Battery pack

Abstract

According to an exemplary embodiment of the present invention, a battery pack is provided. The battery pack includes a plurality of first battery devices mounted on a housing and spaced apart from each other, and a plurality of second battery devices mounted on the housing and interposed between the plurality of first battery devices. Each of the plurality of first battery devices includes a plurality of first battery cells including a first positive electrode active material, and each of the plurality of second battery devices includes a plurality of second battery cells including a second positive electrode active material different from the first positive electrode active material.

Description

Technical Field

[0001] The present invention relates to a battery pack. This application claims the benefit of Korean Application No. 10-2022-0168151, filed on December 5, 2022, and Korean Application No. 10-2023-0024931, filed on February 24, 2023, which are hereby incorporated by reference in their entirety.

Background Art

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various wireless devices such as handsets, notebook computers, and wireless vacuum cleaners. In recent years, due to improvements in energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has decreased significantly, and as the driving range of battery electric vehicles (BEVs) has increased to a level comparable to that of fuel vehicles, the main application of secondary batteries has shifted from mobile devices to mobility.

[0003] As secondary batteries are used for mobility, the requirements for the safety of secondary batteries are increasing. When an accident such as a fire occurs in a secondary battery used for mobility, the life of the driver can be put at risk, so research on technologies to improve the safety of secondary batteries is essential.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the technical idea of the present invention is to provide a battery pack with improved safety.

Means for Solving the Problems

[0005] According to an exemplary embodiment of the present invention for solving the above problems, a battery pack is provided. The battery pack includes a plurality of first battery devices mounted on a housing and spaced apart from each other, and a plurality of second battery devices mounted on the housing and interposed between the plurality of first battery devices. Each of the plurality of first battery devices includes a plurality of first battery cells including a first positive electrode active material, and each of the plurality of second battery devices includes a plurality of second battery cells including a second positive electrode active material different from the first positive electrode active material.

[0006] The first positive electrode active material includes nickel and manganese.

[0007] The second positive electrode active material includes iron and phosphorus.

[0008] The area of each of the plurality of first battery devices is different from the area of each of the second battery devices.

[0009] The area of each of the plurality of first battery devices is smaller than the area of each of the second battery devices.

[0010] The area of each of the plurality of first battery devices is larger than the area of each of the second battery devices.

[0011] Each of the plurality of first battery devices includes a first bus bar plate including a first positive electrode terminal and a first negative electrode terminal connected to each of the plurality of first battery cells.

[0012] Each of the plurality of second battery devices includes a second bus bar plate including a second positive electrode terminal and a second negative electrode terminal connected to each of the plurality of second battery cells.

[0013] Each of the plurality of first battery devices includes a thermal separator interposed between the plurality of first battery cells.

[0014] The thermal separator includes any one of a ceramic material, a coated glass fiber, a calcium silicate, an aramid, and an expandable material.

[0015] The thermal separator includes a channel for the coolant to flow through.

[0016] The thermal separator is configured to release either a fire retarding material or a fire extinguishing agent when neighboring ones of the plurality of first battery cells are in a thermal runaway state.

[0017] Each of the plurality of second battery cells of each of the plurality of second battery devices is in contact with a neighboring one of the plurality of second battery cells.

[0018] Each of the plurality of second battery devices does not include a thermal separator.

[0019] Each of the plurality of first battery devices is spaced apart from each other with neighboring ones of the plurality of second battery devices interposed therebetween.

Advantages of the Invention

[0020] According to an exemplary embodiment of the present invention, a second battery device may be arranged between first battery devices each including a first battery cell containing nickel and manganese as a positive electrode active material. The second battery device includes a second battery cell containing phosphoric acid and iron as a positive electrode active material. In this case, since the second battery cell has relatively high fire stability, heat propagation within the battery pack can be delayed. Further, since the first battery device includes a plurality of thermal separators interposed between the first battery cells and the second battery device does not include a thermal separator, the energy efficiency of the battery pack can be improved.

[0021] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those with ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, the unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those with ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts that conform to the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the terms in order to explain his own invention in the best way.

[0024] Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. So, there can be various equivalents and modifications that can replace them at the time of this application.

[0025] In addition, in the description of the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

[0026] Embodiments of the present invention are provided to more fully explain the present invention to an ordinary technician. Therefore, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and ratios of the respective components do not fully reflect the actual sizes and ratios.

[0027] (First Embodiment) FIG. 1 is a plan view for explaining a battery pack according to an exemplary embodiment.

