The present disclosure relates to an ESS (Energy Storage System) including a
5 superabsorbent sheet, and more particularly, to an ESS including a superabsorbent sheet,
which is adapted for effective cooling just with a relatively small amount of cooling water when an abnormal temperature rise occurs due to heating of a battery module.
The present application claims priority to Korean Patent Application No. 10-2020-
0024461 filed on February 27, 2020 in the Republic of Korea, the disclosures of which are
10 incorporated herein by reference.
BACKGROUND ART
In an ESS including a plurality of battery cells, if an abnormality such as a short
circuit occurs in some battery cells, the temperature of the battery cells continuously rises.
15 As a result, if the temperature of the battery cells exceeds a critical temperature, a thermal
runaway phenomenon occurs. If a thermal runaway phenomenon occurs in some battery
cells, safety issues may arise.
If a flame is generated in a battery module including the battery cell due to the
thermal runaway phenomenon occurring in some battery cells, the temperature of
20 neighboring battery modules rises rapidly, which may propagate the thermal runaway
phenomenon to the entire ESS within a short time.
As a result, if the thermal runaway phenomenon occurring in some battery cells is not quickly handled, the damage caused by the thermal runaway may be expanded to the
2

battery module, which is a battery unit with a larger capacity than the battery cell, or to a
sub ESS including a plurality of battery modules. If the expansion of damage caused by
the thermal runaway is not appropriately handled, this may lead to disasters such as
ignition and explosion of the battery module and the sub ESS, which may cause not only
5 property damage but also safety issues.
Therefore, when flame occurs due to thermal runaway in some battery cells inside
the battery module, it is important to block the expansion of the flame generation range
inside the sub ESS. In addition, if the flame is already expanded entirely inside one sub
ESS, it is important to increase the efficiency of fire extinguishing and cooling so that the
10 flame does not move to sub ESSs adjacent to the sub ESS where the flame is generated.
DISCLOSURE
Technical Problem
The present disclosure is designed to solve the problems of the related art, and
15 therefore the present disclosure is directed to performing proper extinguishing and cooling
when the flame is expanded entirely inside one sub ESS, so that the flame does not move to sub ESSs adjacent to the sub ESS where the flame is generated.
In addition, the present disclosure is directed to performing proper extinguishing
and cooling so that flame is not propagated to neighboring battery modules, when the
20 flame is generated in some battery modules included in one sub ESS.
However, the technical object to be solved by the present disclosure is not limited to the above, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following disclosure.
3

Technical Solution
In one aspect of the present disclosure, there is provided an ESS (Energy Storage
System), comprising: a sub ESS stack including a plurality of sub ESSs, each having a
5 plurality of battery modules and a battery rack for accommodating the plurality of battery
modules; an ESS housing configured to accommodate the plurality of sub ESSs; a sensor
installed in the ESS housing to sense at least one of temperature and smoke inside the ESS
housing; a first blocking sheet interposed between the sub ESSs adjacent to each other; a
fire extinguishing device configured to supply a fire extinguishing agent into the ESS
10 housing; and a cooling device configured to supply a cooling water to the first blocking
sheet.
The first blocking sheet may be a superabsorbent sheet.
The first blocking sheet may include a superabsorbent fiber capable of absorbing
and containing 20 g to 200 g of cooling water per 1 g.
15 The battery module may include a cell stack formed by stacking a plurality of
battery cells; and a module housing configured to accommodate the cell stack.
The plurality of battery modules may be stacked up and down inside the battery rack.
The ESS may further comprise at least one second blocking sheet interposed
20 between the battery modules adjacent to each other along an upper and lower direction
inside the battery rack.
The second blocking sheet may be disposed to penetrate through the battery rack and traverse from one side of the sub ESS stack in a stacking direction to the other side
4

