Description:TECHNICAL FIELD
[0001] The present subject matter relates generally to a power source unit. More particularly but not exclusively the present subject matter relates to a venting structure for the power source unit.
BACKGROUND
[0002] Nowadays, with the advancement in the technology, an electric or hybrid electric vehicle make use of one or more power source pack to drive the vehicle. The one or more powers source is a battery to provide power to run a motor which in turn runs one or more wheels of the vehicle. The battery pack includes one or more cells and are connected through one or more interconnectors to provide an electrical connection. The one or more cells are arranged in a module consisting of a top casing and a bottom casing. The one or more cells are welded to a metal strip known as the interconnector, forming a battery pack. The one or more interconnector is connected to a BMS (Battery management system). The BMS obtains the individual parameters of the one or more cells to monitor the SoC (state of charge) and SoH (state of health) of the battery pack.
[0003] Generally, in electric or hybrid electric vehicles, utilizing batteries as the power source to drive the vehicle, the lithium ion batteries used in above-mentioned vehicles undergo heat generation during charging and discharging process. The battery manufacturer recommends that the discharge temperature should be higher than charging temperature. Once the batteries are operated, its temperature rises during discharge and immediate charging of the batteries becomes difficult. In addition to this, the lithium ion battery pack having a plurality of cells are closely packed, the cells located at the central part are inhibited from exhibiting satisfactory thermal radiation due to their neighboring cells and thus results in temperature rise. The plastic cell holder used in lithium ion batteries are not capable of dissipating the heat sufficiently out of the battery pack. Dissipation of heat within the battery pack results in rise in temperature which is not desirable and also affects the life of the battery. With the better efficiency of the Li-ion cells, issues related to high temperature sometimes may result in failure or malfunctioning of the lithium ion battery in operation.
[0004] Further, batteries are usually sealed so as to improve the reliability of batteries and meet the basic waterproof and dustproof requirements. The battery failure caused by battery heating or altitude changes affects the safety of the battery while in use, resulting in different internal pressure and external pressure of the battery. However, too high, or too low air pressure inside the battery is likely to cause structural damage of the sealing surface, resulting in battery failure. Fire and explosion in batteries can take place due to dangerous or abnormal chemical reactions as the battery contains toxic liquids and gases. There is thermal danger which can occur due to high temperature and also there is a possibility of short circuit while carrying out nail penetration test. All above mentioned events triggers the thermal runaway and renders the battery pack unsafe to use.
[0005] Another problem with batteries having large cells is safety. The energy released in the cell going into thermal runaway is proportional to the amount of available electrolyte present in the cell during the thermal runaway event. As the cell becomes larger, more free space is available for electrolyte to fully saturate an electrode structure. Since the amount of the electrolyte per watt hour for large cells is usually greater than for small cells, large cell batteries are generally systems that gain more momentum during thermal runaway and are therefore less secure, hence, the larger the fuel (electrolyte), the larger is the flame. In addition, once a large cell is in thermal runaway mode, the heat generated by the cell triggers a thermal runaway reaction in adjacent cells, causing the entire battery pack to be destroyed, with massive destruction to the battery pack and peripheral devices. The user may be in a dangerous state by causing a cascade effect to ignite the battery pack.
[0006] In order to avoid any thermal runaway situation, pressure build up and the gasses due to which the pressure has been built up inside the battery pack has to be vented out. Now-a-days, a breather valve type vent has been provided in the battery pack to release the pressure from the battery pack when the vehicle is on high altitude. The breather valve type vent will adjust the difference in the pressure. There are 2 types of breather valve, first type of breather valve adjusts the pressure changes, and the second type of valve is known as thermal runaway vent valve which arrests the thermal runaway in the battery pack. If the temperature inside the battery pack keeps rising beyond a threshold limit, let’s say 80 degree, a separator between an anode and a cathode melts and short circuit takes place as the anode and cathode comes into direct contact to each other. Due to this, the electrolyte decomposition and anode dissolution takes place, leading to high temperature from let’s say 130 degree to 200 degree is reached within 2-3 seconds, followed by explosion of the cells. Such high temperatures can ignite adjacent combustibles, thereby creating a fire hazard. High temperatures can also cause decomposition of some materials and initiation of gas generation. Gases generated during these events can be toxic and / or flammable and can further increase the risks associated with uncontrolled thermal runaway event which is a self-enhanced increasing temperature loop that can lead to battery fires and explosions.
