Patent Description:
Existing lithium ion battery cells are equipped with a safety vent. When the battery cell undergoes a thermal event, the pressure within the battery cell can exceed a threshold value. In such instances, the safety vent is configured to relieve the internal pressure of the battery cell by venting materials, such as gases, liquid, and solids into the air surrounding the battery cells. However, the materials that are vented are typically flammable. If these materials are ignited, the resulting fire event could heat up the neighboring battery cells causing a cascading thermal event to occur. Further, the accumulation of the exhausted materials within the area surrounding the battery cells may achieve a concentration which may create a potential risk of explosion.

<CIT> teaches a battery with a degassing system. The battery comprises a plurality of battery cells within a cell module and a base plate positioned adjacent to an end of the cell module. The base plate has a collecting trough formed therein, and a degassing opening of each cell is connected to the trough via an aperture extending through the base plate.

<CIT> teaches a method of mitigating battery cell failure comprising coupling a battery pack and an internal combustion engine exhaust system such that battery cell exhaust can pass from the battery cell to the engine exhaust system.

Both of <CIT> and <CIT> relate to a battery pack that reduces the risk of secondary ignition or explosion.

<CIT> teaches a battery pack including a fire extinguishing system. The battery pack has a housing and an agent storage unit that stores fire extinguishing agent and injects this into the housing when an abnormal temperature is detected at the battery module.

According to a first aspect of the invention, a battery energy storage system is provided, comprising a battery mounting area, a venting area fluidly isolated from the battery mounting area, and a battery cell arranged at least partially within the battery mounting area. The battery cell includes at least one safety vent that is fluidly coupled to the venting area. The battery energy storage system is characterized in that the at least one safety vent is directly coupled to the venting area and a portion of the battery cell including the at least one safety vent is arranged within the venting area. The at least one safety vent may be one or more safety vents.

The venting area may be located directly adjacent to the battery mounting area.

The venting area may be located remotely from the battery mounting area.

The battery cell may comprise a battery can having a first open end, a second closed end, and a sidewall extending between the first open end and the second closed end; and a cap affixed to the battery can adjacent to the first open end.

The at least one safety vent may be formed in the sidewall. The at least one safety vent may also be considered as one of the one or more safety vents.

The at least one safety vent may be formed in the cap. The at least one safety vent may also be considered as one of the one or more safety vents.

The system may comprise a movement mechanism operable to move exhaust materials output from the at least one safety vent to the venting area. The at least one safety vent may also be considered as one of the one or more safety vents.

The system may comprise an inerting system in fluid communication with the venting area, the inerting system including: at least one spray nozzle (e.g., one or more spray nozzles), a source of inerting agent, and a delivery piping system fluidly connecting the source of inerting agent and the at least one spray nozzle. The at least one spray nozzle may also be considered as one of the one or more spray nozzles.

The system may comprise a suppression system in fluid communication with the venting area, the suppression system including at least one spray nozzle (e.g., one or more spray nozzles), a source of suppression agent, and a delivery piping system fluidly connecting the source of suppression agent and the at least one spray nozzle. The at least one spray nozzle may also be considered as one or another of the one or more spray nozzles.

According to another aspect of the invention, a method of managing a battery energy storage system according to the first aspect includes operating the battery cell and venting an exhaust material from the battery cell in response to a thermal event. Venting the exhaust material from the battery cell comprises venting the exhaust material directly to the venting area.

The method may comprise inerting the exhaust material within the venting area via an inerting system.

The method may comprise suppressing a fire within the venting area via a suppression system.

Venting the exhaust material to the venting area fluidly isolated from the battery mounting area may comprise drawing the exhaust material into the venting area via a movement mechanism.

Venting of the exhaust material may occur in response to an increase in a pressure within the battery cell in response to the thermal event.

Venting of the exhaust material may occur when the pressure within the battery cell exceeds a predetermined threshold.

Optional embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings.

