89results about How to "Large discharge capacity" patented technology

A carbonaceous material has a plane space d002 of a (002) plane less than 0.337 nm in an X-ray wide angle diffraction method, a crystallite size (Lc) of 90 nm or higher, an R value, as a peak intensity ratio of a peak intensity of 1360 cm<HIL><−1 </SP><PDAT>to a peak intensity of 1580 cm<HIL><−1 </SP><PDAT>in a Raman spectrum in use of an argon ion laser, of 0.20 or higher, and a tap density of 0.75 g/cm<HIL><3 </SP><PDAT>or higher. Also disclosed is a multilayer structure carbonaceous material for electrode, which is manufactured by carbonizing some organic compounds where the carbonaceous material for electrode is mixed with the organic compounds. The battery using the carbonaceous material for electrode or the multilayer structure carbonaceous material for electrode has a large capacity, a small irreversible capacity admitted in the initial cycle, excellent capacity maintaining rate of the cycle, and particularly, largely improved quick charging and discharging characteristics.</PTEXT>

A positive-electrode active material with improved electrical conductivity, and a power storage device using the material are provided. A positive-electrode active material with large capacity, and a power storage device using the material are provided. A core including lithium metal oxide is used as a core of a main material of the positive-electrode active material, and one to ten pieces of graphene is used as a covering layer for the core. A hole is provided for graphene, whereby transmission of a lithium ion is facilitated, resulting in improvement of use efficiency of current.

Provided is a method for manufacturing a power storage device in which a crystalline silicon layer including a whisker-like crystalline silicon region is formed as an active material layer over a current collector by a low-pressure CVD method in which heating is performed using a deposition gas containing silicon. The power storage device includes the current collector, a mixed layer formed over the current collector, and the crystalline silicon layer functioning as the active material layer formed over the mixed layer. The crystalline silicon layer includes a crystalline silicon region and a whisker-like crystalline silicon region including a plurality of protrusions which project over the crystalline silicon region. With the protrusions, the surface area of the crystalline silicon layer functioning as the active material layer can be increased.

A lithium-air battery includes a lithium negative electrode, a positive electrode including a catalyst containing gold, and a non-aqueous electrolyte interposed between the positive electrode and the lithium negative electrode. The catalyst includes gold supported on a cerium-containing oxide, such as a cerium-zirconium compound oxide or a cerium-aluminum compound oxide. The amount of catalyst of the positive electrode is in the range of 0.01 to 50 weight percent relative to the total weight of the positive electrode.

The invention provides a non-aqueous electrolyte cell having a high working voltage in a low temperature range of 0° C. or below and thereby attaining excellent low temperature discharge characteristics, a reduced internally-generated gas, and an excellent safety against heat. This is achieved by a cell comprising a non-aqueous electrolyte containing propylene carbonate and LiN(SO2C2F5)2 as an electrolyte salt, a graphite negative electrode, and a positive electrode having a positive electrode active material comprising a Ti-attached LiCoO2 in which a particle of titanium and/or titanium compound is attached on a surface of a particle of lithium cobalt oxide and a mole ratio of titanium and/or titanium compound in the Ti-attached LiCoO2 is within the range of from 0.00001 to 0.02.

A surface graphitized carbon material comprising a graphitic surface and a carbonaceous internal part. This surface graphitized carbon material can be produced by contacting a carbon material with a metal having catalytically graphitizing activity or a compound thereof to thereby cause the metal or compound thereof to be present in a surface of the carbon material and heating the carbon material at 300 to 1500 DEG C. in an inert atmosphere. By virtue of the possession of a graphitic surface and a carbonaceous internal part, the surface graphitized carbon material of the present invention simultaneously has the properties of the carbon material such that, when used in a negative electrode for lithium-ion secondary battery, a negative electrode having high charge and discharge capacities, being excellent in performance at low temperature, and facilitating a display of residual capacity can be obtained, and the properties of the graphite material such that a negative electrode whose cycle deterioration of charge and discharge capacities is slight can be obtained.

