Abstract: A battery pack assembly method includes compressing a first cell stack, compressing a second cell stack, and inserting the first cell stack together with the second cell stack into a cell-receiving opening of an enclosure structure. Another traction battery pack assembly method includes simultaneously inserting a plurality of separate cell stacks into an enclosure structure when the plurality of cell stacks are each compressed by a compression fixture and, after the inserting, compressing the plurality of cell stacks using the enclosure structure.

Abstract: A method includes electrically connecting a first battery cell to a second battery cell by joining a first tab terminal of the first battery cell to a second tab terminal of the second battery cell. The method further includes compressing the first tab terminal and the second tab terminal after the joining. A battery assembly includes a first tab terminal extending from a first housing of a first battery cell, and a second tab terminal extending from a second housing of a second battery cell. The second tab terminal is connected directly to the first tab terminal. The method further includes an insulating layer that encloses the first and second tab terminals against the first and second housings.

Abstract: A battery pack assembly method includes holding a cell stack with a compression machine. The compression machine engages a first load plate at a first end of the cell stack and a second load plate at an opposite, second end of the cell stack during the holding. The method further includes aligning the cell stack relative to an enclosure structure while the compression machine holds the cell stack, inserting the cell stack into a cell-receiving opening of an enclosure structure, and disengaging the compression machine from the first load plate and the second load plate.

Abstract: A traction battery pack for an electrified vehicle may include a protection bracket for shielding a vent feature of the traction battery pack. An exemplary protection bracket may be made of a polymeric material and is designed to shield the vent feature from debris impingement. The protection bracket may include features such as a mesh venting pattern and a melting point that is lower than the temperature of battery vent byproducts that may be released during battery thermal events of the traction battery pack.

Abstract: Traction battery packs are disclosed that include battery systems. A cell stack/cell matrix of the battery system may be positioned within an enclosure tray of the traction battery pack. A wedge insert may be positioned at an interface between the cell stack/cell matrix and a side wall of the enclosure tray. The side wall may include a draft angle. The wedge insert may be configured to translate the draft angle in order to apply a compressive load in a direction that is substantially normal to the cell stack/cell matrix.

Abstract: Foldable pouch battery cells are provided for use within traction battery packs. An exemplary pouch battery cell may include flexible portions that can be folded to provide a more compact packaging design compared to conventional pouch style battery cells. The proposed designs move sensitive components of the pouch cell further away from a layered body of an electrode assembly of the pouch cell. The flexible portions of the pouch cell are capable of being bent by 90 degrees or more. The compact design facilities increased energy density compared to conventional pouch battery cell designs.

Abstract: A traction battery pack assembling method includes compressing a first cell stack within a first compression fixture, compressing a second cell stack within a second compression fixture, positioning the first cell stack and the first compression fixture next to the second cell stack and the second compression fixture, and inserting the first and second cell stacks into a cell-receiving opening of an enclosure structure by pushing the first and second cell stacks together into the cell-receiving opening.

Abstract: An electrochemical system having a thermal barrier layer is provided. The thermal barrier layer includes a polymer network having an inorganic portion and an organic portion such as silicone or a polysiloxane polymer network. The polymer network may further include filler component dispersed therein such as oxidized polyacrylonitrile milled fiber, Aerogel, hollow glass microspheres, and mica.

Abstract: Cover attachments are disclosed for securing an enclosure cover to a cell row/battery cell separator on traction battery packs that include cell-to-pack battery systems. One or more separators of a cell-to-pack battery system may be configured to separate cell stack rows or battery cells within the cell-to-pack battery system. A cover attachment (e.g., a clip, an adhesive puck, a magnet assembly, a hook and loop assembly, a ball-and-socket assembly, etc.) may connect to a portion of the separator for securing the enclosure cover directly to the cell-to-pack battery system. The combination of the cover attachments and the separators provides for enclosure cover retention at interior regions of the cell-to-pack battery system, maintains the enclosure cover at a spaced distance apart from the battery cells of the cell-to-pack battery system, and creates a desired amount of pack-level stiffness for distributing loads through the cell-to-pack battery system.

Abstract: A battery pack cell stack removal method includes compressing a cell stack with an enclosure structure when the cell stack is received within a cell-receiving opening of the enclosure structure, and pulling a cell stack removal strap to withdrawn the cell stack from the cell-receiving opening of the enclosure structure.

