Cambridge, MA, United States

Massachusetts Institute of Technology

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Cambridge, MA, United States

The Massachusetts Institute of Technology is a private research university in Cambridge, Massachusetts. Founded in 1861 in response to the increasing industrialization of the United States, MIT adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. Researchers worked on computers, radar, and inertial guidance during World War II and the Cold War. Post-war defense research contributed to the rapid expansion of the faculty and campus under James Killian. The current 168-acre campus opened in 1916 and extends over 1 mile along the northern bank of the Charles River basin.MIT, with five schools and one college which contain a total of 32 departments, is traditionally known for research and education in the physical science and engineering, and more recently in biology, economics, linguistics, and management as well. The "Engineers" sponsor 31 sports, most teams of which compete in the NCAA Division III's New England Women's and Men's Athletic Conference; the Division I rowing programs compete as part of the EARC and EAWRC.MIT is often cited as among the world's top universities. As of 2014, 81 Nobel laureates, 52 National Medal of Science recipients, 45 Rhodes Scholars, 38 MacArthur Fellows, and 2 Fields Medalists have been affiliated with MIT. MIT has a strong entrepreneurial culture and the aggregated revenues of companies founded by MIT alumni would rank as the eleventh-largest economy in the world. Wikipedia.

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Patent
Massachusetts Institute of Technology and 24M Technologies | Date: 2017-09-06

The present invention provides an energy storage device comprising an electroactive zone defined at least partially by a current collector and an ion-permeable membrane, the electroactive zone configured to contain a semi-solid electrode comprising a suspension of an ion-storing solid phase material in a liquid electrolyte, the ion-storing solid phase material being capable of taking up or releasing ions without dissolving in the electrolyte.

Claims which contain your search:

1. An energy storage device comprising an electroactive zone defined at least partially by a current collector and an ion-permeable membrane, the electroactive zone configured to contain a semi-solid electrode comprising a suspension of an ion-storing solid phase material in a liquid electrolyte, the ion-storing solid phase material being capable of taking up or releasing ions without dissolving in the electrolyte.

2. The energy storage device of claim 1, wherein the semi-solid electrode has a thickness of 250 m to 800 m.

3. The energy storage device of claim 1 or claim 2, wherein the volume percentage of the ion-storing solid phase material in the semi-solid electrode is between 5% and 70%.

4. The energy storage device of claim 1 or claim 2, wherein the volume percentage of the ion-storing solid phase material in the semi-solid electrode is greater than 25%, preferably 40%.

5. The energy storage device of any of the preceding claims, wherein the semi-solid electrode includes a conductive additive and the total volume percentage of the solids including the conductive additive is between 10% and 75%.

6. The energy storage device of claim 5, wherein the ion-storing solid phase material forms a percolating network in the semi-solid electrode.

7. The energy storage device of claim 5 or claim 6, wherein the conductive additive is selected from metal carbides, metal nitrides, carbon black, graphitic carbon powder, carbon fibers, carbon microfibers, vapor-grown carbon fibers (VGCF), fullerenes, carbon nanotubes (CNTs), multiwall carbon nanotubes (MWNTs), single wall carbon nanotubes (SWNTs) and graphene sheets.

8. The energy storage device of any of the preceding claims, wherein the ion-storing solid phase material stores at least one of Li^(+), Na^(+) and H^(+).

9. The energy storage device of claim 8, wherein the ion is lithium and the ion-storing solid phase material includes an intercalation compound selected fromLiMPO_(4), in which M comprises one or more of Mn, Fe, Co and Ni;(Li_(1-x)Z_(x))MPO_(4), where M is one or more of V, Cr, Mn, Fe, Co, and Ni; Z is one or more of Ti, Zr, Nb, Al and Mg; and x ranges from 0.005 to 0.05; andLi_(1-x-z)M_(1+z)PO_(4), where M comprises at least one first row transition metal selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni; x is from 0 to 1; and z can be positive or negative.