With reference now to <FIG>, an exemplary battery <NUM>, such as a lithium ion battery for example, is illustrated. As shown, the battery <NUM>, also referred to herein as a cell or battery cell, includes a battery housing or can <NUM>. The battery can <NUM> may have a first open end <NUM>, a second sealed end <NUM>, and at least one sidewall <NUM> extending between the first end <NUM> and the second end <NUM> to define a hollow interior <NUM> therein. Further, the battery can <NUM> may be formed from any suitable material, including but not limited to a metal material. Although the battery can <NUM> illustrated in the FIGS. is generally rectangular in shape, it should be understood that examples where the battery can <NUM> has another configuration, such as where the battery can <NUM> is cylindrical in shape for example, are also within the scope of the disclosure. A cap or lid <NUM> is connected to the first open end <NUM> of the battery can <NUM> to seal the hollow interior <NUM>. The cap <NUM> may be a generally flat panel and has a size and shape corresponding to the size and shape of the battery can <NUM>. The cap <NUM> may, but need not be formed from the same material as the battery can <NUM>.

A battery unit, illustrated schematically at <NUM>, is arranged within the hollow interior <NUM> of the battery can <NUM>. The battery unit <NUM> includes an electrode assembly having a positive electrode <NUM> and a negative electrode <NUM>. The positive and negative electrodes <NUM>, <NUM> may be sheets stacked on top of one another and separated from one another by a separator <NUM> to form the battery unit <NUM>. Furthermore, the stacked positive electrode <NUM>, separator <NUM>, and negative electrode <NUM>, may be wound into a coil prior to installation within the hollow interior <NUM> of the battery can <NUM>.

At least one safety vent <NUM> may be located at a surface of the battery can <NUM>. Although the safety vent <NUM> in <FIG> is illustrated as being positioned near the first end <NUM> of the battery can <NUM>, examples including a safety vent <NUM> arranged at another location of the battery can <NUM>, such as at the sidewall <NUM> thereof for example, and/or examples where a safety vent <NUM> is formed in the cap <NUM> are also within the scope of the disclosure. During normal operation of the battery cell <NUM>, the safety vent <NUM> is closed such that the interior <NUM> of the battery can <NUM> remains hermetically sealed. However, when necessary, such as when a pressure within the interior <NUM> of the battery can <NUM> reaches a predetermined threshold due to an abnormality of the battery cell <NUM> for example, the safety vent <NUM> is automatically activated. Activation of the safety vent <NUM> may include opening the safety vent <NUM> to exhaust material, such as one or more of gases, liquids, and solids, from the interior <NUM> of the battery can <NUM>, thereby reducing the pressure within the battery can <NUM>. The battery cell <NUM> illustrated and described herein is intended as an example only and it should be understood that a lithium ion battery cell <NUM> having another configuration is also contemplated herein.

With reference now to <FIG>, an exemplary battery energy storage system (BESS) <NUM> including one or more battery cells <NUM> is illustrated. In the illustrated, non-limiting example, the BESS <NUM> includes a plurality of substantially identical battery cells <NUM>, such as similar to battery cell <NUM>, for example. However, examples where a configuration of one or more of the battery cells <NUM> varies relative to another of the battery cells <NUM> is within the scope of the disclosure. In addition, although the BESS <NUM> shown in the FIGS. includes a plurality of battery cells <NUM>, it should be understood that a BESS <NUM> having a single battery cell is also within the scope of the disclosure.

As shown, the BESS includes a first space or area <NUM>, also referred to herein as a battery mounting area, and at least a portion of one or more of the battery cells <NUM> is mounted within battery mounting area <NUM>. In the illustrated, non-limiting example, a majority or substantially the entirety of each of the plurality of battery cells <NUM> is arranged within the battery mounting area <NUM>. In an example, the BESS <NUM> includes a second space or area <NUM>, also referred to herein as a venting area, that is fluidly isolated from the battery mounting area <NUM>. The venting area <NUM> may be located directly adjacent to the battery mounting area <NUM> as shown in the FIGS. , or alternatively, may be located remotely from the battery mounting area <NUM>.

