b extend from beneath the bulge portion. The first surface 301a of the hollow cushioning member 301 is a 30 convex surface. The hollow cushioning member 301 is formed of a resilient
12
material, such as, rubber
. In an embodiment, beneath the first surface 301a, four extenders, such as, 301b are provided. The extenders 301b are also made of the resilient material. The extenders 301b are flat and firm to engage with ribs 302d of the solid seat member 302. The number of extenders 301b is designed based on the number of the ribs 302d of the seat member 302. 5
[00036]
One side profile of the cushioning member 301 is the convex first surface 301a with sides 301c extending longer than the extenders 301b. A top profile of the solid seat member 302 as exemplarily illustrated, is a four walled structure. Two raised opposite walls 302b in the top profile of the solid seat member 302 are enclosed by the sides 301c of the cushioning member 301 in an engaged 10 condition of the cushioning member 301 and solid seat member 302. Thus, on engaging of the cushioning member 301 with the seat member 302, the two raised opposite walls 302b of the seat member 302 are enclosed within the cushioning member 301. The end 301e of the convex first surface 301a is in abutment contact with a lower wall 302c of the solid seat member 302, when the seat member 302 is 15 engaged with the cushioning member 301.
[00037]
The solid seat member 302, when viewed from top, comprises a centrally configured depression or recess with ribs 302d bound by the walls 302b and 302c of the solid seat member 302. The ribs 302d are designed in a pattern corresponding to the design of the extenders 301b. The ribs 302d are raised edges 20 of the material of the seat member 302 that engage in the spaces between the extenders 301b of the cushioning member 301. The ribs 302d diagonally extend as exemplarily illustrated in Fig. 4 from an epicenter portion 302e which is located in the depression or recess. In an embodiment, the ribs 302d extend sideways from the epicenter portion 302e in the depression. The seat member 302 is made of a 25 polymeric or resin material that is firm and sturdy to hold the cushioning member 301 at the predetermined locations of the cell holders 105a and 105b.
[00038]
As per an additional embodiment, the bottom profile of the solid seat member 302 comprises the groove 302a that matches with the profile of the depression (not labelled) in the cell holders 105a and 105b. The solid seat member 30 302 rests at the predetermined recess locations 204a of the cell holders 105a and
13
105b
. The cushioning member 301 and the seat member 302 engaged with each other are locked in the aperture 204b at the predetermined location 204a of the cell holders 105a and 105b using the stem portion 303 preferably in a snug fit or interference fit manner.
[00039]
Fig. 5 exemplarily illustrates a bottom perspective view of the 5 cushioning member 301 of the damper 107a. As exemplarily illustrated, the extenders 301b extend from underneath the first surface 301a. Further, the extenders 301b appear to originate from an empty epicenter portion 301d underneath the first surface 301a. The extenders 301b are designed corresponding to the design of the ribs 302d of the seat member 302. 10
[00040]
Figs. 6A-6B exemplarily illustrate the perspective view of the solid seat member 302 of the damper 107a. As exemplarily illustrated in Fig. 6A, four ribs, such as, 302d in the depression of the solid seat member 302 may originate from the epicenter portion 302e. Fig. 6B exemplarily illustrates only two ribs , such as, 302d originating from the epicenter portion 302e and extending sideways from 15 the epicenter portion 302e to the walls 302b of the seat member 302.