10. The energy storage device of any of the preceding claims, wherein the liquid electrolyte is a non-aqueous liquid electrolyte.


Patent
The Regents Of The University Of California and Massachusetts Institute of Technology | Date: 2015-08-11

Metal-sulfur energy storage devices also comprising new redox mediator compounds are described.

Claims which contain your search:

1. An energy storage device comprising: an anode; a cathode comprising:a metal sulfide Ma redox mediator having a redox potential suitable for reducing or oxidizing Man electrolyte, a membrane separator between the anode and the cathode; and a current collector in electrical contact with the anode and cathode.

2. The energy storage device of claim 1, wherein the anode comprises lithium.

3. The energy storage device of claim 1, wherein the metal M is selected from the group consisting of an alkali metal, an alkali earth metal, and a transition metal.

4. The energy storage device of claim 1, wherein the metal M is lithium.

5. The energy storage device of claim 1, wherein the metal sulfide comprises at least one of Li _(2)S _(8 )and Li _(2)S _(6).

6. The energy storage device of claim 1, wherein the redox mediator is a polycyclic aromatic hydrocarbon redox mediator.

7. The energy storage device of claim 1, wherein the redox mediator is a perylene bisimide (PBI) or a benzoperyleneimide (BPI).

8. The energy storage device of claim 1, wherein the redox mediator is a compound of Formula I:

9. The energy storage device of claim 1, wherein the redox mediator is a compound of Formula II:

10. The energy storage device of claim 1, wherein the electrolyte comprises a metal salt.

11. The energy storage device of claim 10, wherein the cation of the metal salt is selected from the group consisting of lithium and sodium; and the anion of the metal salt is selected from the group consisting of bis(trifluoromethyl)sulfonimide, trifluoromethylsulfonate, fluorosulfonimide, perchlorate, tetrafluoroborate, hexafluorophosphate, nitrate, fluoride, chloride, bromide, and iodide.

12. The energy storage device of claim 1, wherein the electrolyte comprises at least one of diglyme, PGMEA, dimethoxyethane, triglyme, tetraglyme, dioxolane, THF, propylene carbonate, dimethylcarbonate, ethylene carbonate, ethyl methyl sulfone (EMS), propyl methyl sulfone (PMS), water, poly(ethylene oxide) and copolymers thereof, dimethylsulfoxide, N-methylpyrrolidinone, and acetonitrile.

13. The energy storage device of claim 1, wherein the cathode further comprises a conductive additive.

14. The energy storage device of claim 13, wherein the conductive additive comprises carbon.

15. The energy storage device of claim 1, wherein the current collector comprises at least one of carbon cloth, carbon felt, carbon paper, carbon particles, carbon nanomaterial, metal chalcogenide, metal, and metal oxide.

16. The energy storage device of claim 1, comprising: the anode comprising lithium; the cathode comprising:Lithe redox mediator having the structure:

17. The energy storage device of claim 1, comprising: the anode comprising lithium; the cathode comprising:Lithe redox mediator having the structure:


Patent
Massachusetts Institute of Technology | Date: 2016-12-21

The present invention generally relates to energy storage devices, and to metal sulfide energy storage devices in particular. Some aspects of the invention relate to energy storage devices comprising at least one flowable electrode, wherein the flowable electrode comprises an electroactive metal sulfide material suspended and/or dissolved in a carrier fluid. In some embodiments, the flowable electrode further comprises a plurality of electronically conductive particles suspended and/or dissolved in the carrier fluid, wherein the electronically conductive particles form a percolating conductive network. An energy storage device comprising a flowable electrode comprising a metal sulfide electroactive material and a percolating conductive network may advantageously exhibit, upon reversible cycling, higher energy densities and specific capacities than conventional energy storage devices.

Claims which contain your search:

6. An energy storage device, comprising: a first electrode comprising an electrode composition comprising a first electroactive material comprising sulfur, wherein the first electroactive material is suspended and/or dissolved in a fluid, wherein the concentration of sulfur is at least about 2 M; and a second electrode in electrochemical communication with the first electrode, wherein the second electrode comprises a second electroactive material comprising an electroactive metal or metal alloy comprising a non-sulfur element.

