409results about How to "Improve discharge characteristics" patented technology

An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one nitrate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkali metal nitrate, alkaline earth metal nitrate and/or an organic alkyl nitrate additive.

An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one phosphonate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl phosphonate additive.

The present invention provides an alkaline battery having good heavy-loading discharge characteristics even after long-term storage at high temperatures. The alkaline battery of the present invention comprises a positive electrode containing manganese dioxide and nickel oxyhydroxide as an active material, a negative electrode containing zinc as an active material, and an alkaline electrolyte. The positive electrode further contains at least one compound selected from the group consisting of an oxygen-containing zinc compound, an oxygen-containing calcium compound, an oxygen-containing yttrium compound, and an oxygen-containing titanium compound.

Carbon powder having low temperature calcined carbon derived from pitch adhered to a portion of the surface of natural graphite powder is obtained by solids mixing of natural graphite powder and pitch powder as a carbon precursor followed by heat treatment at 900-1500° C. to carbonize the pitch. The amount of pitch powder is such that the ratio V2/V1 of the pore volume V2 of pores having a diameter of 50-200 nm to the pore volume V1 of pores having a diameter of 2-50 nm in a pore size distribution curve obtained by analysis of the nitrogen desorption isotherm of the resulting carbon powder by the BJH method is at least 1. This carbon powder can be used as a negative electrode material for a nonaqueous secondary battery able to operate at low temperatures.

A non-aqueous electrolyte secondary battery including: a positive electrode; a negative electrode; a separator interposed between the positive electrode and the negative electrode; a non-aqueous electrolyte; and a porous insulating film adhered to a surface of at least one selected from the group consisting of the positive electrode and the negative electrode, the porous insulating film including an inorganic oxide filler and a film binder, wherein the ratio R of actual volume to apparent volume of the separator is not less than 0.4 and not greater than 0.7, and wherein the ratio R and a porosity P of the porous insulating film satisfy the relational formula: −0.10≦R−P≦0.30.

A negative electrode for a lithium secondary battery obtained by providing an active material layer containing particles of an active material and a binder on a surface of a current collector which is an electrically conductive metal foil, and sintering the layer under a non-oxidizing atmosphere; wherein the mean diameter of the particles of the active material is not smaller than 1 mum and not greater than 10 mum, and the particle size distribution of the particles is such that at least 60 volume % of the particles are in a range of not smaller than 1 mum and not greater than 10 mum.

An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one nitrite additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl nitrite additive.

The object is to provide a nonaqueous-electrolyte battery having high charge/discharge efficiency and excellent high-rate performance. This subject is accomplished by using a nonaqueous electrolyte which comprises an organic solvent and a lithium salt dissolved therein and is characterized by containing at least one quaternary ammonium salt in an amount of 0.06 mol/L or larger and 0.5 mol/L or smaller. This effect is thought to be attributable to the following mechanism: in a relatively early stage (stage in which the negative-electrode potential is relatively noble) in a first charge step, a satisfactory protective coating film is formed on the negative electrode by the action of the quaternary ammonium salt and, hence, the organic solvent employed in the nonaqueous electrolyte is inhibited from decomposing.

Provided is a lithium secondary battery having improved discharge characteristics in a range of high-rate discharge while minimizing a dead volume and at the same time, having increased cell capacity via increased electrode density and electrode loading amounts, by inclusion of two or more active materials having different redox levels so as to exert superior discharge characteristics in the range of high-rate discharge via sequential action of cathode active materials in a discharge process, and preferably having different particle diameters.

Silicon oxide based composite anode active materials including amorphous silicon oxides are provided. In one embodiment, the amorphous silicon oxide is represented by SiO_x (where 0<x<2), has a binding energy of about 103 to about 106 eV, a silicon peak with a full width at half maximum (FWHM) ranging from about 1.6 to about 2.4 as measured by X-ray photoelectron spectrometry, and an atomic percentage of silicon greater than or equal to about 10 as calculated from an area of the silicon peak. The anode active material is a composite anode active material obtained by sintering hydrogen silsesquioxane (HSQ). Anodes and lithium batteries including the anode active material exhibit improved charge and discharge characteristics.

A lithium ion secondary battery is provided. The lithium ion secondary battery generally comprises an electrode assembly, a container for accommodating the electrode assembly; and an electrolyte. The electrode assembly comprises two electrodes having opposite polarities and a separator. The separator comprises a porous membrane comprising clusters of ceramic particles. The porous membrane is formed by bonding the particle clusters with a binder. Each particle cluster is formed either by sintering or by dissolving and re-crystallizing all or a portion of the ceramic particles. The ceramic particles comprise a ceramic material having a band gap. Each particle cluster may have the shape of a grape bunch or a lamina, and may be formed by laminating scale or flake shaped ceramic particles.

