Abstract: A electrode assembly includes an electrode pair having a positive electrode and a negative electrode that are arranged crosswise and each z-folded while being cross-woven together in a continuous manner. The electrode assembly includes an electrode stack in which portions of the positive electrode are stacked along a stack axis so as to alternate with portions of the negative electrode.

Abstract: A battery pack includes a battery housing and electrochemical cells disposed in the battery housing in a stacked configuration. Elastic bladders are disposed between adjacent cells of a cell stack. The elastic bladders are configured to serve as a compression spring that provide a predetermined compression force to each cell while accommodating cell growth during use. The elastic bladders may include surface features such as strategically shaped and/or located protrusions or restrained regions that are configured to permit compliance and can be tuned to address the requirements of a specific application and permit application of varying stiffness characteristics across a surface of a cell.

Abstract: A battery module includes a battery module housing, cells disposed in the battery module housing, and spacers disposed between adjacent cells. Each spacer is electrically insulating and includes a body portion having a curvilinear, for example elliptical, outer peripheral shape. The body portion is suspended from the cell housing by hangers, and overlies a central region of a cell housing surface corresponding to large deflection due to cell growth. In addition, the body portion is spaced apart from a periphery of the cell housing surface.

Abstract: An electrochemical cell includes a cell housing and an electrode assembly disposed in the cell housing. The electrode assembly includes an electrode pair that is arranged to form a winding having a polygonal spiral wound shape in which a radius of the corner portions of each turn of the winding is constant, regardless of the number of turns. In addition, a length of the linear portions of one turn of the winding is different than a length of the linear portions of another turn of the winding. Since each turn of the winding includes the corner portions having a desired radius, the volumetric efficiency of the electrode assembly including the winding within a cell housing is improved relative to some cells that use conventional windings. An apparatus and method of forming a polygonal spiral wound winding are disclosed.

Abstract: An electrochemical cell has a prismatic cell housing and an electrode assembly disposed in the cell housing. The cell housing is six-sided and includes a first end, a second end, and a sidewall that extends between the first and second ends. The sidewall includes a pair of major sides joined by a pair of minor sides, where each side of the pair of major sides is larger in area than each side of the pair of minor sides. The electrode assembly includes positive electrode plates alternating with negative electrode plates and separated by at least one separator to form an electrode stack. The electrode stack is oriented within the cell housing such that a stack axis that extends parallel to a stacking direction of the positive and negative electrode plates is normal to, and passes through, each side of the pair of minor sides.

Abstract: A method of manufacturing an electrochemical cell is provided. The cell includes a rigid housing and an electrode assembly disposed in the housing. The method includes providing a housing that includes a first end, a second end formed separately from the first end, and a tubular sidewall formed separately from each of the first end and the second end. After the electrode assembly is inserted into the sidewall, the first end is welded to one end of the sidewall, and the second end is welded to the other end of the sidewall.

Abstract: A pressure relief device attached to an outer surface of a battery pack includes an adhesive arranged around an opening in the outer surface of the battery pack and a hat portion arranged over the opening. The hat portion includes an outer ring portion attached to the outer surface of the battery pack via the adhesive and an inner portion that is recessed from the outer surface of the battery pack to form a gap between the opening and the inner portion. A diameter of the inner portion is greater than a diameter of the opening, and a diameter of the gap is greater than the diameter of the opening.

Abstract: A battery pack includes a battery pack housing and an array of pouch cells disposed in the pack housing. The battery pack also includes a force generating assembly disposed in the battery pack housing. The force generating assembly is configured to apply a force to the array of cells along a first direction corresponding to a row of cells, and a force to the array of cells along a second direction corresponding to a column of cells. The forces result in a weld-free, direct electrical connection being formed between a first pair of adjacent cells within a row, and the second force results in a weld-free, direct electrical connection being formed between a second pair of adjacent cells within a column.

Abstract: There is disclosed a battery module that includes a housing. At least one terminal is melt joined with the bus member of the housing sealing the terminal relative to the bus member and providing a conductive path to an interior of the battery module. The terminal may be melt joined in an ultrasonic joining operation or in a thermal insertion operation. A plurality of cells are disposed in the housing with each of the cells electrically coupled via bus bars integrated into a bus member. Each of the cells includes a plurality of positive and negative electrodes that are spaced by a separator. The negative electrode includes a substrate having tab meeting at a flange that is connected to an active material portion of the electrode. The positive electrode includes a substrate having a tab meeting at a flange that is connected to an active material portion of the electrode.

Abstract: A battery pack includes a battery housing and electrochemical cells disposed in the battery housing in a stacked configuration. Elastic members are disposed between adjacent cells of a cell stack. Each elastic member is a bladder that is formed of a pair of contoured plate portions stacked in a mirrored arrangement, whereby the plate portions cooperate to form a bellows-type compression spring. The elastic members provide a predetermined compression force to each cell while accommodating cell growth during use. The elastic members may include surface features such as strategically shaped and/or located protrusions that are configured to permit compliance and can be tuned to address the requirements of a specific application and permit application of varying stiffness characteristics across a surface of a cell.

Abstract: An electrochemical cell includes an electrode assembly disposed in a cell housing. A first U-shaped current collector is disposed between the cell housing and the electrode assembly, and is electrically connected to a positive electrode portion of the electrode assembly. A second U-shaped current collector is disposed between the cell housing and the electrode assembly, and is electrically connected to a negative electrode portion of the electrode assembly. The first and second current collectors cooperate to surround all sides of the electrode assembly and to retain the electrode assembly in the desired configuration without requiring a separate restraint.

Abstract: A circuit that measures isolation resistance in a battery pack that is associated with a load includes four resistors. Two resistors are connected between terminals of the battery pack and another two resistors are connected in the load in parallel to the resistors in the battery pack. A controller operates two contactors to disconnect the battery from the load and measure first and second voltages in the battery pack and one of the two resistors. The controller operates the two contactors to connect the battery to the load and measures third and fourth voltages in the battery pack and one of the two resistors. The controller identifies the isolation resistance with reference to resistance values of the four resistors and the first, second, third, and fourth measured voltages.

Abstract: A system includes a battery control module that determines at least one temperature associated with a battery pack of an electric vehicle. An electric vehicle control module selects between a plurality of operating modes of the electric vehicle based on the at least one temperature. The plurality of operating modes includes a first mode and a second mode. In the first mode the electric vehicle control module prevents the electric vehicle from being turned on. In second mode the electric vehicle control module allows the electric vehicle to be turned on in response to a determination that the battery pack has sufficient energy to adjust the at least one temperature a predetermined amount and to drive the vehicle a predetermined distance.

Abstract: A pressure relief device attached to an outer surface of a battery pack includes an adhesive arranged around an opening in the outer surface of the battery pack and a hat portion arranged over the opening. The hat portion includes an outer ring portion attached to the outer surface of the battery pack via the adhesive and an inner portion that is recessed from the outer surface of the battery pack to form a gap between the opening and the inner portion. A diameter of the inner portion is greater than a diameter of the opening, and a diameter of the gap is greater than the diameter of the opening.