EP-4738545-A1 - BATTERY ASSEMBLY AND BATTERY PACK INCLUDING SAME

EP4738545A1EP 4738545 A1EP4738545 A1EP 4738545A1EP-4738545-A1

Abstract

A battery assembly according to an embodiment of the present disclosure comprises a plurality of battery cells; and a cell frame in which the plurality of battery cells are stored. The inside of the cell frame is provided with a cooling flow path through which a coolant flows while being in direct contact with at least a part of the battery cells. The cooling flow path comprises a plurality of cooling flow paths arranged along a longitudinal direction of the battery cells in which the battery cells extend. A flow direction of the coolant in any one of the plurality of cooling flow paths and a flow direction of the coolant in the other of the plurality of cooling flow paths are opposite to each other.

Inventors

JUNG, MINYONG
CHOI, BUM
CHOI, Seungbin
CHUNG, JAEHEON

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260506
Application Date: 20250325

Claims (20)

A battery assembly comprising: a plurality of battery cells; and a cell frame in which the plurality of battery cells are stored; wherein the inside of the cell frame is provided with a cooling flow path through which a coolant flows while being in direct contact with at least a part of the battery cells, wherein the cooling flow path comprises a plurality of cooling flow paths arranged along a longitudinal direction of the battery cells in which the battery cells extend, and wherein a flow direction of the coolant in any one of the plurality of cooling flow paths and a flow direction of the coolant in the other of the plurality of cooling flow paths are opposite to each other.
The battery assembly according to claim 1, wherein the longitudinal direction is a direction between one surface of the battery cell and the other surface facing the one surface, and at least one of electrode terminals of the battery cells is located on the one surface of the battery cells.
The battery assembly according to claim 1, wherein the cell frame comprises an inlet port into which the coolant flows, with the coolant flowing through the cooling flow path and being in direct contact with the battery cells, and an outlet port through which the coolant is discharged.
The battery assembly according to claim 3, wherein any one of the plurality of cooling flow paths is connected to the inlet port, and the other of the plurality of cooling flow paths is connected to the outlet port.
The battery assembly according to claim 3, wherein the coolant flowing into the inlet port flows along the cooling flow paths and is then discharged through the outlet port.
The battery assembly according to claim 1, wherein the area where at least one cooling flow path made to match with the flow direction of the coolant among the plurality of cooling flow paths is in contact with the battery cell is 30% or more and 70% or less of the area where all of the plurality of cooling flow paths are in contact with the battery cell.
The battery assembly according to claim 1, wherein the cooling flow paths comprise a first cooling flow path and a second cooling flow path, and the flow direction of the coolant in the first cooling flow path and the flow direction of the coolant in the second cooling flow path are opposite to each other.
The battery assembly according to claim 7, wherein the cell frame comprises a separation part that partitions the first cooling flow path and the second cooling flow path and is located between the first cooling flow path and the second cooling flow path.
The battery assembly according to claim 8, wherein based on the longitudinal direction of the battery cell, the separation part is located in a space between the 30% point of the height of the battery cell and the 70% point of the height of the battery cell.
The battery assembly according to claim 1, wherein the cell frame comprises a connection hole that connects a plurality of cooling flow paths.
The battery assembly according to claim 10, wherein in the connection hole, the width of the space through which the coolant flows is constant.
The battery assembly according to claim 10, wherein the connection hole has a region where the width of the space where the coolant flows is narrowed.
The battery assembly according to claim 12, wherein in the connection hole, the width difference between the widest part of the space where the coolant flows and the narrowest part of the space where the coolant flows is 1.0 mm or more, and is not more than 5 times the gap between the battery cells.
The battery assembly according to claim 10, wherein the cell frame comprises an inlet port and an outlet port through which the coolant flows in and is discharged, with the coolant flowing through the cooling flow path and being in direct contact with the battery cells, at least one of the inlet port or the outlet port is provided with a distribution mechanism that divides the coolant into a plurality of cooling channels, and the connection holes are provided in plurality of numbers, and the plurality of connection holes correspond one to one to the cooling channels distributed by the distribution mechanism.
The battery assembly according to claim 1, wherein the gap between the battery cells is 1.5 mm or more and 2.5 mm or less.
The battery assembly according to claim 1, wherein the cell frame comprises a bottom cell frame on which the battery cells are seated and a cover cell frame located on the bottom cell frame.
The battery assembly according to claim 16, wherein the cover cell frame comprises a middle cell frame and a top cell frame located on the middle cell frame, and the space between the middle cell frame and the bottom cell frame and the space between the top cell frame and the middle cell frame correspond to the cooling flow paths, respectively.
The battery assembly according to claim 17, wherein each of the middle cell frame and the top cell frame is a member that includes an upper surface part and a side surface part facing downward from an edge of the upper surface part.
The battery assembly according to claim 17, wherein the middle cell frame is a member that includes an intermediate part, a first side surface part facing upward from an edge of the intermediate part, and a second side surface part facing downward from an edge of the intermediate part, and the top cell frame is a plate-shaped member.
The battery assembly according to claim 1, wherein the battery cells are mounted directly to a vehicle or chassis in a state of being stored in the cell frame.

