【TECHNICAL FIELD】
Cross Citation with Related Application(s)
This application claims the benefit of Korean Patent Application No. 10-2021-0003183
filed on January 11, 2021 with Korean Intellectual Property Office, the disclosure which is
incorporated herein by reference in its entirety.
10 The present disclosure relates to a battery module and a battery pack including the same,
and more particularly, to a battery module having improved cooling performance and a battery
pack including the same.
【BACKGROUND】
In modern society, as portable devices such as a mobile phone, a notebook computer, a
15 camcorder and a digital camera has been daily used, the development of technologies in the fields
related to mobile devices as described above has been activated. In addition,
chargeable/dischargeable secondary batteries are used as a power source for an electric vehicle
(EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (P-HEV) and the like, in
an attempt to solve air pollution and the like caused by existing gasoline vehicles using fossil fuel.
20 Therefore, there is a growing need for development of the secondary battery.
Currently commercialized secondary batteries include a nickel cadmium battery, a nickel
hydrogen battery, a nickel zinc battery, a lithium secondary battery, and the like. Among them,
the lithium secondary battery has come into the spotlight because they have advantages, for
example, hardly exhibiting memory effects compared to nickel-based secondary batteries and thus
25 being freely charged and discharged, and having very low self-discharge rate and high energy
density.
Such lithium secondary battery mainly uses a lithium-based oxide and a carbonaceous
material as a positive electrode active material and a negative electrode active material,
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respectively. The lithium secondary battery includes an electrode assembly in which a positive
electrode plate and a negative electrode plate each coated with the positive electrode active
material and the negative electrode active material are disposed with a separator being interposed
between them, and a battery case that seals and houses the electrode assembly together with an
5 electrolyte solution.
Generally, the lithium secondary battery may be classified based on the shape of the
exterior material into a can type secondary battery in which the electrode assembly is mounted in
a metal can, and a pouch-type secondary battery in which the electrode assembly is mounted in a
pouch made of an aluminum laminate sheet.
10 In the case of a secondary battery used for small-sized devices, two to three battery cells
are disposed, but in the case of a secondary battery used for a middle or large-sized device such as
an automobile, a battery module in which a large number of battery cells are electrically connected
is used. In such a battery module, a large number of battery cells are connected to each other in
series or in parallel to form a cell stack, thereby improving capacity and output. In addition, one
15 or more battery modules may be mounted together with various control and protection systems
such as BMS (battery management system) and a cooling system to form a battery pack.
When the temperature of the secondary battery rises higher than an appropriate
temperature, the performance of the secondary battery may be deteriorated, and in the worst case,
there is also a risk of an explosion or ignition. In particular, a large number of secondary batteries,
20 that is, a battery module or a battery pack having battery cells, can add up the heat generated from
the large number of battery cells in a narrow space, so that the temperature can rise more quickly
and severely. In other words, a battery module in which a large number of battery cells are
stacked, and a battery pack equipped with such a battery module can obtain high output, but it is
not easy to remove heat generated from the battery cells during charging and discharging. When
25 the heat dissipation of the battery cell is not properly performed, deterioration of the battery cells
is accelerated, the lifespan is shortened, and the possibility of explosion or ignition increases.
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Moreover, in the case of a middle or large-sized battery module included in a vehicle
battery pack, it is frequently exposed to direct sunlight and can be subjected to high-temperature
conditions such as summer or desert areas.
Therefore, when a battery module or a battery pack is configured, it may be very important
5 to stably and effectively ensure the cooling performance.
Fig. 1 is a perspective view of a conventional battery module. Fig. 2 is a cross-sectional
view showing a cross section taken along the cutting line A-A' of Fig. 1. At this time, a heat
transfer member and a heat sink located under the battery module are further shown in Fig. 2.
Referring to Figs. 1 and 2, the conventional battery module 10 is configured such that a
10 plurality of battery cells 11 are stacked to form a battery cell stack 20, and the battery cell stack
20 is housed in the module frame 30.
As described above, since the battery module 10 includes a plurality of battery cells 11, it
generates a large amount of heat in a charge and discharge process. As a cooling means, the battery
module 10 may include a thermal conductive resin layer 40 that is located between the battery cell
15 stack 20 and the bottom portion 31 of the module frame 30. In addition, when the battery module
10 is mounted on the pack frame to form a battery pack, a heat transfer member 50 and a heat sink
60 may be sequentially located under the battery module 10. The heat transfer member 50 may be
a heat dissipation pad, and the heat sink 60 may have a refrigerant flow passage formed therein.
The heat generated from the battery cell 11 passes through the thermal conductive resin
20 layer 40, the bottom portion 31 of the module frame 30, the heat transfer member 50, and the heat
sink 60 in this order, and then is transmitted to the outside.
By the way, in the case of the conventional battery module 10, the heat transfer path is
complicated as described above and thus, it is difficult to effectively transfer the heat generated
from the battery cell 11. The module frame 30 itself may deteriorate heat transfer properties, and
25 a fine air layer such as an air gap, which can be formed in the space between the module frame 30,
the heat transfer member 50, and the heat sink 60, respectively, may also be a factor that
deteriorates the heat transfer properties.
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As for the battery module, since other demands such as downsizing of module and an
increase in capacity are also continuing, it can be said that it is practically necessary to develop a
battery module capable of satisfying these various requirements while improving the cooling
performance.
5 【DETAILED DESCRIPTION OF THE INVENTION】
【Technical Problem】
It is an object of the present disclosure to provide a battery module having improved
cooling performance and a battery pack including the same.
However, the problem to be solved by embodiments of the present disclosure is not limited
10 to the above-described problems, and can be variously expanded within the scope of the technical
idea included in the present disclosure.
【Technical Solution】
According to one embodiment of the present disclosure, there is provided a battery module
comprising: a battery cell stack in which a plurality of battery cells including electrode leads are
15 stacked; an elastic member for covering a front surface, rear surface and both side surfaces of the
battery cell stack; a heat sink located under the battery cell stack; and a thermal conductive resin
layer located between the battery cell stack and the heat sink, wherein the elastic member is opened
in its lower portion, and a lower surface of the battery cell stack comes into contact with the thermal
conductive resin layer.
20 The elastic member may be continuously connected along the front surface, the rear
surface and both side surfaces of the battery cell stack.
The heat sink may include an upper plate and a lower plate that form a space in which
refrigerant flows, the upper plate may include upper extension portions extending from both sides
of the upper plate, and the lower plate may include lower extension portions extending from both
25 sides of the lower plate to a portion where the upper extension portion is located.
An upper through-hole into which a refrigerant-delivering bolt can be inserted may be
formed in the upper extension portion, and a lower through-hole into which the refrigerantdelivering bolt can be inserted may be formed in the lower extension portion.
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The lower plate may include a base portion joined to the upper plate, and a recessed
portion that is recessed downward from the base portion to form a refrigerant flow path.
The battery module may further include a first sensing block and a second sensing block
each covering the front surface and the rear surface of the battery cell stack from which the
5 electrode leads protrude. At least two of the electrode leads may pass through a slit of the first
sensing block or a slit of the second sensing block, and then may be bent and joined to form an
electrode lead joint. The elastic member may be continuously connected along the first sensing
block, the second sensing block, and the both side surfaces of the battery cell stack.