Mitigating Thermal Runaway Propagation in Lithium-Ion Battery Packs

Abstract

The lithium-ion battery assembly includes a plurality of spaced-apart, generally parallel-arranged battery cells, each extending along a central axis and having a first end with a negative terminal and a second end with a positive terminal. The assembly includes a first capture plate and a second capture plate, at least the first capture plate defining capture plate openings corresponding to the plurality of battery cells, the first capture plate being spaced apart from and oriented generally parallel to the second capture plate. Each of the plurality of battery cells extends between the first and second capture plates and is positioned coaxially with one of the capture plate openings in the first capture plate. The assembly optionally includes a body between the capture plates, the body defining a gap for each battery cell.

Description

[Technical Field]

[0001]

[0001] This disclosure relates generally to battery technology, and more particularly to mitigating thermal runaway propagation in battery packs. [Background technology]

[0002]

[0002] A lithium-ion battery or Li-ion battery is a type of rechargeable battery that has a high energy density and generally no memory effect. Batteries can be used individually or together in groups packaged into battery packs. Lithium-ion batteries and battery packs are commonly used, for example, in portable electronic devices (e.g., cell phones), electric vehicles, and consumer cordless power tools. Lithium-ion batteries are also used in military and aerospace applications.

[0003]

[0003] Lithium-ion cells provide electrical current when lithium ions move from the negative electrode to the positive electrode through an electrolyte. Lithium ions move in the reverse direction when the cell is charged. In some examples, the positive electrode includes lithium cobalt oxide (LiCoO2), lithium iron phosphate (LiFePO4), or lithium manganese oxide (LiMn2O4 or Li2MnO3). The negative electrode typically includes graphite. The electrolyte may be a mixture of an organic carbonate and a lithium ion complex. For example, the electrolyte may include ethylene carbonate or diethyl carbonate.

[0004] Lithium-ion cells can have a variety of form factors, including cylinders, flats, pouches, and rigid plastic cases with threaded terminals. In one example, a cylindrical lithium-ion cell typically includes a metal container that provides the cell's primary structure and functions as the negative electrode. The container can be made of aluminum or steel. The electrode assembly, or "jelly roll," includes current collector sheets separated by a porous membrane rolled into a cylindrical shape. The electrode assembly is placed within the container and functions as the electrical energy storage component. The current collector may include copper or aluminum foil coated with an active material, and the porous membrane can be polymeric or ceramic. An electrolyte fills the remaining volume of the container and permeates the active material on the current collector and separator. A cap, which functions as the positive electrode, is crimped into place on top of the can, enclosing the electrode assembly within the container.

[0005]

[0005] Lithium-ion battery cells may also include a positive temperature coefficient disk ("PTC disk") and / or a current interrupt device ("CID") between the electrode assembly and the cap as a protection device. For example, a PTC disk is made from a material that exhibits increased electrical resistance at high temperatures, thereby reducing current flow at higher temperatures. When the pressure inside the cell exceeds a threshold, a CID device, such as a pressure plate, may rupture, severing the electrical connection and venting gas from the cell. Summary of the Invention

[0006]

[0006] The present disclosure relates to methods and battery assemblies configured to mitigate or inhibit the propagation of thermal runaway. In one example, the battery assembly is a cell module or a battery pack, such as a lithium-ion battery pack. Numerous embodiments will be recognized in light of this disclosure. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view of a lithium-ion battery cell according to an embodiment of the present disclosure. [Figure 2A]

[0008] FIG. 2A is a top view of a battery pack or cell module having battery cells arranged in a rectangular grid, according to an embodiment of the present disclosure. [Figure 2B]

[0009] FIG. 2B is a top view of a battery pack or cell module having battery cells arranged in a triangular grid, according to an embodiment of the present disclosure. [Figure 3]

[0010] 1 is a cross-sectional view of a portion of a battery pack showing a single battery cell, according to an embodiment of the present disclosure. [Figure 4A]

[0011] FIG. 4A is a perspective view of a battery cell having a layer of fire-resistant material around the container sidewall, according to an embodiment of the present disclosure. [Figure 4B]

[0012] FIG. 4B is a perspective view of a battery cell having a fire-resistant material around the edges of the battery cell according to an embodiment of the present disclosure. [Figure 4C]

[0013] FIG. 4C is a perspective view of a battery cell having a fire-resistant material and sleeve around the container according to an embodiment of the present disclosure. [Figure 5]

[0014] FIG. 5 is a cross-sectional view of a battery cell of a battery pack showing emissions from the positive terminal during a thermal runaway event, according to an embodiment of the present disclosure. [Figure 6]

[0015] FIG. 6 is a partially exploded perspective view of a cell module including battery cells each having an end wrapped with a fire-resistant material and a layer of fire-resistant material around an assembly of battery cells according to an embodiment of the present disclosure. [Figure 7]

[0016] FIG. 7 is a partially exploded perspective view of a battery pack assembly according to an embodiment of the present disclosure. [Figure 8]

[0017] FIG. 8 is a cross-sectional view of a battery pack including cell modules spaced apart and physically separated from one another within a housing according to an embodiment of the present disclosure.

[0008]

[0018] The drawings depict various embodiments of the present disclosure for purposes of illustration only and are not necessarily drawn to scale. Numerous variations, configurations and other embodiments will become apparent from the following detailed description. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0019] Methods and structures are disclosed for mitigating the propagation of thermal runaway in battery packs, such as lithium-ion battery packs. According to some exemplary embodiments, the battery assembly is a cell module or battery pack that includes a plurality of battery cells arranged in a generally parallel, spaced-apart configuration. As part of the thermal management strategy, the battery cells are positioned to prevent direct contact between the battery cells and to avoid line-of-sight from one battery cell to another.

[0010]

[0020] In one example, each battery cell extends along a central axis and has a first end with a negative terminal and a second end with a positive terminal. Each battery cell is housed within a gap defined within a body, sometimes referred to as a honeycomb. A first capture plate is on one side of the body, and a second capture plate is on the opposite side of the body. At least the first capture plate defines capture plate openings corresponding to the battery cells, such that each of the plurality of battery cells extends between the first and second capture plates and is coaxially positioned with one of the capture plate openings. For example, the body extends the entire axial length of the battery cells such that any waste from the battery cells is directed axially away from the cells through the capture plate openings.

[0011]

[0021] In some embodiments of the present disclosure, the body can be made of a thermally conductive material, such as aluminum, and the body acts as a heat sink, for example, drawing heat away from a battery cell experiencing thermal runaway. In other embodiments of the present disclosure, the body can be made of a thermally insulating material, and acts to inhibit the spread of heat to adjacent battery cells during a thermal runaway event. Optionally, a fire-resistant or potting material can be placed within the capture plate openings to shield the ends of the battery cells from effluents emitted by nearby battery cells.

