Nippon Electric Co., Ltd.

Nec Corporation

Masatomo Yonezawa

Tomeji Ohno

Kazuaki Utsumi

Akira Kobayashi

Tatsuji Numata

Masato Shirakata

Chika Kanbe

Susumu Saito

Atsushi Ochi

Takeshi Yano

Hiroshi Yageta

Toshio Takada

Masao Kiyama

Sadayuki Takahashi

Izumu Fukui

Takeshige Hamatsuki

Keizo Iwase

Haruhiko Miyamoto

Toshikazu Akita

A secondary battery including an electricity generating element, which includes at least a positive electrode implemented by a lithium-manganese compound oxide, a negative electrode, an electrolyte and a separator, and films encasing the electricity generating element is disclosed. The secondary battery further includes a composition causing the electrolyte to react with water to thereby produce hydrogen ions, and a hydrogen ion uptaking agent so positioned as to contact the electrolyte existing in the battery. The battery is desirable in charge-discharge cycle characteristic, storage characteristic, and safety. In addition, the battery swells little despite a repeated charge-discharge cycle or storage.

Nonaqueous electrolyte type secondary battery with a film casing

A positive electrode of a nonaqueous electrolyte solution secondary battery comprises (A) a lithium-manganese composite oxide and (B1) at least one lithium-nickel composite oxide which has a specific surface area X of 0.3&lE;X (m /g) and which is selected from a group consisting of LiNiO , Li NiO , LiNi O , Li Ni O and LiNi M O (0<x&lE;0.5 is satisfied, and M represents at least one metal element selected from a group consisting of Co, Mn, Al, Fe, Cu and Sr), whereby it is possible to obtain a nonaqueous electrolyte solution secondary battery which is superior in battery properties, especially charge and discharge cycle properties, retention properties and safety.

Nonaqueous electrolyte solution secondary battery using lithium-manganese composite oxide for positive electrode

A ceramic composition comprising a solid solution of the ternary system consisting essentially of lead magnesium-niobate (Pb(Mg.sub.1/3 Nb hd 2/3)O.sub.3), lead nickel-niobate (Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3) and lead titanate (PbTiO.sub.3) as a major constituent, and an additional constituent consisting essentially of lead manganese-niobate (Pb(Mn.sub.1/3 Nb.sub.2/3)O.sub.3). The ternary system is expressed by the general formula [Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 ].sub.x -[Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3 ].sub.y -[PbTiO.sub.3 ].sub.z wherein the subscripts x, y and z satisfy the equation x+y+z=1 and fall within the region defined by the line segments joining the seven points A, B, C, D, E, F and G within the triangular ternary-system diagram shown in the accompanying drawing. Preferably, the lead manganese-niobate (Pb(Mn.sub.1/3 Nb.sub.2/3)O.sub.3) is contained in a proportion of 0.01 mol % to 10 mol % to the major constituent.

Ceramic composition with improved electrical and mechanical properties

A multilayer electrostrictive element has electrostrictive sections (31) defined by internal electrodes (32) in a stack, with a peripheral surface which has a predetermined outline perpendicularly of an axis of the stack, each internal electrode with an outline which is approximately congruent with the predetermined outline (constant cross-section). In order that external electrodes (33, 34) may readily be connected to the internal electrodes grouped by twos, each internal electrode may have a peripheral end which is partly recessed from the predetermined outline, as in FIG. 8. Alternatively, the internal electrodes of each group may be connected together by a conductor rod which passes through the electrostrictive sections, preferably along their edges, contacting alternate electrodes. For a great number of internal electrodes, an element may be manufactured by laminating conductive-paste-printed green sheets transversely of the stack axis and then sintering the lamination. Each internal electrode may include a ceramic material, such as an electrostrictive material of the electrostrictive sections, another electrostrictive material of a lower sintering temperature, or glass.

Multilayer electrostrictive element which withstands repeated

The ceramic composition comprises lead magnesium tungstate [Pb(Mg1/2 W1/2)O.sub.3 ], lead titanate [PbTiO.sub.3 ] and lead nickel niobate [Pb(Ni1/3 Nb2/3)O.sub.3 ]. When the ternary composition is expressed by [Pb(Mg1/2 W1/2)O.sub.3 ]x [PbTiO.sub.3 ]y [Pb(Ni1/3Nb2/3)O.sub.3 ]z where x+y+z=1.00, it lies on lines interconnecting five points (x=0.693, y=0.297, z=0.01), (x=0.495, y=0.495, z=0.01), (x=0.195, y=0.465, z=0.35), (x=0.10, y=0.40, z=0.50) and (x=0.06, y=0.24, z=0.70) and in a region bonded by the lines. In modifications, for the purpose of improving the mechanical strength, 0.02 to 3 mol % of at least one auxiliary ingredient selected from the group consisting of Nb, Ta and Sb, 0.05 to 8 mol % of [Pb(Mn1/3 Ta2/3)O.sub.3 ] 0.05 to 10 mol % of [Pb(Mn1/3 Nb2/3)O.sub.3 ] or 0.05 to 6 mol % of [Pb(Mn1/3 Sb2/3)O.sub.3 ] is added.

Ceramic compositions having high dielectric constant and high specific

A ceramic capacitor is prepared by corting an electrode paste on the opposite surfaces of a green ceramic body. The electrode paste contains an inorganic binder having the same composition as the green ceramic body. Then the green ceramic body is sintered and at the same time the electrode paste is baked to form electrodes for attaching lead wires.

Method of manufacturing ceramic capacitors

A ceramic composition consisting essentially of Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3, Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 which allows low-temperature sintering and has a high dielectric constant and a good dielectric constant temperature coefficient.

Ceramic compositions

A ceramic composition allowing low-temperature sintering at a temperature below 1000.degree. C and having a high dielectric constant over 5000 essentially contains Pb(Fe 2/3 W 1/3)O.sub.3 and Pb(Fe 1/3 Nb 2/3)O.sub.3, in which the molecular ratio of Pb(Fe 2/3 W 1/3)O.sub.3 to Pb(Fe 1/3 Nb 2/3)O.sub.3 ranges from about 0.2 to 0.5.

Ceramic compositions having high dielectric constant

Fine crystalline powder, from 0.02 to 0.2 micron in average particle size, of a composition Pb(Zr.Ti)O.sub.3. Parts of Zr and Ti of the composition may be substituted for with Mn and Sb, Nb, and/or Ta. The powder is produced by preparing an acidic aqueous solution of the constituent metallic ions, neutralizing the solution to provide a suspension of hydroxides of the metals, and subjecting the suspension to hydrothermal reaction at 150.degree.-300.degree.C. The powder provides piezoelectric ceramics of a high sintered density without resorting to hot pressing.

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Tokyo, Japan

Masatomo Yonezawa