[0028] FIG. 2 is a cross-sectional view taken along the cutting line AA-AA' of FIG. 1.

[0029] FIG. 3 is a cross-sectional view taken along the cutting line BB-BB' of FIG. 1.

[0030] Referring to FIGS. 1 to 3, the battery pack 100 may include a housing 110, a plurality of first battery devices 120, a plurality of second battery devices 130, a center beam 141, a plurality of cross beams 143, a plurality of exhaust devices 150, and a plurality of bus bars 160. The battery pack 100 is the final form of a battery system mounted on mobility or the like.

[0031] The housing 110 may provide a space for mounting the plurality of first battery devices 120 and the plurality of second battery devices 130. The housing 110 may include a bottom plate 110B and a plurality of side walls 110W.

[0032] Two directions substantially parallel to the bottom plate 110B of the housing 110 are defined as the X direction and the Y direction, and a direction substantially perpendicular to the bottom plate 110B of the housing 110 is defined as the Z direction. Each of the X direction, the Y direction, and the Z direction may be substantially perpendicular to each other.

[0033] A plurality of first battery devices 120 and a plurality of second battery devices 130 can be arranged on the bottom plate 110B. The bottom plate 110B can support the plurality of first battery devices 120 and the plurality of second battery devices 130.

[0034] The plurality of side walls 110W can horizontally surround the plurality of first battery devices 120 and the plurality of second battery devices 130. The plurality of side walls 110W can protect the plurality of first battery devices 120 and the plurality of second battery devices 130.

[0035] Each of the plurality of first battery devices 120 and each of the plurality of second battery devices 130 can be of the module - less type. Each of the plurality of first battery devices 120 and the plurality of second battery devices 130 may not include a module frame.

[0036] Each of the plurality of first battery devices 120 can include a plurality of first battery cells 121 and a first bus bar plate 125. Each of the plurality of second battery devices 130 can include a plurality of second battery cells 131 and a second bus bar plate 135.

[0037] The plurality of first battery cells 121 and the plurality of second battery cells 131 are the basic units of a lithium - ion battery, that is, a secondary battery. Each of the plurality of first battery cells 121 and the plurality of second battery cells 131 includes an electrode assembly, an electrolyte, and a case. The plurality of first battery cells 121 and the plurality of second battery cells 131 are classified into lithium - ion batteries, lithium - ion polymer batteries, lithium polymer batteries, etc. according to the configuration of the electrode assembly and the electrolyte. Lithium - ion polymer batteries have less possibility of electrolyte leakage, are easy to manufacture, and are increasing their occupancy rate in secondary batteries.

[0038] Each of the plurality of first battery cells 121 and the plurality of second battery cells 131 can be any one of a cylindrical battery cell, a prismatic battery cell, and a pouch-type battery cell. The electrode assembly of the cylindrical battery cell is built into a cylindrical metal can. The electrode assembly of the prismatic battery cell is built into a prismatic metal can. The electrode assembly of the pouch-type battery cell is built into a pouch case including an aluminum laminate sheet.

[0039] The electrode assembly built into the battery case includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The electrode assembly is classified into a jelly roll type and a stack type according to the form of assembly. The jelly roll type is formed by winding a positive electrode, a negative electrode, and a separator interposed therebetween. The stack type includes a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators sequentially laminated therebetween.

[0040] The positive electrode may include a positive electrode current collector and a positive electrode active material. The negative electrode may include a negative electrode current collector and a negative electrode active material. The thickness of the positive electrode current collector can be in the range of about 3 μm to about 500 μm (Ranges from about 3 μm to about 500 μm). The positive electrode current collector may not induce a chemical change in the finally manufactured secondary battery and may have high conductivity. The positive electrode current collector may include, for example, stainless steel, aluminum, nickel, titanium, fired carbon, and aluminum. The positive electrode current collector can also include stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The surface of the positive electrode current collector may include a fine uneven structure for enhancing the adhesive force of the active material. The positive electrode current collector may have a shape such as a film, a sheet, a foil, a net, a porous material, a foam, a non-woven fabric, etc.

[0041] The thickness of the negative electrode current collector can be in the range of about 3 μm to about 500 μm. The negative electrode current collector may not induce chemical changes in the ultimately manufactured secondary battery and may have high conductivity. The negative electrode current collector may include copper, stainless steel, aluminum, nickel, titanium, fired carbon, and aluminum-cadmium alloy. The negative electrode current collector can also include stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The surface of the negative electrode current collector may include a fine uneven structure for enhancing the adhesive force of the active material. The negative electrode current collector may have shapes such as film, sheet, foil, net, porous, foam, non-woven fabric, etc.

