Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Showa Denko K.k.

Showa Denka K.k.

Noboru Ebato

Shinpei Matsuda

Toshiki Kahara

Kohki Tamura

Kazunori Fujita

Shigeoki Nishimura

Hiroyuki Sugimoto

Atsuko Tohyama

Tatsuo Horiba

Osamu Asai

Tatuo Horiba

A secondary cell comprises opposed positive and negative electrodes of polymers, each having conjugated double bonds, such as polyacetylene, poly-phenylene, polythienylene and polypyrrole, and an electrolyte solution comprising an electrolyte dissolved in a nitrile compound and being interposed between the two electrodes.

Secondary cell

A secondary battery having at least one electrode made from a polymer having conjugated double bonds in a main chain such as polyacetylene can be improved remarkably in charge-discharge cycle life by making the electrode surface area of a negative electrode greater than that of a positive electrode.

Secondary battery

The present invention provides a sheet-shaped polymer secondary battery of layer built type which is a laminate of plurality of sheet-shaped unit cells each of which comprising the following elements (a) to (c):

Sheet-shaped polymer secondary battery of layer built type

A positive plate composite agent consisting of a mixture of manganese dioxide, carbon powder and polytetrafluoroethylene powder is press-molded at a pressure in the range of 1 to 5 t/cm.sup.2. The resulting molded article is then pulvertized into massive particles having a particle size ranging from 0.03 to 15 mm.sup.3. The massive particles are then press-molded into a positive plate having a predetermined shape at a pressure in the range of 0.2 to 1 t/cm.sup.2. There is thus obtained a positive plate of an enclosed type battery which comprises a portion consisting of the compactly formed massive particles of the positive plate composite agent and a portion consisting of the coarsely formed small particles of the composite agent interposed between the massive particles so as to define paths or voids for the passage of an electrolyte.

Structure of positive plate of enclosed type battery

A primary battery comprises a negative active material such as lithium, a positive active material and a non-aqueous electrolyte, wherein the positive active material further comprises a main positive active material such as manganese dioxide which takes main part in a primary discharge reaction together with the negative active material through the non-aqueous electrolyte and a precursor such as vanadium pentoxide or lead dioxide which takes part in the primary discharge reaction and produces a sub-positive active material, which takes part in a secondary discharge reaction.

Primary battery

This invention relates to a non-aqueous electrolyte cell having an improved utilization of manganese dioxide. The utilization of manganese dioxide of a conventional non-aqueous electrolyte cell comprising a negative active material which comprises lithium, sodium or the like; a positive active material which comprises manganese dioxide; and a non-aqueous electrolyte can be greatly improved by limiting the particle sizes of manganese dioxide powder, carbon powder and optional binder powder contained in the positive mass to, respectively, up to 30 .mu.m, up to 5 .mu.m and up to 3 .mu.m.

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Hitachi, Japan

Noboru Ebato