TECHNICAL FIELD

The present disclosure relates to a battery module having a path through which a coolant introduced therein may flow when a thermal runaway phenomenon occurs, a battery pack and an energy storage system (ESS) including the battery module, and more specifically, to a battery module having a structure in which a coolant introduced therein may smoothly move between unit modules adjacent to each other when water is injected into a battery module at which a thermal runaway phenomenon occurs, and a battery pack and an ESS including the battery module.

The present application claims priority to Korean Patent Application No. 10-2019-0063999 filed on May 30, 2019 in the Republic of Korea, the disclosures of which are incorporated herein by reference.

The present application claims priority to Korean Patent Application No. 10-2019-0068053 filed on Jun. 10, 2019 in the Republic of Korea, the disclosures of which are incorporated herein by reference.

BACKGROUND ART

In a battery module that includes a plurality of battery cells, if an abnormality such as a short circuit occurs in some battery cells to raise temperature continuously so that the temperature of the battery cell exceeds a critical temperature, a thermal runaway phenomenon occurs. If a thermal runaway phenomenon occurs in some battery cells as described above, safety issues may be generated.

If a flame or the like is generated due to the thermal runaway phenomenon occurring in some battery cells, the flame rapidly raises the temperature of adjacent battery cells, and thus the thermal runaway phenomenon may be propagated to adjacent cells within a short time.

Eventually, if the thermal runaway phenomenon occurring in some battery cells is not quickly responded, it may lead to disasters such as ignition and explosion of a battery module or a battery pack, which is a battery unit with a greater capacity than the battery cell, and this may not only result in property damage but also cause safety problems.

Thus, if a flame occurs due to the thermal runaway phenomenon in some battery cells inside the battery module, it is urgently necessary to quickly lower the temperature inside the battery module to prevent the flame from spreading further.

A cell stack accommodated inside the battery module has a structure in which a pad for securing a space capable of absorbing swelling is interposed between every adjacent unit modules, using a certain number of battery cells as one unit module.

In the battery module having the above structure, if a thermal runaway phenomenon occurs therein, even though a coolant is introduced into the battery module, the coolant may not flow smoothly between adjacent unit modules due to the pad.

Therefore, it is demanded to develop a battery module having a structure capable of ensuring a smooth flow of coolant while employing the pad-inserted structure.

In addition, a battery module adopting an air-cooled structure has an air channel through which a coolant leaks without staying inside even though the coolant is introduced to lower the temperature inside the battery module and extinguish the flame. Thus, it is demanded to develop a battery pack having a structure capable of blocking the air channel when a coolant is introduced into a battery module where a thermal runaway phenomenon has occurred.

DISCLOSURE

Technical Problem

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to preventing a flame from spreading greatly by rapidly lowering the temperature inside a battery module when the flame is generated in some battery cells in the battery module due to a thermal runaway phenomenon.

However, the technical problem to be solved by the present disclosure is not limited to the above, and other objects not mentioned herein will be understood from the following description by those skilled in the art.

Technical Solution

In one aspect of the present disclosure, there is provided a battery module, comprising: a unit module stack formed by stacking a plurality of unit modules, each unit module having a plurality of battery cells stacked on each other; a swelling absorption pad interposed between the unit modules adjacent to each other; and a module housing configured to accommodate the unit module stack and the swelling absorption pad, wherein the swelling absorption pad has a coolant channel formed to extend along a longitudinal direction thereof.

The coolant channel may include an input port provided to one side of the swelling absorption pad in the longitudinal direction; an output port provided to the other side of the swelling absorption pad in the longitudinal direction; and a cooling portion configured to connect the input port and the output port to each other and having a greater sectional area than the input port and the output port.

The coolant channel may have an opened shape such that a coolant flowing through the coolant channel directly contacts a pair of battery cells in contact with the swelling absorption pad.

The input port may be located higher than the output port.

The module housing may include an air inlet formed through the module housing at a first side of the unit module stack in a stacking direction; and an air outlet med through the module housing at a second side of the unit module stack in the stacking direction.

The battery module may include an expansion pad disposed inside the air inlet and the air outlet and configured to expand due to the contact with a coolant introduced into the battery module to close the air inlet and the air outlet.

The battery module may include a pair of bus bar frames respectively coupled to a first side and a second side of the unit module stack in a width direction.

The air inlet and the air outlet may be formed at locations corresponding an empty space formed between each of the pair of bus bar frames and the module housing.

The battery module may include a coolant tube insert hole formed through the module housing to communicate with an empty space formed between each of the pair of bus bar frames and the module housing.

A battery pack according to an embodiment of the present disclosure includes a plurality of battery modules according to an embodiment of the present disclosure as described above.

An energy storage system (ESS) according to an embodiment of the present disclosure includes a plurality of battery modules according to an embodiment of the present disclosure as described above.

Advantageous Effects

According to one aspect of the present disclosure, when a flame is generated in some battery cells inside the battery module due to a thermal runaway phenomenon, it is possible to prevent the flame from spreading further by lowering the temperature inside the battery module quickly. That is, it is possible to quickly lower the temperature inside the battery module by solving the problem that a coolant is not able to flow smoothly between adjacent unit modules due to a pad when the coolant is introduced into the battery module having a structure in which the pad for absorbing swelling is interposed between adjacent unit modules.

In addition, according to another aspect of the present disclosure, in a battery pack including an air-cooled battery module, when a coolant is introduced into the battery module where a thermal runaway phenomenon occurs, it is possible to effectively prevent the thermal runaway phenomenon from propagating by adopting a structure in which the air channel for cooling is blocked so that the coolant stays inside the battery module.