7. The energy storage device of claim 6, wherein at least one of the electrodes of the energy storage device is substantially fluid prior to first use.

8. The energy storage device of claim 7, wherein the fluid comprises TEGDME, DME, diglyme, triglyme, DOL, THF, methyl-TFH, GBL, and/or mixtures thereof.

9. The energy storage device of claim 6, further comprising a layer adjacent the second electrode of the energy storage device.

10. The energy storage device of claim 9, wherein the layer comprises LiNO _(3).

11. The energy storage device of claim 9, wherein the layer comprises a ceramic and/or a polymer.

12. The energy storage device of claim 6, wherein the second electrode comprises lithium metal.

13. The energy storage device of claim 6, further comprising an ionically conductive membrane separating the first and second electrodes.

14. The energy storage device of claim 6, further comprising a metal salt.

15. The energy storage device of claim 14, wherein the metal salt comprises LiTFSI, lithium triflate, sodium triflate, lithium perchlorate, sodium perchlorate, lithium tetrafluoroborate, and/or sodium tetrafluoroborate.

16. The energy storage device of claim 6, wherein the electronically conductive particles comprise carbon black particles.

17. The energy storage device of claim 6, wherein the concentration of the first electroactive material in the fluid is at least about 1 M.

18. The energy storage device of claim 6, wherein the viscosity of the electrode composition is less than about 100 Pa-s at a shear rate of about 100 s ^(1).

19. The energy storage device of claim 6, wherein the yield stress of the electrode composition is less than about 1000 Pa.

20. The energy storage device of claim 6, wherein the electronic conductivity of the first electrode is at least about 0.1 mS/cm.

21. A method of operating an energy storage device, comprising: reversibly cycling an energy storage device containing a flowable electrode such that a metal sulfide is precipitated and subsequently dissolved in the flowable electrode during the cycling.

24. The method of claim 21, wherein the flowable electrode of the energy storage device is in motion during at least a portion of the cycling.

25. The method of claim 21, wherein reversible cycling of the energy storage device comprises: transporting the flowable electrode through an electrode compartment; inhibiting the flow of the flowable electrode; at least partially charging or discharging a portion of the flowable electrode; and transporting the flowable electrode out of the electrode compartment.


Ramadass Y.K.,Massachusetts Institute of Technology | Chandrakasan A.P.,Massachusetts Institute of Technology
IEEE Journal of Solid-State Circuits | Year: 2011

A battery-less thermoelectric energy harvesting interface circuit to extract electrical energy from human body heat is implemented in a 0.35 μ CMOS process. A mechanically assisted startup circuit enables operation of the system from input voltages as low as 35 mV. An efficient control circuit that performs maximal transfer of the extracted energy to a storage capacitor and regulates the output voltage at 1.8 V is presented. © 2010 IEEE.

Document Keywords (matching the query): storage capacitor, electrical energy, battery less, energy harvesting, thermoelectric energy, thermoelectric energy harvesters.


Kolpak A.M.,Massachusetts Institute of Technology | Grossman J.C.,Massachusetts Institute of Technology
Nano Letters | Year: 2011

Solar thermal fuels, which reversibly store solar energy in molecular bonds, are a tantalizing prospect for clean, renewable, and transportable energy conversion/storage. However, large-scale adoption requires enhanced energy storage capacity and thermal stability. Here we present a novel solar thermal fuel, composed of azobenzene-functionalized carbon nanotubes, with the volumetric energy density of Li-ion batteries. Our work also demonstrates that the inclusion of nanoscale templates is an effective strategy for design of highly cyclable, thermally stable, and energy-dense solar thermal fuels. © 2011 American Chemical Society.

Document Keywords (matching the query): high energy densities, volumetric energy densities, solar energy, renewable energy, li ion batteries, renewable energies, energy storage capacity.


