Seiko Instruments Inc

Seiko Electronic Components Ltd.

Sii Micro Parts Ltd.

Kensuke Tahara

Tsugio Sakai

Shunji Watanabe

Akifumi Sakata

Hideki Ishikawa

Fumiharu Iwasaki

Hideharu Onodera

Seiji Yahagi

Yoshibumi Nakamura

Tsuneaki Tamachi

Shinichi Takasugi

Tomio Sasaki

Akira Sato

Ryo Sato

Takumi Sawayama

Kazumi Tanaka

Tadahito Suzuki

Hideo Sakamoto

Masaaki Naito

Tomohiko Kida

An electric double layer capacitor with a low resistance value is disclosed. The electric double layer capacitor includes an electrochemical device in the inside of a housing container and capable of achieving charge and discharge via external terminals, wherein the electrochemical device includes a pair of electrodes, a separator disposed between the pair of electrodes, and an electrolytic solution with which the pair of electrodes and the separator are impregnated; when a volume between the pair of electrodes is designated as Ve, and a volume of a void in an inter-electrode part of the separator disposed between the pair of electrodes is designated as Se, an inter-electrode part void ratio Re is defined as Re=Se/Ve&#xd7;100 (%); and when a thickness of the inter-electrode part is designated as L2 (&#x3bc;m), and a separator evaluation index Ie is defined as Ie=L2/Re (&#x3bc;m/%), a relation of Ie&#x2266;1.0 (&#x3bc;m/%) is satisfied.

Electrochemical cell

Provided are an electrolytic solution for a nonaqueous electrolyte secondary battery and a nonaqueous electrolyte secondary battery each of which not only has heat resistance enough to resist reflow soldering but also can maintain the discharge capacity of the battery even in a low-temperature environment. The nonaqueous electrolyte secondary battery is provided with an electrolytic solutionincluding a solute and a solvent containing a polyethylene glycol dialkyl ether and an ethylene glycol dialkyl ether, a positive electrode, a negative electrode, and a separatorformed of glass fibers and placed between the positive electrodeand the negative electrode

Electrolytic solution for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery using the electrolytic solution

An electrochemical cell has a container having a main surface and a cavity containing therein a positive electrode, a negative electrode, a separator separating the positive and negative electrodes from one another, and an electrolyte. A sealing plate that seals the cavity of the container is bonded to the main surface of the container with an unoxidized weld.

An electrochemical cell has a container containing a positive electrode, a negative electrode, and an electrolyte. The container has a bottom face and a hole formed in the bottom face. A positive electrode current collector is embedded in the bottom face of the container so that the hole formed in the bottom face exposes a portion of the positive electrode current collector. A covering portion is adhered to the positive electrode and covers the exposed portion of the positive electrode current collector. The positive electrode current collector is electrically connected to the positive electrode via the covering portion. A lid seals the container.

Electrochemical cell having container with embedded positive electrode current collector

An electrochemical cell has an outer case formed of one of ceramics and glass. An electrochemical cell element is hermetically sealed in the outer case. The electrochemical cell element contains a positive pole, a negative pole, and a non-aqueous electrolyte containing an organic solvent. A metal layer is formed on an edge of the outer case. A sealing plate is resistance welded to the metal layer. The sealing plate is made of an alloy containing, in weight percentage, Co by 1 to 50%, Ni by 1 to 70%, Fe by 20% or higher, Cr by 10% or lower, Mn by 2.0% or lower, Si by 1.0% or lower and C by 1.0% or lower.

A 1.5 V non-aqueous electrolyte secondary battery having high energy density, excellent charge and discharge characteristics and long cycle life is provided. The non-aqueous electrolyte secondary battery uses, as the negative electrode active material, lithium-containing silicon oxide represented by the compositional formula Li.sub.x SiO.sub.y and defined such that the lithium content x and oxygen amount y are satisfied with 1.5.ltoreq.x.ltoreq.4.5 and 0&lt;y&lt;2, respectively, and also uses, as the positive electrode, lithium-containing titanium oxide represented by the general formula Li.sub.x Ti.sub.y O.sub.4 wherein 0.ltoreq.x.ltoreq.3 and 1.6.ltoreq.y.ltoreq.2.2 or lithium-containing iron sulfide represented by the general formula Li.sub.x FeS.sub.y wherein x.ltoreq.1.1 and 0.5.ltoreq.y.ltoreq.2.5, so that a secondary battery of about 1.5 V having high energy density, less inner resistance and excellent charge and discharge characteristics can be obtained. The non-aqueous electrolyte secondary battery has high charge and discharge efficiency, does not cause defect such as inner short-circuit due to formation of dendrite, and it is very stable with a long cycle life.

