41results about How to "Inhibition of capacity decline" patented technology

The present invention provides a water based lithium secondary battery that can inhibit deteriorations in capacity owing to charge-and-discharge operations and maintain a high capacity even after it is charged and discharged repeatedly. The water based lithium secondary battery includes a positive electrode, a negative electrode, a separator sandwiched between these, and an aqueous electrolyte solution obtained by dissolving an electrolyte made of a lithium salt in a water based solvent. As the water based solvent, a pH buffer solution is employed. The buffer solution is obtained by dissolving an acid and its conjugate base's salt, a base and its conjugate acid's salt, a salt made from a weak acid and a strong base, a salt made from a weak base and a strong acid, or a salt made from a weak acid and a weak base in water.

A lithium secondary battery according to the present invention includes: a positive electrode having a positive-electrode active material capable of occluding and releasing lithium ions; a negative electrode having a negative-electrode active material capable of occluding and releasing lithium ions; a separator interposed between the positive electrode and the negative electrode; and an electrolyte having lithium-ion conductivity. The positive-electrode active material contains a nickel-type lithium-containing complex oxide. The negative-electrode active material contains a graphite-type material having a reversible capacity of 350 mAh/g or more and an irreversible capacity of 30 mAh/g or less. A ratio Qc/Qa between an irreversible capacity Qc per unit area in a portion of the positive electrode that opposes the negative electrode and an irreversible capacity Qa per unit area in a portion of the negative electrode that opposes the positive electrode is equal to or greater than 0.50 but less than 1.13. As a result, the charge-discharge cycle characteristics can be improved while ensuring a high capacity.

An auxiliary power unit of the present invention has an auxiliary lithium-ion secondary battery, a charge connector connected to the auxiliary lithium-ion secondary battery and adapted to receive power from an external charger, and a supply connector connected to the auxiliary lithium-ion secondary battery and adapted to supply power of the auxiliary lithium-ion secondary battery to an external portable device, and the auxiliary lithium-ion secondary battery is constructed so that each of thicknesses of cathode active material and anode active material layers is in the range of 10 to 40 μm.

A lithium ion secondary battery includes a positive electrode containing a composite lithium oxide, a negative electrode capable of absorbing and desorbing lithium ions, a sheet-like separator interposed between the positive electrode and the negative electrode, a non-aqueous electrolyte and a porous electron-insulating film attached to the surface of the negative electrode. The sheet-like separator is a monolayer film made of polypropylene resin or a multilayer film whose layer to be in contact with the positive electrode is made of polypropylene resin. The porous electron-insulating film includes an inorganic oxide filler and a binder. The sheet-like separator has a thickness not less than 1.5 times the thickness of the porous electron-insulating film.

[Object] Provided is a means capable of suppressing a decrease in capacity and improving output characteristics of a non-aqueous electrolyte secondary battery when the battery is used for a long period of time.

[Solving Means] Disclosed is a positive electrode active substance for a non-aqueous electrolyte secondary battery, in which the true density/tap density of secondary particles of a lithium composite oxide containing nickel as the main component is within the range of 1.6 to 2.3, and in the secondary particles, the average porosity on the center side of the half (R/2 [μm]) of the particle radius (R) of D50 of the secondary particles is larger than the average porosity on the surface side.

[Object] Provided is a means which is capable, with respect to a non-aqueous electrolyte secondary battery, of suppressing a decrease in capacity when the battery is used for a long period of time, and improving cycle characteristics.

[Solving Means] Disclosed is a positive electrode active substance for a non-aqueous electrolyte secondary battery comprising a composite oxide containing lithium and nickel, in which the positive electrode active substance has a structure of secondary particles formed by aggregation of primary particles, the average particle diameter of the primary particles (D1) is 0.9 μm or less, and the average particle diameter of the primary particles (D1) and the standard deviation (σ) of the average particle diameter of the primary particles (D1) meet the relationship of D1/σ²≧24.

A battery capable of inhibiting decrease in capacity and inhibiting swollenness even in hot environment is provided. A battery comprises a cathode, an anode and an electrolyte inside a film exterior member. The electrolytic solution contains carboxylate ester or ketone, in which a third alkyl group is directly bonded to a carbonyl group. Thereby, decomposition reaction of the solvent in the cathode is inhibited.

Provided is a battery in which an area density S (mg/cm²) of a positive electrode active material layer is 27 mg/cm² or greater, and a porous film included in a separator has a structure satisfying the following Expressions.

