6881results about "Electrode manufacturing processes" patented technology

The present invention relates to novel electroactive energy storing polyacetylene-co-polysulfur (PAS) materials of general formula (C2Sx)n wherein x is greater than 1 to about 100, and n is equal to or greater than 2. This invention also relates to novel rechargeable electrochemical cells containing positive electrode materials comprised of said polyacetylene-co-polysulfur materials with improved storage capacity and cycle life at ambient and sub-ambient temperatures.

A high kinetics rate electrochemical cell in which at least one of the electrodes is composed of a mesostructural electroactive material comprising nanoparticles forming a three-dimensional framework structure of mesoporous texture having a bicontinuous junction of large specific surface area with the electrolyte. A low temperature method of preparation of the electrodes employs a high-speed deposition of the electrically active material in the form of a thin film. The application of said electrodes in high power lithium ion insertion batteries, photovoltaic cells, supercapacitors and fast electrochromic devices is disclosed.

A compound comprising a composition A_x(M′_1-aM″_a)_y(XD₄)_z, A_x(M′_1-aM″_a)_y(DXD₄)_z, or A_x(M′_1-aM″_a)_y(X₂D₇)_z, and have values such that x, plus y(1-a) times a formal valence or valences of M′, plus ya times a formal valence or valence of M″, is equal to z times a formal valence of the XD₄, X₂D₇, or DXD₄ group; or a compound comprising a composition (A_1-aM″_a)_xM′_y(XD₄)_z, (A_1-aM″_a)_xM′_y(DXD₄)_z(A_1-aM″_a)_xM′_y(X₂D₇)_z and have values such that (1-a)_x plus the quantity ax times the formal valence or valences of M″ plus y times the formal valence or valences of M′ is equal to z times the formal valence of the XD₄, X₂D₇ or DXD₄ group. In the compound, A is at least one of an alkali metal and hydrogen, M′ is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, molybdenum, and tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is at least one of oxygen, nitrogen, carbon, or a halogen, 0.0001<a≦0.1, and x, y, and z are greater than zero. The compound can have a conductivity at 27° C. of at least about 10⁻⁸ S/cm. The compound can be a doped lithium phosphate that can intercalate lithium or hydrogen. The compound can be used in an electrochemical device including electrodes and storage batteries and can have a gravimetric capacity of at least about 80 mAh/g while being charged/discharged at greater than about C rate of the compound.

Combinations of materials are described in which high energy density active materials for negative electrodes of lithium ion batteries. In general, metal alloy/intermetallic compositions can provide the high energy density. These materials can have moderate volume changes upon cycling in a lithium ion battery. The volume changes can be accommodated with less degradation upon cycling through the combination with highly porous electrically conductive materials, such as highly porous carbon and/or foamed current collectors. Whether or not combined with a highly porous electrically conductive material, metal alloy/intermetallic compositions with an average particle size of no more than a micron can be advantageously used in the negative electrodes to improve cycling properties.

An Si/C composite includes carbon (C) dispersed in porous silicon (Si) particles. The Si/C composite may be used to form an anode active material to provide a lithium battery having a high capacity and excellent capacity retention.

A powder material which can electrochemically store and release lithium ions rapidly in a large amount is provided. In addition, an electrode structure for an energy storage device which can provide a high energy density and a high power density and has a long life, and an energy storage device using the electrode structure are provided. In a powder material which can electrochemically store and release lithium ions, the surface of particles of one of silicon metal and tin metal and an alloy of any thereof is coated by an oxide including a transition metal element selected from the group consisting of W, Ti, Mo, Nb, and V as a main component. The electrode structure includes the powder material. The battery device includes a negative electrode having the electrode structure, a lithium ion conductor, and a positive electrode, and utilizes an oxidation reaction of lithium and a reduction reaction of lithium ion.