[0012]

[0022] Multiple cell modules, each having multiple battery cells as described above, can be assembled together within a battery pack housing. The battery cells are arranged and configured in a cell module to eliminate direct line of sight with other battery cells within the battery pack. In some embodiments of the present disclosure, each cell module is configured with the positive terminal of the battery cell facing outward toward the housing. The battery pack can optionally include one or more partitions of fire-resistant material that physically separate adjacent cell modules. Optionally, each cell module can be encased in fire-resistant material.

[0013]

[0023] This disclosure will be described with reference to lithium-ion battery cells and battery assemblies. However, it will be understood that the principles and structures disclosed herein can be applied to battery assemblies utilizing other chemistries. Numerous variations and embodiments will become apparent in light of this disclosure.

[0014] General Overview

[0024] Several significant issues remain regarding lithium-ion battery packs. One challenge for lithium-ion battery technology is thermal management. A continuing concern is the potential for thermal runaway during the use, handling, or transportation of lithium-ion batteries. Thermal runaway occurs when a series of self-sustaining exothermic side reactions leads to complete cell failure and, in some cases, fire and / or explosion. A battery cell that experiences thermal runaway can emit hot gases, flames, and high-velocity jets of molten particulate matter, known as effluent. Most lithium-ion batteries have the potential to experience thermal runaway due to the chemistry of lithium-ion technology. While significant progress has been made over time to improve cell performance (e.g., reducing capacity fade, increasing available power, etc.), challenges with thermal runaway and its propagation remain. For example, the materials and structure of individual battery cells or battery packs can result in localized hot spots or heating, which can lead to cell failure. Additionally, over-constraining battery cells can result in large pressure gradients that can lead to failure of mechanical components, such as plates and fasteners, surrounding the battery cell. Similarly, the lack of venting of emissions can result in the momentary formation of localized hot spots that can cause thermal runaway in nearby battery cells. Therefore, there is a need for structures and methodologies to mitigate the propagation of thermal runaway in lithium-ion battery packs.

[0015]

[0025] The present disclosure addresses this and other needs. According to some embodiments of the present disclosure, thermal runaway propagation can be mitigated or stopped entirely using an approach that considers multiple design factors, including: (i) the individual battery cell experiencing the thermal runaway, (ii) cells adjacent to the cell or cell module experiencing the thermal runaway, (iii) the battery cell packaging material, and (iv) the spatial and structural relationship of the battery cell or cell module to adjacent battery cells or cell modules experiencing the thermal runaway event.

[0016]

[0026] More specifically, as understood in light of the present disclosure, mitigating or stopping the propagation of thermal runaway involves controlling various aspects of the emissions, including controlling how the emissions exit the battery cell, directly controlling the path of the emissions and other objects in their path, and controlling the landing points of the emissions particles. For example, providing sufficient structure around the battery cell can be used to direct the emissions axially away from the cell module and adjacent battery cells.

[0017]

[0027] When thermal runaway occurs, the propagation of thermal runaway can be mitigated or stopped by considering the relationship between adjacent battery cells or cell modules. For example, battery cells adjacent to a thermal runaway event may enter thermal runaway if the bulk temperature of the battery cells exceeds the melting point (or threshold temperature) of the separator material between the anode and cathode. Such a condition may be referred to as a bulk heating failure. In one example, a bulk heating failure may occur when the temperature of the packaging material exceeds the cell's threshold temperature for a sufficient period of time to allow one or more battery cells to reach or exceed the threshold temperature.

[0018]

[0028] Bulk heating failure can be mitigated by careful selection of the packaging material for the battery cells, such as the material of the body (or "honeycomb") that houses the battery cells. In one exemplary embodiment of the present disclosure, the body can be made from a thermally conductive material such as aluminum or copper. The body can be configured to have sufficient thermal mass and thermal conductivity to conduct heat away from a thermal runaway event so that the bulk temperature does not exceed a threshold temperature. Alternatively, the body can be made from a thermal insulating material. In such an embodiment, the body material insulates the battery cells so that none of the battery cells adjacent to the thermal runaway event exceed a threshold temperature. When a thermal insulating material is used, the insulating material should be able to maintain its integrity (i.e., not melt) throughout the duration of the thermal runaway event.

[0019]

[0029] If a heat source raises the temperature of a portion of a battery cell above the melting point (or threshold temperature) of the separator material between the anode and cathode, battery cells adjacent to the thermal runaway event may also enter thermal runaway. This condition can be referred to as a localized heating failure. Localized heating failure can occur, for example, when a battery cell is exposed to direct contact with flames or effluent from a cell experiencing thermal runaway. In embodiments of the present disclosure, localized and bulk heating failures can be mitigated or stopped by encasing the battery cell in a flame-resistant or fire-resistant material that can withstand the flames and effluents, and / or by encapsulating or covering exposed battery cell ends with a high-temperature and flame-resistant material (or "potting material").

[0020]

[0030] The relationship between adjacent cell modules or adjacent battery cells can also be configured to mitigate or stop the propagation of thermal runaway. In some battery packs, individual lithium-ion battery cells are combined through a set of series and parallel connections. In some such embodiments, it may be impractical to connect all of the battery cells together in a single, one-layer slab. Thus, the battery pack may be divided into subsections or cell modules, each with several arrangements of series and parallel connections. The cell modules can be assembled into a battery pack. If a battery cell in any module goes into thermal runaway, it could pose an imminent threat to adjacent cell modules. To mitigate this propagation, the battery pack can be assembled to include one or more layers of flame-resistant or fire-resistant material, such as glass pack, fiberglass, metal mesh, alkaline earth silicate wool, or expanding tape. One such product is sold by Unifrax under the trademark FyreWrap®. In some such embodiments, adjacent cell modules wrapped in fire-resistant material can be separated by an air gap. In another exemplary embodiment, the fire-resistant material can be formed into a baffle that prevents line-of-sight between adjacent cell modules.

[0021]

[0031] According to some embodiments of the present disclosure, these various approaches can be used individually or together to mitigate or eliminate thermal runaway propagation within a battery pack assembly. Numerous variations and embodiments will become apparent in light of the present disclosure.

[0022]

[0032] As used in the discussion and claims herein, the term "about" indicates that the recited value may be varied somewhat as long as the variation does not result in process or device incompatibility. For example, for some elements, the term "about" may refer to a variation of +-0.1%, while for other elements, the term "about" may refer to a variation of +-1% or +-10%, or any point therein. Also, as used herein, terms defined in the singular are intended to include terms defined in the plural, and vice versa.