thereof.
The first blocking sheet may have a first coupling slit, and the second blocking sheet may be inserted into the first coupling slit and coupled to the first blocking sheet.
The second blocking sheet may have a second coupling slit, and the first blocking
5 sheet may be inserted into the second coupling slit and coupled to the second blocking
sheet.
The second blocking sheet may be a superabsorbent sheet.
The second blocking sheet may include a superabsorbent fiber capable of
absorbing and containing 20 g to 200 g of cooling water per 1 g.
10 The superabsorbent fiber may include a superabsorbent resin containing at least
one of a starch-based material, a cellulose-based material and a synthetic polymer-based material.
The ESS may further comprise a control device configured to control the operation
of the fire extinguishing device and the cooling device by referring to at least one of the
15 information about temperature and the information about smoke generation, sensed by the
sensor.
Advantageous Effects
According to an embodiment of the present disclosure, it is possible to perform
20 proper extinguishing and cooling when the flame is expanded entirely inside one sub ESS,
so that the flame does not move to sub ESSs adjacent to the sub ESS where the flame is generated.
In addition, according to an embodiment of the present disclosure, it is possible to
5

perform proper extinguishing and cooling so that flame is not propagated to neighboring battery modules, when the flame is generated in some battery modules included in one sub ESS.
5 DESCRIPTION OF DRAWINGS
The accompanying drawings illustrate a preferred embodiment of the present
disclosure and together with the foregoing disclosure, serve to provide further
understanding of the technical features of the present disclosure, and thus, the present
disclosure is not construed as being limited to the drawing.
10 FIG. 1 is a diagram showing an ESS according to an embodiment of the present
disclosure.
FIG. 2 is a diagram showing a sub ESS and a first blocking sheet, employed at the ESS according to an embodiment of the present disclosure.
FIG. 3 is a diagram showing a battery module according to the present disclosure.
15 FIG. 4 is a block diagram showing a control logic for automation of fire
extinguishing and cooling of the ESS according to an embodiment of the present disclosure. FIG. 5 is a diagram showing an ESS according to another embodiment of the present disclosure.
FIG. 6 is a diagram showing a sub ESS, a first blocking sheet and a second
20 blocking sheet, employed at the ESS according to another embodiment of the present
disclosure.
FIGS. 7 and 8 are diagrams showing a coupled configuration of the first blocking sheet and the second blocking sheet, employed at the ESS according to another
6

embodiment of the present disclosure.
BEST MODE
Hereinafter, preferred embodiments of the present disclosure will be described in
5 detail with reference to the accompanying drawings. Prior to the description, it should be
understood that the terms used in the specification and the appended claims should not be
construed as limited to general and dictionary meanings, but interpreted based on the
meanings and concepts corresponding to technical aspects of the present disclosure on the
basis of the principle that the inventor is allowed to define terms appropriately for the best
10 explanation. Therefore, the description proposed herein is just a preferable example for
the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.
15 An ESS (Energy Storage System) according to an embodiment of the present
disclosure will be described with reference to FIGS. 1 to 4.
First, referring to FIGS. 1 and 2, the ESS according to an embodiment of the present disclosure includes a plurality of sub ESSs 100, an ESS housing 200, a first blocking sheet 300, a fire extinguishing device 400, a cooling device 500 and a sensor 600.
20 The sub ESS 100 includes a battery rack 110 and a plurality of battery modules
120 accommodated in the battery rack 110. The battery rack 110 has open front and rear surfaces. The plurality of sub ESSs 100 are arranged side by side in a left and right directions so that the side surfaces of the battery racks 110 face each other, thereby
7

