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KR-20260063174-A - BATTERY CELL AND BATTERY ASSEMBLY

KR20260063174AKR 20260063174 AKR20260063174 AKR 20260063174AKR-20260063174-A

Abstract

According to the present disclosure, a battery cell capable of suppressing the occurrence of thermal runaway or propagation, and a battery assembly capable of improving safety, comprises an electrode assembly including a unit cell; a cell case accommodating the electrode assembly; and a non-aqueous electrolyte, wherein the unit cell comprises a positive electrode; a negative electrode; and a separator disposed between the positive electrode and the negative electrode, and the separator comprises a substrate layer; an outer layer disposed on one or both sides of the substrate layer and comprising an adhesive polymer; and an inner layer disposed between the substrate layer and the outer layer and comprising a gaseous particle and an organic particle, wherein the melting point of the organic particle is within the range of 125°C to 135°C, and the self-heating temperature of the battery cell may be within the range of 120°C to 150°C.

Inventors

  • 이주성
  • 박성은

Assignees

  • 주식회사 엘지화학

Dates

Publication Date
20260507
Application Date
20241030

Claims (16)

  1. A battery cell comprising: an electrode assembly including a unit cell; a cell case accommodating the electrode assembly; and a non-aqueous electrolyte. The above unit cell comprises an anode; a cathode; and a separator disposed between the anode and the cathode, and The above separator comprises: a substrate layer; an outer layer disposed on one or both sides of the substrate layer and comprising an adhesive polymer; and an inner layer disposed between the substrate layer and the outer layer and comprising inorganic particles and organic particles. The melting point of the above organic particles is within the range of 125 ℃ to 135 ℃, and A battery cell in which the self-heating temperature of the above battery cell is within the range of 120 ℃ to 150 ℃.
  2. In Article 1, The above unit cell is a battery cell further comprising a SEI layer disposed between the cathode and the separator.
  3. In Article 2, The above SEI layer is a battery cell that decomposes at a temperature within the range of 60 ℃ to 90 ℃.
  4. In Paragraph 3, The decomposition of the above SEI layer is a battery cell that is a heat generation process.
  5. In Article 1, The above positive electrode is a battery cell comprising a positive electrode active material having a charging potential of 4.45 V or higher.
  6. In Article 1, A battery cell in which the melting point of the above organic particles is within the range of 128 ℃ to 132 ℃.
  7. In Article 1, The above organic particles comprise one or more types selected from the group consisting of polyolefin-based polymers and polyvinylidene fluoride-based polymers, forming a battery cell.
  8. In Article 1, A battery cell in which the D50 of the organic particles is within the range of 0.5 to 1.5 times the D50 of the inorganic particles.
  9. In Article 1, A battery cell in which the D50 of the above-mentioned inorganic particles is within the range of 200 nm to 600 nm.
  10. In Article 1, A battery cell in which the D50 of the above organic particles is within the range of 100 nm to 900 nm.
  11. In Article 1, A battery cell in which the ratio (IP:OP) of the weight of the inorganic particles (IP) and the weight of the organic particles (OP) of the inner layer is within the range of 40:60 to 85:15.
  12. In Article 1, The above outer layer is a battery cell that does not contain inorganic particles.
  13. In Article 1, A battery cell comprising: a non-aqueous electrolyte; a non-aqueous solvent; and a lithium salt dissolved in the non-aqueous solvent.
  14. In Article 13, The above-mentioned non-aqueous solvent comprises a carbonate-based solvent, an ether-based solvent, an ester-based solvent, a solvent containing polar functional groups, or a mixture thereof, in a battery cell.
  15. In Article 13, A battery cell comprising one or more lithium salts selected from the group consisting of LiPF6 , LiBF4 , LiCl, LiBr, LiI , LiClO4 , LiAsF6 , LiCH3CO2 , LiCF3SO3, LiN( CF3SO2 ) 2 , and LiC( CF2SO2 ) 3 .
  16. A cell assembly comprising a plurality of battery cells; and an assembly case accommodating the cell assembly; comprising, The above battery cell comprises an electrode assembly including a unit cell; a cell case housing the electrode assembly; and a non-aqueous electrolyte. The above unit cell comprises an anode; a cathode; and a separator disposed between the anode and the cathode, and The above separator comprises: a substrate layer; an outer layer disposed on one or both sides of the substrate layer and comprising an adhesive polymer; and an inner layer disposed between the substrate layer and the outer layer and comprising inorganic particles and organic particles. The melting point of the above organic particles is within the range of 125 ℃ to 135 ℃, and A battery assembly in which the self-heating temperature of the above battery cell is within the range of 120 ℃ to 150 ℃.

