Patents by Inventor Umamaheswari Viswanathan

Umamaheswari Viswanathan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230155174
    Abstract: An electrolyte for a lithium metal battery includes a nonaqueous aprotic organic solvent, a lithium salt dissolved in the nonaqueous aprotic organic solvent and, by volume, from 1% to 10% of a flame retardant additive. The flame retardant additive is at least one of an organophosphate compound, an organophosphite compound, organophosphonate compound, or a phosphazene compound.
    Type: Application
    Filed: November 12, 2021
    Publication date: May 18, 2023
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Seung-Woo Chu, Li Yang, Umamaheswari Viswanathan, Mary E Fortier
  • Patent number: 11646450
    Abstract: An electrolyte is provided. The electrolyte includes a solvent containing propylene carbonate (PC); a lithium salt dissolved in the solvent; a first additive dissolved in the solvent, the first additive being configured to stabilize an anode solid electrolyte interphase; a second additive dissolved in the solvent, the second additive being configured to stabilize at least one of an anode, a cathode, or the lithium salt; and a third additive dissolved in the solvent, the third additive being configured to stabilize at least one of an anode, a cathode, or the lithium salt. The first, second, and third additives are chemically distinct. Electrochemical cells including the electrolyte are also provided.
    Type: Grant
    Filed: October 29, 2020
    Date of Patent: May 9, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Li Yang, Umamaheswari Viswanathan, Mary E. Fortier
  • Patent number: 11637285
    Abstract: 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 LixMn2O4 (where 1.05?x?1.30) and LiMn(2?x)NixO4 (where 0?x?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%.
    Type: Grant
    Filed: October 2, 2020
    Date of Patent: April 25, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Mary E. Fortier, Bing Tan, Li Yang, Umamaheswari Viswanathan, Vijay P. Saharan, Sherman H. Zeng
  • Publication number: 20220399574
    Abstract: An electrolyte solution for a lithium metal battery is provided. The electrolyte solution includes lithium bis(fluorosulfonyl)imide dissolved in a fluorinated ether solvent. The electrolyte solution further includes a first additive including fluoroethylene carbonate and a second additive including lithium difluorophosphate. In one embodiment, the fluorinated ether solvent includes fluorinated 1,4 dimethoxy butane.
    Type: Application
    Filed: June 15, 2021
    Publication date: December 15, 2022
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Umamaheswari Viswanathan, Li Yang, Vijay P. Saharan, Mary E. Fortier
  • Publication number: 20220140396
    Abstract: An electrolyte is provided. The electrolyte includes a solvent containing propylene carbonate (PC); a lithium salt dissolved in the solvent; a first additive dissolved in the solvent, the first additive being configured to stabilize an anode solid electrolyte interphase; a second additive dissolved in the solvent, the second additive being configured to stabilize at least one of an anode, a cathode, or the lithium salt; and a third additive dissolved in the solvent, the third additive being configured to stabilize at least one of an anode, a cathode, or the lithium salt. The first, second, and third additives are chemically distinct. Electrochemical cells including the electrolyte are also provided.
    Type: Application
    Filed: October 29, 2020
    Publication date: May 5, 2022
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Li YANG, Umamaheswari VISWANATHAN, Mary E. FORTIER
  • Publication number: 20220109151
    Abstract: 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 LixMn2O4 (where 1.05?x?1.30) and LiMn(2?x)NixO4 (where 0?x?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%.
    Type: Application
    Filed: October 2, 2020
    Publication date: April 7, 2022
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Mary E. FORTIER, Bing TAN, Li YANG, Umamaheswari VISWANATHAN, Vijay P. SAHARAN, Sherman H. ZENG
  • Publication number: 20210408605
    Abstract: Presented are electrolyte compositions with fluorinated cosolvents, methods for making/using such electrolyte compositions, and electric-drive vehicles with lithium-ion battery cells using such electrolyte compositions. An electrolyte composition for a lithium-ion electrochemical device includes a lithium salt, a nonaqueous solvent, and a fluorinated cosolvent. The lithium salt may include one or more soluble ionic salts, whereas the solvent may include one or more non-aqueous organic solvents. The fluorinated cosolvent includes a cyclic carbonate with a fluorine atom that is bonded directly to the cyclic ring, to a single atom bonded to the cyclic ring, or to a single side chain group bonded to the cyclic ring. The fluorinated cosolvent may be a fluoroethylene carbonate, a difluoroethylene carbonate, a trifluoropropylene carbonate, or a difluoropropylene carbonate. The side chain group may be an R-group, such as a 3-C chain, with at least one carbon atom bonded directly to the cyclic ring.
    Type: Application
    Filed: June 24, 2020
    Publication date: December 30, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Li Yang, Bing Tan, Umamaheswari Viswanathan, Mary E. Fortier
  • Patent number: 8252461
    Abstract: An improved cathode suitable for lithium-sulfur batteries, a battery including the cathode, and a battery including a separator containing inorganic fillers are disclosed. The cathode includes sulfur and a metal oxide and optionally includes an additional polymeric material. The metal oxide reduces dissolution of sulfur at the cathode and reduces sulfur-containing deposits on the battery anode, thereby providing a battery with relatively high energy density and good partial discharge performance. The separator also reduces unwanted diffusion of sulfur species.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: August 28, 2012
    Assignee: Eaglepicher Technologies, LLC
    Inventors: Viet Vu, Ramanathan Thillaiyan, Mai Sayarath, Ernest Mdzebet, Umamaheswari Viswanathan
  • Publication number: 20090226809
    Abstract: An improved cathode suitable for lithium-sulfur batteries, a battery including the cathode, and a battery including a separator containing inorganic fillers are disclosed. The cathode includes sulfur and a metal oxide and optionally includes an additional polymeric material. The metal oxide reduces dissolution of sulfur at the cathode and reduces sulfur-containing deposits on the battery anode, thereby providing a battery with relatively high energy density and good partial discharge performance. The separator also reduces unwanted diffusion of sulfur species.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 10, 2009
    Applicant: EAGLEPICHER TECHNOLOGIES, LLC
    Inventors: Viet Vu, Ramanathan Thillaiyan, Mai Sayarath, Ernest Mdzebet, Umamaheswari Viswanathan