The battery cell <NUM> is positioned such that at least one safety vent(s) <NUM> of at least one battery cell <NUM> is arranged in fluid communication with the venting area <NUM>. In the illustrated, non-limiting example of <FIG>, each battery cell <NUM> includes two safety vents <NUM> and both safety vents <NUM> of each battery cell <NUM> are arranged within the venting area <NUM>. In such examples, the exhaust materials that are released from the battery cell <NUM> via the safety vents <NUM> are released directly into the venting area <NUM> from the interior of the battery cell <NUM>. In another example, best shown in <FIG>, a safety vent <NUM> of one or more of the battery cells <NUM> is indirectly fluidly coupled to the venting area <NUM> by a pipe or other conduit <NUM>. By positioning the safety vent <NUM> in fluid communication with the venting area <NUM>, the exhaust materials are configured to flow into the venting area <NUM> as a result of the pressure within the battery cell <NUM>. However, examples where one or more movement mechanisms <NUM>, such as a fan for example, is configured to further facilitate the flow of the exhaust materials towards the venting area <NUM> are also within the scope of the disclosure. In such examples the movement mechanism <NUM> may be arranged within the vent area <NUM>, as shown in <FIG>.

By directing the exhaust gases and other materials from the battery cells <NUM> into the venting area <NUM>, the flammable and/or explosive exhaust gases and other materials are substantially isolated from the battery cells <NUM> of the BESS <NUM>. As a result, the thermal runaway of a battery cell <NUM> would not have a cascading effect on the adjacent battery cells <NUM>, and the potential occurrence of a fire event within the battery mounting area <NUM> is significantly reduced.

With reference now to <FIG>, in an example, an inerting and/or suppression system <NUM> is arranged in fluid communication with the venting area <NUM>. As shown, the inerting or suppression system <NUM> includes at least one spray nozzle <NUM> associated with the venting area <NUM> and a source of a suppression agent 74a and/or a source of inerting agent 74b. In an example, the sources of suppression agent and inerting agent 74a, 74b are in the form of self-contained pressure vessels. Examples of suitable suppression agents or inerting agents include, but are not limited to water, clean agent, inert gas or other approved media. The source of suppression agent 74a and/or the source of inerting agent 74b is arranged in fluid communication with the nozzles <NUM> via a delivery path defined by a delivery piping system <NUM>. Upon detection of the presence of exhaust materials within the venting area <NUM>, inerting agent from the source thereof 74b, is allowed to flow through the delivery piping system <NUM> to the one or more spray nozzles <NUM> for release directly into the venting area <NUM>. Accordingly, the system <NUM> may be configured to inert the exhaust materials as they are evacuated from the BESS into the venting area <NUM>. Upon detection of smoke, fire, or an explosion within the venting area <NUM>, the suppression agent from the source of suppression agent 74a is allowed to flow through the delivery piping system <NUM> to the one or more spray nozzles <NUM> for release directly into the venting area <NUM>. Such operation of the system <NUM> prevents, or at least mitigates, flames present in the venting area from spreading back into the battery cell <NUM> or into the BESS <NUM>.

Although a single system <NUM> is illustrated and described herein as being operable to perform both inerting and fire suppression, it should be understood that examples where the system <NUM> is configured to perform only one of inerting and fire suppression are also contemplated herein. In such examples, a secondary system having a similar or different configuration may be arranged in fluid communication with the venting area <NUM> to perform the other of the inerting and fire suppression.

Claim 1:
A battery energy storage system (<NUM>) comprising:
a battery mounting area (<NUM>);
a venting area (<NUM>) fluidly isolated from the battery mounting area (<NUM>); and
a battery cell (<NUM>; <NUM>) arranged at least partially within the battery mounting area (<NUM>), the battery cell (<NUM>; <NUM>) including at least one safety vent (<NUM>; <NUM>), the at least one safety vent (<NUM>; <NUM>) being fluidly coupled to the venting area (<NUM>);
characterized in that the at least one safety vent (<NUM>; <NUM>) is directly coupled to the venting area (<NUM>) and a portion of the battery cell (<NUM>; <NUM>) including the at least one safety vent (<NUM>; <NUM>) is arranged within the venting area (<NUM>).