Patents Assigned to Valence Technology, Inc.
  • Method of making lithium-containing materials
    Patent number: 6528033
    Abstract: The invention provides novel lithium-mixed metal materials which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-mixed metal materials. Methods for making the novel lithium-mixed metal materials and methods for using such lithium-mixed metal materials in electrochemical cells are also provided. The lithium-mixed metal materials comprise lithium and at least one other metal besides lithium. Preferred materials are lithium-mixed metal phosphates which contain lithium and two other metals besides lithium.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: March 4, 2003
    Assignee: Valence Technology, Inc.
    Inventors: Jeremy Barker, M. Yazid Saidi, Jeffrey Swoyer
  • Battery package with integral disconnect mechanism
    Patent number: 6524741
    Abstract: A battery package assembly comprises a package having an interior volume sealingly containing at least one electrochemical cell therein, and opposite polarity electrical connectors adapted to connect said at least one electrochemical cell to an external load. At least one of the opposite polarity electrical connectors is adapted to automatically shut down the battery in response to a sufficient increase in internal pressure within the battery package.
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: February 25, 2003
    Assignee: Valence Technology, Inc.
    Inventor: Aiden Bryan
  • Method and apparatus for preparing electrochemical cells
    Patent number: 6467156
    Abstract: A method of fabricating electrochemical cells and batteries wherein the successive anode and cathode layers are separated by a polymeric electrolyte layer having a protruding polymer edge around its perimeter which reduces the likelihood of inadvertent contact between the anode and cathode current collectors is provided. The polymer edge functions as a non-conducting physical barrier positioned between adjacent current collectors. An apparatus for preparing electrochemical cells is also disclosed.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: October 22, 2002
    Assignee: Valence Technology, Inc.
    Inventors: David A. Velasquez, Douglas B. Holmes, E. Lawrence Goglin
  • Active material having extended cycle life
    Patent number: 6468695
    Abstract: In one embodiment, the invention provides a novel composition which is stabilized against decomposition when used as an active material for an electrochemical cell. The active material of the present invention comprises particles of spinel lithium manganese oxide (LMO) enriched with lithium by a decomposition product of lithium hydroxide forming a part of each of the LMO particles. The spinel LMO product formed by the decomposition of lithium hydroxide in the presence of the LMO is characterized by a reduced surface area and increased capacity retention (reduced capacity fading) as compared to the initial, non-treated, non-enriched spinel. In another aspect, the treated spinel LMO product is combined with lithium carbonate in a cathode mixture.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: October 22, 2002
    Assignee: Valence Technology Inc.
    Inventor: Jeremy Barker
  • Methods of fabricating electrochemical cells
    Patent number: 6468690
    Abstract: Conditioning secondary lithium ion cells at elevated temperatures above ambient reduces the time required to complete this process and produces cells and batteries which demonstrate improved electrochemical performance. Conditioning includes subjecting an electrochemical cell to at least one full charge/discharge cycle whereby gases generated and removed before the cell is sealed and ready for use. The cell is placed in an environment that is maintained at a temperature of at least 30° C., charged and discharged, and sealed.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: October 22, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Jeremy Barker, Steven D. Cochran
  • Lithium based phosphates, method of preparation, and uses thereof
    Patent number: 6447951
    Abstract: The invention provides an electrochemical cell which comprises an electrode having a lithium metal phosphorous compound.
    Type: Grant
    Filed: November 19, 1998
    Date of Patent: September 10, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Jeremy Barker, M. Yazid Saidi
  • Low impedance folded polymeric laminate rechargeable battery and method of making
    Patent number: 6444354
    Abstract: Single cell laminated polymeric rechargeable battery sheets are folded in irregularly alternating directions about parallel fold axes to provide battery cell structures presenting available terminal locations requiring reduced collector element current travel distance to thereby significantly reduce battery impedance. An embodiment enables the use of equilateral cell sheets which are folded about orthogonal axes in two dimensions to yield battery cells with exceptionally high ratios of active area to collector-origin impedance.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: September 3, 2002
    Assignee: Valence Technology, Inc.