Description

Battery Cell and Battery Assembly The present disclosure relates to a battery cell. The present disclosure relates to a battery assembly. A battery assembly, such as a battery module or a battery pack, may include a plurality of battery cells. The battery module may be an assembly of a plurality of battery cells. The battery pack may be an assembly of a plurality of the battery modules. Thermal runaway (TR) refers to a situation where the internal temperature of a battery rises in a chain reaction, leading to explosions. The cause of thermal runaway can be abnormal mechanical, electrical, and/or thermal behavior of the battery. The phenomenon of thermal propagation (TP) may refer to a situation in which thermal runaway originating from one battery cell propagates flames and heat to adjacent battery cells. If thermal propagation at the battery cell or battery module level is delayed or blocked, the safety of the battery assembly may be improved. The above-mentioned battery cell may generate heat spontaneously at a specific temperature. The self-heating temperature may refer to the lowest temperature at which the heat generation begins. The self-heating temperature of the above-mentioned battery cell may vary depending on the type of material constituting it and/or thermal capacity, etc. The self-heating temperature of the above-mentioned battery cell is generally decreasing. If the self-heating temperature of the battery cell is low, it can generate heat easily even at low temperatures, and consequently, thermal runaway or propagation may also occur easily. The battery cell may form a Solid Electrolyte Interphase (SEI) layer between the internal separator and the negative electrode during initial charging. The SEI layer can prevent further decomposition reactions of the electrolyte. The SEI layer can facilitate the smooth movement of charge carriers. The SEI layer may decompose if the battery cell is exposed to a temperature above a certain temperature. This decomposition reaction may be an exothermic process. Therefore, even if the SEI layer decomposes at a temperature above a certain temperature, if the heat from the decomposition is not transferred to the battery cell, thermal runaway or propagation can be suppressed even if the self-heating temperature of the battery cell is low. The present disclosure is described in detail below. One embodiment of the present disclosure relates to a battery cell. The above battery cell may refer to a basic unit of a secondary battery capable of charging and discharging electrical energy. The above battery may include any device that performs an electrochemical reaction. The above battery may refer to any type of primary or secondary battery, fuel cell, solar cell, or capacitor, etc. In particular, the above battery may refer to a lithium secondary battery. The above lithium secondary battery may refer to a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery, etc. Specifically, the above battery may be a lithium ion secondary battery. The above battery cell may include an electrode assembly and a cell case. The cell case may accommodate the electrode assembly. The battery cell may be classified into pouch type, prismatic type, cylindrical type, or coin type, etc., depending on the shape of the cell case. The electrode assembly can convert electrical energy into chemical energy, or chemical energy into electrical energy, through an oxidation-reduction reaction. The electrode assembly may include a unit cell. The electrode assembly may include at least one unit cell. The electrode assembly may include a plurality of unit cells. The plurality of unit cells may have a stacked structure in the electrode assembly. The above unit cell may include a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The positive electrode may be an electrode that undergoes a reduction reaction during discharge. The negative electrode may be an electrode that undergoes an oxidation reaction during discharge. The electrode of the above unit cell may include an electrode active material attached to an electrode current collector. The above positive electrode may include a positive electrode current collector and a positive electrode active material layer attached to one or both sides of the positive electrode current collector and comprising a positive electrode active material. The above positive current collector may be a foil of a metal comprising one or more selected from the group consisting of aluminum and nickel. The above positive active material may include a lithium intercalation material. The lithium intercalation material may include a lithium transition metal oxide. The lithium intercalation material may include one or more selected from the group consisting of lithium manganese oxide, lithium cobalt oxide, lithium nic