[00041]
Fig. 7 exemplarily illustrates a front perspective view of an embodiment of the damper 107a of the battery module 100. The hollow cushioning member 301 of the embodiment of the damper 107a illustrated in Fig. 7 comprises a depression 701 on the first surface 301a for inserting a fastener to fasten the 20 cushioning member 301 and the seat member 302 (shown in Fig 4) to the cell holders 105a and 105b (shown in Fig 2A). The aperture 702 in the depression 701 for the fastener is in-line with the depression on the cell holders 105a and 105b of the battery module 100. In such an embodiment of the damper 107a, the stem portion, such as, 303 (shown in Fig 4) is absent and the damper 107a is held in 25 position at the predetermined location 204a (shown in Fig 2A) of the cell holders 105a and 105b (shown in Fig 2A) using the fasteners inserted through the cushioning member 301. In an embodiment, the aperture 702 in the depression 701 in the cushioning member 301 may include threads for screwing a fastener into the aperture 702. 30
14
[00042]
Figs. 8A- 8B exemplarily illustrate a rear perspective view of a front end cover 101 and a partially exploded rear perspective view of the front end cover 101 respectively, showing the rear surface 101b of the front end cover 101. The rear surface 101b of the front end cover 101 comprises mounting provisions 809 for mounting a wire clamp 801 for holding the external connector 108, where the 5 provisions 809 protrude inwards from the front surface 101a of the front end cover 101. Further, the rear surface 101b comprises a plurality of stopper ribs 805 extending from first edges 804 of the front end cover 101 to the cell holders 105a, 105b (shown in Fig 2A) for guided attachment of the front end cover 101 to the casing 103. The length of the stopper ribs 805 is greater than length of the sides 806 10 of the front end cover 101. As per one embodiment, the stopper ribs 805 limit the amount of tightening torque being applied to attach the front end cover 101 to the front side 103e of the casing 103. The rear surface 101b further comprises reinforcement ribs 802 to improve the strength of the front end cover 101. The opening 807 for pouring the thermal conductive material is also provided in the 15 front end cover 101. The thermal conductive material once poured through this opening 807 will flow and surround the cells 201 (shown in Fig 2C) in the cell holders 105a, 105b through the enclosed space between the cell holders 105a, 105b and the front end cover 101. A first sealant member 808 is positioned between rear surface 101b of the front end cover 101 and edges of the front side 103e of the 20 casing 103. The rear surface 101b has a peripheral groove 810 to receive the first sealant member 808. The peripheral groove 810 in the rear surface 101b of the front end cover 101 comprises a depression 810a for receiving a ridge of the first sealant member 808, a second flat section 810e for receiving a first flat section of the first sealant member 808, and raised portions 810d interspersed in the second flat section 25 810e for disposing raised projections of the first sealant member 808 around its periphery. Further, the depression 810a at predetermined location has limiters such as 810b, 810c on the walls defining the depression 810a to restrict the first sealant member 810 from dislocating from the depression 810a. The second flat section 810e further comprises interspersed apertures 810f for attaching the front end cover 30 101 to the casing 103. The first sealant member 808, may be a gasket or a filler
15
foam
and may have provisions corresponding to the peripheral groove 810 for the sealant member 808 to be accommodated within the first end cover 101 and seal any gap between the casing 103 and the front end cover 101. The peripheral groove 810 has one or more discontinuities 810g in it on one of the walls defining the depression 810a. The discontinuities 810g act as locators for positioning of the 5 sealant member 808 within the peripheral groove 810.
[00043]
Fig. 9 exemplarily illustrates a perspective view of the rear end cover 105. On the rear end cover 104, a safety valve 903 with a plug 904 for expelling gases emitted by the plurality of cells 201 (shown in Fig 2C) is provided. Further, on the rear surface 104b, multiple reinforcement ribs 104c are provided for 10 strengthening the rear end cover 104 as seen in Fig. 1. A second sealant member 901 is positioned between the rear end cover 104 and the rear side 103f of the casing 103. The rear end cover 104, similar to the front end cover 101 also has a peripheral groove (not shown) that accommodates the second sealant member 901 in it. The structure of the second sealant member 901 is similar to the structure of the first 15 sealant member 808.