The invention provides a carbon material for a battery electrode, which comprises a carbon powder material as a composite of carbonaceous particles and an a carbon material derived from an organic compound prepared by allowing the organic compound serving as a polymer source material to deposit onto and/or permeate into the carbonaceous particles to thereby polymerize the polymer material and then heating at 1,800 to 3,300° C., and which has an intensity ratio of 0.1 or more for peak intensity attributed to a (110) plane to peak intensity attributed to a (004) plane determined through X-ray diffraction spectroscopic analysis on a mixture of the carbon material and a binder resin when pressed at 10³ kg/cm² or higher. The carbon material which undergoes less deformation/orientation due to application of pressure, has high discharge capacity and small irreversible capacity and exhibiting excellent coulombic efficiency, cycle characteristics and leakage-current load characteristics.

The invention provides novel lithium-containing phosphate materials having a high proportion of lithium per formula unit of the material. Upon electrochemical interaction, such material deintercalates lithium ions, and is capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-containing phosphates.

An object of the present invention is to provide an electrolyte solution for lithium-ion secondary batteries comprising a tetraalkylphosphonium salt which improves the cycle characteristics and safety of lithium-ion batteries, and to provide a lithium-ion secondary battery using the electrolyte solution. Disclosed is an electrolyte comprising a tetraalkylphosphonium salt represented by general formula (1)

wherein R₁ represents a linear, branched or alicyclic alkyl group having 2 to 6 carbon atoms and R₂ represents a linear, branched or alicyclic alkyl group having 1 to 14 carbon atoms, provided that R₁ and R₂ are different from each other and the total number of carbon atoms in the phosphonium cation is 20 or less; and X represents an anion.

Lithium cobalt oxide, which can provide a nonaqueous electrolyte secondary battery having an excellent initial capacity and an excellent capacity retention, and a method for manufacturing the same are provided. The lithium cobalt oxide has a tap density of at least 1.7 g/cm³ and a pressed density of 3.5 to 4.0 g/cm³. A method for manufacturing the lithium cobalt oxide includes the step of selecting a lithium cobalt oxide (A) and a lithium cobalt oxide (B) so that a difference in the tap density between the lithium cobalt oxide (A) and the lithium cobalt oxide (B) is at least 0.2 g/cm³; and mixing the lithium cobalt oxide (A) and the lithium cobalt oxide (B).

Provided is a negative-electrode material powder for a lithium-ion secondary battery including a conductive carbon film on the surface of a silicon oxide powder, in which the total content of tar components is not less than 1 ppm and not more than 4000 ppm, and in the Raman spectrum, peaks exist at 1350 cm⁻¹ and 1580 cm⁻¹, while the peak at 1580 cm⁻¹ has a half-value width of not less than 50 cm⁻¹ and not more than 100 cm⁻¹. In the negative-electrode material powder, a specific surface area is preferably not less than 0.3 m²/g and not more than 40 m²/g, and the proportion of the conductive carbon film is preferably not less than 0.2 mass % and not more than 10 mass %. This makes it possible to provide a negative-electrode material powder which can be used to obtain a lithium-ion secondary battery with large discharge capacity and satisfactory cycle characteristics.

A positive electrode active material including lithium (Li), nickel (Ni), manganese (Mn) and a transition metal that can be in the hexavalent state is used. As the transition metal that can be in the hexavalent state, for example, one or both of tungsten (W) and molybdenum (Mo) can be used. As the positive electrode active material including a plurality of materials as mentioned above, LiNi_0.5Mn_0.5O₂ can be used. As a negative electrode, a carbon material or a silicon material capable of storing and releasing lithium ions can be used.

Providing a negative-electrode material for nonaqueous-electrolyte secondary battery, the negative-electrode material including lithium silicate particles coated by a carbonaceous substance, a production process for the same, a negative electrode for nonaqueous-electrolyte secondary battery, and a nonaqueous-electrolyte secondary battery.

A negative-electrode material for nonaqueous-electrolyte secondary battery includes lithium silicate particles having a surface at least some of which is coated by a carbonaceous substance formed by heating a carbon-containing compound at a thermal decomposition temperature of the carbon-containing compound or more and 1,100° C. or less, the carbon-containing compound being a solid at ordinary temperature and exhibiting a zeta-potential absolute value being 60 or more against N-methyl-2-pyrrolidone (or NMP).

An object of the present invention is to provide a non-aqueous electrolyte air battery with large discharge capacity and excellent rate characteristics. Disclosed is a non-aqueous electrolyte air battery including an air cathode, an anode and a non-aqueous electrolyte present between the air cathode and anode, wherein the non-aqueous electrolyte includes an ionic liquid as the solvent, the ionic liquid including bis(fluorosulfonyl)amide as the anion portion.