[0023]

[0033] Reference herein to any range of numerical values expressly includes each number encompassed by that range, including fractional and integer numbers. For illustrative purposes, reference herein to a range of "at least 50" or "at least about 50" includes integers such as 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractional numbers such as 50.1, 50.2, 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In further illustration, references herein to ranges of "less than 50" or "less than about 50" include integers such as 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and decimals such as 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc.

[0024]

[0034] As used herein, the terms "substantially" or "substantial" are equally applicable when used in a negative sense to refer to a complete or nearly complete lack of an action, feature, characteristic, state, structure, item, or result. For example, a surface that is "substantially" flat is completely flat or nearly flat so that the effect is the same as if it were completely flat.

[0025] architecture

[0035] Referring to FIG. 1 , a cross-sectional view illustrates a portion of a battery cell 100 having a cylindrical shape oriented along a central axis 101, according to an embodiment of the present disclosure. In this example, the battery cell 100 includes a container 110 enclosing a volume 111 sized to accommodate an electrode assembly 120 and an electrolyte 130. The electrode assembly 120 (also referred to as a "jelly roll") includes a first current collector 122, a second current collector 124, a first separator 126 a, and a second separator 126 b arranged in a layered stack 129, with the current collectors 122, 124 interleaved with the separator 126. The stack 129 is then wound into a cylindrical shape to form a spiral-wound electrode assembly 120, for example, as illustrated in FIG. 1 . The battery cell 100 can have any standard or non-standard dimensions, including diameters and lengths of 18 mm x 65 mm, 21 mm x 70 mm, and 26 mm x 65 mm, to name a few.

[0026]

[0036] In one example, the container 110 is made of a metal or other conductive material and has a container sidewall 110a extending axially between a closed first end 112 (e.g., a bottom end) and an open second end 114 (e.g., a top end). In some embodiments, the container 110 functions as the negative terminal 104 of the battery cell 100. Suitable materials for the container 110 include aluminum, aluminum alloys, and steel, among other conductive materials.

[0027]

[0037] In one example, the first current collector 122 includes a first electrode material and the second current collector 124 includes a second electrode material. According to some embodiments, the first electrode material may be selected as the anode material and the second electrode material may be selected as the cathode material, or vice versa.

[0028]

[0038] Examples of first electrode materials include aluminum (Al), lithium (Li), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), alloys of these elements, and intercalable carbon or graphite materials (lithiated carbon, LiTiO). 12 ), silicon (Si), tin (Sn), and any combination of these materials.

[0029]

[0039] In embodiments, the second electrode material is a compound of the formula (CF x ) n or (C2F) n where x is from about 0.5 to about 1.2 (also referred to as graphite fluoride, carbon monofluoride, and other terms). Other suitable materials for the second electrode material include copper sulfide (CuS), copper oxide (CuO), lead dioxide (PbO), iron sulfide (FeS), iron disulfide (FeS), pyrite, copper chloride (CuCl), silver chloride (AgCl), silver oxide (AgO, AgO), sulfur (S), bismuth oxide (BiO), copper bismuth oxide (CuBiO), cobalt oxide, vanadium oxide (VO), tungsten trioxide (WO), molybdenum trioxide (MoO), molybdenum disulfide (MoS), titanium disulfide (TiS), transition metal polysulfides, lithium metal oxides and sulfides (e.g., lithium cobalt and / or nickel oxide), lithium manganese oxide, lithium titanium sulfide (Li x TiS2), lithium iron sulfide (Li xFeS2), lithium iron phosphate (LiFePO4), lithium iron niobium phosphate (LiFeNbPO4), and mixtures of any of the foregoing materials.

[0030]

[0040] Each separator 126 can include one or more materials, such as insulating, impermeable, substantially impermeable, or microporous materials, selected from one or more of polypropylene, polyethylene, and combinations thereof. The material of each separator 126 can include fillers, such as oxides of aluminum, silicon, titanium, and combinations thereof. Each separator 126 can also be manufactured from microfibers, such as by meltblown nonwoven film technology. Each separator 126 can have a thickness of about 8 to about 30 microns or more. Each separator 126 can also have few or no pores. In one example, one or both separators 126 include pores with a pore size range of about 0.005 to about 5 microns, or a pore size range of about 0.005 to about 0.3 microns. Each separator 126 may have little or no porosity, or in some embodiments, may have a porosity ranging from about 30 to about 70 percent, preferably from about 35 to about 65 percent.

[0031]

[0041] The volume 111 within the container 110 that is not filled by the electrode assembly 120 (and any other components within the container 110) is occupied by a liquid electrolyte 130. The electrolyte 130 contacts the surfaces of the first current collector 122, the second current collector 124, and the separator 126. In some embodiments, the electrolyte 130 permeates the separator 126 and / or the active materials on the first current collector 122 and the second current collector 124. The electrolyte 130 can be any suitable electrolyte in liquid form, such as a solution of lithium hexafluorophosphate (LiPF6).

[0032]

[0042] The battery cell includes a cap 134 that is attached to the container 110 in any suitable manner, thereby closing the second end 114 of the container 110 and forming a liquid-tight volume 111 within the container 110. The cap 134 is electrically insulated from the container 110 by a gasket 136. The cap 134 may be configured as a terminal (e.g., a positive terminal) of the battery cell 100. In one example, the first current collector 122 is electrically connected to the container 110 and the second current collector 124 is electrically connected to the cap 134, or vice versa, such as by a tab, wire, physical contact, or other suitable electrical connector.

[0033]

[0043] The battery cell 100 optionally includes a suitable current interrupt device (CID) 140 between the cap 134 and the electrode assembly 120. In this example, the CID 140 includes a pressure disk 141 designed to rupture under excessive pressure within the battery cell 100, thereby cutting off the flow of current and venting gases through the second end 114 of the container 110. The CID 144 includes an electrical connector 143 (e.g., a plate or disk) in electrical contact with the first current collector 122 or the second current collector 124, and an optional additional electrical connector 142 (e.g., a wire or tab). During operation, when the battery cell 100 is connected by the container 110 and cap 134, electrons flow from one current collector to the other (e.g., from the first current collector 122 to the second current collector 124) to generate an electric current.

[0034]

[0044] The battery cell 100 optionally includes a positive temperature coefficient disk (PTC disk) 146 in the current path to the cap 134. For example, the PTC disk 146 is between the CID and the cap 134. The PTC disk 146 may be ceramic or other suitable material or combination of materials whose resistance increases with increasing temperature, as will be appreciated. The PTC disk 146 functions to reduce the current flow through the battery cell 100 during high temperatures. In some embodiments, the PTC disk 146 has a circular shape, and in other embodiments, the PTC disk 146 has an annular shape. Numerous variations and embodiments will become apparent in light of this disclosure.

