Gm Global Technolgoy Operations, Inc.

John M Moote

Qian Lin

Wayne Cai

Debejyo Chakraborty

Teresa J Rinker

Anthony Ottomano

Stephen Joel Harris

Edgar P Calderon

Yue Qi

Patrick M Hanley

Michael P Balogh

Chih-Hung Yen

David T Renke

Steven J Weber

Xiaoyu Huang

Thomas D Hagen

Karl C Dorgan

Vijay P Saharan

Richard A Kaatz

Faruk Sohag

Rajesh K Bhagirath

Elaine E Parkanzky

Daniel R Thompson

Mark A Hughes, Jr

A thermal barrier for use in a power module assembly having at least one battery cell and corresponding method of forming. The thermal barrier includes at least one compressible member having one or more pockets. A first layer and a second layer are positioned adjacent to the compressive member at a first side and a second side, respectively. The thermal barrier includes one or more phase change materials configured to be deposited into the pockets. The phase change materials are configured to undergo an endothermic phase change reaction when a temperature is at or above an activation temperature. The first layer and the second layer may be configured to at least partially reflect radiant heat. In one example, the phase change materials include a bicarbonate salt.

Thermal barrier incorporating phase change material for a power module assembly

A method and a test fixture for evaluating a battery cell are described, wherein the battery cell is composed of a cell body having a plurality of electrode foils that are joined to both a positive terminal and a negative terminal at weld junctions. The method includes retaining the cell body of the battery cell in a first clamping device and gripping one of the positive and negative terminals in a terminal gripper. A dynamic stress end effector coupled to the terminal gripper is employed to apply a vibrational excitation load to the one of the positive and negative terminals. Impedance between the positive terminal and the negative terminal is monitored via a controller, and integrity of the weld junction of the one of the positive and negative terminals is evaluated based upon the impedance.

Method and apparatus for evaluating an ultrasonic weld junction

An electrochemical cell comprises an electrolyte capable of facilitating ion transfer between an anode and a cathode. A method for identifying and/or characterizing a soft short in an electrochemical cell comprises cooling the electrochemical cell to an observation temperature at which inter-electrolyte ion migration is substantially inhibited, observing the open circuit voltage (OCV) of the electrochemical cell at the observation temperature for a period of time, and determining the presence of a soft short in the electrochemical cell if the OCV reaches a minimum threshold voltage prior to the expiration of the period of time. The method can optionally further include generating an impedance spectrum for the cell via potentiostatic electrochemical impedance spectroscopy (PETS) at or below the observation temperature, and defining the cell leakage resistance as the maximum impedance limit of the impedance spectrum. The observation temperature can comprise the glass transition temperature of the electrolyte.

Methods for determining and characterizing soft shorts in electrochemical cells

According to aspects of the present disclosure, a vehicle includes a braking system, at least one controller, and at least one memory. The braking system includes a brake fluid therein and a brake pedal. The at least one memory stores instructions that, when executed by the at least one controller, are configured to: determine, via a boiling-point module, a boiling point of a brake fluid within a braking system of a vehicle; determine, via a fluidic-properties module, fluidic properties of the brake fluid; determine, via a corrosion-inhibitor module, an amount of corrosion inhibitors within the brake fluid; determine, via a reserve-alkalinity module, a reserve alkalinity of the brake fluid; estimate, a brake-fluid life module, a remaining effective life of the brake fluid using the boiling point, the fluidic properties, the amount of corrosion inhibitors, and the reserve alkalinity; and adjust a response curve of the braking system.

Brake fluid life monitoring

A method of detecting metallic lithium present on an electrode of a lithium ion secondary battery includes depositing a lithium-reactive solution including an oxidized fluorescent dye onto the electrode to form a coated electrode. Concurrent to depositing, the method includes reducing the oxidized fluorescent dye to form a reduced dye and a plurality of lithium ions. The method further includes, after reducing, drying the coated electrode to again form the oxidized fluorescent dye. After drying, the method includes exposing the oxidized fluorescent dye to ultraviolet radiation having a wavelength of from 100 nm to 500 nm to thereby illuminate and detect the metallic lithium. A lithium ion secondary battery system is also disclosed.

Method of detecting metallic lithium present on an electrode

A number of variations may include a method that may include providing a glass substrate that may include a first surface and a second surface; disposing a ceramic frit that may include at least one bus bar and at least one grid line on the first surface to form a window assembly; bathing the window assembly in a first bath solution; and drying the window assembly.

Treated heated window grid for improved durability in harsh environments

A method and a test fixture for evaluating a battery cell composed of a cell body having a plurality of electrode foils, a positive terminal and a negative terminal, wherein the positive terminal and the negative terminal are each joined to the cell body at weld junctions. This includes retaining the cell body of the battery cell in a first clamping device. The terminal is grasped in a terminal gripper. A dynamic stress end effector coupled to the terminal gripper applies a vibrational excitation load to the terminal. A static stress end effector applies a static load to the terminal. Integrity of the weld junction is evaluated based upon the applied static load.

A battery module is provided. The battery module includes a plurality of battery cell assemblies configured to electrically communicate with each other. Each battery cell assembly has an electrode stack enclosed by a case. The electrode stack is positioned in the case to form one or more peripheral spaces between the electrode stack and the case. Support members are positioned adjacent to each of the battery cell assemblies to contact a desired portion of the electrode stack. The support members are configured to focus a compressive force on a desired portion of the electrode stack. The compressive force urges gases formed during operation of the electrode stack into the peripheral spaces within the case.

Battery module for mitigating gas accumulation and methods thereof

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Plymouth, MI, United States of America

John M Moote