    Inventor: Paul C. Warren
  • Electrolytes having improved low temperature performance
    Patent number: 6444370
    Abstract: The present invention provides a novel electrolyte solvent which is usable with a variety of carbonaceous and metal oxide electrode active materials, providing improved performance over a broad temperature range, and which is stabilized to maintain cell capacity over a number of cycles.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: September 3, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Jeremy Barker, Feng Gao, Arnold Stux
  • Method for producing a battery cell having notched layers
    Patent number: 6436155
    Abstract: A method for producing a battery cell having a plurality of film layers, a plurality of current collector layers, and at least one separator layer, with each current collector layer including a predetermined lead portion. The method includes the steps of providing at least one notch in each layer, and stacking the layers with the notches positioned with respect to one another to expose the predetermined lead portion of each current collector layer. A battery cell including an electrode having an area defined by a perimeter including an edge, a counter electrode having an area defined by a perimeter including an edge, and a separator having an area defined by a perimeter including an edge is also provided. The separator is sandwiched between the electrode and the counter electrode in a layered relationship with at least portions of the edges being continuous.
    Type: Grant
    Filed: August 9, 2001
    Date of Patent: August 20, 2002
    Assignee: Valence Technology, Inc.
    Inventor: Oliver J. Gross
  • Electrolytes having improved stability comprising an N,N-dialkylamide additive
    Patent number: 6395431
    Abstract: The invention provides an electrochemical cell having an electrolyte which comprises a solute, a solvent, and an additive. The additive is a dialkylamide. The dialkylamide lessens the extent of decomposition of the solute, which is a lithium salt. The ionic species of the lithium salt are thereby preserved. The additive also prevents damage to active material by absorbing excess charge energy below the breakdown potential of the active material.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: May 28, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Feng Gao, Jeremy Barker, Hang Shi, Tracy Kelley, Chariclea Scordilis-Kelley
  • Lithium metal fluorophosphate materials and preparation thereof
    Patent number: 6387568
    Abstract: The invention provides new and novel lithium-metal-fluorophosphates which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-metal-fluorophosphates. The lithium-metal-fluorophosphates comprise lithium and at least one other metal besides lithium.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: May 14, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Jeremy Barker, M. Yazid Saidi, Jeffrey Swoyer
  • Method for removing acidic impurities in a solid electrolyte
    Patent number: 6361902
    Abstract: A method for removing HF from a solid electrolyte using alumina is disclosed. The solid electrolyte contains a polymeric matrix, a salt, a solvent, and a toughening agent. The toughening agent may include alumina, silica, zeolite, and metal oxides (e.g., calcium oxide and magnesium oxide), and mixtures thereof. The toughening agent acts as a drying agent to remove excess solvent in the electrolyte. The solid electrolytes have improved mechanical strength and adherence to the anode and cathode.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: March 26, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Ralph Brodd, Benjamin Chaloner-Gill, Milton Neal Golovin, Mark Isaacson, Joseph Lundquist
  • Electrochemically stable plasticizer
    Patent number: 6342320
    Abstract: A laminate structure or precursor paste thereof characterized by being formed from a composition comprising a polymeric material and a plasticizer. The plasticizer being at least one compound represented by the following general formula where R is a low alkyl selected from the group consisting of methyl, ethyl, butyl, pentyl and hexyl.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: January 29, 2002
    Assignee: Valence Technology, Inc.
    Inventors: Peikang Liu, Porter Mitchell, Jeffrey Swoyer, Jeremy Barker
  • Lithium manganese oxide-based active material
    Patent number: 6322744
    Abstract: The invention provides an electrochemically active material comprising particles of spinel lithium manganese oxide having on the surface of each particle cationic metal species bound to the spinel at anionic sites of the particle surface; where the cationic metal species includes a metal selected from the group consisting of transition metals, non-transition metals having a +3 valence state, and mixtures thereof. The active material is characterized by a reduced surface area and increased capacity expressed in milliamp hour per gram as compared to the spinel alone.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: November 27, 2001
    Assignee: Valence Technology, Inc.
