Abstract: Exemplary thermal barrier systems are provided for traction battery packs. Exemplary battery thermal barrier systems may include one or more thermal barrier structures that are positioned between neighboring groupings of battery cells of a cell bank and/or elsewhere within a battery array of the traction battery pack. The thermal barrier structures may include a foam-insulation-foam multi-layer structure, an insulation-foam-insulation multi-layer structure, or an insulation-foam multi-layer structure. The thermal barrier structures are designed to manage cell-to-cell transfers of heat and electrical energy during battery thermal events.

Abstract: Battery thermal barrier and venting systems are provided for battery arrays. Exemplary battery thermal barrier and venting systems may include one or more endothermic intumescent aerogel sheets that are configured to activate when surrounding battery temperatures exceed a predefined temperature threshold, thereby mitigating cell-to-cell thermal propagation. The endothermic intumescent aerogel sheets may be incorporated as part of thermal barrier structures that are positioned between neighboring battery cells of a cell bank, as part of partition structures that are positioned between adjacent cell banks of a battery array, or both. The battery thermal barrier and venting systems may further include one or more vent ports and vent port covers for venting gases and other effluents from the battery array.

Abstract: A battery includes a cell and a thermal barrier. The cell is configured to store and discharge electrical energy. The thermal barrier is disposed along an exterior surface of the cell. The the thermal barrier includes a thermal insulator. The thermal barrier also includes an endothermic and intumescent material. The thermal insulator engages the exterior surface of the cell. The endothermic and intumescent material is disposed on an exterior of the thermal insulator such that the thermal insulator is disposed between the cell and the endothermic and intumescent material. The endothermic and intumescent material is configured to, in response to an increase in a temperature of the cell and heat generated by the cell consuming the thermal insulator, (i) expand, (ii) engage the exterior surface of the cell, and (iii) absorb the heat generated by the cell.

Abstract: A vehicle includes an engine and a non-selectable-gear transmission having an electric machine mechanically coupled to the engine. The vehicle may have one or more controllers programmed to, in response to a request for passive neutral mode, pull-down the engine and inhibit engine pull-up while disabling the electric machine such that the vehicle coasts with minimal rotational inertia and electrical losses. The one or more controllers may be further programmed to, in response to a subsequent request for drive mode during the passive neutral mode, permit engine pull-up while enabling the electric machine such that the vehicle resumes drive.

Abstract: A vehicle includes an engine and a non-selectable-gear transmission having an electric machine mechanically coupled to the engine. The vehicle may have one or more controllers programmed to, in response to a request for passive neutral mode, pull-down the engine and inhibit engine pull-up while disabling the electric machine such that the vehicle coasts with minimal rotational inertia and electrical losses. The one or more controllers may be further programmed to, in response to a subsequent request for drive mode during the passive neutral mode, permit engine pull-up while enabling the electric machine such that the vehicle resumes drive.

Abstract: A hybrid-electric powertrain and control method for a vehicle having forward traction wheels and rearward traction wheels in an all-wheel drive configuration. An engine and an electric motor deliver power through delivery paths to the traction wheels. The power delivery paths may have multiple ratio gearing so that more power can be delivered mechanically to improve powertrain performance and to allow the electric motor size to be reduced. The powertrain includes a controller for automatically balancing power distribution to the forward and rearward traction wheels to avoid wheel slip.

Abstract: A hybrid-electric powertrain and control method for a vehicle having forward traction wheels and rearward traction wheels in an all-wheel drive configuration. An engine and an electric motor deliver power through delivery paths to the traction wheels. The power delivery paths may have multiple ratio gearing so that more power can be delivered mechanically to improve powertrain performance and to allow the electric motor size to be reduced. The powertrain includes a controller for automatically balancing power distribution to the forward and rearward traction wheels to avoid wheel slip.