Abstract: In the non-aqueous electrolyte secondary battery of the present invention, the separator includes a heat-resistant resin having chlorine atoms as an end group and the positive electrode active material includes a lithium-containing complex oxide containing aluminum atoms in its composition. Even if the chlorine atoms are liberated into the non-aqueous electrolyte, aluminum contained in the positive electrode active material is selectively leached into the non-aqueous electrolyte, thereby suppressing the leaching of other component elements. Consequently, there can be obtained a non-aqueous electrolyte secondary battery excellent in safety and high temperature storage characteristics.

Abstract: A method for evaluating the safety of a battery under an internal short-circuit condition. The method for evaluating an internal short-circuit of a battery is characterized in that a short-circuit can be caused at a desired location inside the battery. According to the evaluation method of the invention, the evaluation result is not affected by the constitution of the outermost part of the battery unlike nail penetration tests which are conventional evaluation methods. Also, unlike crush tests which are conventional evaluation methods, the locations of short-circuits do not vary among tests and the safety under an internal short-circuit condition can be evaluated accurately.

Abstract: A charging system is provided which includes: a secondary battery which includes a heat-resistant member having a heat-resistance property between a negative electrode and a positive electrode thereof; a charging-voltage supply section which supplies a charging voltage for charging the secondary battery; a charge control section which controls the operation of the charging-voltage supply section on the basis of a reference voltage corresponding to the voltage between the negative electrode and the positive electrode in a full-charge state where the lithium-reference electric potential of the negative electrode is substantially zero volts; and a mode-setting acceptance section which chooses and accepts the setting of either of an ordinary charge mode and a high-voltage charge mode, in which if the mode-setting acceptance section accepts the setting of the ordinary charge mode, then the charge control section allows the charging-voltage supply section to supply, to the secondary battery, a first set voltage equ

Abstract: A charging system is provided with a secondary battery, a charging current supplier for supplying a charging current to the secondary battery, an internal resistance detector for detecting the resistance value of the internal resistance of the secondary battery, and a charge controller for increasing the charging current to be supplied to the secondary battery by the charging current supplier as the resistance value detected by the internal resistance detector decreases.

Abstract: A cell evaluation device has a short circuit detection portion to detect an internal short circuit within a test cell that has been subjected to nail penetration or crushing using the pressure from a pressurization portion, a pressure control portion to halt the operation of the pressurization portion on detection of a short circuit, and a cell information detection portion to collect and record cell information such as the cell temperature. By using such a cell evaluation device, the location of an internal short circuit during an abuse test is specified, and variations in the cell temperature increase accompanying the internal short circuit is minimized.

Abstract: There is provided a lithium ion secondary battery that includes a positive electrode having high thermal stability and is capable of greatly reducing the possibility of causing thermal runaway even in a nail penetration test. A lithium ion secondary battery including a positive electrode including a lithium composite oxide and a porous film bonded to at least one of a surface of the positive electrode and a surface of a negative electrode, wherein the porous film includes an inorganic oxide filler and a film binder, and the lithium composite oxide is represented by the formula: Lia(Co1-x-yMx1My2)bO2 (wherein element M1 is at least one selected from the group consisting of Mg, Sr, Y, Zr, Ca and Ti, element M2 is at least one selected from the group consisting of Al, Ga, In and Tl, and 0<a?1.05, 0.005?x?0.15, 0?y?0.05 and 0.85?b?1.1).

Abstract: A positive electrode for use in a lithium secondary battery comprises a positive electrode current collector, and a positive electrode film which is carried on the positive electrode current collector and includes a plurality of mixture layers. The positive electrode film contains, as a positive electrode active material, two or more kinds of lithium-containing compounds having exothermic initiation temperatures different from each other. At least one kind of the two or more kinds of lithium-containing compounds has the exothermic initiation temperature of 300° C. or higher. A first mixture layer of the plural mixture layers closest to the positive electrode current collector contains at least one kind of the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher.

Abstract: A lithium secondary battery including: an electrode group, a non-aqueous electrolyte and a battery case housing the electrode group and the non-aqueous electrolyte, the electrode group including a positive electrode, a negative electrode and a separator layer interposed between the positive electrode and the negative electrode, wherein an end-of-charge voltage and an end-of-discharge voltage are set in such a manner that the electrode group has an energy density of not less than 700 Wh/L, the separator layer includes a porous heat-resistant layer, and a short circuit area A produced when an internal short circuit has occurred between the positive electrode and the negative electrode, and a reduced area B of the porous heat-resistant layer that is produced by heat generation satisfy 1?(A+B)/A?10.

Abstract: A non-aqueous electrolyte secondary battery including: a positive electrode having a positive electrode material mixture containing a composite lithium oxide; a negative electrode; a polyolefin separator; a non-aqueous electrolyte; and a heat-resistant insulating layer interposed between the positive and negative electrodes. The positive electrode material mixture has an estimated heat generation rate at 200° C. of not greater than 50 W/kg. The positive electrode and the negative electrode are wound together with the separator and the heat-resistant insulating layer interposed therebetween.