[0035]

[0045] 2A and 2B, multiple battery cells 100 can be assembled into a battery pack 200, as shown here looking at the ends or terminals of the battery cells 100. Similarly, the battery cells 100 can be assembled into cell modules 150, and multiple cell modules are assembled to create the battery pack 200. The characteristics of the battery pack 200 described in these examples can be equally applied to the cell modules 150 according to some embodiments. Details of the battery pack 200 are described in more detail below.

[0036]

[0046] 2A-2B, the battery cells 100 each have a cylindrical shape, and adjacent battery cells 100 are oriented so that their central axes 101 (shown in FIG. 1) are generally parallel to each other and to the sidewalls 201 of the body 202. The ends or terminals of the battery cells 100 are arranged in a rectangular or triangular lattice or grid. In some embodiments, all of the positive terminals 102 face the same direction, as in FIG. 2B, while in other embodiments, some positive terminals 102 face in the opposite direction from other positive terminals 102, as in FIG. 2A. The battery pack 200 (or cell module 150) can include any number of battery cells 100, including 2, 3, 4, 8, 10, 20, 30, 50, 100, or any other number required for a particular voltage or application. Additionally, the overall shape of the battery pack 200, cell module 150, or other subset of the battery pack 200 can have any one of a variety of geometric shapes, including rectangular, hexagonal, triangular, irregular, or a combination of such shapes, as will be understood. The battery cells 100 can be arranged in a uniform or non-uniform rectangular lattice (e.g., a square lattice), a uniform or non-uniform hexagonal lattice, or a uniform or non-uniform triangular lattice, to name a few.

[0037]

[0047] As shown in FIG. 2B , for example, each battery cell 100 has at least three adjacent battery cells 100, with each adjacent battery cell 100 positioned the same or substantially the same distance D apart. For example, a battery cell 100 positioned at a vertex of a hexagon has three adjacent battery cells 100, all of which are spaced the same distance D from the vertex battery cell 100. In contrast, each battery cell 100 at the corner vertex 203 shown in FIG. 2A has, as will be understood, two adjacent battery cells 100 spaced a distance D1 apart and another battery cell 100 positioned diagonally at a distance D2 greater than D1. Regardless of the arrangement, the distance D between the outer surfaces of adjacent battery cells 100 (e.g., the container sidewall 110a) or the outer surface of the fire-resistant material 210 around the container 110 can be equal to or substantially equal to the thickness of the body 202 between adjacent gaps 204. This distance D can be at least 1 mm, at least 1.5 mm, at least 2 mm, at least 3 mm, at least 5 mm, at least 7 mm, at least 10 mm, 10 mm or less, 7 mm or less, 5 mm or less, 3 mm or less, 2 mm or less, 1.5 mm or less, 1 mm or less, or a range inclusive between any of these values.

[0038]

[0048] 3, a cross-sectional view shows a battery cell 100 as part of a battery pack 200, according to an embodiment of the present disclosure. The battery cells 100 are held within gaps 204 defined within a block or body 202. In some embodiments, the body 202 is referred to as honeycomb due to the structure of the interstitial material between adjacent gaps 204.

[0039]

[0049] In some embodiments, the body 202 is made of a thermally conductive material, such as aluminum. In such an approach, the body 202 has sufficient thermal mass to conduct heat away from battery cells 100 experiencing thermal runaway so that the temperature of adjacent battery cells 100 does not exceed a cell threshold temperature. As will be appreciated, suitable materials may depend on the size and configuration of each battery cell 100 and the distance between battery cells 100 within the battery pack 200 or cell module 150. Conversely, the material of the body 202 and / or parameters of the battery cells 100 within the battery pack 200, such as operating temperature, physical dimensions, current capacity, material, etc., may determine the minimum cell spacing.

[0040]

[0050] In other embodiments, the body 202 is made from a thermal insulating material so that adjacent battery cells 100 are sufficiently insulated from the heat of the battery cell 100 undergoing a thermal runaway event to avoid inducing thermal runaway in adjacent battery cells 100. Some examples of suitable materials include high temperature plastics such as a 30% glass-reinforced polyetherimide sold as Ultem™ 2300, a polyetheretherketone (PEEK) material sold by Ensinger as Tecapeek®, and a polyamideimide sold by Solvay as Torlon®.

[0041]

[0051] In some embodiments, each gap 204 in the body 202 has a shape that matches the shape of the battery cell 100, including any fire-resistant material 210 and / or sleeve 116 that may be around the battery cell 100. In this example, the gap 204 is cylindrical and accommodates the cylindrical shape of the battery cell 100 with one or more layers of fire-resistant material 210 wrapped around the battery cell 100. The gap 204 can be sized to fit snugly within the battery cell 100. The snug fit can enhance heat transfer between the battery cell 100 and the body 202 and can also provide structural support to the container 110 (shown in FIG. 1 ). In some embodiments, the body 202 extends at least the axial length of the battery cell 100. In this example, the body 202 extends axially beyond the positive terminal 102 and beyond the negative terminal 104. An annular gasket 117 in the gap 204 adjacent the battery cell 100 accounts for the difference in axial length of each terminal 102, 104 between the battery cell 100 and the surface of the body 202. The gasket 117 can be made from foam, plastic, rubber, metal, or other suitable material.

[0042]

[0052] In other embodiments, the gap 204 can have a cross-sectional shape that is different from the cross-sectional shape of the battery cell 100. For example, the gap 204 can have a hexagonal cross-sectional shape sized to snugly receive the cylindrical battery cell 100. Such an embodiment can direct effluent 300 axially away from the battery cell 100 through the space between the body 202 and the battery cell 100 along the vertices of the hexagonal shape. If the container 110 is breached along the container sidewall 110a or the first end 112, gas can escape along a path between the body 202 and the container sidewall 110a, reducing the pressure within the battery cell 100. In doing so, the escaping gas is directed axially away from the positive terminal 102 and can simultaneously be vented.

[0043]

[0053] The capture plate 118 contacts each side of the body 202 and defines a capture plate opening 118a for each terminal 102, 104 of the battery cell 100. Generally, the size of each capture plate opening 118a is smaller than the diameter of the battery cell 100 so as to prevent the battery cell 100 from escaping from the body 202. In some embodiments, the capture plate opening 118a is about 80 to 90%, or about 85%, of the diameter of the battery cell 100. This size of the capture plate opening 118a is large enough to allow the battery cell 100 to vent from the positive terminal 102 during a thermal runaway event without being overly restrictive, yet small enough to effectively retain the battery cell 100 within the body 202.