Description

[TECHNICAL FIELD] Cross-Reference to Related Application(s) This application claims priority to and the benefit of Korean Patent Application no. KR10-2024-0056163, filed on April 26, 2024, and Korean Patent Application no. KR10-2024-0153476, filed on November 1, 2024, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. The present disclosure relates to a battery assembly and a battery pack including the same, and more particularly, to a battery assembly using an immersion cooling system and a battery pack including the same [BACKGROUND ART] Secondary batteries which are highly applicable to various products and exhibit superior electrical properties such as high energy density, etc. are commonly used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electrical power sources. Such a secondary battery is widely used as a novel energy source for enhancing environment friendliness and energy efficiency, in that it has a primary advantage of remarkable reducing the use of fossil fuels, and also generates no by-products resulting from the use of energy. The types of secondary batteries currently include a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydride battery, a nickel zinc battery, and the like. An operating voltage of the unit secondary battery cell, namely a unit battery cell, is about 2.5V to 4.5V. Therefore, when an output voltage higher than the operating voltage is required, a plurality of battery cells may be connected in series to configure a battery pack. In addition, depending on the charge/discharge capacity required for the battery pack, a plurality of battery cells may also be connected in parallel to configure a battery pack. Thus, the number of battery cells included in the battery pack may be variously set in accordance with the required output voltage or charge/discharge capacity. Meanwhile, when a plurality of battery cells are connected in series/parallel to configure a battery pack, a common method employs a process of first making a battery assembly including a plurality of battery cells and housing it in a module case to configure a battery module, and then gather one or more battery modules and adding other components thereto to configure a battery pack, or a process of disposing a plurality of battery cells in a pack frame and adding other components thereto to configure a battery pack. Since these battery cells are constituted of secondary batteries that can be recharged and discharged, such high-output, large-capacity secondary batteries generate a large amount of heat in a charge and discharge process. In this case, the heat emitted from the plurality of battery cells is accumulated in a narrow space, which may raise the temperature of the battery module quickly and severely. In other words, a battery module including a large number of battery cells can obtain high output, but it is not easy to remove heat generated from the battery cells during charging and discharging. When the heat dissipation of the battery cell is not properly performed, deterioration of the battery cells is accelerated, the lifetime is shortened, and the possibility of explosion or ignition increases. Moreover, in the case of a vehicle battery pack, it is frequently exposed to direct sunlight and may be placed under high-temperature conditions such as summer or desert areas. Further, since a plurality of battery modules are concentratedly disposed to increase the mileage of the vehicle, the flame or heat generated in any one of the battery cells can easily propagate to adjacent battery cells, which may eventually lead to ignition or explosion of the battery pack itself. Conventionally, the battery assembly has adopted a bottom cooling or side cooling system in which a heat sink is mounted in the module case of the battery module for cooling. However, in the case of battery modules using such a cooling system, heat generated in the battery cells is transferred to the heat sink on one side of the module case and cooled, so that a heat transfer path is not easily provided on the other side of the module case. Thereby, they have a limitation that the temperature deviation between one end and the other end of the battery assembly is deepened, or the cooling efficiency is not satisfactory as a whole. If the temperature deviation is not resolved, it will cause safety and durability issues for the battery module. If the cooling efficiency is not good, it may accelerate deterioration of the battery cells, or it may not be possible to quickly address when thermal runaway occurs in some battery cells, which leads to thermal runaway propagation. This may lead to disasters such as ignition and explosion of a battery module or a battery pack containing the same, which may cause not only property damage but also safety problems. In order to solve these problems, it