[00044]
Figs. 10A-10B exemplarily illustrate the first sealant member 808. The structure of the second sealant member 901 is similar to the first sealant member 808. The first sealant member 808 comprises a first flat section 808e along an entire length of the first sealant member 808 and a ridge 808a extending from 20 the flat section 808e along periphery of the first sealant member 808. The first sealant member 808 further comprises a plurality of rings 808d interspersed in the flat section 808e of the first sealant member 808. Further, the first sealant member 808 comprises a plurality of T-projections 808g extending inwards from the ridge 808a. Also, the first sealant member 808 comprises a raised projection 808b being 25 configured around a periphery of each of the plurality of rings 808d. Further there are cut-outs 808f in the first sealant member 808 that are inline with the apertures 810f (shown in Fig 8B) in the front end cover 101 to mount the front end cover 101 to the casing 103.
[00045]
The depression 810a (shown in Fig 8B) in the peripheral groove 810 30 (shown in Fig 8B) receives the ridge 808a of the first sealant member 808, the
16
second flat section
810e (shown in Fig 8B) in the peripheral groove 810 (shown in Fig 8B) receives the first flat section 808e of the first sealant member 808, and raised portions 810d (shown in Fig 8B) are inserted into the rings 808d of the first sealant member 808 and surrounded by the raised projections 808b. The T-projections 808g are inserted into the discontinuities 810g (shown in Fig 8B) in the 5 peripheral groove 810 (shown in Fig 8B) for guided placement of the first sealant member 808 in the peripheral groove 810 (shown in Fig 8B). Also, the ridge 808a is limited in the depression 810a (shown in Fig 8B) by the limiters 810a, 810b (shown in Fig 8B). The height of the raised projections 808b is equal to the height of the raised portions 810d (shown in Fig 8B) in the peripheral groove 810 (shown 10 in Fig 8B).
[00046]
Figs. 11A-11B exemplarily illustrate different views of the wire clip 209 of the battery module 100. The wire clip 209 is mounted to the cell holder 105b (shown in Fig 2B) through an aperture 212 (shown in Fig 2C) in the BMS board 106 (shown in Fig 2C) for routing wires originating from the cells 201 and the BMS 15 board 106 (shown in Fig 2C) to connect to the external connector 108 through the wire clamp 801 (shown in Fig 8B). The wire clip 209 comprises a strap member 209a holding the wires 1101 together and an umbrella structure 209b that rests on the BMS board 106. A stem member 209c of the wire clip 209 is inserted into the aperture 212 (shown in Fig 2C) in the BMS board 106 (shown in Fig 2A) and 20 screwed into the cell holder 105b (shown in Fig 2A) as shown in Fig. 12A.
[00047]
Figs. 12A-12B exemplarily illustrate different sectional views of the battery module 100. As shown in Fig. 12A in the zoomed view, the wire clip 209 resting on the BMS board 106 (shown in Fig 2A) is screwed into the cell holder 105b. As shown in Fig. 12B, the first sealant member 808 is squeezed between the 25 front end cover 101 and the casing 103, when the first sealant member 808 is positioned in the peripheral groove 810. Similarly, the second sealant member 901 is also squeezed between the rear end cover 104 and the casing 103.
[00048]
Figs. 13A-13B exemplarily illustrate a method of assembly of the battery module 100, comprising steps of: At step 1301, the cells holders 105a, 105b 30 are obtained and the cells 201 are sorted and positioned in between the cell holders
17
105a
, 105b. At step 1302, the cells 201 are interconnected to form a series connection or a parallel connection using the interconnect sheets 210. At step 1303, floating nuts 213 are disposed in predetermined locations 211 on the cell holders 105a, 105b to connect the interconnect sheets 210 with the control board 106 of the battery module 100. At step 1304, a safety plate 202 (shown in Fig 2B) is positioned 5 in contact with the cell holders 105a, 105b at the top and the bottom of the battery pack 102. At step 1305, the control board 106 is mounted to the cell holders 105a, 105b using the floating nuts 213. At step 1306, a protection circuit 207 (shown in Fig 2A), a wire guide 208 (shown in Fig 2A), and at least one heat sink 206 (shown in Fig 2A) are mounted on the control board 106. At step 1307, the first sealant 10 member 808 is positioned in the peripheral groove 810 of the front end cover 101 and a second sealant member 901 is positioned in the peripheral groove of the rear end cover 104. At step 1308, the rear end cover 104 is mounted to the casing 103 of the battery module 100. At step 1309, dampers 107 are positioned on the cell holders 105a, 105b at the predetermined locations 204a 204b. The wire clip 209 is 15 mounted to the cell holder 105b through the aperture 212 in the control board 106. The wire clamp 801 is mounted to the front end cover 101 at the mounting provisions 809. Further, at step 1310, electrical connections between the protection circuit 207 on the control board 106 and the external connector 108 of the battery module 100 is established. At step 1311, the battery pack 102 having the cells 20 holders 105a, 105b, safety plate 202, dampers 107, and the control board 106 are slid into the casing 103. At step 1312, the front end cover 101 with the first sealant member 808 is fastened to the casing 103 at the mounting provisions to obtain a battery module 100.