Patent
Massachusetts Institute of Technology | Date: 2015-04-03

Electrochemical cells having molten electrodes having an alkali metal provide receipt and delivery of power by transporting atoms of the alkali metal between electrode environments of disparate chemical potentials through an electrochemical pathway comprising a salt of the alkali metal. The chemical potential of the alkali metal is decreased when combined with one or more non-alkali metals, thus producing a voltage between an electrode comprising the molten alkali metal and the electrode comprising the combined alkali/non-alkali metals.

Claims which contain your search:

1. A method for charging or discharging an energy storage device with the aid of an external load, comprising: (a) providing the energy storage device, comprising:(i) a negative electrode comprising an active alkali metal, wherein the negative electrode has a first volume;(ii) a positive electrode that comprises (i) an active element other than the active alkali metal and (ii) an additive that is present at an amount that decreases a melting point of the positive electrode, wherein the melting point is at a temperature below about 500 C., and wherein the positive electrode has a second volume; and(iii) a liquid electrolyte disposed between the negative electrode and the positive electrode, wherein the liquid electrolyte comprises a halide salt of the active alkali metal that conducts the active alkali metal from the electrolyte to the positive electrode or from the positive electrode to the electrolyte; and (b) charging or discharging the energy storage device through the external load that is electrically coupled to the energy storage device, wherein (i) during discharge of the energy storage device, the first volume decreases and the second volume increases, or (ii) during charge of the energy storage device, the first volume increases and the second volume decreases.

3. The method of claim 1, wherein the negative electrode, the positive electrode, or both is liquid at an operating temperature of the energy storage device.

9. The method of claim 1, wherein the energy storage device has a discharge voltage of less than about 0.7 V when cycled at a current density of about 250 mA/cm ^(2).

10. The method of claim 1, wherein (i) during discharge of the energy storage device, the liquid electrolyte conducts the active alkali metal from the negative electrode, and (ii) during charge of the energy storage device, the liquid electrolyte conducts the active alkali metal from the positive electrode.

11. The method of claim 1, wherein (i) during discharge of the energy storage device, the first volume decreases and the second volume increases, and (ii) during charge of the energy storage device, the first volume increases and the second volume decreases.

12. The method of claim 1, wherein the energy storage device has an energy storage capacity of at least about 30 kWh at an operating temperature of at least about 400 C.

14. An energy storage device comprising: an active alkali metal present in each of a negative electrode, a positive electrode and an electrolyte disposed between the negative electrode and the positive electrode, wherein the electrolyte is liquid at an operating temperature of the energy storage device, and the negative electrode, the positive electrode, or both are liquid at the operating temperature of the energy storage device, and wherein the positive electrode comprises (i) an active element and (ii) an additive that is present at an amount that decreases a melting point of the positive electrode, wherein the melting point is at a temperature below about 500 C.

15. The energy storage device of claim 14, wherein the active alkali metal is present in each of an elemental form in the negative electrode, an alloy form in the positive electrode, and a salt in the electrolyte.

16. The energy storage device of claim 14, wherein the positive electrode is liquid at the operating temperature of the energy storage device.

17. The energy storage device of claim 14, wherein the active element is a material selected from the group consisting of bismuth, antimony, tellurium, selenium and combinations thereof.

18. The energy storage device of claim 14, wherein the additive is lead.

19. The energy storage device of claim 14, wherein the active alkali metal (i) alloys with the active element upon discharge, (ii) de-alloys from the active element upon charge, or (iii) both alloys with the active element upon discharge and de-alloys from the active element upon charge.

20. The energy storage device of claim 14, wherein a ratio of the active element to the additive is between about 18:82 and 66.6:33.3.

21. The energy storage device of claim 14, wherein the electrolyte has a volume that remains substantially constant upon charging or discharging of the energy storage device.

22. The energy storage device of claim 14, wherein, during operation of the energy storage device, the positive electrode increases in volume as the negative electrode decreases in volume, and vice versa.

