28754results about "Li-accumulators" patented technology

The present invention relates to nanostructured materials (including nanowires) for use in batteries. Exemplary materials include carbon-comprising, Si-based nanostructures, nanostructured materials disposed on carbon-based substrates, and nanostructures comprising nanoscale scaffolds. The present invention also provides methods of preparing battery electrodes, and batteries, using the nanostructured materials.

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.

The electrode material for a lithium secondary battery according to the present invention includes particles of a solid state alloy having silicon as a main component, wherein the particles of the solid state alloy have a microcrystal or amorphous material including an element other than silicon, dispersed in microcrystalline silicon or amorphized silicon. The solid state alloy preferably contains a pure metal or a solid solution. The composition of the alloy preferably has an element composition in which the alloy is completely mixed in a melted liquid state, whereby the alloy has a single phase in a melted liquid state without presence of two or more phases. The element composition can be determined by the kind of elements constituting the alloy and an atomic ratio of the elements.

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.

Active metal and active metal intercalation electrode structures and battery cells having ionically conductive protective architecture including an active metal (e.g., lithium) conductive impervious layer separated from the electrode (anode) by a porous separator impregnated with a non-aqueous electrolyte (anolyte). This protective architecture prevents the active metal from deleterious reaction with the environment on the other (cathode) side of the impervious layer, which may include aqueous or non-aqueous liquid electrolytes (catholytes) and/or a variety electrochemically active materials, including liquid, solid and gaseous oxidizers. Safety additives and designs that facilitate manufacture are also provided.

Non-aqueous alkali metal (e.g., Li)/oxygen battery cells constructed with a protected anode that minimizes anode degradation and maximizes cathode performance by enabling the use of cathode performance enhancing solvents in the catholyte have negligible self-discharge and high deliverable capacity. In particular, protected lithium-oxygen batteries with non-aqueous catholytes have this improved performance.

A method of modifying the surface of carbon materials such as vapor grown carbon nanofibers is provided in which silicon is deposited on vapor grown carbon nanofibers using a chemical vapor deposition process. The resulting silicon-carbon alloy may be used as an anode in a rechargeable lithium ion battery.

A non-aqueous electrolyte battery separator comprising a heat-resistant nitrogen-containing aromatic polymer and a ceramic powder.

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 system and method for battery protection. In some aspects, a method of conducting an operation including a battery pack, includes the acts of monitoring a first battery pack condition at a first monitoring rate, determining when a second battery pack condition reaches a threshold, after the second battery pack condition reaches the threshold, monitoring the first battery pack condition at a second monitoring rate, the second monitoring rate being different than the first monitoring rate. In some aspects, a method of conducting an operation including a battery, the battery including a cell having a voltage, power being transferable between the cell and the electrical device, a controller operable to control a function of the battery pack, the controller being operable with a voltage at least one of equal to and greater than an operating voltage threshold, the cell being operable to selectively supply voltage to the controller, includes the act of enabling the controller to operate when the voltage supplied by the cell is below the operating voltage threshold.

Disclosed are compositions and methods for alleviating the problem of reaction of lithium or other alkali or alkaline earth metals with incompatible processing and operating environments by creating a ionically conductive chemical protective layer on the lithium or other reactive metal surface. Such a chemically produced surface layer can protect lithium metal from reacting with oxygen, nitrogen or moisture in ambient atmosphere thereby allowing the lithium material to be handled outside of a controlled atmosphere, such as a dry room. Production processes involving lithium are thereby very considerably simplified. One example of such a process in the processing of lithium to form negative electrodes for lithium metal batteries.

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.

The present invention relates to a negative electrode for a lithium metal battery and a lithium metal battery comprising the same. The negative electrode of the present invention comprises a negative active material layer of metallic lithium or a lithium alloy, and a passivation layer formed on the negative active material layer. The passivation layer has a structure comprising a 3-dimensionally cross-linked polymer network matrix penetrated by linear polymers. The passivation layer formed on the surface of the negative electrode reduces reactivity of the negative electrode and stabilizes the surface, so that it offers a lithium metal battery having superior life cycle characteristics.

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.

A number of materials with the composition Li_1+xNi_αMn_βCo_γM′_δO_2−zF_z (M′=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, α is between about 0.2 and 0.6, β is between about 0.2 and 0.6, γ is between about 0 and 0.3, δ is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling.

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.

Electrochemical cells including anode compositions that may enhance charge-discharge cycling efficiency and uniformity are presented. In some embodiments, alloys are incorporated into one or more components of an electrochemical cell, which may enhance the performance of the cell. For example, an alloy may be incorporated into an electroactive component of the cell (e.g., electrodes) and may advantageously increase the efficiency of cell performance. Some electrochemical cells (e.g., rechargeable batteries) may undergo a charge/discharge cycle involving deposition of metal (e.g., lithium metal) on the surface of the anode upon charging and reaction of the metal on the anode surface, wherein the metal diffuses from the anode surface, upon discharging. In some cases, the efficiency and uniformity of such processes may affect cell performance. The use of materials such as alloys in an electroactive component of the cell have been found to increase the efficiency of such processes and to increase the cycling lifetime of the cell. For example, the use of alloys may reduce the formation of dendrites on the anode surface and/or limit surface development.