    Inventors: Tracy E. Kelley, Porter H. Mitchell, Chariclea A. Scordilis-Kelley
  • Vanadate cathode active material and method of making same
    Patent number: 6322927
    Abstract: A method of making a composition of the nominal general formula NayKxV3O8, with a unit structure of preferred nominal general formula Na1−xKxV3O8, such structure being able to accept lithium ions. The method as exemplified by the formation of Na1−xKxV3O8, comprises forming a mixture of hydroxides of sodium and potassium and then adding vanadium pentoxide (V2O5) in an amount sufficient to provide a stoichiometric ratio of approximately 1:3 of Na1−xKx to vanadium and preferably heating the mixture while stirring to cause formation of a precipitate product of the formula Na1−xKxV3O8. The new composition preferably contains x greater than or equal to 0.3 and less than or equal to 0.4. Preferred compositions have the nominal general formula Na0.7K0.3V3O8 and Na0.6K0.4V3O8.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: November 27, 2001
    Assignee: Valence Technology, Inc.
    Inventor: Gianfranco Pistoia
  • Use of polymer mesh for improvement of safety, performance and assembly of batteries
    Patent number: 6319627
    Abstract: The use of a polymer mesh made of material that melts under thermal runaway helps improve the safety of an electrochemical device. The mesh material can increase the impedance of the battery during the thermal runaway and absorb some of the heat produced.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: November 20, 2001
    Assignee: Valence Technology, Inc.
    Inventors: Kent Snyder, Wei Liu, Zhen Yang
  • Apparatus for coating current collectors
    Patent number: 6306215
    Abstract: Apparatus and process for continuously coating a web of current collectors with an electrically conductive adhesive material for electrochemical cells and batteries. The apparatus includes: (a) a source of the web of current collector material; (b) a reservoir containing the liquid composition; (c) a first rotatable roller having an exterior surface that is at least partially submerged in the liquid composition whereby liquid composition adheres to the exterior surface of the first rotatable roller which comes into contact with the liquid composition; and (d) a second rotatable roller that is positioned adjacent to the first rotatable roller and wherein an exterior surface of the second rotatable roller and an exterior surface of the first rotatable roller defines a nip through which the web of current collector material traverses.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: October 23, 2001
    Assignee: Valence Technology, Inc.
    Inventor: James T. Larkin
  • Battery cell having notched layers
    Patent number: 6294288
    Abstract: The invention provides a battery cell including an electrode having an area defined by a perimeter including an edge, a counter electrode having an area defined by a perimeter including an edge, and a separator having an area defined by a perimeter including an edge. The separator is sandwiched between the electrode and the counter electrode in a layered relationship with at least portions of the edges being contiguous. The separator and one of the electrode and the counter electrode each include a first notch in the edge exposing a portion of the other of the electrode and counter electrode. The separator and the other of the electrode and the counter electrode each include a second notch in the edge exposing a portion of the one of the electrode and the counter electrode.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: September 25, 2001
    Assignee: Valence Technology, Inc.
    Inventor: Oliver J. Gross
  • Grid placement in lithium ion bi-cell counter electrodes
    Patent number: 6291097
    Abstract: Disclosed herein is a battery design for bi-cell polymer matrix batteries. Each bi-cell comprises, sequentially, a first counter electrode, a first separator membrane, a centrally located electrode, a second separator membrane, and a second counter electrode. The current collector of each of the counter electrodes is positioned other than medially within the counter electrode. Generally, the current collector of the counter electrode is located within the outer half of the counter electrode. When the current collector is located at the extreme outer edge of the counter electrode, a capping film of polymer matrix material is preferably laminated to the perforated current collector, and, through the perforated current collector, to the counter electrode material itself.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: September 18, 2001
    Assignees: Valence Technology, Inc., Delphi Technologies, Inc.
    Inventors: Jeremy Barker, Wade Guindy, Howard Kisner, Porter Mitchell, Mohammad Parsian
  • Fastener system of tab bussing for batteries
    Patent number: 6242128
    Abstract: A fastener system for tab bussing for the multicell batteries and the apparatus to assist this system are described. The holding device is used to hold the tab bussing structure together. The holding device can be a bolt or a rivet. It minimizes the electrical resistance of the multicell battery, allows rework and achieves high energy efficiency and small dimensions for the multicell lithium-polymer batteries.
    Type: Grant
    Filed: December 6, 1993
    Date of Patent: June 5, 2001
    Assignee: Valence Technology, Inc.
    Inventors: Drew Tura, David Brongiel