Nanotek Instruments, Inc.

Samsung Electronics Co., Ltd.

Global Graphene Group, Inc.

Qing Fang

Bor Z Jang

Aruna Zhamu

Guorong Chen

Yanbo Wang

Jinjun Shi

Xiqing Wang

Yu-Sheng Su

Hui He

Xiging Wang

Minjie Li

Wei Xiong

Jun Yin

Ming C Wang

An electrochemical battery cell comprising an anode having a primary anode active material, a cathode, and an ion-conducting electrolyte, wherein the cell has an initial output voltage, Vi, measured at 10% depth of discharge (DoD), selected from a range from 0.3 volts to 0.8 volts, and a final output voltage Vf measured at a DoD no greater than 90%, wherein a voltage variation, (Vi&#x2212;Vf)/Vi, is no greater than &#xb1;10% and the specific capacity between Vi and Vf is no less than 100 mAh/g or 200 mAh/cmbased on the cathode active material weight or volume, and wherein the primary anode active material is selected from lithium (Li), sodium (Na), potassium (K), magnesium (Mg), aluminum (Al), zinc (Zn), titanium (Ti), manganese (Mn), iron (Fe), vanadium (V), cobalt (Co), nickel (Ni), a mixture thereof, an alloy thereof, or a combination thereof.

Battery having a low output voltage

Disclosed herein is a composite particulate comprising a plurality of active material particles; and a single graphene sheet or a plurality of graphene sheets surrounds the plurality of active material particles and a surface of the composite particulate, wherein a single graphene sheet or a plurality of graphene sheets provides an electron-conducting path.

Graphene-enhanced anode particulates for lithium ion batteries

A dual electroplating cell comprising: (a) an electrolyte component containing therein ions of a first metal; (b) a porous cathode current collector having surface areas to capture and store metal ions directly thereon, wherein the cathode current collector has a specific surface area greater than 100 m/g that is in direct contact with said electrolyte; (c) a porous anode current collector having surface areas to capture and store metal ions thereon, wherein the anode current collector has a specific surface area greater than 100 m/g that is in direct contact with the electrolyte; (d) a porous separator disposed between the anode and the cathode; and (e) an ion source of the first metal disposed in the anode current collector or the cathode current collector and in electronic contact therewith to obtain an open circuit voltage (OCV) from 0.3 volts to 3.5 volts when the cell is made.

Rechargeable dual electroplating cell

A nano graphene-enhanced particulate for use as a lithium-ion battery anode active material, wherein the particulate is formed of a single sheet of graphene or a plurality of graphene sheets and a plurality of fine anode active material particles with a size smaller than 10 &#x3bc;m. The graphene sheets and the particles are mutually bonded or agglomerated into the particulate with at least a graphene sheet embracing the anode active material particles. The amount of graphene is at least 0.01% by weight and the amount of the anode active material is at least 0.1% by weight, all based on the total weight of the particulate. A lithium-ion battery having an anode containing these graphene-enhanced particulates exhibits a stable charge and discharge cycling response, a high specific capacity per unit mass, a high first-cycle efficiency, a high capacity per electrode volume, and a long cycle life.

A process for producing an anode layer, comprising: (a) dispersing catalyst metal-coated Si particles, graphene sheets, and an optional blowing agent in a liquid medium to form a graphene/Si dispersion; (b) dispensing and depositing the dispersion onto a supporting substrate to form a wet layer and removing the liquid medium from the wet layer to form a dried layer of graphene/Si mixture material; and (c) exposing the dried layer to a high temperature environment, from 300&#xb0; C. to 2,000&#xb0; C., to induce volatile gas molecules from graphene sheets or to activate the blowing agent for producing the graphene foam and, concurrently, to enable a catalyst metal-catalyzed growth of multiple Si nanowires emanated from Si particles as a feed material in pores of the foam to form the anode layer; wherein the Si nanowires have a diameter of 5-100 nm and a length-to-diameter aspect ratio of at least 5.

Lithium ion battery anode containing silicon nanowires grown in situ in pores of graphene foam and production process

Disclosed is a process for producing silicon nanowires having a diameter or thickness less than 100 nm, comprising: (A) preparing a solid silicon source material in a particulate form having a size from 0.2 &#x3bc;m to 20 &#x3bc;m or in a porous structure form having a specific surface area greater than 50 m/g; (B) depositing a catalytic metal, in the form of nano particles having a size from 0.5 nm to 100 nm or a coating having a thickness from 1 nm to 100 nm, onto surfaces of the silicon source material to form a catalyst metal-coated silicon material; and (C) exposing the catalyst metal-coated silicon material to a high temperature environment, from 300&#xb0; C. to 2,000&#xb0; C., for a period of time sufficient to enable a catalytic metal-catalyzed growth of multiple silicon nanowires from the silicon source material.