[00049]
The structure of the first sealant member and the second sealant 25 member disclosed in the present invention corresponds to the structure of the peripheral groove. This correspondence, ensures there is guided positioning of the sealant members in the end covers. This guided attachment reduces time and effort for manufacturing, assembly, and servicing. Further, the sealant being limited by the limiters in the peripheral groove ensures the sealant members do not displace 30 from the peripheral groove in the process of assembly of the battery module. The
18
sealant
members once positioned ensure there is no gap between the casing and the end covers during the life of the battery module. The sealing of the gap between the casing and the end covers prevents ingress of any dust and water into the battery module. Further, the dove tail pattern in the casing also aids in the ease in assembly of the battery module. 5
[00050]
Also, stopper ribs of the front end cover limit the amount of tightening torque in the process of assembly of the end covers to the casing to prevent breakage of the end covers and aid in assembly of the battery module, the stopper ribs prevent movement of the front end cover, once they touch the cell holders. Similarly, the reinforcing ribs on the rear end cover prevent the excessive 10 motion of the end cover towards the casing. The protection circuit improves the durability of the battery module by protecting the electrical terminals of the cells from short circuiting. The wire clip, the wire guide, and the wire clamp together prevent slacking, entangling of the wires connecting the terminal of the cells to the control board and the external connector, and prevent any accidents from occurring. 15 The heat sink on the control board monitors the temperature of the cells and performs cooling of the components on the control board, preventing thermal runaway of the cells and catastrophe of the battery module.
[00051]
The different embodiments of the damper disclosed herein are positioned at the edges of the cell holders and allow the easy sliding in and sliding 20 out of the battery pack from the casing. The damper fills the gap between the casing and the battery pack. The cushioning member of the damper provides impact/shock resistance to the battery pack. The resilient material of the cushioning member of the damper functions as a vibration absorber that is experienced by the casing of the battery module. During the assembly of the battery module, the positioning of 25 the dampers is simple and requires only insertion of the stem portion of the damper at the predetermined locations of the cell holders. The number of parts to position the dampers are reduced also, thereby reducing the cost of manufacture, assembly, maintenance, and servicing. If incase, the BMS board of the battery module needs to be serviced, the dampers do need to be removed from their location as the 30 mounting location of the BMS board to the cell holders and the dampers is clearly
19
distinguished. In cases where the same casing used for battery packs of different
capacity, the dampers will fill the gap between the battery pack and the casing. In an embodiment, only the dampers are to be altered if the gap between the battery pack and the casing is varied. By retaining the same damper or altering the damper, the cost of redesigning the casing and the cell holders is completely avoided, 5 thereby saving manufacturing cost of the new battery module and giving tremendous flexibility for a manufacturer to have variety of battery packs with various capacities to cater to different product variants, different markets etc. without compromising on the complexity of manufacturing, increasing variety as well as complexity of assembly. 10
[00052]
Thus, the dampers, the sealant members, and the end covers as per present invention provide mechanical stability, thermal stability, durability, vibration isolation, and impact resistance to the battery module while enabling breaking of trade-off on variety creation versus ease of manufacturing and assembly leading to a reliable energy module for a powered device along with a robust casing 15 capable of withstanding various loads arising out of its usage as well as its process of assembly cum manufacturing.