[0042] The negative electrode active material may include carbon such as graphitizable carbon and graphite-based carbon. For example, the negative electrode active material may be Li x Fe2O3 (0 ≦ x ≦ 1), Li x WO2 (0 ≦ x ≦ 1), Sn x Me 1-x Me’ y O z (where Me is any one of Mn, Fe, Pb, and Ge, and Me’ is any one of Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, and halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), etc. The negative electrode active material may include, for example, lithium metal; lithium alloy; silicon-based alloy; tin-based alloy. The negative electrode active material may include, for example, metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5. The negative electrode active material may include, for example, conductive polymers such as polyacetylene; Li-Co-Ni-based materials, etc.

[0043] According to an exemplary embodiment, each of the plurality of first battery cells 121 may include a first positive electrode active material. According to an exemplary embodiment, each of the plurality of second battery cells 131 may include a second positive electrode active material. According to an exemplary embodiment, the first positive electrode active material may be different from the second positive electrode active material. Here, the first positive electrode active material and the second positive electrode active material are substances that can undergo an electrochemical reaction. The first positive electrode active material and the second positive electrode active material may be lithium transition metal oxides.

[0044] According to an exemplary embodiment, the first positive electrode active material may include a layered structure. According to an exemplary embodiment, the first positive electrode active material may include nickel and manganese. According to an exemplary embodiment, the first positive electrode active material may be, for example, a layered compound such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2) substituted with one or more transition metals; lithium manganese oxide substituted with one or more transition metals; a chemical formula LiNi 1-y M y O2 (where M is any one of Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn, and Ga, and 0.01 ≦ y ≦ 0.7) of lithium nickel-based oxides; Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, Li 1+z Ni 0.4 Mn 0.4 Co 0.2 O2 such as Li 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e (where -0.5 ≦ z ≦ 0.5, 0.1 ≦ b ≦ 0.8, 0.1 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.2, 0 ≦ e ≦ 0.2, b + c + d < 1, M is any one of Al, Mg, Cr, Ti, Si, and Y, and A is any one of F, P, and Cl) may include any one of lithium nickel cobalt manganese composite oxides represented thereby.

[0045] According to an exemplary embodiment, the second positive electrode active material may include an olivine structure. According to an exemplary embodiment, the second positive electrode active material may include iron and phosphorus. According to an exemplary embodiment, the second positive electrode active material has the chemical formula Li 1+x M 1-y M’ y PO4 -z X z (where M is a transition metal, more specifically, any one of Fe, Mn, Co, and Ni, M’ is any one of Al, Mg, and Ti, X is any one of F, S, and N, -0.5 ≦ x ≦ +0.5, 0 ≦ y ≦ 0.5, and 0 ≦ z ≦ 0.1), and may include an olivine-based lithium metal phosphate represented thereby.

[0046] According to an exemplary embodiment, the energy density of each of the plurality of first battery cells 121 may be even greater than the energy density of each of the plurality of second battery cells 131. According to an exemplary embodiment, the safety and stability of each of the plurality of second battery cells 131 may be even higher than the safety and stability of each of the plurality of first battery cells 121. According to an exemplary embodiment, the lifespan of each of the plurality of first battery cells 121 may be even shorter than the lifespan of each of the plurality of second battery cells 131.

[0047] The second positive electrode active material having an olivine structure has a lattice structure in which hexahedrons in crystal form are organically connected to each other, and thus is superior in lifespan and fire stability compared to the first positive electrode active material. On the other hand, the first positive electrode active material has a high energy density compared to the second positive electrode active material, and particularly has excellent low-temperature performance compared to the second positive electrode active material.

[0048] Each of the plurality of first battery cells 121 may include a first positive electrode tab and a first negative electrode tab. Each of the plurality of first battery cells 121 may further include a first positive electrode lead and a first negative electrode lead for connection to the outside. For each of the plurality of first battery cells 121, the first negative electrode lead may be connected to the first positive electrode lead of a subsequent first battery cell 121. For each of the plurality of first battery cells 121, the first negative electrode lead may be welded to the first positive electrode lead of a subsequent first battery cell 121. Thereby, the plurality of first battery cells 121 may be connected in series, and each of the plurality of first battery devices 120 may be configured to output a high voltage.