Abstract: A lithium secondary battery including: an electrode group, a non-aqueous electrolyte and a battery case housing the electrode group and the non-aqueous electrolyte, the electrode group including a positive electrode, a negative electrode and a separator layer interposed between the positive electrode and the negative electrode, wherein an end-of-charge voltage and an end-of-discharge voltage are set in such a manner that the electrode group has an energy density of not less than 700 Wh/L, the separator layer includes a porous heat-resistant layer, and a short circuit area A produced when an internal short circuit has occurred between the positive electrode and the negative electrode, and a reduced area B of the porous heat-resistant layer that is produced by heat generation satisfy 1?(A+B)/A?10.

Abstract: A non-aqueous electrolyte secondary battery including: a positive electrode having a positive electrode material mixture containing a composite lithium oxide; a negative electrode; a polyolefin separator; a non-aqueous electrolyte; and a heat-resistant insulating layer interposed between the positive and negative electrodes. The positive electrode material mixture has an estimated heat generation rate at 200° C of not greater than 50 W/kg. The positive electrode and the negative electrode are wound together with the separator and the heat-resistant insulating layer interposed therebetween.

Abstract: Disclosed is a lithium ion secondary battery wherein an active material layer of at least one of positive and negative electrodes, or a separator carries a porous insulating layer, and the surface of the active material layer or separator carrying the porous insulating layer has a first region in which the porous insulating layer is formed and a second region including plural discontinuous deficient hole portions where the porous insulating layer is not formed. When a given reference deficient hole portion is selected from the plural deficient hole portions and a given circle having an area ten times that of the reference deficient hole portion is set on the surface of the active material layer or separator, the area of a part of the second region surrounded by the circle is controlled to not less than 10 ?m2 and not more than 100 mm2.

Abstract: A non-aqueous electrolyte secondary battery including: a positive electrode having a positive electrode material mixture containing a composite lithium oxide; a negative electrode; a polyolefin separator; a non-aqueous electrolyte; and a heat-resistant insulating layer interposed between the positive and negative electrodes. The positive electrode active material mixture has an estimated heat generation rate at 200° C. of not greater than 50 W/kg. The estimated heat generation rate is determined by obtaining a relation between absolute temperature T and heat generation rate V of the positive electrode material mixture using an accelerating rate calorimeter; plotting a relation between the inverse of absolute temperature T and the logarithm of heat generation rate V according to the Arrhenius law; obtaining a straight line fitted to the plotted points in a heat generation temperature range of T<200° C.; and extrapolating the straight line to the temperature of 200° C.

Abstract: A cell evaluation device has a short circuit detection portion to detect an internal short circuit within a test cell that has been subjected to nail penetration or crushing using the pressure from a pressurization portion, a pressure control portion to halt the operation of the pressurization portion on detection of a short circuit, and a cell information detection portion to collect and record cell information such as the cell temperature. By using such a cell evaluation device, the location of an internal short circuit during an abuse test is specified, and variations in the cell temperature increase accompanying the internal short circuit is minimized.

Abstract: A battery has an electrode with a mixture layer including electroactive material formed on a current collector whose exposed part is welded to a lead, and also a separator that shrinks with heat. In the battery, a heat shrinkage-preventing layer is provided on a portion of the separator that faces the lead. As a result, even if a minor short-circuit occurs and a large amount of current is flown to a minor short-circuit region, the heat shrinkage-preventing layer prevents expansion of a short-circuit area resulting from heat shrinkage of the separator. Thus, a conspicuous decrease in battery properties is prevented.

Abstract: The present invention relates to a nonaqueous electrolyte secondary battery, and more particularly to its separator, and it is an object thereof to prevent electrolyte leakage accident due to elevation of cell internal pressure even if the cell is exposed to high temperature without sacrificing the cell capacity. To achieve the object, by using the polyolefin group separator large in endothermic calorie per unit area by the heat of fusion in a temperature range of 70 to 150° C., and selecting appropriate graphite powder for negative electrode and organic solvent in nonaqueous electrolyte, the electrolyte leakage accident can be successfully eliminated by suppressing the reaction between the cell active substance and organic solvent, thereby suppressing elevation of cell internal pressure.

Abstract: The present invention relates to a lithium ion secondary battery using as the negative active material thereof a carbon material that enables the absorption and release of lithium ions and has volume resistivity not exceeding 5.0×10−3 ohmcm, thereby preventing battery temperatures from increasing abruptly due to low volume resistivity of the carbon material even when short-circuiting takes place inside of the battery.

Abstract: Graphite powder for a negative electrode in prior arts, which allows lithium ions to repeat intercalation and deintercalation reversibly by charge and discharge, has failed to attain a specific capacity close to the theoretical capacity of 372 mAh per 1 g. Also, there was a problem in storage property at a high temperature when it is attempted to improve the high rate charge and discharge characteristics. An object of the present invention is to solve these problems. In the process of pulverizing flaky graphite particles of which plane interval (d002) of (002) plane is 3.350 to 3.

Abstract: The present invention relates to a nonaqueous electrolyte secondary battery, and more particularly to its separator, and it is an object thereof to prevent electrolyte leakage accident due to elevation of cell internal pressure even if the cell is exposed to high temperature without sacrificing the cell capacity.