0.04≦Ri≦−0.07L−0.09×S+4.99

ε′=[{(L×ε/100)−Rz×0.46/3}/L]×100

τ={(1.216×ε′Td×10⁻⁴)/L}^0.5  (Expressions)

A lithium ion secondary battery comprising: a positive electrode comprising a positive electrode active material; a negative electrode comprised mainly of a material capable of storing and releasing lithium ions; and an electrolytic liquid,

• • the positive electrode active material being a lithium-iron-manganese complex oxide having a layered rock salt structure and represented by a chemical formula:

Li_xFe_sM¹_(z-s)M²_yO_2-δ

• •  wherein 1.05≦x≦1.32, 0.06≦s≦0.50, 0.06≦z≦0.50, 0.33≦y≦0.63, and 0≦δ≦0.80; M¹ represents a metal selected from the group consisting of Co, Ni, Mn and a mixture thereof; and M² represents a metal selected from the group consisting of Mn, Ti, Zr and a mixture thereof,
  • the electrolytic liquid comprising 1,1,2,3,3,3-hexafluoropropyl difluoromethyl ether represented by the following formula (1):

The invention discloses a lithium ion battery, and belongs to the field of material preparation. The lithium ion battery comprises a shell, a base material of the shell is magnesium alloy, and the surface of the shell is provided with a micro-arc oxidized ceramic layer; the thickness of the micro-arc oxidized ceramic layer is 5 micrometers to 40 micrometers, and the phase composition mainly comprises magnesium fluoride, trifluoro-magnesium potassium and a small amount of magnesium oxide, wherein the PBR of magnesium fluoride is larger than 1. The invention further discloses a preparation method of the battery shell. According to the lithium ion battery, magnesium alloy of which the surface is provided with the micro-arc oxidized ceramic layer is applied to the lithium-ion power battery shell, and therefore the mass of the prepared battery shell is decreased by about 60% relative to a stainless steel shell; the battery shell does not spontaneously burn if the battery shell burns within 5 minutes at 1,000 DEG C; through 1,000 times of circulating charge and discharge testing, no obvious lithium inserting phenomenon is generated in a Mg-Li electric pair.

Provided is a lithium secondary cell which has high capacity, suppresses deterioration in capacity and improves cycle characteristics particularly when used in high-temperature environments and has long lifespan. Provided is a lithium secondary cell including a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material and an electrolytic solution for immersing the positive and negative electrode active material layers, wherein the electrolytic solution contains at least one certain ester compound.

A positive electrode active material for a lithium ion secondary battery having high discharge energy and capable of suppressing capacity drop with cycles and a secondary battery using the same are provided at lower cost. A positive electrode active material for a secondary battery according to a first aspect of the exemplary embodiment is represented by the following formula (I): Li_a(Fe_xNi_yMn_2-x-y)O₄ (I) where 0.2<x≦1.2, 0<y<0.5 and 0≦a≦1.2. Furthermore, a positive electrode active material for a secondary battery according to a second aspect of the exemplary embodiment is represented by the following formula (II): Li_a(Fe_xNi_yMn_2-x-y-zA_z)O₄ (II) where 0.2≦x≦1.2, 0<y<0.5, 0≦a≦1.2 and 0<z≦0.3; A is at least one selected from the group consisting of Li, B, Na, Mg, Al, K and Ca.

An electrolyte solution comprising: a non-aqueous solvent; a lithium salt; at least one fluorine-containing compound selected from the group consisting of a fluorine-containing ether compound represented by formula (1) and a fluorine-containing carbonate compound represented by formula (2); and at least one of an ionic liquid represented by formula (3) and an ionic liquid represented by formula (4).

Provided are a positive electrode active material for a lithium ion secondary battery and a secondary battery using the same, by which high discharge energy is obtained at low cost and capacity drop with cycles can be suppressed. A positive electrode active material for a secondary battery according to the embodiment of the present invention is represented by the following formula (I):

Li_a(Fe_xNi_yMn_2-x-y-zA_z)O₄  (I)

wherein 0.2<x≦1.2, 0<y<0.5, 0≦a≦1.2 and 0<z≦0.3; A is at least one selected from the group consisting of Li, B, Na, Mg, Al, K and Ca.

A semiconductor system includes a semiconductor memory device suitable for storing data, and a host suitable for controlling the semiconductor memory device in response to an external command signal, in which the semiconductor memory device includes a buffer block suitable for storing first data programmed under control of the host, and a main block suitable for storing the second data programmed under control of the host or a copy of the first data stored in the buffer block at a sudden power fail.