forming one sub ESS stack.
Referring to FIG. 2, the plurality of battery modules 120 are stacked in an upper and lower direction inside the battery rack 110 to form one module stack.
Referring to FIG. 3, the battery module 120 includes a plurality of battery cells
5 121, a bus bar frame 122, a module housing 123, an air inlet 124 and an air outlet 125.
The battery cell 121 is provided in plural, and the plurality of battery cells 121 are
stacked to form one cell stack. As the battery cell 121, a pouch-type battery cell may be
applied, as an example. The battery cell 121 includes a pair of electrode leads 121a,
which are respectively drawn to both sides in a longitudinal direction.
10 The bus bar frame 122 is provided in a pair, and the pair of bus bar frames 122
cover one side and the other side of the cell stack in a width direction, respectively. The electrode lead 121a of the battery cell 121 is drawn out through a slit formed at the bus bar frame 122 and may be bent and electrically connected by the bus bar frame 122.
The module housing 123 has a substantially rectangular parallelepiped shape and
15 accommodates the cell stack therein. The air inlet 124 and the air outlet 125 are formed
at one longitudinal side and the other longitudinal side of the module housing 123.
The air inlet 124 is formed at one side of the cell stack in the stacking direction,
namely at one longitudinal side of the battery module 120, and is formed in the form of a
hole through the module housing 123. The air outlet 125 is formed at the other side of the
20 cell stack in the stacking direction, namely at the other longitudinal side of the battery
module 120, and is formed in the form of a hole through the module housing 123.
The air inlet 124 and the air outlet 125 are located at opposite sides diagonally along the longitudinal direction of the battery module 120.
8

Meanwhile, an empty space is formed between the bus bar frame 122 and the
module housing 123. That is, an empty space is formed between one of six outer surfaces
of the module housing 123, which faces one longitudinal side and the other longitudinal
side of the battery cell 121, and the bus bar frame 122 so that air for cooling the battery cell
5 121 may flow therethrough. The empty space is formed at both sides of the battery
module 120 in the width direction.
The air inlet 124 is formed at a position corresponding to the empty space formed
at one side of the battery module 120 in the width direction, and the air outlet 125 is
formed at a position corresponding to the empty space formed at the other side of the
10 battery module 120 in the width direction.
In the battery module 120, the air introduced into the battery module 120 through
the air inlet 124 cools the battery cell 121 while moving from the empty space formed at
one side of the battery module 120 in the width direction to the empty space formed at the
other side of the battery module 120 in the width direction, and then is discharged through
15 the air outlet 125. That is, the battery module 120 corresponds to an air-cooled battery
module.
Since the battery module 120 applied to the present disclosure has an air-cooled
structure as described above, flame is likely to be ejected out of the module housing 123.
That is, if an abnormality occurs in some of the battery cells 121 included in the battery
20 module 120 so that the temperature inside the battery cells 121 rises and thus gas is leaked
out by venting, a flame may be generated. The generated flame may be ejected out of the module housing 123 through the air inlet 124 and the air outlet 125, which are formed for air cooling.
9

Referring to FIGS. 1 and 2, when an abnormal temperature rise occurs and thus a
flame is generated in some battery module 120 as described above, the first blocking sheet
300 prevents the flame from moving to sub ESSs 100 adjacent to the sub ESS 100 that
5 includes the battery module 120 with the above problem.
To perform the above function, the first blocking sheet 300 is interposed between
the sub ESSs 100 adjacent to each other. The first blocking sheet 300 is a super absorbent
sheet. That is, the first blocking sheet 300 includes a super absorbent fiber, and the
superabsorbent fiber may absorb and contain approximately 20 g to 200 g of cooling water
10 per 1 g. The superabsorbent fiber may include, for example, a super absorbent resin (or a
super absorbent polymer) including at least one of a starch-based material, a cellulose-based material or a synthetic polymer-based material. The superabsorbent fiber is obtained by spinning a superabsorbent resin into a net form.
If a cooling water supplied from the cooling device 500, the first blocking sheet
15 300 may quickly absorb the cooling water, and the first blocking sheet 300 absorbing the
cooling water may prevent the abnormal temperature rise and/or the flame occurring in some sub ESS 100 from being propagated to neighboring sub ESSs 100.
The first blocking sheet 300 preferably has an area corresponding to the side
surface of the sub ESS 100 in order to minimize the amount of used cooling water and
20 maximize the cooling effect and the flame expansion blocking effect. However, a
longitudinal end of the first blocking sheet 300 may be exposed to the top of the sub ESS
stack in order to quickly absorb the cooling water supplied from the cooling device 500.
10