23. The energy storage device of claim 14, wherein the positive electrode comprises the active element and the additive when the positive electrode is fully depleted of the active alkali metal.

24. The energy storage device of claim 14, wherein the active element and the additive remain in the positive electrode upon charge/discharge.

25. The energy storage device of claim 14, wherein the active alkali metal is a material selected from the group consisting of lithium, sodium, potassium, and combinations thereof.

26. The energy storage device of claim 14, wherein the operating temperature is below about 500 C.

27. The energy storage device of claim 26, wherein the operating temperature is between about 400 C. and 500 C.

28. The energy storage device of claim 14, wherein the electrolyte transfers cations of the alkali metal (i) from the negative electrode to the electrolyte during discharging and (ii) from the positive electrode to the electrolyte during charging.

29. The energy storage device of claim 14, wherein each of the negative electrode, positive electrode and electrolyte is liquid at the operating temperature of the energy storage device.

30. The energy storage device of claim 29, wherein, at the operating temperature, at least two of the negative electrode, positive electrode and electrolyte form a layered structure that is vertically stacked according to respective densities of the negative electrode, the positive electrode and the electrolyte, and wherein the layered structure spontaneously self-assembles upon heating.

31. The energy storage device of claim 14, wherein the electrolyte is at least about 50% thinner than (i) the positive electrode or (ii) the negative electrode.

32. The energy storage device of claim 14, wherein, when fully discharged, the negative electrode is not completely used.


Patent
Massachusetts Institute of Technology | Date: 2015-06-30

An energy storage device configured to exchange energy with an external device includes a container having walls, a lid covering the container and having a safety pressure valve, a negative electrode disposed away from the walls of the container, a positive electrode in contact with at least a portion of the walls of the container, and an electrolyte contacting the negative electrode and the positive electrode at respective electrode/electrolyte interfaces. The negative electrode, the positive electrode and the electrolyte include separate liquid materials within the container at an operating temperature of the battery.

Claims which contain your search:

1. An energy storage device configured to exchange energy with an external device, the energy storage device comprising: a container having walls; a lid that covers the container, the lid having a safety pressure valve; a negative electrode disposed away from the walls of the container; a positive electrode in contact with at least a portion of the walls of the container; and an electrolyte contacting the negative electrode and the positive electrode at respective electrode/electrolyte interfaces, wherein the negative electrode, the positive electrode and the electrolyte comprise separate liquid materials within the container at an operating temperature of the battery.

2. The energy storage device of claim 1, further comprising a structure extending away from the lid and configured to hold the negative electrode away from the walls of the container, wherein the structure extends away from the lid in a direction that is substantially perpendicular to the lid.

3. The energy storage device of claim 1, wherein (i) the negative electrode comprises calcium, magnesium, or a mixture thereof, (ii) the positive electrode includes a material selected from the group consisting of tin, lead, bismuth, antimony, tellurium, selenium, and combinations thereof, or (iii) the negative electrode comprises calcium, magnesium, or a mixture thereof, and the positive electrode includes a material selected from the group consisting of tin, lead, bismuth, antimony, tellurium, selenium, and combinations thereof.

4. The energy storage device of claim 1, wherein the energy storage device comprises one or more cells, and wherein an individual cell comprises the negative electrode, the positive electrode and the electrolyte.

5. The energy storage device of claim 1, wherein, during charge/discharge, a thickness of the electrolyte remains substantially constant.

6. The energy storage device of claim 1, wherein the energy storage device has a power capacity greater than about 1 MW.

7. The energy storage device of claim 1, wherein the positive electrode is liquid, and wherein at least a portion of the positive electrode is capable of providing mass transport rates in excess of diffusive transport rates.

8. The energy storage device of claim 1, wherein, at the operating temperature, at least two of the negative electrode, the positive electrode and the electrolyte form a layered structure that is vertically stacked according to respective densities of the at least two of the negative electrode, the positive electrode and the electrolyte, and wherein the vertically stacked, layered structure spontaneously self-segregates upon heating.