[0044]

[0054] In some embodiments, one or both capture plates 118 are made of a thermally conductive material such as aluminum, copper, steel, alloys of these materials, or other metals. Thus, the capture plates 118 can function as a heat sink, conducting heat away from one or both ends (e.g., terminals 102 or 104) of the battery cell 100. In one example, the gasket 117 is omitted at the negative terminal 104, such that the first end 112 (e.g., the bottom end) directly contacts the capture plate 118. In some such embodiments, the capture plate 118 directly contacts the negative terminal 104 and functions as a heat sink, conducting heat away from the ends of the battery cell 100.

[0045]

[0055] A fire-resistant material or potting material 119 can be used to fill the space left open by the annular gasket 117 and capture plate opening 118a at the positive terminal 102. As shown in this example, the outer surface of the potting material 119 is substantially flush with the outermost surface of the capture plate 118. In other embodiments, the potting material 119 can be flush with the bus bar 160 or flush with a location between the capture plate 118 and the bus bar 160. The potting material can be a high-temperature foam, polymer, flame-retardant material, or other suitable material that protects the exposed ends of the battery cell 100 from emissions released by other cells during a thermal runaway event, while not inhibiting the venting or exhaust function of the battery cell 100 during a thermal runaway event.

[0046]

[0056] Optionally, potting material 119 can be disposed between the first end 112 (e.g., the negative terminal 104) of the battery cell 100 and the spacer 164 or the cold plate 162. For example, neither the cold plate 162 nor the spacer 164 adjacent the first end 112 define an opening, and thus, potting material 119 can optionally be used to fill any open space between the first end 112 of the battery cell 100 and the spacer 164. In other embodiments, this open space is left unfilled so that the first end 112 of the battery cell 100 can vent, reducing pressure within the battery cell 100.

[0047]

[0057] In some embodiments, at each of the first end 112 and second end 114 of the battery cell 100, the spacer 164 abuts the outer surface of the bus bar 160, and the cold plate 162 abuts the outer surface of the spacer 164. At the second end 114, the spacer 164 defines a spacer opening 164a, and the cold plate 162 defines a cold plate opening 162A, each of which is generally concentric with and positioned above the second end 114 of the battery cell 100 to allow effluent to escape, for example, in the event of a thermal runaway event. In contrast, according to some embodiments, the spacer 164 and cold plate 162 adjacent to the first end 112 are continuous and do not define openings. The spacer 164 may be a thermally and electrically insulating material, such as plastic. In such embodiments, the spacer 164 electrically insulates the cold plate 162 from the bus bar 160. The cold plate may be a metal, a composite material, or another structurally rigid material.

[0048]

[0058] According to some embodiments, all or part of the exterior of the battery cell 100, except for allowing electrical connection to the positive terminal 102 and the negative terminal 104, can be wrapped with a fire-resistant material 210. The fire-resistant material 210 can provide thermal and / or electrical insulation for the battery cell 100. Examples of fire-resistant material 210 include mica tape and the meta-aramid material (also known as polycarbonamide) manufactured by Dow Chemical and sold as Nomex® tape. In most cases, one or more layers of the fire-resistant material 210 are tightly wrapped around the container sidewall 110a, and the wrapped battery cell 100 is placed within the body 202 with the fire-resistant material 210 in contact with the body 202.

[0049]

[0059] In one example, as shown in FIG. 4A , the fire-resistant material 210 is around the cylindrical container side wall 110a but does not cover the positive terminal 102 or the negative terminal 104. In another example, as shown in FIG. 4B , the fire-resistant material 210 is around only the end portions of the container side wall 110a adjacent to the positive terminal 102 and adjacent to the negative terminal 104 but does not cover the terminals 102, 104. In one such embodiment, the middle portion of the container 110 is devoid of the fire-resistant material 210. In yet another example, as shown in FIG. 4C , the fire-resistant material 210 can be wrapped around the ends of the container 110, with the middle portion of the container side wall 110a having a reduced thickness of the fire-resistant material 210 or being devoid of the fire-resistant material 210. In some such embodiments, the fire-resistant material 210 is only around the end portions of the battery cell 100. Optionally, sleeve 116 is around vessel sidewall 110a between refractory material 210 and vessel 110 to provide structural support to vessel 110, preventing sidewall failure, for example, during a thermal runaway event. In an embodiment, sleeve 116 is made from stainless steel or a similar material that provides structural support to vessel 110. Sleeve 116 can be used, for example, when vessel 110 does not contact or otherwise receive structural support from body 202.

[0050]

[0060] 5 illustrates a cross-sectional view of a portion of the battery pack 200 of FIG. 4 during an example of a thermal runaway event of the battery cell 100, according to an embodiment. Here, the temperature of the battery cell 100 exceeds a threshold temperature, resulting in failure of the current interrupt device 144 (shown in FIG. 1 ), and effluent 300 is emitted from the positive terminal 102 at the second end 114. In some embodiments, the effluent 300 can pass through the potting material 119 (shown in FIG. 4 ) such that the potting material 119 remains partially intact adjacent the second end 114. In other embodiments, the effluent 300 may remove or destroy all or a portion of the potting material 119.

[0051]

[0061] A passageway is defined from the second end 114 to the surroundings through the openings in the annular gasket 117, the capture plate opening 118a, the cold plate opening 162A, and the spacer opening 164a, directing the effluent 300 axially away from the second end 114. The container sidewall 110a is structurally supported by the body 202, which is in intimate contact with or in close contact with the battery cells 100 or the fire-resistant material 210 surrounding the battery cells 100. While the first end 112 may vent to a limited extent toward the spacer 164 and cold plate 162 adjacent the first end 112, such venting is prevented by the spacer 164 and cold plate 162, thereby protecting the adjacent battery cells 100 from the effluent 300. Due to the pressure relief features of the current interrupt device 140 and the pressure disk 141, the effluent 300 is expected to exit primarily or exclusively through the positive terminal 102 at the second end 114.