In an electrode structure for a lithium secondary battery including: a main active material layer formed from a metal powder selected from silicon, tin and an alloy thereof that can store and discharge and capable of lithium by electrochemical reaction, and a binder of an organic polymer; and a current collector, wherein the main active material layer is formed at least by a powder of a support material for supporting the electron conduction of the main active material layer in addition to the metal powder and the powder of the support material are particles having a spherical, pseudo-spherical or pillar shape with an average particle size of 0.3 to 1.35 times the thickness of the main active material layer. The support material is one or more materials selected from a group consisting of graphite, oxides of transition metals and metals that do not electrochemically form alloy with lithium. Organic polymer compounded with a conductive polymer is used for the binder. There are provided an electrode structure for a lithium secondary battery having a high capacity and a long lifetime, and a lithium secondary battery using the electrode structure and having a high capacity, a high energy density and a long lifetime.

Positive electrode active materials are described that have a very high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCO_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the cell. Methods for producing these materials include, for example, a co-precipitation approach involving metal hydroxides and sol-gel approaches.

Methods and articles relating to separation of electrolyte compositions within lithium batteries are provided. The lithium batteries described herein may include an anode having lithium as the active anode species and a cathode having sulfur as the active cathode species. Suitable electrolytes for the lithium batteries can comprise a heterogeneous electrolyte including a first electrolyte solvent (e.g., dioxolane (DOL)) that partitions towards the anode and is favorable towards the anode (referred to herein as an “anode-side electrolyte solvent”) and a second electrolyte solvent (e.g., 1,2-dimethoxyethane (DME)) that partitions towards the cathode and is favorable towards the cathode (and referred to herein as an “cathode-side electrolyte solvent”). By separating the electrolyte solvents during operation of the battery such that the anode-side electrolyte solvent is present disproportionately at the anode and the cathode-side electrolyte solvent is present disproportionately at the cathode, the battery can benefit from desirable characteristics of both electrolyte solvents (e.g., relatively low lithium reactivity of the anode-side electrolyte solvent and relatively high polysulfide solubility of the cathode-side electrolyte solvent).

An electrode for a rechargeable lithium battery which includes a thin film composed of active material that expands and shrinks as it stores and releases lithium, e.g., a microcrystalline or amorphous silicon thin film, deposited on a current collector, characterized in that said current collector exhibits a tensile strength (=tensile strength (N/mm²) per sectional area of the current collector material×thickness (mm) of the current collector) of not less than 3.82 N/mm.

The invention disclosed herein provides for methods and apparatuses that yield electrodes having at least one functional gradient therein. In many embodiments, the electrodes comprise an electrode matrix having a plurality of layers, where at least two of the layers differs functionally, in composition, structure, or, organization. High-throughput electrode screening apparatuses are disclosed that include array formers and testers. Electrodes and battery cells arising from the methods and apparatuses disclosed herein are likewise disclosed. The methods, apparatuses, and resulting electrode and cell devices are, in some embodiments, ideally suited for use in lithium-ion batteries.

There is provided a powder of a lithium transition-metal compound for a positive-electrode material in a lithium secondary battery, in which the use of the powder as that of a positive-electrode material in a lithium secondary battery achieves a good balance among improvement in battery performance, cost reduction, resistance to a higher voltage, and a higher level of safety. The powder of the lithium transition-metal compound for a positive-electrode material in a lithium secondary battery is characterized in that in a mercury intrusion curve obtained by mercury intrusion porosimetry, the amount of mercury intruded is in the range of 0.8 cm³/g to 3 cm³/g when the pressure is increased from 3.86 kPa to 413 MPa.

A system provides an environmental barrier also useful for providing a circuit, for example, one having a thin-film battery such as one that includes lithium or lithium compounds connected to an electronic circuit. An environmental barrier is deposited as alternating layers, at least one of the layers providing a smoothing, planarizing, and/or leveling physical-configuration function, and at least one other layer providing a diffusion-barrier function. The layer providing the physical-configuration function may include a photoresist, a photodefinable, an energy-definable, and/or a maskable layer. The physical-configuration layer may also be a dielectric. A layered structure, including a plurality of pairs of layers, each pair including a physical configuration layer and a barrier layer with low gas-transmission rates, may be used in reducing gas transmission rate to beyond currently detectable levels.