9. An energy storage device, comprising: a container having walls; a lid that covers the container; a negative electrode disposed away from the walls of the container; a positive electrode in contact with at least a portion of the walls of the container; and an electrolyte contacting the negative electrode and the positive electrode at respective electrode/electrolyte interfaces, wherein the electrolyte is liquid at an operating temperature of the energy storage device, wherein the negative electrode, the positive electrode, or both are liquid at the operating temperature of the energy storage device, and wherein the negative electrode comprises an active metal and at least one additional element that is present at an amount that (i) decreases a melting point of the negative electrode or (ii) reduces a thermodynamic activity of the active metal in the negative electrode.

10. The energy storage device of claim 9, wherein the operating temperature is less than about 750 C., and wherein the melting point of the negative electrode is less than or equal to the operating temperature.

11. The energy storage device of claim 10, wherein the operating temperature is greater than about 300 C. and less than about 700 C.

12. The energy storage device of claim 9, wherein the active metal is an active alkaline earth metal, wherein the electrolyte comprises a salt of the active alkaline earth metal and a supporting electrolyte salt that suppresses dissolution of the active alkaline earth metal from the negative electrode into the electrolyte, and wherein the supporting electrolyte salt is ligand-donating.

13. The energy storage device of claim 9, wherein the active metal is an active alkaline earth metal, and wherein the electrolyte comprises a halide salt of the active alkaline earth metal in an amount from about 5 mol % to about 50 mol %, which halide salt of the active alkaline earth metal conducts the active alkaline earth metal from the electrolyte to the positive electrode or from the positive electrode to the electrolyte.

14. The energy storage device of claim 9, wherein the active metal is an active alkaline earth metal, and wherein the electrolyte comprises a mixture of a halide salt of the active alkaline earth metal and a halide salt of an alkali metal.

15. The energy storage device of claim 14, wherein the electrolyte comprises a mixture of calcium chloride with a halide salt of potassium or sodium, and wherein the halide salt of potassium or sodium comprises a chloride, an iodide or a bromide salt of potassium or sodium.

16. The energy storage device of claim 9, wherein the electrolyte has an electrical conductivity of at least about 0.01 siemens/cm.

17. The energy storage device of claim 9, wherein the active metal is calcium and the at least one additional element is magnesium, lithium or sodium.

18. The energy storage device of claim 9, wherein a concentration of the active metal in the negative electrode is (i) greater than about 20% on an atomic basis, (ii) less than about 80% on an atomic basis, or (iii) greater than about 20% on an atomic basis and less than about 80% on an atomic basis.

19. The energy storage device of claim 9, wherein each of the negative electrode, the positive electrode and the electrolyte includes the active metal when the energy storage device is not fully charged, and wherein the positive electrode is nominally free of the active metal when the energy storage device is fully charged.

20. The energy storage device of claim 19, wherein the active metal is present in an elemental form in the negative electrode, an alloy form in the positive electrode and a salt in the electrolyte, and wherein the electrolyte comprises cations of the active metal.

21. The energy storage device of claim 9, wherein each of the negative electrode, positive electrode and electrolyte is liquid at the operating temperature.

22. The energy storage device of claim 9, wherein, during operation, the positive electrode comprises the active metal and at least two additional elements, wherein at least one of the at least two additional elements is present at an amount that adjusts a melting point of the positive electrode, and wherein at least one of the at least two additional elements reduces a thermodynamic activity of the active alkaline earth metal.

23. The energy storage device of claim 22, wherein at least one of the at least two additional elements is tin, lead, bismuth, antimony, tellurium or selenium.

24. The energy storage device of claim 22, wherein the active metal (i) alloys with at least one of the at least two additional elements upon discharge, (ii) de-alloys from at least one of the at least two additional elements upon charge, or (iii) both alloys with at least one of the at least two additional elements upon discharge and de-alloys from at least one of the at least two additional elements upon charge.

