David O Ofer

US Patent:

7497968, Mar 3, 2009

Filed:

May 20, 2005

Appl. No.:

11/134583

Inventors:

David Ofer - Needham MA, US
Bindu R. Nair - Framingham MA, US
John D. Larouco - Milford MA, US
William A. Stevenson - Concord MA, US
Leslie S. Rubin - Newton MA, US

Assignee:

Foster-Miller, Inc. - Waltham MA

International Classification:

C09K 19/52
C09K 19/54
C08J 3/20
H01M 8/00

US Classification:

25229901, 252 622, 2522995, 428 11, 4283084, 428910, 429 30, 429 33, 429188, 521 27

Abstract:

The invention features dilute solutions of rigid rod or extended rod lyotropic liquid crystalline polymers prepared from high concentration polymerization mixtures. The invention also features methods of preparing such dilute solutions which utilize high mechanical shear to induce mix the high concentration solution with a diluent. The invention further provides articles of manufacture, including films and fibers, having a porous microstructure which are prepared from the dilute homogeneous solutions of the invention.

US Patent:

7550216, Jun 23, 2009

Filed:

May 22, 2004

Appl. No.:

10/851478

Inventors:

David Ofer - Needham MA, US
Bindu R. Nair - Framingham MA, US
Emily J. Stoler - Somerville MA, US
Robert F. Kovar - Wrentham MA, US

Assignee:

Foster-Miller, Inc. - Waltham MA

International Classification:

H01M 8/10

US Classification:

429 30, 429 33, 429188, 429192, 429314, 524602

Abstract:

The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with a water soluble ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

US Patent:

8313866, Nov 20, 2012

Filed:

May 19, 2008

Appl. No.:

12/451592

Inventors:

David Ofer - Needham MA, US
Bookeun Oh - Burlington MA, US

Assignee:

Tiax LLC - Lexington MA

International Classification:

H01M 6/18
H01M 4/13

US Classification:

429321, 4292313, 429322, 429329, 429330

Abstract:

An electrochemical cell includes a cathode capable of reversibly releasing and receiving an alkali metal; an anode capable of reversibly releasing and receiving the alkali metal; and a non-aqueous electrolyte including one or more dissolved lithium salts, one or more nitriles, sulfur dioxide, and one or more other polar aprotic solvents. In some embodiments, the non-aqueous electrolyte is substantially free of one or more other polar aprotic solvents.

US Patent:

20060003210, Jan 5, 2006

Filed:

May 20, 2005

Appl. No.:

11/134110

Inventors:

David Ofer - Needham MA, US
Bindu Nair - Framingham MA, US
Robert Kovar - Wrentham MA, US
Emily Stoler - Somerville MA, US
Carlos Pascoal - Weymouth MA, US
John Larouco - Milford MA, US
William Stevenson - Concord MA, US
Leslie Rubin - Newton MA, US

International Classification:

H01M 8/10
C08J 5/22

US Classification:

429030000, 521027000, 429033000

Abstract:

The present invention relates to solid polymer electrolyte membranes (SPEMs) which include a co-processed mixture of a substrate polymer and an ion-conducting material membrane, or more preferably include a membrane comprising a polymer blend of a substrate polymer and an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells.

US Patent:

20120182021, Jul 19, 2012

Filed:

Jan 17, 2012

Appl. No.:

13/351695

Inventors:

Christopher H. McCoy - Sherborn MA, US
David Ofer - Needham MA, US

Assignee:

TIAX LLC - Lexington MA

International Classification:

G01N 27/416

US Classification:

324433

Abstract:

A system for determining battery characteristics based on differential current monitoring includes a first battery; a second battery, the second battery being connected in parallel with the first battery; and a differential current measurement module comprising at least one current measuring device, the differential current measurement module being configured to determine a differential current associated with the first battery and the second battery. A method for determining battery characteristics based on differential current monitoring includes determining a differential current associated with a first battery and a second battery, the first battery being connected in parallel with the second battery.

US Patent:

52231178, Jun 29, 1993

Filed:

May 3, 1991

Appl. No.:

7/695254

Inventors:

Mark S. Wrighton - Winchester MA
James J. Hickman - Falls Church VA
Paul E. Laibinis - Plains PA
David Ofer - Newton MA
Chad A. Mirkin - Skokie IL
James R. Valentine - Medford MA
George M. Whitesides - Newton MA

Assignee:

Mass. Institute of Technology - Cambridge MA
Pres. & Fellows of Harvard College - Cambridge MA

International Classification:

G01N 2726

US Classification:

204415

Abstract:

Self-assembly of a chemically insensitive redox material, such as ferrocenyl thiol, and a chemically sensitive redox material, such as a quinone thiol, onto microelectrodes forms the basis for a two-terminal, voltammetric microsensor having reference and sensor functions on the same electrode. Detection is based on measuring the potential difference of current peaks for oxidation and reduction of the reference (ferrocene) and indicator (quinone) in aqueous electrolyte in a two-terminal, linear sweep voltammogram using a counterelectrode of relatively large surface area. Use of microelectrodes modified with monolayer coverages of reference and indicator molecules minimizes the size of the counterelectrode and the perturbation of the solution interrogated. Key advantages are that the sensor requires no separate reference electrode and the sensor functions as long as current peaks can be located for reference and indicator molecules.

US Patent:

56274726, May 6, 1997

Filed:

Jan 26, 1995

Appl. No.:

8/378688

Inventors:

David Ofer - Newton MA
Gary M. Searle - North Smithfield RI
Joseph Bernier - Cambridge MA

Assignee:

Duracell Inc. - Bethel CT

International Classification:

G01N 27416
G01R 3136

US Classification:

324435

Abstract:

A tester for determining the condition of an electrochemical power source, e. g. a battery or main cell, is disclosed. The tester may comprise an electrolytic (coulometric) cell connected in series to a auxiliary cell. The auxiliary cell is a miniature electrochemical power cell. The electrolytic (coulometric) cell may have no electromotive force of its own and may comprise an anode and cathode of the same material, desirably silver, with an electrolyte contacting at least a portion of both the anode and cathode. The tester may be permanently connected in parallel to a main cell being tested and is thin enough to be integratable into a label for the main cell. As the main cell discharges, the electrolytic cell anode clears proportionally to the discharge of one of the electrodes of the main cell to provide a continuous visually discernible indication of the state of charge of the main cell.

US Patent:

20200328416, Oct 15, 2020

Filed:

Apr 12, 2019

Appl. No.:

16/383079

Inventors:

- Lexington MA, US
David Ofer - Needham MA, US
Daniel Kaplan - Lexington MA, US
Suresh Sriramulu - Arlington MA, US

International Classification:

H01M 4/525
H01M 4/485
H01M 2/16
H01M 4/66
H01M 10/0525

Abstract:

Provided are electrochemical secondary cells that exhibit excellent abuse tolerance, deep discharge and overcharge conditions including at extreme temperatures and remain robust and possess excellent performance. Cells as provided herein include: a cathode a polycrystalline cathode electrochemically active material including the formula LiMO, wherein −0.9≤x≤0.3, −0.3≤y≤0.3, and wherein M includes Ni at 80 atomic percent or higher relative to total M, the cathode electrochemically active material comprising a non-uniform distribution of Co; an anode including an anode electrochemically active material of the formula LiTiOwherein −0.3≤a≤3.3, −0.3≤b≤0.3; and wherein the anode and the cathode each independently include a current collector substrate comprising aluminium.