Abstract: A structural assembly for an electric vehicle includes a vehicle frame, a battery structure, a pair of mounting structures, and a plurality of fasteners. The vehicle frame includes opposed longitudinal rails. The battery structure is disposed between the opposed longitudinal rails and includes a battery housing configured to house power storage units. Each mounting structure is secured to a respective side of the battery housing and supports a corresponding longitudinal rail. The plurality of fasteners extend through a corresponding mounting structure of the pair of mounting structures and a corresponding longitudinal rail of the opposed longitudinal rails to secure the vehicle frame and the battery structure to each other. An outer periphery of the corresponding mounting structure is substantially flush with an outer periphery of the corresponding longitudinal rail.

Abstract: Retention assemblies are disclosed for retaining a battery cell stack/matrix relative to an enclosure tray on traction battery packs that include cell-to-pack battery systems. The retention assemblies may be positioned between a cell stack/cell matrix and an interior surface of the enclosure tray. The retention assemblies may include features such as slider panels, clips, adhesive, and/or shims designed for holding the cell stacks down at the cell stack-to-enclosure tray interface.

Abstract: Battery pack designs for use in electrified vehicles may include a polymer-based enclosure having features for sealing external joints, retaining components inside the battery pack, securing electrical and coolant lines to the polymer-based enclosure, etc. The proposed designs reduce the number of overall parts in assembly, such as fasteners and brackets, and simplify the overall battery pack manufacturing and assembly processes.

Abstract: Thermal barrier systems are provided for use within traction battery packs. An exemplary thermal barrier system may include one or more expandable gap fillers configured to transition from a compressed state to an uncompressed state when a temperature near the expandable gap filler exceeds a predefined temperature threshold. In the uncompressed state, the expandable gap filler reduces a free air volume of a void space of the traction battery pack, thereby managing or even preventing the transfer of thermal energy to nearby structures.

Abstract: A battery pack assembly method includes compressing at least one cell stack, inserting the at least one cell stack into a cell-receiving opening of an enclosure structure, and pushing at least one cell of the at least one cell stack out of the enclosure structure using a pusher. Another traction battery pack assembly method includes moving a cell stack into an enclosure structure from a compression fixture that compresses the cell stack. The cell stack includes a plurality of battery cells. After the moving, the method compresses the cell stack using the enclosure structure. The method then includes establishing electrical connections between the battery cells of the cell stack, and testing the electrical connections prior to securing a busbar to the cell stack.

Abstract: Thermal barrier assemblies are provided for inhibiting the transfer of thermal energy inside a traction battery pack while simultaneously accommodating battery cell swelling forces and providing sufficient structural stiffness. An exemplary thermal barrier assembly may include a structural barrier, a thermal insulation medium, and one or more flexible structures that are arranged to contain the thermal insulation medium within an outer perimeter provided by the structural barrier. The flexible structures may be configured as flexible links or film layers that are capable of mechanically isolating a first portion of the structural barrier that contacts a battery cell undergoing swelling from a second portion of the structural barrier that is not in contact with the battery cell, thereby providing uniform resistance to the battery cell swelling forces while also providing structural stiffness.

Abstract: A battery pack venting system, including: a structural member having a first channel and a second channel, the first channel configured to communicate a flow of vent byproducts received through at least one first inlet in a first direction to a first outlet from the structural member, the second channel configured to communicate a flow of vent byproducts received through at least one second inlet in a second direction to second outlet from the structural member.

Abstract: Techniques are provided for electrically connecting groups of battery cells within a traction battery pack. The battery cells within each groping may include cell tab terminals of a common length for direct welding relative to a cross-member assembly. Groups of cell tab terminals may be received through cell tab openings of the cross-member assembly and then bent into place relative to a backing tab for welding. The cross-member assembly may include various lead-in and bending features that facilitate cell tab terminal bending and welding.

Abstract: A method of assembling a battery pack includes inserting a guide within a slot of a slotted assembly; guiding one or more terminals into the slot using the guide; and withdrawing the guide from the slot while the one or more terminals remain in the slot. A traction battery pack assembly includes a terminal guide; and an actuator assembly that rotates the terminal guide back and forth between a guiding position and a withdrawn position. The terminal guide is at least partially disposed within a slot of a slotted assembly when in the guiding position such that the terminal guide can guide insertion of one or more terminals into the slot. The terminal guide is withdrawn from the slot when in the withdrawn position.

Abstract: A battery assembly includes at least one enclosure structure that is thermoformed about a battery assembly of a battery pack. A method of enclosing a battery assembly can include placing a sheet of material adjacent a battery assembly of a battery pack; and thermoforming the sheet of material about the battery assembly to provide an enclosure structure for the battery assembly.