Non-aqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery comprises a negative electrode having an active material comprised of lithium or a material capable of absorbing and releasing lithium, a lithium ion conductive non-aqueous electrolyte, and a positive electrode. The positive electrode active material is comprised of a composite represented by composition formula Li.sub.a R.sub.b L.sub.c M.sub.d O.sub.2 where R is one or more metalloid elements selected from boron B and silicon Si, L is at least one element selected from metals and metalloids of Groups IIIA and IVA of the periodic table, alkaline earth metals, and metals selected from the group consisting of Ti, Mn, Cu and Zn, M represents transition metal elements comprising at least Ni and Co, R, L and M are different, and a, b, c and d satisfy 0&lt;a.ltoreq.1.15, 0.85.ltoreq.b+c+d.ltoreq.1.3, 0&lt;b+c.ltoreq.0.5, 0&lt;b and 0.ltoreq.c.

A non-aqueous electrolyte secondary battery comprises at least a negative electrode, a positive electrode and a non-aqueous electrolyte. The negative electrode has an active material comprised of silicon or a silicon alloy containing lithium represented by composition formula Li.sub.x Si where x satisfies 0.ltoreq..times..ltoreq.5. The positive electrode has an active material comprised of a transition metal oxide. The non-aqueous electrolyte is a lithium ion-conductive non-aqueous electrolyte having at least one lithium compound comprised of one of an organic solvent and a solid polymer. The negative electrode active material is formed by absorption of lithium ions into the silicon resulting from an electrochemical reaction between the negative electrode and a lithium metal and/or a material containing lithium. A secondary battery having high voltage, high energy density, high reliability, improved current charge and discharge characteristics and a long cycle life is obtained.

Non-aqueous electrolyte secondary battery and production method of the

A non-aqueous electrolyte secondary battery has a negative electrode, a positive electrode and a non-aqueous electrolyte with lithium ion conductivity. A composite oxide containing lithium represented by composition formula Li.sub.x Si.sub.1-y M.sub.y O.sub.z (where M is one or more kinds of elements selected from metals other than alkaline metals, and metalloids other than silicon, and x, y and z satisfy O.ltoreq.x, 0&lt;y&lt;1, and 0&lt;z&lt;2) is used as an active material for the negative electrode. The battery exhibits a negative active material with a lower and baser potential and a large charging/discharging capacity to produce a long cycle service life secondary battery which facilitates a large current charging and discharging and reduces deterioration due to excess charging and excess discharging.

Non-aqueous electrolyte secondary battery and method of producing the

A non-aqueous electrolyte secondary battery has a negative electrode, a positive electrode and a non-aqueous electrolyte with lithium ion conductivity. A composite oxide produced from a metal or a metalloid and lithium represented by composition formula Li.sub.x MO (where M represents metals or metalloids other than alkali metals, and x satisifies 0.ltoreq.x) is used as an active material of one or both of the negative electrode and the positive electrode. The battery exhibits a large charging/discharging capacity and a high energy density together with smaller polarization (internal resistance) on charging and discharging which facilitates a large current charging and discharging with a long cycle life and reduces deterioration due to excess charging and excess discharging.

A non-aqueous electrolyte secondary battery has a negative electrode, a positive electrode and a lithium ion-conductive non-aqueous electrolyte. A silicon oxide or a silicate containing lithium is used as the negative electrode active material. The potential of the negative electrode active material is low, the charge and discharge capacity in a base potential region of 0-1 V with respect to metallic lithium is large, and the polarization (internal resistance) during charge and discharge is small. A secondary battery having a high voltage and a high energy density is obtained in which large current charge and discharge characteristics are facilitated, the deterioration due to excessive charge and excessive discharge is reduced, the cycle life is long and the reliability is high.

Non-aqueous electrolyte secondary battery and its production method

A nonaqueous electrolyte secondary battery uses lithium or a substance capable of absorbing and releasing lithium as a negative active material of a negative electrode, and uses a layer-like composite oxide of the formula Li.sub.x M.sub.y L.sub.z O.sub.2, where M is one or more transistion metal elements selected from Groups IIIB, IVB, VB, VIB, VIIB and VIII of the periodic table, L is one or more elements selected from nonmetal, metalloid and semimetal elements selected from Groups IIIA, IVA and VA of the periodic table, alkaline earth metal elements and metal elements of Zn and Cu as a positive active material constituting a positive electrode. The polarization (internal resistance) at the time of charging and discharging is reduced and an effective charging-discharging capacity is enhanced. Charging and discharging at a large current become easy, and a cycle deterioration is improved.

Monaqueous electrolyte secondary battery and process for producing

An organic electrolyte cell having a negative electrode composed of Li, a positive electrode composed mainly of Bi.sub.2 O.sub.3 and an organic electrolyte. The Bi.sub.2 O.sub.3 is heat-treated above 650.degree. C. to increase the discharge capacity of the cell.

Growing community of inventors

Miyagi, Japan

Kensuke Tahara