25. The energy storage device of claim 9, wherein: (a) the energy storage device is coupled to (i) a power generator, (ii) an intermittent renewable energy converter, (iii) a load center on a transmission line, or (v) a distribution system coupled to a transmission line; or (b) the energy storage device provides (i) load leveling, (ii) re-locatable power supply capacity coupled to a transmission line, (iii) backup or uninterruptible power for a load coupled to a distribution system, or (iv) power buffering between an electrical grid and a load.


Patent
Massachusetts Institute of Technology | Date: 2013-05-09

An apparatus for wirelessly charging an energy storage element is disclosed. The apparatus includes a coil, a set of capacitors, a set of switches and a rectifier. The coil, which has multiple taps, is capable of being energized by a charger via inductive coupling. The capacitors are connected to the coil at various taps. The switches selectively connect the rectifier to at least one of the capacitors to charge the energy storage element that is connected to the rectifier.

Claims which contain your search:

1. An apparatus for wirelessly charging an energy storage element, said apparatus comprising: a rectifier configured to connect to said energy storage element; a coil capable of being energized by a charger via inductive coupling, wherein said coil includes a plurality of taps for supplying various inductances; a plurality of capacitors connected to said coil at said plurality of taps; and a plurality of switches for selectively connecting said rectifier to at least one of said plurality of capacitors for charging said energy storage element.

2. The apparatus of claim 1, wherein said apparatus further includes a resistance measuring circuit for measuring instantaneous resistance of said energy storage element.

5. The apparatus of claim 1, wherein said energy storage element is a rechargeable battery.

6. The apparatus of claim 1, wherein said energy storage element is a capacitor.

9. A method for wirelessly charging an energy storage element, said method comprising: connecting a rectifier to said energy storage element; providing a coil capable of being energized by a charger via inductive coupling, wherein said coil includes a plurality of taps for supplying various inductances; connecting a plurality of capacitors to said coil at said plurality of taps; and selectively connecting said rectifier to at least one of said plurality of capacitors for charging said energy storage element.

10. The method of claim 9, wherein said method further includes measuring instantaneous resistance of said energy storage element.


Patent
Massachusetts Institute of Technology | Date: 2014-02-04

The present invention generally relates to energy storage devices, and to metal sulfide energy storage devices in particular. Some aspects of the invention relate to energy storage devices comprising at least one flowable electrode, wherein the flowable electrode comprises an electroactive metal sulfide material suspended and/or dissolved in a carrier fluid. In some embodiments, the flowable electrode further comprises a plurality of electronically conductive particles suspended and/or dissolved in the carrier fluid, wherein the electronically conductive particles form a percolating conductive network. An energy storage device comprising a flowable electrode comprising a metal sulfide electroactive material and a percolating conductive network may advantageously exhibit, upon reversible cycling, higher energy densities and specific capacities than conventional energy storage devices.

Claims which contain your search:

1. A rechargeable battery, comprising: an anode comprising magnesium; a cathode comprising sulfur; and an electrolyte comprising an equimolar mixture of Mg[N(SO_(2)CF_(3)F)_(2)]_(2 )and a linear ether.


Patent
Massachusetts Institute of Technology | Date: 2015-05-11

A converter circuit and related technique for providing high power density power conversion includes a reconfigurable switched capacitor transformation stage coupled to a magnetic converter (or regulation) stage. The circuits and techniques achieve high performance over a wide input voltage range or a wide output voltage range. The converter can be used, for example, to power logic devices in portable battery operated devices.

Claims which contain your search:

1. A converter circuit comprising: a switched capacitor transformation stage having a transformation stage input port and a transformation stage output port, said switched capacitor transformation stage comprising one or more switches and one or more capacitors and said switched capacitor transformation stage configured to accept an input voltage at the transformation stage input port and provide an intermediate output voltage at the transformation stage output port; an auxiliary converter stage having an input coupled to said switched capacitor transformation stage, said auxiliary converter stage comprising one or more switches and one or more magnetic energy storage components configured to recover energy normally dissipated in capacitors of said switched capacitor transformation stage via said one or more magnetic energy storage components.

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