[0049] Each of the plurality of second battery cells 131 may include a second positive electrode tab and a second negative electrode tab. Each of the plurality of second battery cells 131 may further include a second positive electrode lead and a second negative electrode lead for connection to the outside. For each of the plurality of second battery cells 131, the second negative electrode lead may be connected to the second positive electrode lead of a subsequent second battery cell 131. For each of the plurality of second battery cells 131, the second negative electrode lead may be welded to the second positive electrode lead of a subsequent second battery cell 131. Thereby, the plurality of second battery cells 131 may be connected in series, and each of the plurality of second battery devices 130 may be configured to output a high voltage.

[0050] The first bus bar plate 125 may include a first positive electrode terminal and a first negative electrode terminal. The first positive electrode terminal and the first negative electrode terminal may have a rod shape (or a rod shape including a bent portion) like a bus bar, but are not limited thereto. The first positive electrode terminal may be connected to the first positive electrode lead of the leading one among the plurality of first battery cells 121 connected in series, and the first negative electrode terminal may be connected to the first negative electrode lead of the last one among the plurality of first battery cells 121 connected in series.

[0051] Each of the plurality of first battery devices 120 may include one first bus bar plate 125. The plurality of first battery cells 121 of each of the plurality of first battery devices 120 may be connected to the first bus bar plate 125 and may operate integrally.

[0052] The second bus bar plate 135 may include a second positive terminal and a second negative terminal. The second positive terminal and the second negative terminal may have a rod shape like a bus bar, but are not limited thereto. The second positive terminal may be connected to the second positive lead of the previous one of the plurality of second battery cells 131 connected in series, and the second negative terminal may be connected to the second negative lead of the last one of the plurality of second battery cells 131 connected in series.

[0053] Each of the plurality of second battery devices 130 may include one second bus bar plate 135. The plurality of second battery cells 131 of each of the plurality of second battery devices 130 may be connected to the second bus bar plate 135 and may operate integrally.

[0054] According to an exemplary embodiment, each of the plurality of first battery devices 120 may further include a plurality of thermal separators 122. The plurality of thermal separators 122 may be interposed between the plurality of first battery cells 121. Thereby, some of the plurality of first battery devices 120 may be in contact with the plurality of thermal separators 122.

[0055] According to an exemplary embodiment, the plurality of thermal separators 122 may delay or prevent the propagation of a thermal runaway event generated in one group to other groups by dividing the plurality of first battery cells 121 into two or more groups.

[0056] <Example of Thermal Barrier>

[0057] According to an exemplary embodiment, the plurality of thermal separators 122 can be a thermal barrier. According to an exemplary embodiment, each of the plurality of thermal separators 122 can have a high melting temperature. According to an exemplary embodiment, each of the plurality of thermal separators 122 can have a low thermal conductivity.

[0058] According to an exemplary embodiment, the melting temperature of each of the plurality of thermal separators 122 can be about 300 °C or higher. According to an exemplary embodiment, the melting temperature of each of the plurality of thermal separators 122 can be about 600 °C or higher. According to an exemplary embodiment, the melting temperature of each of the plurality of thermal separators 122 can be about 1000 °C or higher. According to an exemplary embodiment, the melting temperature of each of the plurality of thermal separators 122 can be 1500 °C or higher.

[0059] According to an exemplary embodiment, the thermal conductivity of each of the plurality of thermal separators 122 can be about 20 W / mK or less. According to an exemplary embodiment, the thermal conductivity of each of the plurality of thermal separators 122 can be about 1 W / mK or less. According to an exemplary embodiment, the thermal conductivity of each of the plurality of thermal separators 122 can be about 0.3 W / mK or less. The thermal conductivity of each of the plurality of thermal separators 122 described above can be measured at room temperature (about 25 °C).

[0060] According to an exemplary embodiment, each of the plurality of thermal separators 122 can include ceramic materials such as aluminum oxide (alumina), magnesium oxide (magnesia), silicon dioxide (silica), silicon nitride, silicon carbide (carborundum), and aluminum silicate. According to an exemplary embodiment, each of the plurality of thermal separators 122 can include any one of calcium-silicate, calcium-magnesium-silicate, and aramid. According to an exemplary embodiment, each of the plurality of thermal separators 122 can include, for example, glass fibers coated with any one of silicone, acrylic, vermiculite, graphite, and polytetrafluoroethylene (PTFE).