[0007] The above-mentioned problems are very critical and therefore, effective method of heat dissipation and degassing of gasses is vital for the operation, safety, and health of the battery structure as well as the user of the vehicle. Thus, there is a need to overcome the above-mentioned problems and other problems of known art.

SUMMARY
[0008] A venting structure comprising a body member, one or more flap members, the one or more flap member being disposed onto the body member. The one or more flap members is configured to move and vent pressure and gases from a power source unit to an outside environment. The body member comprising a plurality of prong members, the plurality of prong members includes one or more first prong members and one or more second prong members. The one or more first prong members being defined by a first proximate end and a first distal end, the first distal end of the one or more first prong members being connected together, the one or more second prong members being defined by a second proximate end and a second distal end. The one or more second prong members being defined by one or more slot extending from the second proximate end up to the second distal end. The one or more second prong members is alternatively disposed on an edge of the one or more first prong members. The one or more flap members is configured to have a first horizontal side with a first width and a second horizontal side with a second width. The first width is greater than the second width. The one or more flap members is defined by an arc shaped structure. The one or more flap members being defined by a flat shaped structure. The first horizontal side of the one or more flap members being configured to be disposed in the one or more slots. The second horizontal side being configured to rest on the one or more first prong members, in a non-operated state. The non-operated state being defined by the resting state of the one or more flap members on the one or more first prong members when no pressure or gas builds up, and an operated state being defined by opening of the one or more flap members when the pressure or gas builds up. The one or more flap members is made up of an electrically insulated, high heat resistant, and high temperature tolerant material. The venting structure comprising one or more front cover being configured to cover a portion of the one or more body member. The one or more front cover being configured with one or more opening, where the one or more openings being configured to form a passage of gases from the power source unit to the outside environment. The one or more front cover being configured with a groove, where the groove being configured to mount the one or more front cover onto a periphery of a top cover of the body member. The one or more openings being configured to face the one or more flap members. The one or more openings being configured between each of the two one or more first prong members, the one or more openings being inline and configured to be disposed at the second proximate end of the one or more second prong members. The one or more openings being defined by one or more rectangular openings. The one or more openings can be one of a single opening or one or more square shaped openings. The one or more flap members being configured to move up to a range of 0-45 degrees. The venting structure being provided onto an exterior region of the power source unit, where the power source unit corresponds to a battery pack.
[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[00010] The details are described with reference to an embodiment of a power source unit along with the accompanying diagrams. The same numbers are used throughout the drawings to reference similar features and components.
[00011] Figure 1 exemplarily illustrates a side view of a power source unit with a power source unit casing.
[00012] Figure 2(a) exemplarily illustrates a front perspective view of a venting structure.
[00013] Figure 2(b) exemplarily illustrates a front view of the venting structure.
[00014] Figure 3(a) and 3(b) exemplarily illustrates a perspective top view and front view respectively of the venting structure.
[00015] Figure 3(c) exemplarily illustrates a perspective view of the top cover of the venting structure.
[00016] Figure 3(d) exemplarily illustrates the perspective view of the one or more front cover of the venting structure.
[00017] Figure 3(e) exemplarily illustrates the one or more flap members of the venting structure.
[00018] Figure 4(a) exemplarily illustrates the one or more flap members in totally closed position in the non-operated condition.
[00019] Figure 4(b) exemplarily illustrates the one or more flap members in partially open position, when a small amount of gas and pressure is built up in the operated condition.
[00020] Figure 4(c) exemplarily illustrates the one or more flap members in fully open position, when the amount of gas and pressure is maximum.

DETAILED DESCRIPTION

[0001] An objective of the present subject matter is to increase safety of the battery pack as well as the safety of the user of a vehicle, while eliminating the thermal runaway by controlling the temperature and venting the pressure buildup and gasses generated during thermal runaway event in the battery pack. The aim of the present subject matter is to provide a vent valve system that have properties of high temperature resistant when thermal runaway takes place and protect the lithium ion cells and thus the battery pack from the maximum damage. It further aims to solve internal pressure raise problem in the battery pack and also the vent valve opening mechanism regulate gases that generated during thermal runaway event.
