Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode (5), a negative electrode (6) and a porous insulation layer (7). The positive electrode (5) includes a positive electrode current collector (51) and a positive electrode mixture layer (52), and the negative electrode (6) includes a negative electrode current collector (61) and a negative electrode active material layer (62). After charging the nonaqueous electrolyte secondary battery, when a surface of the positive electrode mixture layer (52) and a surface of the negative electrode active material layer (62) are brought in contact with each other, terminals are provided, respectively, on the positive electrode current collector (51) and the negative electrode current collector (62) and a resistance value between the terminals is measured, the resistance value is 1.6 ?·cm2 or more.

Abstract: An object of the present invention is to provide a high-energy density nonaqueous electrolyte secondary battery that controls the rise in temperature during short circuiting. Used is a nonaqueous electrolyte secondary battery 1, including a battery case 2, and a positive electrode plate 5 having a positive electrode current collector and a positive electrode mixture layer containing a cathode material capable of absorbing and desorbing lithium, a negative electrode plate 6 having a negative electrode current collector and a negative electrode mixture layer containing an anode material capable of absorbing and desorbing lithium, a separator 7 held between the positive and negative electrode plates, and a nonaqueous electrolyte that are enclosed in the battery case, wherein at least one of the positive electrode plate 5 and the negative electrode plate 6 has an electrode plate resistance, as determined in the charged state in the thickness direction when pressurized at 50 kg/cm2, of 0.4 ?·cm2 or more.

Abstract: It is aimed to provide a battery pack capable of securing safety by preventing A battery contained in the battery pack from entering a burning state even if the battery releases high-temperature gas in an abnormal state. An exhaust duct 1C for permitting the flow of gas released from the battery is provided and the gas is exhausted to the outside after reducing the temperature thereof in the exhaust duct 1C. A flow passage area of the exhaust duct 1C is in the range of not less than 0.5 mm2 and not more than 15 mm2 per 1 Ah of the battery capacity. The exhaust duct 1C is provided with a gas cooling portion 1L and a spark trapping portion 1M.

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 battery pack includes a battery having a risk of releasing a gas under abnormal conditions, a case that accommodates the battery, and an oxygen reducing portion that reduces an amount of oxygen within the case.

Abstract: A nonaqueous electrolyte secondary battery includes: a positive electrode 4; a negative electrode 6; a separator 5; and a battery case 1 in which an electrode plate group 7 including the positive electrode 4 and the negative electrode 6 spirally wound or stacked with the separator 5 interposed therebetween is stored with an electrolyte. In the nonaqueous electrolyte secondary battery, after charging, when the separator 5 is removed to bring a surface of the positive electrode mixture layer and a surface of the negative electrode mixture layer in contact with each other, terminals are respectively provided on the positive electrode current collector and the negative electrode current collector and a resistance value between the terminals is measured, the resistance value is 1.6 ?·cm2 or more, and the battery case 1 is electrically insulated from the positive electrode 4 and the negative electrode 6.

Abstract: Methods for evaluating battery safety under internal short-circuit conditions are improved to eliminate variations in evaluation results and accurately evaluate battery safety under internal short-circuit conditions. An internal short-circuit is caused in a battery by using an internal short-circuit causing method in which battery information obtained upon the occurrence of an internal short-circuit hardly changes with the structure of the battery. At this time, the battery information is detected to accurately evaluate the safety of the battery upon the internal short-circuit and identify the safety level.

Abstract: In an electricity storage device buried with a storage battery accommodated in a housing, it is aimed to prevent a positive electrode terminal and a negative electrode terminal from being corroded even upon condensation in the housing. An electricity storage device of the present invention is provided with a storage battery 4 including a positive electrode terminal 7 and a negative electrode terminal 8 and a housing 5 for accommodating this storage battery 4 and is so constructed as to satisfy at least one of a first condition of maintaining the potential of the negative electrode terminal 8 lower than a ground surface potential and a second condition of maintaining the potential of the positive electrode terminal 7 higher than the ground surface potential. Alternatively, at least one of the positive electrode terminal 7 and the negative electrode terminal 8 is arranged to face downward.

Abstract: A battery includes an electrode group, a case, a sealing member, and a mesh portion. The electrode group includes a positive electrode, a negative electrode opposing the positive electrode, an electrolyte interposed between the positive electrode and the negative electrode. The case has an opening and contains the electrode group. The sealing member closes the opening of the case. The mesh portion is provided so as to face an exhaust hole formed in at least one of the case and the sealing member.

Abstract: To operate a safety mechanism normally even when an accident happens. For this object, an electrochemical element includes an exhaust valve that operates when an internal pressure in a casing 4 reaches a predetermined pressure to release gas occurring in the casing to the outside, and a perforated plate 2 having holes 5a and 5b, which is provided between an electrode group 3 and the exhaust valve. The area of the perforated plate 2 excluding the holes 5a and 5b is 20% or more and 50% or less of the area of the opening of the casing. The perforated plate 2 is adapted for electrically insulating the electrode group 3 from the sealing member 1.