[0052]

[0062] FIG. 6 illustrates a perspective view of multiple battery cells 100 packaged together in a cell module 150 according to an embodiment of the present disclosure. The top capture plate 118 is shown separated from the assembly in this example for clarity of illustration. The top capture plate 118 defines a capture plate opening 118a that is positioned over the positive terminal 102 when the top capture plate 118 is assembled with the cell module 150. In this example, the bottom capture plate 118b is solid or continuous (i.e., lacks the capture plate opening 118a) to shield the negative terminal 104 (not visible). In this embodiment, each battery cell 100 includes a sleeve 116 around the container 110 to reinforce the container 110 and reduce the possibility of breakage in the container sidewall 110a. For example, the sleeve 116 is made of steel and extends the entire axial length of each battery cell 100. The ends of the sleeve 116 are encased in a fire-resistant material 210. The fire-resistant material 210 of adjacent battery cells 100 abuts against each other, and the battery cells 100 are packaged in a rectangular grid. Due to the presence of the sleeve 116 and the fire-resistant material 210 around the ends of the sleeve 116, the body 202 is not used. The rectangular grid is wrapped with one or more layers of the fire-resistant material 210. In this embodiment, the battery cells 100 do not directly contact each other because of the fire-resistant material 210 around the ends of the sleeve 116 and the air gap between the middle portions of the sleeve 116. This feature reduces heat transfer between the battery cells 100. The negative terminal 104 is also shielded by the bottom capture plate 118b. Furthermore, due to the fire-resistant material 210 and the top capture plate 118b, none of the positive terminals 102 have a line of sight to any of the other battery cells 100. Furthermore, in the event of a sidewall failure, the adjacent battery cells 110 are protected by the fire-resistant material 210 and the sleeve 116.

[0053]

[0063] FIG. 7 is a perspective and partially exploded view of a portion of a battery pack 200 according to an embodiment of the present disclosure. In this example, the battery pack 200 includes a plurality of battery cells 100 held (or configured to be held) within gaps 204 defined within a body 202. In this example, some of the gaps 204 are empty to better illustrate the structure of the battery pack 200. Each battery cell 100 has a positive terminal 102, a negative terminal 104, and an optional layer of fire-resistant material 210 around the container sidewall 110a (shown in FIG. 1). The body 202 is arranged between adjacent battery cells 100 in the general shape of a honeycomb to prevent direct contact between adjacent battery cells 100 and to block line of sight between adjacent battery cells 100. As a result of these and other features, propagation of a thermal runaway event in one battery cell 100 can be significantly reduced or eliminated. For example, it has been found that direct contact between adjacent battery cells 100 nearly ensures the propagation of a thermal runaway event from one battery cell 100 to another.

[0054]

[0064] The capture plate 118 abuts the body 202 and defines a capture plate opening 118a over the positive terminal 102, the negative terminal 104, or both. A potting material 119 occupies the volume of the capture plate opening 118a to protect the terminals from effluent 300 (shown in FIG. 5 ) that may be emitted from the adjacent battery pack 200, for example, during a thermal runaway event.

[0055]

[0065] The bus bar 160 may be a plate with connector tabs 161, wire bonds, ribbon bonds, spring contacts, chemical bonds, or other suitable electrical connectors or combinations configured to electrically contact multiple battery cells 100 in the battery pack 200, cell module 150, or some other group. In an embodiment, the bus bar 160 is formed from aluminum, copper, or nickel. The electrical connection between the battery cells 100 and the bus bar 160 may be formed using, for example, laser welding, resistance welding, ultrasonic welding, or friction stir welding. The bus bar 160 may utilize series connections, parallel connections, or both between groups of battery cells 100. For example, the positive terminals 102 of a string of battery cells 100 may be connected in series, and adjacent strings may be connected in parallel. Numerous variations will become apparent in light of this disclosure. In FIG. 7 , one bus bar 160 is shown installed on the battery pack 200 with the tab 168 contacting the positive terminal 102 of the battery cell 100 (the potting material 119 and other details are not shown to reveal the tab 168), and another bus bar 160 is shown separated from the battery pack 200 to better show the structure of the plate 166 and tab 168.

[0056]

[0066] 7, the body 202 and / or capture plate 118 extend axially beyond the terminals 102, 104 of the battery cells 100, so that none of the installed battery cells 100 have line-of-sight to one another. For example, the positive terminal 102 and negative terminal 104 of each battery cell 100 are recessed below the surface of the body 202. In this way, any effluent emitted from the positive terminal 102 of a battery cell 100 during a thermal runaway event is blocked by the body 202 and capture plate 118 from a direct path to any other battery cell 100 in the battery pack 200. Adjacent battery cells 100 are also isolated from one another by the body 202 in the event of a breach in the container sidewall 110a.

[0057]

[0067] FIG. 8 illustrates a cross-sectional view of a battery pack 200 including multiple cell modules 150 according to an embodiment of the present disclosure. Each cell module 150 in this example includes a battery cell 100 and the other components shown in FIG. 4 and described above. The sidewalls 201 of each cell module 150 are encased in a fire-resistant material 210. The battery pack 200 has a housing 212 that houses the multiple cell modules 150. The cell modules 150 are separated by baffles or partitions 180 made of fire-resistant material, examples of which are described above. The partitions 180 act as physical barriers to reduce or prevent heat transfer between adjacent cell modules 150 and provide a barrier to prevent effluent 300 from one battery cell 100 from landing on another battery cell 100 or cell module 150.

[0058]

[0068] Also, note that in this example, the positive terminal 102 is generally aligned to face outward toward the housing 212, away from the other cell modules 150 and the adjacent partition 180. The negative terminal 104 of each battery cell 100 is also sealed by a cold plate 162 and a spacer 164. These features, individually or in combination, prevent effluent 300 from a thermal runaway event from exiting through the negative terminal 104 and instead direct any effluent 300 to exit axially through the positive terminal 102 of the battery cell 100. Each cell module 150 is also surrounded on some or all sides by an air gap 214. The air gap 214 further reduces heat transfer between adjacent cell modules 150, thus mitigating the propagation of thermal runaway. The air gap 214 can act as an insulator, providing spacing between adjacent cell modules 150 and providing volume for the expansion of effluent 300 in the event of a thermal runaway event. The arrangement of cell modules 150 and partitions 180 shown in FIG. 8 requires a tortuous path for the exhaust 300 from one battery cell 100 to land on another battery cell 100 .

[0059] Further illustrative embodiments

[0069] The following examples relate to further embodiments, from which numerous permutations and configurations will become apparent.

[0060]

[0070] Example 1 is a lithium ion battery assembly comprising a plurality of spaced apart, generally parallel arranged battery cells, each of the battery cells extending along a central axis and having a first end with a negative terminal and a second end with a positive terminal, a first capture plate and a second capture plate, at least the first capture plate defining capture plate openings corresponding to the plurality of battery cells, the first capture plate being spaced apart from and oriented generally parallel to the second capture plate, wherein each of the plurality of battery cells extends between the first and second capture plates and is positioned coaxially with one of the capture plate openings of the first capture plate.