The invention discloses a precipitation method for preparing nanometer level iron phosphate lithium coated with carbon. The method comprises the following steps: firstly, weighing iron salt, deionized water and a compound of metallic elements; after the stirring and the mixing are performed, adding a phosphorous compound and citric acid diluted with water to the mixture; after the stirring is performed again, adding a precipitation agent to the mixture and controlling to the neutrality; stirring to react in a container, and after the static placement, respectively adding the deionized water, a carbon source and lithium salt to mix uniformly after the precipitate is filtered and washed; stirring again to react, and drying the water at 30 to 160 DEG C and warming up at the heating rate under the protection of non-oxidized gas after a product is crashed; baking at a constant temperature of 450 to 850 DEG C, cooling down to a room temperature at a cooling rate or with a stove, and finally obtaining the nanometer level ferric phosphate lithium coated with the carbon after crashing is performed. The precipitation method has the advantage that the raw material cost and the processing cost are low because bivalent iron is taken as the raw material. The iron phosphate lithium prepared by using the process has the characteristics of good physical processing performance and good electrochemistry performance, and is suitable for industrialized production.

Disclosed herein is a cathode active material coated with a fluorine compound for lithium secondary batteries. The cathode active material is structurally stable, and improves the charge-discharge characteristics, cycle characteristics, high-voltage characteristics, high-rate characteristics and thermal stability of batteries.

This invention discloses a silicon carbon compound negative material and its preparation method for Li ionic batteries, which takes silicon and carbon phase compound particles as the base of sphericity or its like covered by a carbon layer. The preparation method includes: crushing the carbon phase particles to be mixed with silicon phase particles and sized to become a compound particle matrix to be covered with the precursor of the organic pyrolyzed carbon then to be carbonized and crushed. Compared with the current technology, this invention takes the compound material of Si and C phase particles as the matrix covered by a compound negative material, in which, the reversible specific volume of which is greater than 450mAh/g, the first circulation coulomb efficiency is greater than 85% and the volume holding rate for 200 times is greater than 80% to greatly reduce the volume effect of the Si activated material when absorbing and discharging Li and improve the diffusion performance of Li in activated materials.

The invention belongs to energy materials, particularly relating to a method for preparing nanometer ferrous phosphate lithium /carbon composite material. In the invention, ferrous source, lithium source, phosphorus source are mixed with a small quantity of doped metal salt and organic macromolecular polymer carbon source according to certain ratio followed by the steps of ball milling, parching and calcining. High temperature sintering is carried out on the above mixture in the atmosphere of non-oxidation gas to obtain nanometer lithium iron phosphate LiMxFe(1-x)PO4/C coated with carbon and LiFe(1-x)NxPO4/C material, and the particle sizes of which are remarkably reduced and are less than 100nm. When the material is applied to battery assemble, 0.2C multiplying power discharge capacity can reach above 160mAh/g at room temperature, 1C multiplying power discharge capacity can be 140-155mAh/g, and 5C multiplying power discharge capacity is 130-150mAh/g. the initial capacity is 120-140mAh/g under the large multiplying power of 10C, and remains more than 90% through thousands of cycles, demonstrating good multiplying power and cycle properties. The invention features low cost, simple production process and fine safety. The prepared nanometer ferrous phosphate lithium /carbon composite material can be widely applied into manufacturing of convenient and fast equipment, electric vehicles and the like.

The invention discloses a preparation method of a multi-place doped lithium iron phosphate anode material and an application thereof, which belong to the technical field of the preparation of electrochemical power materials. The multi-place doped lithium iron phosphate anode material is expressed by the following formula: Li1-xAxFe1-yByP1-zCzO4Ddelta, wherein, at least two of x, y, x and delta can not be expressed zero at the same time. Multi-place doped anode material lithium iron phosphate powder which is used in a secondary lithium-ion battery and has good crystallization performance and even composition is prepared by adopting a solid phase method and a simple mixing and drying process; compared with the method doping in a certain crystal lattice place, the multi-place doped anode material lithium iron phosphate powder has wide doping material source, which can greatly improve the basic capacity and cycling electrical performance of matrix and is applied to a stable industrialized production and non-high-purity materials. The multi-place lithium iron phosphate of the invention is taken as the anode material and is usually used in the secondary lithium-ion battery and the secondary lithium-ion battery is taken as a power source.