[0061] According to an exemplary embodiment, each of the plurality of thermal separators 122 may also contain an expandable material. Here, the expandable material is a material whose volume increases upon heat exposure. The expandable material can isolate the object to be protected (e.g., the plurality of first battery cells 121) from a fire source (e.g., the battery cell 121 in which a thermal runaway event has occurred) due to the expansion of its volume. Fire extinguishing by the expandable material is generally referred to as passive fire extinguishing, and typical examples of the expandable material are silicone and acrylic.

[0062] <Examples of the cooling member>

[0063] According to an exemplary embodiment, in addition to physically and thermally separating the group of the plurality of first battery cells 121, each of the plurality of thermal separators 122 may include a fluid circulation system for extracting or absorbing heat from the plurality of first battery cells 121, such as a cooling plate. According to an exemplary embodiment, each of the plurality of thermal separators 122 may include channels for a fluid (i.e., a coolant), such as water or a glycol-water mixture, to flow through.

[0064] <Examples of the fire extinguishing member>

[0065] According to an exemplary embodiment, each of the plurality of thermal separators 122 may be configured to release either a fire retarding material or a fire extinguishing agent when a thermal runaway event occurs in an adjacent one of the plurality of first battery cells.

[0066] Here, a fire extinguishing agent is a substance that has a fire extinguishing effect, that is, preferably a combustion suppressing effect, and / or prevents the occurrence of a fire. The fire extinguishing effect is an effect of preventing a fire, which means an effect that can suppress or weaken the continuation of an already occurring fire or the occurrence of a new fire. A fire extinguishing agent is a substance that isolates chemical reactants necessary for the continuation of a fire from the ignition source or suppresses chemical reactions necessary for ignition or the continuation of a fire. A fire extinguishing agent may preferably contain a fire extinguishing additive and a solvent (or a carrier substance).

[0067] As an example, the fire extinguishing agent may contain carbon dioxide, nitrogen, and argon. As another example, the fire extinguishing agent may contain any one of fluoroform, haloform, halocarbon, heptafluoropropane, bromotrifluoromethane, and bromochlorodifluoromethane.

[0068] In FIG. 2, four first battery cells 121 are shown to form one group, and the above group is shown to be alternately arranged with a plurality of thermal separators 122, but this is for illustration purposes and does not limit the technical idea of the present invention in any sense. The plurality of first battery cells 121 can be grouped into any number, and the number of first battery cells 121 included in each group can also be different from each other.

[0069] According to an exemplary embodiment, each of the plurality of second battery devices 130 may not include a thermal separator. According to an exemplary embodiment, each of the plurality of second battery cells 131 may be in contact with an adjacent one of the plurality of second battery cells 131. According to an exemplary embodiment, each of the plurality of second battery cells 131 may be separated from the plurality of thermal separators 122. According to an exemplary embodiment, each of the plurality of second battery cells 131 may not be in contact with the plurality of thermal separators 122.

[0070] Although not explicitly shown, a metal strap and a TIM (Thermal Interface Material) may be further interposed between the plurality of first battery cells 121 and the bottom plate 110B, between the plurality of thermal separators 122 and the bottom plate 110B, and between the plurality of second battery cells 131 and the bottom plate 110B. Also, a sheet containing an insulating material may be further disposed on the upper surfaces of the plurality of first battery cells 121, the upper surfaces of the plurality of thermal separators 122, and the upper surfaces of the plurality of second battery cells 131.

[0071] According to an exemplary embodiment, each of the plurality of first battery devices 120 may further include a first end plate that covers the first bus bar plate 125. According to an exemplary embodiment, each of the plurality of second battery devices 130 may further include a second end plate that covers the second bus bar plate 135.

[0072] The plurality of first battery devices 120 and the plurality of second battery devices 130 may be alternately arranged along the X direction. A plurality of second battery devices 130 may be interposed between adjacent ones of the plurality of first battery devices 120. The plurality of first battery devices 120 and the plurality of second battery devices 130 may be alternately arranged along the Y direction. In FIG. 1, the number of the plurality of first battery devices 120 and the plurality of second battery devices 130 arranged in the X direction is three, and the number of the plurality of first battery devices 120 and the plurality of second battery devices 130 arranged in the Y direction is two. Therefore, such an arrangement of the plurality of first battery devices 120 and the plurality of second battery devices 130 can be said to be a 3*2 arrangement.