[0002] The present subject matter further aims to provide a compact, safe to operate, easy to manufacture, assemble, and service of the battery pack. The present subject matter is described using an exemplary battery pack which is used in the vehicle, whereas the claimed subject matter can be used in any other type of application employing above-mentioned battery pack, with required changes and without deviating from the scope of invention. The embodiments of the present invention will now be described in detail with reference to a power source pack along with the accompanying drawings. However, the present invention is not limited to the present embodiments. The present subject matter is further described with reference to accompanying figures. Wherever convenient, the same reference numbers are used throughout the drawings to refer to the same or like parts. While examples and features of disclosed principles are described herein, modifications, adaptations, and other implementations are possible without departing from the scope of the disclosed embodiments. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0003] Fig.1 exemplarily illustrates exemplarily illustrates a side view of a power source unit 100 with a power source unit casing 102. The power source unit casing 102 protects the power source unit 100 from outside environment and prevents the power source unit 100 from getting damage. The power source unit 100 includes one or more cells (not shown) disposed in one or more holder (not shown) to hold it still in its required position, during the operation of a vehicle (not shown) and also to maintain the required cell arrangement and cell spacing. The power source unit 100 includes the one or more cells (not shown), one or more cell holder (not shown), and one or more interconnectors (not shown). The one or more cells provides the electric energy to drive the vehicle (not shown). In the present embodiment, the power source unit casing 102 includes one or more side casing 102a, and a top casing 102b. The one or more side casing 102a supports the one or more cells from all the sides and a bottom portion of the power source unit 100. The top casing 102b covers the power source unit 100 from a top portion of the power source unit 100. In an embodiment, the one or more power source unit casing 102 can be one of the aluminum casing. The one or more interconnectors are used to make electrical connection between the one or more cells. The top casing 102b includes a connector for taking connections out of the power source unit 100 using one or more power cord sets (not shown).
[0004] Fig.2(a) exemplarily illustrates a front perspective view of a venting structure 200. Fig.2(b) exemplarily illustrates a front view of the venting structure 200. Fig 2(a) and fig 2(b) shall be discussed together. The venting structure 200 is provided to vent the pressure build up and to degass the power source unit 100. As already known, thermal runaway creates a pressure build-up in the power source unit casing 102. The pressure must be evacuated quickly, if not, the risk of an explosion is highly likely in most of the situations. So, a degassing mechanism is provided by the present invention. In the present embodiment, the venting structure 200 includes a pressure relief valve in the form of one or more flap members 204 is provided. The one or more flap members 204 gets activated whenever a pressure piles up. During pressure pile up, the one or more flap members 204 having a wing type of arrangement gets opened to a predetermined angle and comes back to its original position whenever the normal condition reaches. Angular opening of wings and degree of opening of the wings is based on pressure variation inside the power source unit 100. Due to opening of wings, gasses are released to an outside environment of the power source unit 100 and also passively regulates the internal pressure of the power source unit 100. Thus, the proposed solution does both thermal management (internal pressure management) and gas ejection during thermal runaway event as a twin role. The venting structure 200 as shown in figure 2(a) and (b) includes a body member 202, the one or more flap members 204, and one or more front cover 210. The one or more flap members 204 is disposed onto the body member 202 and the one or more front cover 210 is configured to cover a portion of the one or more body member 202. The one or more flap members 204 is configured to move to vent pressure and gases from the power source unit 100 to the outside environment.
[0005] Fig.3(a) and Fig.3(b) exemplarily illustrates a top and front view respectively of the venting structure 200. Fig.3(c) exemplarily illustrates a top cover 216 of the venting structure 200. Fig.3(d) exemplarily illustrates the one or more front cover 210 of the venting structure 200. Fig.3(e) exemplarily illustrates the one or more flap members 204 of the venting structure 200. Fig.3(a), fig.3(b), fig.3(c), fig.3(d) and fig.3(e) shall be discussed together. The body member 202 includes a plurality of prong members 206. The plurality of prong members 206 includes one or more first prong members 206a and one or more second prong members 206b. The one or more first prong members 206a is defined by a first proximate end and a first distal end. The first distal end of the one or more first prong members 206a is connected together. The one or more second prong members 206b is defined by a second proximate end and a second distal end. The one or more second prong members 206b is defined by one or more slots 208 extending from the second proximate end up to the second distal end. The one or more second prong members 206b is alternatively disposed on an edge of the one or more first prong members 206a. The one or more second prong members 206b is disposed alternatively such that the one or more slots 208 faces towards the alternate one or more slots 208. The one or more second prong members 206b is disposed between the one or more first prong members 206a to form a supporting structure on which the one or more flap members 204 rests, in a non-operated position.