[00053]
Improvements and modifications may be incorporated herein without deviating from the scope of the invention.
20
List of reference numerals
100- battery module
101- front end cover
102-battery pack
103-casing 5
104-rear end cover
105-cell holders
106-BMS board
107-dampers
108-electrical connector 10
109-wire guide
110-cover
201-cells
202-safety plate
203-recesses 15
204- predetermined locations
205-vertices
206-heat sink
207-protection circuit
208-wire guide 20
209-wire clip
210-interconnect sheets
211-mounting locations
212-aperture
213- floating nuts 25
301-cushioning member
302-seat member
303-stem portion
701-depression
702-aperture 30
801-wire clamp
21
802- reinforcing ribs
804-first edges
805-stopper ribs
807-opening
808-first sealant member 5
810-peripheral groove
901-second sealant member
903-safety valve
904-plug
1101-wires , Claims:I/We claim:
1.
A battery module (100) comprising:
a plurality of cells (201) electrically connected in at least one of a series connection and a parallel connection; 5
a casing (103) comprising four walls (103a, 103b, 103c, 103d) for enclosing the plurality of cells (201) from four sides;
a front end cover (101) enclosing the plurality of cells (201) in the casing (103) on a front side (103e) of the casing (103) and a rear end cover (104) enclosing the plurality of cells (201) in the casing (103) on a rear side 10 (103f) of the casing (103);
a first sealant member (808) positioned between the front end cover (101) and the front side (103e) of the casing (103); and
a second sealant member (901) positioned between the rear end cover (104) and the rear side (103f) of the casing (103). 15
2.
The battery module (100) as claimed in claim 1, comprising:
one or more cell holders (105a and 105b) for holding the plurality of cells (201) within the casing (103), between the front end cover (101) and the rear end cover (104), 20
a safety plate (202) disposed between each of the one or more cell holders (105a, 105b) and one of the four walls (103b, 103d) of the casing (103);
a control board (106) for controlling an operation of the battery module (100), disposed between the one or more cell holders (105a, 105b) 25 and the front end cover (101);
one or more dampers (107a, 107b, …107h) positioned at predetermined locations (204a) of the one or more cell holders (105a and 105b) for packaging a gap between the casing (103) and the plurality of cells (201). 30
23
3.
The battery module (100) as claimed in claim 2, wherein a front surface (101a) of the front end cover (101) comprises:
an opening (807) with a cover (110) for pouring a thermally conductive material into the casing (103) for extracting heat dissipated by the plurality of cells (201); 5
an external connector (108) protruding inwards from the front surface (101a) for electrically connecting the battery module (100) in a powered device; and
an external wire guide (109) configured proximal to the external connector (108) for guiding external cable of the battery module (100) 10 originating from the external connector (109).
4.
The battery module (100) of claim 2, wherein a rear surface (101b) of said front end cover (101) comprises a plurality of stopper ribs (805) extending from each of first edges (804) of the first end cover (101) and come in 15 contact with the plurality of cell holders (105a, 105b), for guided attachment of the front end cover (101) to the casing (103).
5.
The battery module (100) as claimed in claim 1, wherein each of the first sealant member (808) and the second sealant member (901) comprises:
a first flat section (808e) along an entire length of the each of the 20 first sealant member (808) and the second sealant member (901);
a ridge (808a) extending from the first flat section (808e) along periphery of the each of the first sealant member (808) and the second sealant member (901);
a plurality of rings (808d) interspersed in the flat section (808e) of 25 the each of the first sealant member (808) and the second sealant member (901);
a plurality of T-projections (808g) extending inwards from the ridge (808);
a raised projection (808b) being configured around a periphery of 30 each of the plurality of rings (808d); and
24
a plurality of cut-outs (808f) in the first flat section, in line with a plurality of apertures (810f) on the front end cover (101) and the rear end cover (104) respectively.
