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EP-4468487-B1 - BATTERY PACK, MANUFACTURING METHOD OF BATTERY PACK, AND VEHICLE

EP4468487B1EP 4468487 B1EP4468487 B1EP 4468487B1EP-4468487-B1

Inventors

  • KIM, GAE-SUNG
  • PARK, TAE-YOUNG
  • CHOI, BUM

Dates

Publication Date
20260513
Application Date
20231024

Claims (14)

  1. A battery pack (A, 10, 20), comprising: a pack case (A1 300, 310); a battery cell (C) assembly comprising a plurality of battery cells (C) accommodated in the pack case (A1 300, 310); a resin layer (D, 200) filling a relatively lower portion of the space between the plurality of battery cells (C), the relatively lower portion being a side closer to a bottom of the pack case (A1, 300,310); and an inorganic layer (E, 250) filling a relatively upper portion of the space between the plurality of battery cells and characterized in that the resin layer (D, 200) and the inorganic layer (E, 250) are a double layer formed by forced phase separation as the composition comprising the base resin (F1) and the inorganic filler (F2) is cured.
  2. The battery pack (10, 20) according to claim 1, wherein the inorganic layer (E, 250) has flame retardancy compared to the resin layer (D, 200).
  3. The battery pack (10, 20) according to claim 1, wherein the battery cell (C) is a cylindrical battery cell (C), the battery cells (C) are accommodated upright in the pack case (A1, 300, 310), and the resin layer (D, 200) and the inorganic layer (E, 250) surround the side surface of the battery cells (C).
  4. The battery pack (10, 20) according to claim 1, wherein the inorganic filler (F2) has a low density compared to the base resin (F1).
  5. The battery pack (10, 20) according to claim 1, wherein the inorganic filler (F2) is a hollow glass bead.
  6. The battery pack (10, 20) according to claim 1, wherein the initial viscosity of the base resin (F1) is 1000 mPas (cP) or less.
  7. The battery pack (10, 20) according to claim 1, wherein the content of the inorganic filler (F2) in the composition is 10% or more.
  8. The battery pack (10, 20) according to claim 1, wherein the base resin (F1) has a Shore hardness A of 80 or more and a Shore hardness D of 30 or more after curing.
  9. The battery pack (10, 20) according to claim 1, wherein the base resin (F1) has an initial curing time of 30 minutes or more.
  10. The battery pack (10, 20) according to claim 1, further comprising an adhesive (400, 420) between the inner surface of the pack case A1 300, 310) and the battery cell (C).
  11. The battery pack (10, 20) according to claim 1, wherein the battery cell (C) comprises a vent portion (115) at the top or bottom thereof, and the inorganic layer (E, 250) surrounds the vent portion (115).
  12. A manufacturing method of a battery pack (10, 20), comprising the following steps of: accommodating a plurality of battery cells (C) in a pack case A1, 300, 310); filling the space between the plurality of battery cells (C) with a composition comprising a base resin (F1) and an inorganic filler (F2); and forming a resin layer (D, 200) filling a relatively lower portion of the space between the plurality of battery cells (C) and an inorganic layer (E, 250) filling a relatively upper portion of the space between the plurality of battery cells (C) by curing the composition, and by forced phase separation of the base resin (F1) and the inorganic filler (F2) according to the density difference during curing.
  13. The manufacturing method of a battery pack (10, 20) according to claim 12, wherein the initial viscosity of the base resin (F1) is 1000 mPas (cP) or less.
  14. The manufacturing method of a battery pack (10, 20) according to claim 12, wherein the base resin (F1) has an initial curing time of 30 minutes or more.

Description

TECHNICAL FIELD The present disclosure relates to a battery pack, and particularly, to a battery pack, a manufacturing method of a battery pack, and a vehicle. The present application claims priority to Korean Patent Application No. 10-2022-0138104 filed on October 25, 2022 in the Republic of Korea. BACKGROUND ART Secondary batteries have high applicability according to product groups and electrical characteristics such as high energy density, and thus are commonly applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power sources. Such secondary batteries are attracting attention as a new energy source to improve eco-friendliness and energy efficiency in that it has not only a primary advantage of dramatically reducing the use of fossil fuels, but also no by-products generated from the use of energy. Secondary batteries widely used at present include lithium-ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. An operating voltage of the unit secondary battery cell, namely a unit battery cell, is about 2.5 V to 4.5 V. Therefore, if a higher output 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 be connected in parallel to configure a battery pack. Thus, the number of battery cells included in the battery pack may be variously set according to the required output voltage or the demanded charge/discharge capacity. Meanwhile, when a plurality of battery cells are connected in series or in parallel to configure a battery pack, it is common to configure a battery module including at least one battery cell first, and then configure a battery pack by using such at least one battery module and adding other components. Therefore, a conventional battery pack includes a plurality of battery cells, a module case accommodating battery cells in module units, and a pack case accommodating all of them. In such a conventional battery pack, for example, when looking at a battery pack including cylindrical battery cells, there is a gap between battery cells accommodated in the module case, and a frame for fixing the battery cells exists in the module case. The gap between the battery cells is filled with the ribs of the frame or left as an empty space, and a plurality of battery modules combined with the battery cells and the frame are assembled to form a battery pack. However, in the case of a conventional battery pack, when a cylindrical battery cell is ignited, there is a possibility of chain ignition due to the ignition of vent portion and side rupture of adjacent battery cells. In addition, since a module case is required in addition to the battery pack case and there are many individual frames within each battery module, there is a problem in that the weight of the battery pack increases and space efficiency within the battery pack decreases. That is, there is a problem that even a battery pack of the same size contains fewer battery cells. Therefore, it is required to find a way to provide a battery pack that reduces the possibility of chain ignition and improves the degradation issue of space efficiency, and a vehicle including the same. KR 2018 0064485 A discloses an electric energy storage module and manufacturing method thereof. CN 103 872 276 A discloses a lithium ion battery filled polymer composition, filing method, lithium battery and application. KR 2022 0115532 A discloses a battery module, battery pack, and vehicle comprising the battery module. DISCLOSURE Technical Problem The present disclosure is directed to providing a battery pack that reduces the possibility of chain ignition and the degradation of space efficiency by preventing side rupture of the battery cell and securing structural rigidity within the battery module. The present disclosure is also directed to providing a method for manufacturing such a battery pack. The present disclosure is still also directed to providing a vehicle including such a battery pack. Technical Solution A battery pack of the present disclosure layer is laid out in appended claim 1. The inorganic layer has flame retardancy compared to the resin layer. The battery cell is a cylindrical battery cell, the battery cells are accommodated upright in the pack case, and the resin layer and the inorganic layer may surround the side surface of the battery cells. The inorganic filler has a low density compared to the base resin. The inorganic filler may be a hollow glass bead. It is preferable that the initial viscosity of the base resin is 1000 mPas (cP) or less. The content of the inorganic filler in the composition may be 10% or more. The base resin may have a Shore hardness A of 80 or more and a Shore hardness D of 30 or more after curing. It is prefer