Referring to FIG. 1, the fire extinguishing device 400 sprays the fire extinguishing
agent into the ESS housing 200 when the internal temperature of the ESS housing 200 rises
above a reference value and/or smoke is sensed, thereby preventing the occurrence of fire
in advance or extinguishing the fire that has already occurred. As the fire extinguishing
5 agent, for example, a clean fire extinguishing agent in the form of a gas such as Novec
1230 may be applied, and also, nitrogen and solid aerosol may be applied.
The fire extinguishing device 400 includes a fire extinguishing agent tank 410 installed at an outer side of the ESS housing 200 to store the fire extinguishing agent and an extinguishing agent injection tube 420 having one side connected to the fire
10 extinguishing agent tank 410 and the other side penetrating the ESS housing 200.
If the internal temperature of the ESS housing 200 rises above the reference value and/or smoke is sensed due to fire, the cooling device 500 sprays the cooling water into the ESS housing 200 to prevent the occurrence of fire in advance or extinguish the fire that has already occurred.
15 More specifically, the cooling device 500 sprays the cooling water directly onto
the first blocking sheet 300. The cooling device 500 includes a cooling water supply tube 520 connected to the cooling water tank 510 that stores the cooling water, and a plurality of cooling water injection tubes 530 branched at an end of the cooling water supply tube 520 and disposed at a position corresponding to each first blocking sheet 300.
20 Even though the drawing of the present disclosure illustrate only the case where
the cooling water supply tube 520 is located at the outer side of the ESS housing 200 and the cooling water injection tube 530 passes through the ESS housing 200, the present disclosure is not limited thereto. That is, it is also possible that the cooling water supply
11

tube 520 passes through the ESS housing 200 and the cooling water injection tube 530 is branched from the cooling water supply tube 520 inside the ESS housing 200.
Referring to FIG. 1, the sensor 600 is installed inside the ESS housing 200 to sense
5 at least one of temperature and smoke generation inside the ESS housing. That is, the
sensor 600 corresponds to a temperature sensor and/or a smoke sensor.
Although not shown in the drawings, the information sensed by the sensor 600
and/or an alarm according to the sensed information may be displayed through a user
interface disposed outside the module housing 200. If a user judges through the sensed
10 information and/or alarm that there is a risk of fire or that a fire has occurred, the user may
operate the fire extinguishing device 400 and the cooling device 500 to extinguish or prevent the fire inside the ESS.
Meanwhile, referring to FIG. 4, the ESS according to an embodiment of the
present disclosure may further include a control device 700, in addition to the above-
15 described components. The control device 700 controls the operation of the fire
extinguishing device 400 and the cooling device 500 by referring to the information about
temperature and/or the information about smoke generation sensed by the sensor 600.
That is, the control device 700 is an element applied to achieve automation of fire
extinguishing and/or cooling by allowing the fire extinguishing device 400 and the cooling
20 device 500 to operate without user manipulation when certain conditions are satisfied.
The reference temperatures for operating the fire extinguishing device 400 and the cooling device 500 may be determined in consideration of the number of the sub ESSs 100, the number of battery modules 120 included in the sub ESS 100, the number of battery cells
12

121 included in the battery module 120, the capacity of the battery cell 121, and the like.
Next, an ESS according to another embodiment of the present disclosure will be
described with reference to FIGS. 5 to 8.
5 The ESS according to another embodiment of the present disclosure is different
from the ESS of the former embodiment only in that a second blocking sheet 310 is
additionally applied, and other components are substantially the same. Accordingly, in
describing the ESS according to another embodiment of the present disclosure, the second
blocking sheet 310 will be described in detail, and other components already described in
10 the former embodiment will not be described in detail again.
Referring to FIGS. 5 and 6, the second blocking sheet 310 is interposed between
the battery modules 120 adjacent to each other along the upper and lower direction inside
the battery rack 110. The second blocking sheet 310 is disposed to penetrate the side
surface of the battery rack 110 and traverse from one side of the sub ESS 100 in the
15 stacking direction to the other side thereof.
One second blocking sheet 310 or a plurality of second blocking sheets 310 may
be provided. If only one second blocking sheet 310 is provided, it is efficient that the
second blocking sheet 310 is disposed at the center of the battery rack 110 along the
stacking direction of the battery module 120. The material of the second blocking sheet
20 310 is the same as the first blocking sheet 300 described above.
Referring to FIG. 7, the first blocking sheet 300 and the second blocking sheet 310 may be coupled to each other by forming a first coupling slit 300a at each first blocking sheet 300 and inserting the second blocking sheet 310 into the first coupling slit 300a. In
13