[0006] One or more top cover 216 is provided to cover the body member 202 from a top side of the body member 202. In the present embodiment, the body member 202 and the one or more top cover 216 is integrated to form a single part. In another embodiment the body member 202 and the one or more top cover 216 can be separate parts. The one or more front cover 210 is configured with one or more openings 212 to facilitate passage of gases and inbuilt pressure from the power source unit 100 to the outside environment. The one or more openings 212 is configured to face the one or more flap members 204. The one or more openings 212 is configured between each of the two one or more first prong members 206a. The one or more openings 212 is inline with the one or more second prong members 206b and the one or more openings 212 is configured to be disposed at the second proximate end of the one or more second prong members 206b. In the present embodiment, the one or more openings 212 is defined by one or more rectangular openings. However, the one or more openings 212 can be one of a single opening or one or more square shaped openings. The one or more front cover 210 is configured with a groove 214 to facilitate mounting of the one or more front cover 210 on the body member 202 through a snap fit mechanism. The groove 214 is configured to mount the one or more front cover 210 onto a periphery of a top cover 216 of the body member 202. However, other mounting means like gluing, fastening, and the like can be used to mount the one or more front cover 210 on to the body member 202, and the mounting mechanism is not limited to above mentioned means.
[0007] In the present embodiment, the one or more flap members 204 is substantially rectangular in shape and is configured to have a first horizontal side 204a with a first width and a second horizontal side 204b with a second width. The first horizontal side 204a with the first width is greater than the second horizontal side 204b with second width. In the present embodiment, the one or more flap members 204 is defined by an arc shaped structure. In another embodiment, the one or more flap members 204 can be a flat shaped structure. However, the shape of the one or more flap members 204 is not limited to above mentioned shapes and can be changed according to requirements and design changes.
[0008] The first horizontal side 204a of the one or more flap members 204 is configured to be disposed in the one or more slots 208. The second horizontal side 204b is configured to rest on the one or more first prong members 206a, in a non-operated state. The non-operated state being defined by the resting state of the one or more flap members 204 on the one or more first prong members 206a when no pressure or gas builds up, and an operated state being defined by opening of the one or more flap members 204 when the pressure or gas builds up. The one or more flap members 204 is made up of an electrically insulated, high heat resistant, and high temperature tolerant material.
[0009] In the best embodiment, the one or more flap members 204 are like butterfly wings. When the gas builds up inside the power source unit 100, the wings tries to open up to a maximum a range of 0-45 degrees to allow the gases and inbuilt pressure to exit in the outside environment with respect to a horizontal line x-x’. The opening of the one or more flap members 204 is facilitated by the inbuilt pressure. If low pressure is built up then the wings tends to open up to say for example-5 to 10 degrees with respect to the horizontal line x-x’, so based on the pressure build up, the one or more flap members 204 opens up to a certain degree for degassing. The one or more flap members 204 itself comes back to its original position, when the inbuilt pressure and gasses are released. The opening degree can be more than the range of 0-45 degrees, given a retracting means (not shown) is provided so that the retracting means helps the one or more flap members 204 to come to its original position after degassing and reduction in inbuilt pressure in the power source unit 100, but adding the retracting means makes the design complex, bulky, and need more space in the power source unit 100 and in the vehicle layout. In the present embodiment, the one or more flap members 204 includes 4 flap members. However, the number of flap members and the size of the flap members depends on the design requirements of the power source unit 100. The one or more flap members 204 are made up of high temperature resistant silicon material to endure the high temperature and aid in opening function.
[00010] Fig.4(a), Fig.4(b) and Fig.4(c) exemplarily illustrates venting of gases and pressure from the venting structure 200 and the opening and closing of the one or more flap members 204. Fig.4(a) shows the one or more flap members 204 in totally closed position in the non-operated condition. When there is no pressure or gas built up, the one or more flap members 204 is closed and touches the one or more first prong members 206a. Fig.4(b) shows the one or more flap members 204 in partially open position, when a small amount of gas and pressure is built up in the operated condition. Fig.4(c) shows the one or more flap members 204 in fully open position, when the amount of gas and pressure is maximum, thus opening the one or more flap members 204 up to its maximum extendable position.
[00011] The above-mentioned configuration helps in release of pressure and gas through the means of one or more flap members 204 acting as a multipurpose vent during thermal runaway event. The pressure inside the power source unit 100 at high altitude can be adjusted to avoid thermal runaway situation by the venting structure 200 by opening and closing of the one or more flap members 204. The functioning of the one or more flap members 204 facilitates in venting out gases and pressure from the power source unit 100 ensuring safety of the user as well as the vehicle.