[0073] A person of ordinary skill in the art can easily arrive at a plurality of first battery devices 120 and a plurality of second battery devices 130 arranged in M*N (where M and N are each integers of 2 or more) based on what is described herein.

[0074] According to an exemplary embodiment, in the X direction, corresponding ones of the plurality of second battery devices 130 may be arranged between two adjacent ones of the plurality of first battery devices 120. According to an exemplary embodiment, in the X direction, corresponding ones of the plurality of first battery devices 120 may be arranged between two adjacent ones of the plurality of second battery devices 130. According to an exemplary embodiment, in the Y direction, corresponding ones of the plurality of second battery devices 130 may be arranged between two adjacent ones of the plurality of first battery devices 120. According to an exemplary embodiment, in the Y direction, corresponding ones of the plurality of first battery devices 120 may be arranged between two adjacent ones of the plurality of second battery devices 130.

[0075] According to an exemplary embodiment, each of the plurality of first battery devices 120 may face either the side wall 110W or any one of the plurality of second battery devices 130. Each of the plurality of first battery devices 120 may not face another first battery device 120.

[0076] According to an exemplary embodiment, each of the plurality of second battery devices 130 may face either the side wall 110W or any one of the plurality of first battery devices 120. Each of the plurality of second battery devices 130 may not face another second battery device 130.

[0077] A plurality of exhaust devices 150 may be coupled to any one of the side walls 110W. The side wall 110W coupled to the plurality of exhaust devices 150 may include a ventilation hole. The ventilation hole may be configured to provide a path for discharging gas and heat inside the battery pack 100.

[0078] The plurality of exhaust devices 150 may be configured to delay thermal propagation by discharging the high-temperature gas inside the battery pack 100 to the outside when at least one of the plurality of first battery devices 120 and the plurality of second battery devices 130 is in a thermal runaway state.

[0079] Here, the thermal runaway of the plurality of first battery devices 120 and the plurality of second battery devices 130 is a state in which the temperature changes of the plurality of first battery devices 120 and the plurality of second battery devices 130 further accelerate the temperature changes, which is an uncontrollable positive feedback. The plurality of first battery devices 120 and the plurality of second battery devices 130 in the thermal runaway state show a rapid temperature rise and discharge a large amount of high-pressure gas and combustion residues.

[0080] The center beam 141 and the plurality of cross beams 143 can isolate the elements mounted on the housing 110 from each other. Thereby, the center beam 141 and the plurality of cross beams 143 can protect the plurality of first battery devices 120 and the plurality of second battery devices 130 and at the same time prevent unnecessary short circuits between them.

[0081] The center beam 141 may extend between a pair of opposing side walls 110W. The center beam 141 may extend in the X direction. The center beam 141 may contact either one of the pair of opposing side walls 110W. The center beam 141 can isolate the plurality of first battery devices 120 from the plurality of second battery devices 130. The center beam 141 may be interposed between the plurality of first battery devices 120 and the plurality of second battery devices 130.

[0082] According to an exemplary embodiment, the plurality of cross beams 143 may extend in a direction perpendicular to the center beam 141 (e.g., the Y direction). According to an exemplary embodiment, the plurality of cross beams 143 may extend between the center beam 141 and the side wall 110W. According to an exemplary embodiment, the plurality of cross beams 143 may be in contact with the center beam 141 and the side wall 110W. The plurality of cross beams 143 may isolate the plurality of first battery devices 120 from the plurality of second battery devices 130. The plurality of cross beams 143 may be interposed between the plurality of first battery devices 120 and the plurality of second battery devices 130.

[0083] The arrangement of the center beam 141 and the cross beam 143 disclosed in FIG. 1, and thus the arrangement of the plurality of first battery devices 120 and the plurality of second battery devices 130, are non-limiting examples and do not limit the technical idea of the present invention in any sense. A person of ordinary skill in the art can easily arrive at a battery pack including various arrangements and numbers of center beams, cross beams, first battery devices, and second battery devices based on what is described herein.

[0084] The battery pack 100 may further include electrical components. The electrical components may be mounted on the housing 110. The electrical components may be arranged between the side wall 110W where the exhaust device 150 is installed and the plurality of first battery devices 120 and the plurality of second battery devices 130. The electrical components may include any electronic elements necessary to drive the battery pack 100.