[0061]

[0071] Example 2 includes the subject matter of Example 1, wherein each of the battery cells includes a container having a cylindrical shape with an open end and a closed end, the container including a negative terminal, an electrode assembly within the container with a lithium ion electrolyte, the electrode assembly including a first electrode, a second electrode, and at least one spacer spirally wound within the container so as to be between the first electrode and the second electrode, and a cap on the open end of the container, the cap including a positive terminal, the negative terminal electrically connected to the first electrode and the positive terminal electrically connected to the second electrode.

[0062]

[0072] Example 3 includes the subject matter of Example 2, further comprising a current interrupt device between the positive terminal and the second electrode.

[0063]

[0073] Example 4 includes the subject matter of Examples 2 or 3, further comprising a pressure disc adjacent the positive terminal, the pressure disc configured to rupture when pressure within the vessel exceeds a threshold pressure.

[0064]

[0074] Example 5 includes the subject matter of any of Examples 1-4, wherein the capture plate openings and the plurality of battery cells are arranged in a grid, and the grid is selected from a rectangular grid, a triangular grid, and a hexagonal grid.

[0065]

[0075] Example 6 includes the subject matter of example 5, wherein the lattice is selected from a uniform square grid lattice, a non-uniform square grid lattice, a non-uniform hexagonal lattice, a uniform triangular lattice, and a non-uniform triangular lattice.

[0066]

[0076] Example 7 includes the subject matter of any of Examples 1-6, wherein a positive terminal of each of the plurality of battery cells is adjacent to the first capture plate.

[0067]

[0077] Example 8 includes the subject matter of any of Examples 1 to 6, wherein positive terminals of some of the plurality of battery cells are adjacent to a first capture plate and positive terminals of other of the plurality of battery cells are adjacent to a second capture plate.

[0068]

[0078] Example 9 includes the subject matter of any of Examples 1 to 8, wherein each of the plurality of battery cells has a diameter x axial length dimension selected from (i) 18 mm x 65 mm, (ii) 21 mm x 70 mm, and (iii) 26 mm x 65 mm.

[0069]

[0079] Example 10 includes the subject matter of any of Examples 1-9, further comprising a layer of fire-resistant material around a sidewall of each of the plurality of battery cells.

[0070]

[0080] Example 11 includes the subject matter of example 10, wherein the layer of fire resistant material is around at least the edge of the sidewall.

[0071]

[0081] Example 12 includes the subject matter of Examples 10 or 11, wherein the layer of fire resistant material is around substantially all of the sidewall.

[0072]

[0082] Example 13 includes the subject matter of any of Examples 10-12, further comprising a sleeve around the sidewall, the sleeve being between the battery cell and the layer of fire-resistant material.

[0073]

[0083] Example 14 includes the subject matter of any of Examples 1 to 13, further comprising a body between the first capture plate and the second capture plate, the body defining gaps corresponding to each of the plurality of battery cells, each of the plurality of battery cells being retained within one of the gaps.

[0074]

[0084] Example 15 includes the subject matter of Example 14, wherein the body has a thickness, the thickness being equal to or greater than an axial length of each of the plurality of battery cells.

[0075]

[0085] Example 16 includes the subject matter of Examples 14 or 15, wherein the body is made from a material having a thermal conductivity at 25° C. of at least 100 W / mK, preferably greater than 200 W / mK, and more preferably greater than 400 W / mK.

[0076]

[0086] Example 17 includes the subject matter of examples 14 or 15, wherein the body is made of a material having a thermal conductivity at 25° C. of 1 W / mK or less, preferably 0.1 W / mK or less, and more preferably 0.05 W / mK or less.

[0077]

[0087] Example 18 includes the subject matter of any of Examples 1 to 17, wherein the second capture plate defines capture plate openings corresponding to the plurality of battery cells, each of the plurality of lithium ion cells being positioned coaxially with one of the capture plate openings in the first capture plate and one of the capture plate openings in the second capture plate.

[0078]

[0088] Example 19 includes the subject matter of any of Examples 1-18, further comprising a bus bar between the first capture plate and the body, the bus bar electrically connected to positive terminals of at least some of the plurality of battery cells.

[0079]

[0089] Example 20 includes the subject matter of example 19, further comprising a spacer between the bus bar and the capture plate, the spacer being an electrically insulating material.

[0080]

[0090] Example 21 includes the subject matter of any of Examples 1-20, wherein a subset of the plurality of battery cells is electrically connected in series and a subset is electrically connected in parallel.

[0081]

[0091] Example 22 includes the subject matter of any of Examples 1-21, wherein the first and second capture plates extend axially beyond ends of the plurality of battery cells, and the assembly further comprises a fire-resistant material within the capture plate opening covering the positive terminal.

[0082]

[0092] Example 23 is a battery pack including a housing, a plurality of cell modules within the housing, each cell module including a plurality of lithium ion battery cells having a positive terminal facing toward the housing, and a partition of fire-resistant material between adjacent cell modules of the plurality of cell modules.

[0083]

[0093] Example 24 includes the subject matter of Example 23, wherein each of the cell modules includes a plurality of spaced-apart, generally parallel-arranged lithium ion cells, each of the lithium ion cells having a first end with a negative terminal and a second end with a positive terminal, and a first capture plate and a second capture plate, at least the first capture plate defining capture plate openings corresponding to the plurality of lithium ion cells, the first capture plate being spaced-apart from and oriented generally parallel to the second capture plate, and each of the plurality of lithium ion cells extending between the first capture plate and the second capture plate and positioned coaxially with one of the capture plate openings of the first capture plate.

[0084]

[0094] Example 25 includes the subject matter of Examples 23 or 24, further comprising a layer of fire-resistant material around a sidewall of each cell module of the plurality of cell modules.

[0085]

[0095] Example 26 includes the subject matter of Examples 23 or 24, wherein the partition and the plurality of cell modules are arranged to define a gap between the cell modules and the partition.

[0086]

[0096] Example 27 includes the subject matter of any of Examples 23-26, wherein the positive terminals of the plurality of lithium ion battery cells are arranged in a square or triangular grid.

[0087]

[0097] Example 28 includes the subject matter of any of Examples 23 to 27, wherein each cell module further comprises: a body defining gaps, each gap housing one of the plurality of lithium ion battery cells; a first capture plate on a first side of the body; and a second capture plate on a second side of the body, the first capture plate defining capture plate openings corresponding to the plurality of lithium ion battery cells.

[0088]

[0098] Example 29 includes the subject matter of any of Examples 23-28, further comprising a fire-resistant material within the capture plate openings, the fire-resistant material covering the positive terminals of the plurality of lithium-ion cells.