A negative electrode material for a lithium ion battery containing a composite material, the composite material including silicon-containing particles, graphitic carbon material particles, and a carbonaceous carbon material, in which the composite material has a ratio (A/B) of an area (A) of a peak near 100 eV derived from metal Si to an area (B) of a peak near 103 eV derived from silicon oxide, as measured by XPS, of not less than 0.10 and not more than 2.30. Also disclosed is a paste including the negative electrode material, as well as a negative electrode for a lithium ion battery including a formed body of the paste and a lithium ion battery including the negative electrode.

The present invention provides a sodium secondary battery capable of reducing the amount used of a scarce metal element such as lithium and cobalt and moreover, ensuring a larger discharge capacity after repeating charge/discharge as compared with conventional techniques, and a mixed metal oxide usable as the positive electrode active material therefor. The mixed metal oxide of the present invention comprises Na, Mn and M¹ wherein M¹ is Fe or Ni, with a Na:Mn:M¹ molar ratio being a:(1-b):b wherein a is a value falling within the range of more than 0.5 and less than 1, and b is a value falling within the range of from 0.001 to 0.5. Another mixed metal oxide of the present invention is a mixed metal oxide represented by the following formula (1): Na_aMn_1-bM¹_bO₂ (1) wherein M¹, a and b each have the same meaning as above. The positive electrode active material for sodium secondary batteries of the present invention comprises the mixed metal oxide above.

According to the present invention, milled carbon fiber is mixed with a boron compound and graphitized in the presence of nitrogen, and thereafter subjected to modifying treatment by applying impact selectively to fiber edge parts of the carbon fiber. The present invention can provide a graphite material produced in such a way that the milled carbon fiber is highly graphitized and the fiber edge parts of the graphitized milled carbon fiber is subjected to a modifying treatment in the above procedure. The graphite material is suitable for a negative electrode of a lithium secondary battery capable of facilitating entering and leaving (doping and undoping) of lithium ions, having large discharge capacity and high charge/discharge efficiency and excellent charge/discharge cyclability. The present invention also provides a process for producing such graphite materials.

The present invention provides an alkaline battery suitable for use as a primary or secondary battery as a power source of electronic appliances. The battery is excellent in discharge characteristics under a heavy load and in cycle characteristics.

The alkaline battery (100) comprises a cathode mix (3) containing β-nickel oxy-hydroxide, an anode mix (5) containing zinc as a main component of anode active material, and an alkali solution as an electrolyte, wherein the cathode mix (3) includes a mixture of β-nickel oxy-hydroxide, graphite powder, and a potassium hydroxide solution in a given weight ratio. The β-nickel oxy-hydroxide is prepared by chemical oxidation and has an approximately spherical shape of particle with a mean particle size in the range of 5 to 50 μm.

A nonaqueous electrolyte secondary battery which comprises a positive electrode including particles of lithium-containing layered nickel oxide represented by a general formula Li_aNi_xCo_yAl_zM_bO₂, wherein 0.3≦a≦1.05, 0.7≦x≦0.87, 0.1≦y≦0.27, 0.03≦z≦0.1, 0≦b≦0.1; M is at least one selected from metallic elements except Ni, Co and Al. In the binding energy of the oxygen 1s spectrum when measuring the particles by XPS, if the peak area appearing at 529 eV is set to D; the peak area appearing at 531 eV is set to E; oxygen concentration ratio is set to D/(D+E); and the oxygen concentration ratios at depths of L1 nm and L2 nm from the particle surface are respectively set to α_L1 and α_L2, the combination of L1 and L2 in which (α_L2−α_L1)/α_L2≦0.1, L1≦100, L2≧500 is present.

The present invention provides an electrode that can be used for a sodium secondary battery having a larger discharge capacity when charging and discharging are performed repeatedly than that of the prior art. This sodium secondary battery electrode contains tin (Sn) powder as an electrode active material. The electrode, particularly, further contains one or more electrode-forming agents selected from the group consisting of poly(vinylidene fluoride) (PVDF), poly(acrylic acid) (PAA), poly(sodium acrylate) (PAANa), and carboxymethylcellulose (CMC), thereby making it possible to provide a sodium secondary battery having even greater electrode performance.