Process for producing silicon nanowires directly from silicon particles

Disclosed is a process for producing graphene-silicon nanowire hybrid material, comprising: (A) preparing a catalyst metal-coated mixture mass, which includes mixing graphene sheets with micron or sub-micron scaled silicon particles to form a mixture and depositing a nano-scaled catalytic metal onto surfaces of the graphene sheets and/or silicon particles; and (B) exposing the catalyst metal-coated mixture mass to a high temperature environment (preferably from 300&#xb0; C. to 2,000&#xb0; C., more preferably from 400&#xb0; C. to 1,500&#xb0; C., and most preferably from 500&#xb0; C. to 1,200&#xb0; C.) for a period of time sufficient to enable a catalytic metal-catalyzed growth of multiple silicon nanowires using the silicon particles as a feed material to form the graphene-silicon nanowire hybrid material composition. An optional etching or separating procedure may be conducted to remove catalytic metal or graphene from the Si nanowires.

Process for silicon nanowire-graphene hybrid mat

A method of operating a lithium-ion cell comprising (a) a cathode comprising a carbon or graphitic material having a surface area to capture and store lithium thereon; (b) an anode comprising an anode active material; (c) a porous separator disposed between the two electrodes; (d) an electrolyte in ionic contact with the two electrodes; and (e) a lithium source disposed in at least one of the two electrodes to obtain an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made; wherein the method comprises: (A) electrochemically forming the cell from the OCV to either a first lower voltage limit (LVL) or a first upper voltage limit (UVL), wherein the first LVL is no lower than 0.1 volts and the first UVL is no higher than 4.6 volts; and (B) cycling the cell between a second LVL and a second UVL.

Method of operating a lithium-ion cell having a high-capacity cathode

Process for mass-producing silicon nanowires and silicon nanowire-graphene hybrid particulates

This invention provides a graphite or graphite-carbon particulate for use as a lithium secondary battery anode material having a high-rate capability. The particulate is formed of a core carbon or graphite particle and a plurality of satellite carbon or graphite particles that are each separately bonded to the core particle wherein the core particle is spherical in shape, slightly elongate in shape with a major axis-to-minor axis ratio less than 2, or fibril in shape, and wherein the satellite particles are disc-, platelet-, or flake-like particles each containing a graphite crystallite with a crystallographic c-axis dimension Lc and a lateral dimension. Preferably, Lc is less than 100 nm and the flake/platelet lateral dimension is less than 1 &#x3bc;m. The core particle may be selected from natural graphite, artificial graphite, spherical graphite, graphitic coke, meso-carbon micro-bead, soft carbon, hard carbon, graphitic fibril, carbon nano-fiber, carbon fiber, or graphite fiber. Preferably, the flat-shaped particles are randomly oriented with respect to one another.

Graphite or carbon particulates for the lithium ion battery anode

A lithium-ion cell comprising: (A) a cathode comprising graphene as the cathode active material having a surface area to capture and store lithium thereon and wherein said graphene cathode is meso-porous having a specific surface area greater than 100 m/g; (B) an anode comprising an anode active material for inserting and extracting lithium, wherein the anode active material is mixed with a conductive additive and/or a resin binder to form a porous electrode structure, or coated onto a current collector in a coating or thin film form; (C) a porous separator disposed between the anode and the cathode; (D) a lithium-containing electrolyte in physical contact with the two electrodes; and (E) a lithium source disposed in at least one of the two electrodes when the cell is made. This new Li-ion cell exhibits an unprecedentedly high energy density.

Lithium-ion cell having a high-capacity anode and a high-capacity cathode

This invention provides a portable computing device powered by a surface-mediated cell (SMC)-based power source, the portable device comprising a computing hardware sub-system and a rechargeable power source electrically connected to the hardware and providing power thereto, wherein the power source contains at least a surface-mediated cell. The portable computing device is selected from a laptop computer, a tablet, an electronic book (e-book), a smart phone, a mobile phone, a digital camera, a hand-held calculator or computer, or a personal digital assistant.

Surface-mediated cell-powered portable computing devices and methods of operating same

A portable power tool comprises an electric motor, actuator, or light-emitting hardware and a rechargeable power source connected to the electric motor, actuator, or light-emitting hardware, wherein the power source contains at least a surface-mediated cell (SMC). The power tools include, but are not limited to, impact driver, air compressor, alligator shear, angle grinder, band saw, belt sander, biscuit joiner, ceramic tile cutter tile saw, chainsaw, circular saw, concrete saw, cold saw, crusher, diamond blade, diamond tools, disc sander, drill, floor sander, grinding machine, heat gun, impact wrench, jackhammer, jointer, jigsaw, lathe, miter saw, nail gun, needle scaler, torque wrench, powder-actuated tools, power wrench, radial arm saw, random orbital sander, reciprocating saw, rotary reciprocating saw, rotary tool, sabre saw, sander, scroll saw, steel cut off saw, table saw, thickness planer, trimmer, wall chaser, wood router, or flashlight.

Growing community of inventors

Fairborn, OH, United States of America

Qing Fang