[0089]

[0099] The foregoing description of the exemplary embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the disclosure be limited not by this detailed description, but rather by the claims appended hereto. Future applications claiming priority to this application may claim the disclosed subject matter in different ways and may generally include any set of one or more limitations as variously disclosed or otherwise demonstrated herein. The following is a summary of the claims as originally filed: [1] A lithium-ion battery assembly, comprising: a plurality of spaced apart, generally parallel, battery cells, each of the battery cells extending along a central axis and having a first end with a negative terminal and a second end with a positive terminal; a first capture plate and a second capture plate, at least the first capture plate defining capture plate openings corresponding to the plurality of battery cells, the first capture plate being spaced apart from the second capture plate and oriented generally parallel to the second capture plate, wherein each of the plurality of battery cells extends between the first and second capture plates and is positioned coaxially with one of the capture plate openings in the first capture plate. [2] Each of the battery cells is a container having a cylindrical shape with an open end and a closed end, the container containing the negative terminal; an electrode assembly within the container with a lithium ion electrolyte, the electrode assembly including a first electrode, a second electrode, and at least one spacer spirally wound within the container so as to be between the first electrode and the second electrode; a cap on the open end of the container, the cap including the positive terminal; a pressure disk adjacent to the positive terminal, the pressure disk configured to rupture when pressure within the container exceeds a threshold pressure; The lithium ion battery assembly according to [1], wherein the negative terminal is electrically connected to the first electrode and the positive terminal is electrically connected to the second electrode. [3] The lithium ion battery assembly according to [1], wherein the capture plate openings and the plurality of battery cells are arranged in a grid pattern, and the grid pattern is selected from a uniform square grid pattern, a non-uniform square grid pattern, a non-uniform hexagonal grid pattern, a uniform triangular grid pattern, and a non-uniform triangular grid pattern. [4] The lithium ion battery assembly according to [1], wherein the positive terminal of each of the plurality of battery cells is adjacent to the first capture plate. [5] The lithium ion battery assembly according to [1], further comprising a layer of fire-resistant material around the sidewall of each of the plurality of battery cells. [6] The lithium ion battery assembly according to [5], wherein the layer of fire-resistant material is around substantially all of the side wall. [7] The lithium ion battery assembly according to [5], further comprising a sleeve around the side wall, the sleeve being between the battery cell and the layer of fire-resistant material. [8] The lithium ion battery assembly of [1], further comprising a body between the first capture plate and the second capture plate, the body defining gaps corresponding to each of the plurality of battery cells, wherein each of the plurality of battery cells is retained within one of the gaps. [9] The lithium ion battery assembly according to [8], wherein the body has a thickness, and the thickness is equal to or greater than the axial length of each of the plurality of battery cells.

[10] The lithium-ion battery assembly according to [8], wherein the body is made of a material having a thermal conductivity of at least 100 W / mK at 25°C.

[11] The lithium-ion battery assembly according to [8], wherein the body is made of a material having a thermal conductivity of 1 W / mK or less at 25°C.

[12] The lithium ion battery assembly according to [1], further comprising a bus bar between the first capture plate and the body, the bus bar being electrically connected to the positive terminals of at least some of the plurality of battery cells.

[13] The lithium ion battery assembly of

[12] , wherein a subset of the plurality of battery cells is electrically connected in series, and wherein the subsets are electrically connected in parallel.

[14] The lithium ion battery assembly according to

[12] , further comprising a spacer between the bus bar and the capture plate, the spacer being an electrically insulating material.

[15] The lithium ion battery assembly of [1], wherein the first and second capture plates extend axially beyond the ends of the plurality of battery cells, and the assembly further comprises a fire-resistant material within the capture plate opening covering the positive terminal.

[16] A battery pack, Housing and a plurality of cell modules within the housing, each cell module including a plurality of lithium ion battery cells, each battery cell having a positive terminal facing toward the housing; a partition made of a fire-resistant material between adjacent cell modules among the plurality of cell modules.

[17] Each of the cell modules comprises: a plurality of lithium ion cells arranged in a spaced apart, generally parallel arrangement, each of said lithium ion cells having a first end with a negative terminal and a second end with a positive terminal; a body defining gaps, each of the gaps housing one of the plurality of lithium ion battery cells;

[16] The battery pack of

[16] , comprising: a first capture plate on a first side of the body and a second capture plate on an opposite second side of the body, at least the first capture plate defining capture plate openings corresponding to the plurality of lithium ion cells, wherein each of the plurality of lithium ion cells extends between the first capture plate and the second capture plate.

[18] The battery pack according to

[17] , further comprising a fire-resistant material within the capture plate opening, the fire-resistant material covering the positive terminals of the plurality of lithium-ion cells.

[19] The battery pack according to

[17] , further comprising a layer of fire-resistant material around the outside of each cell module of the plurality of cell modules.

[20] The battery pack according to

[19] , wherein the partition and the plurality of cell modules are arranged to define a gap between the cell modules and the partition.

Claims

1. 1. A lithium ion battery assembly comprising: a plurality of spaced apart, generally parallel arranged battery cells, each of said battery cells extending along a central axis and having a first end with a negative terminal and a second end with a positive terminal; a first capture plate and a second capture plate, at least the first capture plate defining capture plate openings corresponding to the plurality of battery cells, the first capture plate being spaced apart from the second capture plate and oriented generally parallel to the second capture plate, wherein each of the plurality of battery cells extends between the first capture plate and the second capture plate and is coaxially positioned with one of the capture plate openings in the first capture plate; the first and second capture plates extend axially beyond ends of the plurality of battery cells, the lithium ion battery assembly further comprising a fire-resistant material within the capture plate opening covering the positive terminal.

2. A battery pack, Housing and a plurality of cell modules within the housing, each cell module including a plurality of lithium ion battery cells, each battery cell having a positive terminal facing toward the housing; a partition made of a fire-resistant material between adjacent cell modules of the plurality of cell modules; Each of the cell modules comprises: a plurality of lithium ion cells arranged in a spaced apart, generally parallel configuration, each of said lithium ion cells having a first end with a negative terminal and a second end with a positive terminal; a body defining gaps, each of the gaps housing one of the plurality of lithium ion battery cells; a first capture plate on a first side of the body and a second capture plate on an opposite second side of the body, at least the first capture plate defining capture plate openings corresponding to the plurality of lithium ion cells, wherein each of the plurality of lithium ion cells extends between the first capture plate and the second capture plate; The battery pack further comprising a fire-resistant material within the capture plate opening, the fire-resistant material covering the positive terminals of the plurality of lithium-ion cells.

3. The battery pack of claim 2 , further comprising a layer of fire-resistant material around the outside of each cell module of the plurality of cell modules.

4. The battery pack according to claim 3 , wherein the partition and the plurality of cell modules are arranged to define a gap between the cell modules and the partition.

Images