Gm Global Technolgoy Operations, Inc.

Edgar P Calderon

Herman K Phlegm

Mahmoud H Abd Elhamid

John M Moote

Sami A Syed

Rajesh K Bhagirath

Andrew J Namou

Roger Michael Brisbane

Evan J Dawley

Srikanth Arisetty

Vijay P Saharan

Karl C Dorgan

Faruk Sohag

Cammi L Siu

Lance W Turner

Patrick M Hanley

Elaine E Parkanzky

Gregory J Rushlow

Hayley Hanchett

Jack Cravener

Lisa J Gross

A method for constant pressure regulation of battery cells includes disposing the cells in a stacked arrangement within a battery cell placement volume of an apparatus configured to maintain a constant pressure on the cells, providing a gas pressure within a chamber of the apparatus, thereby causing an initial pressure to be applied on the battery cells, and detecting an expansion of the battery cells during a predetermined timespan using a linear displacement sensor. During the predetermined timespan, if the detected expansion is less than a maximum allowable expansion minus a predetermined measurement error, then the gas pressure within the chamber is increased, and if the detected expansion is greater than the maximum allowable expansion plus the predetermined measurement error, then the gas pressure within the chamber is decreased. An apparatus for constant pressure regulation of battery cells is also provided.

Apparatus and method for constant pressure regulation of one or more battery cells

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

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

A high voltage battery module includes a plurality of battery cells, a plurality of cooling fins dispersed between the battery cells, and a frame for holding the plurality of battery cells and the plurality of fins. An intumescent layer is proximate to at least one battery module component selected from the battery cells, the plurality of cooling fins, and the frame. The intumescent layer includes sodium silicate having formula NaSiO, pentaerythitol, a resin that is cross-linked by melamine, boron nitride particles, and triammonium phosphate.

Thermal propagation mitigation for HV battery modules

A method of leak testing a fluid passage of a part manufactured from a low conductivity material includes measuring an electrical resistance between an interior wall surface of the fluid passage of the part, and an exterior wall surface of the fluid passage of the part. The measured electrical resistance is compared to a threshold value to determine if the measured electrical resistance is equal to or greater than the threshold value, or if the measured electrical resistance is less than the threshold value. The threshold value is equal to a nominal wall thickness of the fluid passage multiplied by a resistivity of the material used to form the part. The part passes the leak test when the measured electrical resistance is equal to or greater than the threshold value. The part fails the leak test when the measured electrical resistance is less than the threshold value.

Method of leak testing a low conductivity part

A method and a test fixture for evaluating a junction between an electrical lead trace and a busbar are described, and include an electric power supply disposed to supply electric power to the electrical lead trace and an electric monitoring device disposed to monitor electrical potential across the junction. A mechanical stress-inducing device is disposed to apply mechanical stress proximal to the junction. The electric monitoring device monitors the electrical potential across the junction of the electrical lead trace coincident with the mechanical stress-inducing device applying mechanical stress proximal to the junction when the electric power supply is supplying electric power to the electrical lead trace. Electrical integrity of the junction is evaluated based upon the monitored electrical potential across the junction.

Method and aparatus for monitoring a junction between electrical devices

A coated electronic device that is fire resistant includes an electronic component and an intumescent layer disposed over the electronic component. The intumescent layer includes sodium silicate having formula NaSiO, pentaerythitol, a resin that is cross-linked by melamine, boron nitride particles, and triammonium phosphate.

Thermal protection system for powered circuit boards including fuses

Systems and methods for monitoring a state of a battery system based on information related to a measured pressure within the battery system are presented. In certain embodiments, the disclosed systems and methods may utilize a pressure-sensitive smart foam material in connection with measuring a pressure within the battery system. Based on the measured pressure information, a variety of information relating to the battery system may be determined. For example, information relating to a state of a battery system, certain events occurring within the battery system, and/or battery lifecycle information may be determined based on the measured pressure information.

Systems and methods for determining battery state information based on internal battery pressure

Systems and methods for scanning a battery cell to identify internal faults are disclosed. In certain embodiments, a method for scanning a battery cell for faults may comprise generating an input signal across first and second charge plates disposed on each side of the battery cell. An open circuit voltage of the battery cell generated in response to the input signal may be measured. The measured open circuit voltage may be compared with a reference signal associated with a reference battery cell having no faults. Based on the comparison, a fault and/or a possible fault within the battery cell being scanned may be identified.

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Sterling Heights, MI, United States of America

Edgar P Calderon