Abstract: A high capacity lithium secondary battery with excellent safety is provided by suppressing expansion of a negative electrode active material during charge and increasing the content of a heat-resistant resin in a separator relative to conventional one. The lithium secondary battery includes: a negative electrode active material that comprises compound particles containing at least one metal element selected from the group consisting of Si, Sn, Al, and Zn; and a separator that has a first porous layer comprising polyolefin and a second porous layer comprising a heat-resistant resin. The separator contains 10 to 60 parts by weight of the second porous layer per 100 parts by weight of the first porous layer.

Abstract: A separator including at least a layer containing a fine particulate filler and a shutdown layer. The fine particulate filler includes a joined-particle filler that is in the form of a plurality of primary particles joined and bonded to one another. A non-aqueous electrolyte secondary battery including this separator exhibits improved safety, high performance and large current discharge capability particularly at low temperatures.

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: In a non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, and a separator, the separator is immersed in a non-aqueous electrolyte, and the separator contains an aromatic resin and an antistatic agent. The precision upon rolling out a reel-like rolled product of the separator is thus improved, and winding misalignment in separators decreases. Also, minute short circuit occurrence decreases drastically. As a result, a reliable quality, high capacity non-aqueous electrolyte secondary battery can be efficiently and advantageously manufactured.

Abstract: A separator for a lithium secondary battery includes a high molecular porous film with a shut-down function and a heat-resistant porous layer integrally formed on each side of the high molecular porous film. The heat-resistant porous layers contain a heat-resistant high-molecular material and a ceramic filler. By using the separator, the occurrence of a short-circuit due to the melting and shrinkage of the high molecular porous film is prevented. Also, in the event of a short-circuit and the generation of heat higher than the melting point of the material of the high molecular porous film, the expansion of the short-circuit is prevented, so that the safety of the lithium secondary battery is improved.

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, a non-aqueous electrolyte, and a separator interposed between the positive electrode and the negative electrode. The separator includes a polyolefin layer and an oxidation-resistant layer. The oxidation-resistant layer includes an oxidation-resistant polymer. A main chain of the oxidation-resistant polymer does not include a —CH2— group and a —CH(CH3)— group. The oxidation-resistant layer faces the positive electrode.

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 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 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 ion secondary battery includes a positive electrode capable of absorbing and desorbing lithium ion, a negative electrode capable of absorbing and desorbing lithium ion, a porous film interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, the porous film being adhered to a surface of at least the negative electrode. The porous film includes an inorganic filler and a first binder: The content of the first binder in the porous film is 1.5 to 8 parts by weight per 100 parts by weight of the filler: The first binder includes a first rubber including an acrylonitrile unit: The first rubber is water-insoluble and has a decomposition temperature of 250° C. or higher. The negative electrode includes a negative electrode active material capable of absorbing and desorbing lithium ion and a second binder, and the second binder includes a second rubber particle and a water-soluble polymer.

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: When the composite particle containing Si or Sn is used for the negative electrode, the ratio of the median diameter “Dc” of the conductive material to the median diameter “Da” of the negative electrode material (Dc/Da) is made from 0.02 to 0.5 in order to improve reduction in electron conductivity, which is attributed to fine division of the particles due to repeated charge/discharge.

Abstract: The present invention provides a battery-driven electronic device for which a long time use of the battery can be achieved and mobile communications equipment such as a portable telephone. Even if the time at which the output voltage of a battery 201 becomes below the supply voltage required by a load 206 including a power amplifier for wireless communications comes earlier than a conventional lithium ion battery because of its discharge characteristics that the battery voltage change ratio is 0.25 or more, a step-up and -down converter 200 operates as follows. When the output voltage of the battery is higher than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-down operation mode. When the output voltage of the battery is decreased and becomes lower than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-up operation mode.

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: 100 parts by weight of a carbon material having irreversible capacity and 20 to 150 parts by weight of a lithium-containing complex nitride represented by the general formula Li3-XMXN wherein M is at least one selected from the group consisting of Co, Ni, Mn and Cu, and wherein 0.2?X?0.8, are included in a negative electrode thereby to compensate for the irreversible capacity of the carbon material by the above-described nitride. This enables the maximum utilization of large capacity possessed by an amorphous carbon or low crystalline carbon, thereby making it possible to provide a non-aqueous electrolyte secondary battery having high capacity and excellent cycle reversibility.

Abstract: A lithium-containing composite nitride with an alkaline metal or an alkaline earth metal added thereto is used as the negative electrode active material, or used as surface layers of core particles of a lithium-containing composite nitride, to provide a negative electrode material for a nonaqueous electrolyte secondary battery with large capacity and high reliability improved in oxidation and decomposition resistance property and thus capacity recovery property after overdischarge.

Abstract: The present invention provides a battery-driven electronic device for which a long time use of the battery can be achieved and mobile communications equipment such as a portable telephone. Even if the time at which the output voltage of a battery 201 becomes below the supply voltage required by a load 206 including a power amplifier for wireless communications comes earlier than a conventional lithium ion battery because of its discharge characteristics that the battery voltage change ratio is 0.25 or more, a step-up and -down converter 200 operates as follows. When the output voltage of the battery is higher than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-down operation mode. When the output voltage of the battery is decreased and becomes lower than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-up operation mode.

Abstract: A non-aqueous electrolyte secondary battery comprises a positive electrode and a negative electrode capable of intercalating and de-intercalating lithium, a non-aqueous electrolyte and separators or solid electrolytes. The negative electrode contains, as a main component, composite particles constructed in such a manner that at least part of the surface of nuclear particles comprising at least one of tin, silicon and zinc as a constituent element, is coated with a solid solution or an inter-metallic compound composed of the element included in the nuclear particles and another predetermined element which is not an element included in the nuclear particles. To improve the ability of the battery, the composite particles mentioned above can include at least one trace element selected from iron, lead and bismuth. The porosity of a mixture layer at the negative electrode is 10% or more and 50% or less.