Abstract: In a non-aqueous secondary battery that includes a strip-shaped positive electrode, a strip-shaped negative electrode, a first insulating layer interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, the width of the positive electrode is smaller than the width of the negative electrode, both longitudinal end faces of the positive electrode are coated with a second insulating layer, and the first insulating layer and the second insulating layer are both porous.

Abstract: An object of the present invention is to provide an electrode for a lithium ion secondary battery that can ensure a high level of safety even when exposed to severe conditions such as a nail penetration test or crush test, and exhibit excellent output characteristics. The present invention relates to an electrode for a lithium ion secondary battery having a material mixture containing active material particles capable of reversibly absorbing and desorbing lithium, and a current collector that carries the material mixture, wherein a surface of the current collector has recessed portions, and an area occupied by the recessed portions accounts for not less than 30% of an a material mixture carrying area of the current collector.

Abstract: A nonaqueous electrolyte secondary battery including a positive electrode including a positive electrode current collector carrying a positive electrode material mixture layer thereon, a negative electrode including a negative electrode current collector carrying a negative electrode material mixture layer thereon, a separator provided between the positive electrode and the negative electrode and a nonaqueous electrolyte solution, wherein the positive electrode current collector is a conductive body containing aluminum and the positive electrode material mixture layer includes a first material mixture layer and a second material mixture layer formed on the first material mixture layer. The first material mixture layer is made of a first material mixture containing a first organic material which is soluble or dispersible in water and the second material mixture layer is made of a second material mixture containing a second organic material which is soluble or dispersible in an organic solvent.

Abstract: A power supply apparatus includes: a plurality of batteries; a changeover portion switching the connection between the plurality of batteries; a short-circuit battery detection portion, if an internal short-circuit is produced in any of the plurality of batteries, detecting this internal short-circuit battery; and a changeover control portion, if the short-circuit battery detection portion detects the internal short-circuit battery, allowing the changeover portion to switch the connection between the plurality of batteries in such a way that this internal short-circuit battery and at least one of the other batteries are connected in series to thereby form a closed circuit.

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, a porous insulating layer and a nonaqueous electrolyte. The porous insulating layer is provided between the positive electrode and the negative electrode and contains a material which does not have a shutdown function. Each of the positive electrode and the negative electrode includes an expandable element.

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, a porous insulating layer and a nonaqueous electrolyte. The porous insulating layer is provided between the positive electrode material mixture layer and the negative electrode material mixture layer and contains a material which does not have a shutdown function. The positive electrode is provided with a PTC layer extending substantially parallel to the positive electrode collector and the negative electrode is provided with a PTC layer extending substantially parallel to the negative electrode collector. Each of the PTC layers contains a material having a positive temperature coefficient of resistance.

Abstract: A non-aqueous electrolytic secondary battery which includes a heat-resistant layer formed by a porous protective film or the like having a resin binder and an inorganic oxide filler between its negative electrode and a positive electrode has such a characteristic that the higher the battery's temperature becomes, the smaller its internal resistance value becomes. In a CC-CV charging method as a general method for charging a secondary battery, using such a characteristic that the internal resistance value of the non-aqueous electrolytic secondary battery lowers as the battery's temperature rises, a VC-charge range where a charge is given using an optimum charging-current value at a maximum level up to which the battery's temperature does not reach an excessive temperature even if a charging current flows is provided within a CC-charge range.

Abstract: The present invention relates to an internal short circuit evaluation method for a battery including an electrode group including a positive electrode plate, a negative electrode plate and a separator disposed between the positive electrode plate and the negative electrode plate, and an outer jacket covering the electrode group, the method including the steps of: (I) processing the electrode group to a predetermined position of the electrode group, from the outside of the electrode group toward the inside thereof; and (II) causing a short circuit between a portion of the electrode plate and a portion of the negative electrode plate of the electrode group that are located inside from the predetermined position, and measuring battery information that is changed by the short circuit, and an evaluation apparatus used for the above-described method.

Abstract: An evaluation method for evaluating safety of a battery having an electrode group including a positive electrode plate, a negative electrode plate and a separator inserted between said electrode plates. The method includes the steps of charging the battery to a predetermined voltage; incorporating conductive foreign matter into the charged battery such that the conductive foreign matter is in contact with the positive electrode plate, and not in contact with the negative electrode plate; immersing said battery into which the conductive foreign matter has been incorporated in an electrolyte to dissolve and deposit the conductive foreign matter, thereby causing an internal short circuit to occur in the battery; and evaluating a thermal behavior of the battery in which the internal short circuit has occurred, and outputting results of the evaluation as safety indices.

Abstract: The invention relates to a method for evaluating the safety of a battery under an internal short-circuit condition. The battery includes an electrode assembly comprising a wound laminate of a positive electrode plate, a negative electrode plate, and a separator interposed between the positive and negative electrode plates. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector, and the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer on the negative electrode current collector. The battery further includes an electrolyte and a casing for housing the electrode assembly and the electrolyte.