this case, the position and shape of the first coupling slit 300a formed at the first blocking sheet 300 correspond to a slit (not shown) formed at the side surface of the battery rack 110 for the passage of the second blocking sheet 310.
Referring to FIG. 8, the first blocking sheet 300 and the second blocking sheet 310
5 may be coupled to each other by forming a second coupling slit 310a at the second
blocking sheet 310 in a number corresponding to the first blocking sheets 300 and inserting the first blocking sheet 300 into the second coupling slit 310a, unlike that shown in FIG. 7.
As the first blocking sheet 300 and the second blocking sheet 310 are connected to
each other in this way, the first blocking sheet 300 may absorb the cooling water supplied
10 from the top of the first blocking sheet 300, and the second blocking sheet 310 may absorb
a part of the absorbed cooling water again, thereby preventing the thermal runaway phenomenon from expanding along the stacking direction of the sub ESS stacks and the stacking direction of the battery modules 120.
15 The present disclosure has been described in detail. However, it should be
understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.

WHAT IS CLAIMED IS:

1.An ESS (Energy Storage System), comprising:
a sub ESS stack including a plurality of sub ESSs, each having a plurality of
5 battery modules and a battery rack for accommodating the plurality of battery modules;
an ESS housing configured to accommodate the plurality of sub ESSs; a sensor installed in the ESS housing to sense at least one of temperature and smoke inside the ESS housing;
a first blocking sheet interposed between the sub ESSs adjacent to each other;
10 a fire extinguishing device configured to supply a fire extinguishing agent into the
ESS housing; and
a cooling device configured to supply a cooling water to the first blocking sheet.
2. The ESS according to claim 1,
15 wherein the first blocking sheet is a superabsorbent sheet.
3. The ESS according to claim 2,
wherein the first blocking sheet includes a superabsorbent fiber capable of absorbing and containing 20 g to 200 g of cooling water per 1 g. 20
4. The ESS according to claim 3,
wherein the superabsorbent fiber includes a superabsorbent resin containing at least one of a starch-based material, a cellulose-based material and a synthetic polymer-15

based material.
5. The ESS according to claim 1,
wherein the battery module includes:
5 a cell stack formed by stacking a plurality of battery cells; and
a module housing configured to accommodate the cell stack.
6. The ESS according to claim 1,
wherein the plurality of battery modules are stacked up and down inside the
10 battery rack.
7. The ESS according to claim 6, further comprising:
at least one second blocking sheet interposed between the battery modules adjacent to each other along an upper and lower direction inside the battery rack. 15
8. The ESS according to claim 7,
wherein the second blocking sheet is disposed to penetrate through the battery rack and traverse from one side of the sub ESS stack in a stacking direction to the other side thereof. 20
9. The ESS according to claim 8,
wherein the first blocking sheet has a first coupling slit, and
the second blocking sheet is inserted into the first coupling slit and coupled to the
16

first blocking sheet.
10. The ESS according to claim 8,
wherein the second blocking sheet has a second coupling slit, and
5 the first blocking sheet is inserted into the second coupling slit and coupled to the
second blocking sheet.
11. The ESS according to claim 7,
wherein the second blocking sheet is a superabsorbent sheet. 10
12. The ESS according to claim 7,
wherein the second blocking sheet includes a superabsorbent fiber capable of absorbing and containing 20 g to 200 g of cooling water per 1 g.
15 13. The ESS according to claim 12,
wherein the superabsorbent fiber includes a superabsorbent resin containing at least one of a starch-based material, a cellulose-based material and a synthetic polymer-based material.
20 14. The ESS according to claim 1, further comprising:
a control device configured to control the operation of the fire extinguishing device and the cooling device by referring to at least one of the information about temperature and the information about smoke generation, sensed by the sensor.