6.
The battery module (100) as claimed in claim 5, wherein a rear surface 5 (101b, 104b) of each of said front end cover (101) and said rear end cover (104) comprises:
a peripheral groove (810) configured to accommodate each of the first sealant member (808) and the second sealant member (901), respectively; and 10
a plurality of reinforcing ribs (802, 104c) for strengthening each of the front end cover (101) and the rear end cover (104).
7.
The battery module (100) as claimed in claim 6, wherein the peripheral groove (810) in the rear surface (101b, 104b) of the each of said front end 15 cover (101) and said rear end cover (104) comprises:
a depression (810a) for receiving the ridge (808a) of the each of the first sealant member (808) and the second sealant member (901);
a second flat section (810e) for receiving the first flat section (808e) of the each of the first sealant member (808) and the second sealant member 20 (901);
a plurality of raised portions (810d) interspersed in the second flat section (810e) for disposing the raised projections (808b) around a periphery of the raised portions (810d) of the each of the first sealant member (808) and the second sealant member (901); 25
a plurality of discontinuities (810g) in one of the walls defining the depression (810a) of the peripheral groove (810) for receiving the T-projections (808g) of the each of the first sealant member (808) and the second sealant member (901); and
the plurality of apertures (810f) for mounting the each of said front 30 end cover (101) and said rear end cover (104) to the casing (103).
25
8.
The battery module (100) as claimed in claim 3, further comprising:
a wire clamp (801) mounted to a rear surface (101b) of the front end cover (101) for holding the external connector (108) protruding inwards from the front surface (101a) of the front end cover (101); 5
a wire clip (209) mounted to one of the one or more cell holders (105a, 105b) through an aperture (212) in the control board (106) for routing a plurality of wires (1101) originating from the plurality of cells (201) and the control board (106) to connect to the external connector (108) through the wire clamp (801); 10
at least one heat sink (206) mounted on the control board (106);
a protection circuit (207) of the battery module (100) mounted on the control board (106), and
a wire guide (208) mounted on the control board (106) for guiding wires originating from the control board to the wire clip (209). 15
9.
The battery module (100) as claimed in claim 6, wherein the rear surface (104b) of said rear end cover (104) comprises a safety valve (903) for expelling gases emitted by the plurality of cells (201).
10.
A method of assembly of the battery module (100) comprising steps of: 20
(Step 1301) sorting and positioning a plurality of cells (201) in between one or more cell holders (105a, 105b);
(Step 1302) interconnecting the plurality of cells (201) to form one of a series connection and a parallel connection using a plurality of interconnect sheets (210); 25
(Step 1303) disposing a plurality of floating nuts (213) in predetermined locations (211) on the one or more cell holders (105a, 105b) to connect the plurality of interconnect sheets (210) with a control board (106);
(Step 1304) positioning a safety plate (202) in contact with the one 30 or more cell holders (105a, 105b);
26
(Step 1305) positioning the control board (106) on the one or more cell holders (105a, 105b) using the plurality of floating nuts (213);
(Step 1306) mounting a protection circuit (207), a wire guide (208), and at least one heat sink (206) on the control board (106);
(Step 1307) positioning a first sealant member (808) in a front end 5 cover (101) and a second sealant member (901) in a rear end cover (104);
(Step 1308) mounting the rear end cover (104) to a casing (103);
(Step 1309) positioning a plurality of dampers (107) on the one or more cell holders (105a, 105b);
(Step 1310) establishing electrical connections between the 10 protection circuit (207) on the control board (106) and an external connector (108);
(Step 1311) sliding the cell holders (105a, 105b) and the control board (106) alongwith the plurality of cells (201) and the safety plate (202) into the casing (103); and 15
(Step 1312) fastening the front end cover (101) on a front side (103e) of the casing (103) at mounting provisions, to obtain a battery module (100).