[0085] The electrical component may include, for example, a BMS (Battery Management System). The BMS may be configured to perform monitoring, balancing, and control of the battery pack 100. The monitoring of the battery pack 100 may include measurement of the voltage and current of specific nodes inside the plurality of first battery devices 120 and the plurality of second battery devices 130, and measurement of the temperature at a set position inside the battery pack 100. The battery pack 100 may include measuring instruments for measuring the above-mentioned voltage, current, and temperature.

[0086] The balancing of the battery pack 100 is an operation to reduce the deviation between the plurality of first battery devices 120 and the plurality of second battery devices 130. The control of the battery pack 100 includes preventing the occurrence of overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing shortening of the respective lifetimes of the plurality of first battery devices 120 and the plurality of second battery devices 130.

[0087] The electrical component may further include a cooling device, a PRA (Power Relay Assembly), a safety plug, etc. The cooling device may include a cooling fan. The cooling fan may prevent overheating of each of the plurality of first battery devices 120 and the plurality of second battery devices 130 by circulating the air inside the battery pack 100. The PRA may be configured to supply or cut off the power of the high-voltage battery to an external load (for example, the motor of a vehicle). The PRA can protect the plurality of first battery devices 120, the plurality of second battery devices 130, and the external load (for example, the motor of a vehicle) by cutting off the power supply to the external load (for example, the motor of a vehicle) in a situation where an abnormal voltage such as a voltage surge occurs.

[0088] A plurality of bus bars 160 can electrically connect a plurality of first battery devices 120 and a plurality of second battery devices 130. The plurality of bus bars 160 can be connected to the first positive terminal and the first negative terminal of the first bus bar plate 125, and the second positive terminal and the second negative terminal of the second bus bar plate 135.

[0089] With the plurality of bus bars 160, each of the plurality of first battery devices 120 can be connected to two adjacent ones of the plurality of second battery devices 130. With the plurality of bus bars 160, each of the plurality of second battery devices 130 can be electrically connected to two adjacent ones of the plurality of first battery devices 120. With the plurality of bus bars 160, the plurality of first battery devices 120 and the plurality of second battery devices 130 can be connected in series, whereby the battery pack 100 can draw a high voltage externally.

[0090] The battery pack 100 may further include a lead plate coupled to the housing 110. The lead plate can cover elements mounted inside the battery pack 100 such as the plurality of first battery devices 120, the plurality of second battery devices 130, and electrical components. The lead plate can be fixed to the battery pack 100 by mechanical coupling means such as bolts, for example.

[0091] (Second Embodiment) FIG. 4 is a plan view for explaining a battery pack 100a according to an exemplary embodiment.

[0092] Referring to FIG. 4, the battery pack 100a may include a housing 110, a plurality of first battery devices 120a, a plurality of second battery devices 130a, a center beam 141, a plurality of cross beams 143, a plurality of exhaust devices 150, and a plurality of bus bars 160.

[0093] The housing 110, the center beam 141, the plurality of cross beams 143, the plurality of exhaust devices 150, and the plurality of bus bars 160 are substantially the same as those described with reference to FIGS. 1 to 3, and thus redundant descriptions thereof are omitted.

[0094] The plurality of first battery devices 120a may include a plurality of first battery cells 121 (see FIG. 2), a thermal separator 122 (see FIG. 2), and a first bus bar plate 125a. The plurality of second battery devices 130a may include a plurality of second battery cells 131 (see FIG. 3) and a first bus bar plate 125a. The plurality of second battery devices 130a may not include a thermal separator.

[0095] According to an exemplary embodiment, the plurality of first battery devices 120a and the plurality of second battery devices 130a are substantially the same as the plurality of first battery devices 120a and the plurality of second battery devices 130a, except for size.

[0096] According to an exemplary embodiment, the respective horizontal areas of the plurality of first battery devices 120a may be different from the respective horizontal areas of the plurality of second battery devices 130a. According to an exemplary embodiment, the respective horizontal areas of the plurality of first battery devices 120a may be even smaller than the respective horizontal areas of the plurality of second battery devices 130a.

[0097] According to an exemplary embodiment, by providing the plurality of second battery devices 130a having a horizontal area larger than the respective horizontal areas of the plurality of first battery devices 120a, the isolation between the plurality of first battery devices 120a can be ensured. Thereby, the safety of the battery pack 100a can be improved.

[0098] (Third Embodiment) FIG. 5 is a plan view for explaining a battery pack 100b according to an exemplary embodiment.

[0099] Referring to FIG. 5, the battery pack 100b may include a housing 110, a plurality of first battery devices 120b, a plurality of second battery devices 130b, a center beam 141, a plurality of cross beams 143, a plurality of exhaust devices 150, and a plurality of bus bars 160.