A battery provided with terminals, which is capable of being mounted on a circuit board without soldering, is disclosed. The battery includes a battery body 2, and terminals 7 for electrically connecting the battery body 2 to conductive portions 6 provided in a circuit board 5. A portion of each of the terminals 7 is a fixing portion 9 for fixing the battery body 2 to the circuit board 5.

The fixing portion 9 of each of the terminals 7 is provided with engaging portions 12, which penetratingly engage a portion where the conductive portion 6 is provided or a portion in the vicinity of the conductive portion 6, and a contacting portion 11, which contacts the conductive portion 6 to electrically connect the conductive portion 6 to the battery body 2, so that the battery body 2 is fixed in a state of being electrically connected to the conductive portions 6 of the circuit board 5.

A nozzle plate includes a silicon substrate, and a nozzle hole formed in the silicon substrate for discharging a liquid droplet provided with: a first nozzle portion formed perpendicularly to a surface of the silicon substrate; a second nozzle portion formed on a same axis as an axis of the first nozzle portion and having a cross-sectional area that is larger than a cross-sectional area of the first nozzle portion; and an inclined portion having a cross-sectional area gradually increasing from the first nozzle portion to the second nozzle portion.

In a secondary battery including a positive electrode, a negative electrode and a porous film bonded to the surface of at least one of the positive electrode and the negative electrode, the porous film includes ceramic particles and a binder, and the ceramic particles include polycrystalline particles obtained by mechanically crushing a fired material comprising a ceramic that is directly synthesized from a ceramic precursor. The porous film has a porosity of 40 to 80%, for example. The porous film can be formed by a method including the steps of: obtaining a fired material comprising a ceramic from a ceramic precursor; obtaining ceramic particles by mechanically crushing the fired material of the ceramic; obtaining a slurry including the ceramic particles and a binder; and applying the slurry onto the surface of an electrode, followed by drying.

A lithium secondary battery has a cathode made of carbon material capable of occluding or emitting a lithium ion, a cathode made of lithium-contained oxide, and a non-aqueous electrolyte. The non-aqueous electrolyte includes a lithium salt containing LiPF₆ and LiBF₄; and a non-linear carbonate-based mixed organic solvent in which (a) a cyclic carbonate having ethylene carbonate or a mixture of ethylene carbonate and propylene carbonate and (b) a propionate-based ester such as ethyl propionate are mixed at a volume ratio (a:b) in the range from about 10:90 to about 70:30. This lithium secondary battery ensures excellent high-rate charging/discharging characteristics and improved life cycle and low-temperature discharging characteristics since it includes a predetermined mixed organic solvent not including a linear carbonate. Also, since gas generation is restrained at a high temperature, a battery set may be mounted in a more improved way.

An air battery that is excellent in heavy-load discharge characteristics and storage characteristics is provided by ensuring the stability of the three-phase interface of a catalyst layer of an air electrode. The air battery has an air electrode including a catalyst layer that is bonded under pressure to a current collector and a water-repellent film. The catalyst layer includes a catalyst for reducing oxygen, a promoter for decomposing a product of the oxygen reduction, conductive carbon, and a binder. A non-polymeric fluorine compound is added to the catalyst layer in order to enhance the water repellency of the catalyst layer.

A cathode active material for a lithium secondary battery includes a lithium metal oxide secondary particle core formed by agglomerating lithium metal oxide primary particles; and a shell formed by coating the secondary particle core with barium titanate and metal oxide. This cathode active material allows making a lithium secondary battery having improved safety, particularly in thermal stability and overcharging characteristics.

Using a graphite material capable of intercalating and de-intercalating lithium ions as the anode, the peak intensity ratio R(=I(110)/I(004)) corresponding to lattice planes (110) and (004) of graphite material obtained by wide angle X-ray diffraction measurement of this anode is in a range of 0.05 to 0.5. Hence, edges of graphite crystals exist adequately on the electrode surface at the interface to the electrolyte, and therefore intercalation of lithium proceeds smoothly, polarization at the time of charging and discharging is suppressed, and a nonaqueous electrolyte secondary battery excellent in high rate discharging characteristic is obtained. The obtained battery is small in deterioration if charging and discharging are repeated.

Stabilized lithiated manganese oxide (LMO) is prepared by reacting cubic spinel lithium manganese oxide particles and particles of an alkali metal compound in air for a time and at a temperature sufficient to decompose at least a portion of the alkali metal compound, providing a treated lithium manganese oxide. The reaction product is characterized as particles having a core or bulk structure of cubic spinel lithium manganese oxide and a surface region which is enriched in Mn⁺⁴ relative to the bulk. X-ray diffraction data and x-ray photoelectron spectroscopy data are consistent with the structure of the stabilized LMO being a central bulk of cubic spinel lithium manganese oxide with a surface layer or region comprising A₂MnO₃, where A is an alkali metal. Electrochemical cells containing the stabilized LMO of the invention have improved charging and discharging characteristics and maintain integrity over a prolonged life cycle. The electrochemical cells are stabilized against decomposition of cell components, including electrode and electrolyte components.