Gm Global Technolgoy Operations, Inc.

Vijay P Saharan

Li Yang

Mark William Verbrugge

Xingcheng Xiao

Gayatri Vyas Dadheech

Gongshin Qi

Sherman H Zeng

Bing Tan

John M Moote

Edgar P Calderon

Sudhakar Inguva

Mary E Fortier

Umamaheswari Viswanathan

Patrick M Hanley

The present disclosure relates to over-lithiated positive electroactive materials for use within an electrochemical cell. For example, the electrochemical cell includes a positive electrode that includes an over-lithiated positive electroactive material that includes one of LiMnO(where 1.05&#x2264;x&#x2264;1.30) and LiMnNiO(where 0&#x2264;x&#x2264;0.5). The electrochemical cell can include a negative electrode that includes a silicon-containing negative electroactive material having a Columbic Efficiency greater than or equal to about 80% and less than or equal to about 90%.

Over-lithiated cathode material

A lithium ion battery is provided that includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. One or more of the separator, positive electrode, and negative electrode includes a transition metal compound capable of catalyzing any gaseous reactants formed in the lithium ion battery to form a liquid. The transition metal compound may include ruthenium (Ru). In certain variations, the lithium ion battery includes an electrolyte that is a conductive medium for lithium ions to move between the positive electrode and the negative electrode. The electrolyte comprises a transition metal compound capable of catalyzing a reaction of any gaseous reactants to form a liquid.

Elimination of gaseous reactants in lithium ion batteries

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

System and methods for determining performance degradation of a battery system are presented. In certain embodiments, the disclosed systems and methods may involve testing, monitoring, and/or modeling of battery system cyclic performance degradation at a single battery system operating temperature. The disclosed systems and methods may offer certain efficiencies over conventional techniques for determining cyclic degradation of a battery system. Such efficiencies may allow the disclosed systems and methods to be implemented in connection with real-time battery state estimation methods.

Systems and methods for determining battery system performance degradation

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Grand Blanc, MI, United States of America

Vijay P Saharan