[0100] The housing 110, the center beam 141, the plurality of cross beams 143, the plurality of exhaust devices 150, and the plurality of bus bars 160 are substantially the same as those described with reference to FIGS. 1 to 3, and thus redundant descriptions thereof are omitted.

[0101] The plurality of first battery devices 120b may include a plurality of first battery cells 121 (see FIG. 2), a thermal separator 122 (see FIG. 2), and a first bus bar plate 125b. The plurality of second battery devices 130b may include a plurality of second battery cells 131 (see FIG. 3) and a first bus bar plate 125b. The plurality of second battery devices 130b may not include a thermal separator.

[0102] According to an exemplary embodiment, the plurality of first battery devices 120b and the plurality of second battery devices 130b are substantially the same as the plurality of first battery devices 120b and the plurality of second battery devices 130b, except for size.

[0103] According to an exemplary embodiment, the respective horizontal areas of the plurality of first battery devices 120b may be different from the respective horizontal areas of the plurality of second battery devices 130b. According to an exemplary embodiment, the respective horizontal areas of the plurality of first battery devices 120b may be even larger than the respective horizontal areas of the plurality of second battery devices 130b.

[0104] According to an exemplary embodiment, by arranging a plurality of second battery devices 130b between a plurality of first battery devices 120b, the stability of the battery pack 100b can be enhanced. At the same time, by providing a plurality of first battery devices 120b having a horizontal area larger than the horizontal area of each of the plurality of second battery devices 130b, the energy density of the battery pack 100b can be improved.

[0105] As described above, the present invention has been described in more detail through the drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention. Therefore, there may be various equivalents and modifications that can replace them at the time of this application.

Description of Reference Numerals

[0106] 100, 100a, 100b Battery Pack 110 Housing 110B Bottom Plate 110W Side Wall 120, 120a, 120b First Battery Device 121 First Battery Cell 122 Thermal Separator 125, 125a, 125b First Busbar Plate 130, 130a, 130b Second Battery Device 131 Second Battery Cell 135 Second Busbar Plate 141 Center Beam 143 Cross Beam 150 Exhaust Device 160 Busbar

Claims

1. A plurality of first battery devices mounted on a housing and spaced apart from each other, and a plurality of second battery devices mounted on the housing and interposed between the plurality of first battery devices, and each of the plurality of first battery devices includes a plurality of first battery cells including a first positive electrode active material, each of the plurality of second battery devices includes a plurality of second battery cells including a second positive electrode active material different from the first positive electrode active material, a battery pack.

2. The battery pack according to claim 1, wherein the first positive electrode active material includes nickel and manganese.

3. The battery pack according to claim 1, wherein the second positive electrode active material includes iron and phosphorus.

4. The battery pack according to claim 3, wherein the area of each of the plurality of first battery devices is different from the area of each of the second battery devices.

5. The battery pack according to claim 3, wherein the area of each of the plurality of first battery devices is smaller than the area of each of the second battery devices.

6. The battery pack according to claim 3, wherein the area of each of the plurality of first battery devices is larger than the area of each of the second battery devices.

7. each of the plurality of first battery devices includes a first bus bar plate including a first positive electrode terminal and a first negative electrode terminal connected to each of the plurality of first battery cells, and each of the plurality of second battery devices includes a second bus bar plate including a second positive electrode terminal and a second negative electrode terminal connected to each of the plurality of second battery cells, the battery pack according to claim 1.

8. The battery pack according to claim 1, wherein each of the plurality of first battery devices includes a thermal separator interposed between the plurality of first battery cells.

9. The battery pack according to claim 8, wherein the thermal separator includes any one of a ceramic material, a coated glass fiber, a calcium silicate, an aramid, and an expandable material.

10. The battery pack according to claim 8, wherein the thermal separator includes a channel for a coolant to flow through.

11. The battery pack according to claim 8, wherein the thermal separator is configured to release any one of a fire suppression substance and a fire extinguishing agent when some of the plurality of first battery cells are in a thermal runaway state.

12. The battery pack according to claim 1, wherein each of the plurality of second battery cells of each of the plurality of second battery devices is in contact with an adjacent one of the plurality of second battery cells.

13. The battery pack according to claim 1, wherein each of the plurality of first battery devices is spaced apart from each other with an adjacent one of the plurality of second battery devices therebetween.

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