[00012] The claimed steps as discussed above are not routine, conventional, or well understood in the art, as the claimed steps enable the following solutions to the existing problems in conventional technologies. The conventional venting structure either deals with the gas ejection alone or a thermal management alone, whereas the present claimed invention having the flaps in the proposed venting structure is able to facilitate to do both thermal management as well as gas ejection during thermal management. The one or more flaps of the venting structure has such a design with varying width of the one or more flap members that helps to release gases even at low pressure as well as at high pressure, which is not achieved by the existing design. Apart from this, the same flaps aids in internal pressure management.
[00013] While the present disclosure has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. Therefore, it is intended that the present disclosure may not be limited to the particular embodiment disclosed, but that the present disclosure will include all embodiments falling within the scope of the appended claims.

List of Reference numerals

100- Power source unit
102- Power source unit casing
102a- One or more side casing
102b- One or more top casing
200- Venting structure
202- Body member
204- One or more flap members
204a- First horizontal side of 204
204b- Second horizontal side of 204
206- Plurality of prong members
206a- One or more first prong members of 206
206b- One or more second prong members of 206
208- One or more slots
210- One or more front cover
212- One or more openings
214- Groove
216- Top cover of 202
, Claims:We claim:
1. A venting structure (200) comprising:
a body member (202);
one or more flap members (204), the one or more flap member (204) being disposed onto the body member (202); and
wherein,
the one or more flap members (204) being configured to move and vent pressure and gases from a power source unit (100) to an outside environment.

2. The venting structure (200) as claimed in claim 1, wherein the body member (202) comprising a plurality of prong members (206), the plurality of prong members (206) includes one or more first prong members (206a) and one or more second prong members(206b).
3. The venting structure (200) as claimed in claim 2, wherein the one or more first prong members (206a) being defined by a first proximate end and a first distal end, the first distal end of the one or more first prong members (206a) being connected together, the one or more second prong members (206b) being defined by a second proximate end and a second distal end, wherein the one or more second prong members (206b) being defined by one or more slot (208) extending from the second proximate end up to the second distal end.
4. The venting structure (200) as claimed in claim 3, wherein the one or more second prong members (206b) being alternatively disposed on an edge of the one or more first prong members (206a).
5. The venting structure (200) as claimed in claim 1, wherein the one or more flap members (204) being configured to have a first horizontal side (204a) with a first width and a second horizontal side (204b) with a second width, wherein the first width being greater than the second width, wherein the one or more flap members (204) being defined by an arc shaped structure.
6. The venting structure (200) as claimed in claim 1, wherein the one or more flap members (204) being defined by a flat shaped structure.
7. The venting structure (200) as claimed in claim 5, wherein the first horizontal side (204a) of the one or more flap members (204) being configured to be disposed in the one or more slots (208), wherein the second horizontal side (204b) being configured to rest on the one or more first prong members (206a), in a non-operated state.
8. The venting structure (200) as claimed in claim 7, wherein the non-operated state being defined by the resting state of the one or more flap members (204) on the one or more first prong members (206a) when no pressure or gas builds up, and an operated state being defined by opening of the one or more flap members (204) when the pressure or gas builds up.
9. The venting structure (200) as claimed in claim 1, wherein the one or more flap members (204) being made up of an electrically insulated, high heat resistant, and high temperature tolerant material.
10. The venting structure (200) as claimed in claim 1, wherein the venting structure (200) comprising one or more front cover (210) being configured to cover a portion of the one or more body member (202), wherein the one or more front cover (210) being configured with one or more opening (212), wherein the one or more openings (212) being configured to form a passage of gases from the power source unit (100) to the outside environment.
11. The venting structure (200) as claimed in claim 10, wherein the one or more front cover (210) being configured with a groove (214), wherein the groove (214) being configured to mount the one or more front cover (210) onto a periphery of a top cover (216) of the body member (202).
12. The venting structure (200) as claimed in claim 10, wherein the one or more openings (212) being configured to face the one or more flap members (204), wherein the one or more openings (212) being configured between each of the two one or more first prong members (206a), wherein the one or more openings (212) being inline and configured to be disposed at the second proximate end of the one or more second prong members (206b).
13. The venting structure (200) as claimed in claim 10, wherein the one or more openings (212) being defined by one or more rectangular openings.
14. The venting structure (200) as claimed in claim 10, wherein the one or more openings (212) can be one of a single opening or one or more square shaped openings.
15. The venting structure (200) as claimed in claim 1, wherein the one or more flap members (204) being configured to move up to a range of 0-45 degrees.
16. The venting structure (200) as claimed in claim 1, wherein the venting structure (200) being provided onto an exterior region of the power source unit (100), wherein the power source unit (100) corresponds to a battery pack.