Namics Corporation

Iomtechnology Corporation

Shoichi Iwaya

Takayuki Fujita

Hiroshi Sato

Noriyuki Sakai

Hitoshi Masumura

Hiroshi Sasagawa

Mamoru Baba

Gou Toida

Conventional ion rechargeable batteries having an electrode layer on an electrolyte layer suffer from an impurity layer formed at the interface, degrading performance. Conventional batteries with no such impurity layer have a problem of weak interface bonding. In the present invention, in a baking process step after an electrode layer is laminated on an electrolyte layer, materials for an electrode layer and an electrolyte layer are selected such that an intermediate layer formed of a reaction product contributing to charging and discharging reactions is formed at the interface of the electrode layer and the electrolyte layer. In addition, a paste that an active material is mixed with a conductive material at a predetermined mixing ratio is used to form a positive electrode layer and a negative electrode layer. Reductions in electrode resistance and interface resistance and improvement of charging and discharging cycle characteristics are made possible.

Lithium ion rechargeable battery and process for producing the lithium ion rechargeable battery

This is to provide an all solid state secondary battery which can be produced by an industrially employable method capable of mass-production and has excellent secondary battery characteristics. This is an all solid state secondary battery containing a laminated material in which a positive-electrode unit and a negative-electrode unit are laminated alternately through an ion conductive inorganic-material layer, the positive-electrode unit has positive active material layers on both surfaces of a positive-electrode collector layer, the above-mentioned negative-electrode unit has negative active material layers on both surfaces of a negative-electrode collector layer, (A) at least one of the positive-electrode collector layer and the negative-electrode collector layer comprises a metal of either of Ag, Pd, Au and Pt, or an alloy containing either of Ag, Pd, Au and Pt, or a mixture containing two or more kinds selected from the metals and alloys, (B) each layer is in a sintered state, or (C) at least the starting material for the ion conductive inorganic material of the ion conductive inorganic-material layer is a calcined powder.

All solid state secondary battery

In multilayer wholly solid lithium ion secondary batteries, a laminate having a collector layer of material with high conductivity superimposed on an active material layer has been disposed so as to attain a lowering of battery impedance. Consequently, in the fabrication of each of positive electrode layer and negative electrode layer, stacking of three layers consisting of an active material layer, a collector layer and an active material layer has been needed, thereby posing the problem of complex processing and high production cost. In the invention, a positive electrode layer and a negative electrode layer are fabricated from paste consisting of active material mixed with conductive substance in a given mixing ratio, and no collector layer is disposed. This realizes process simplification and manufacturing cost reduction without deterioration of battery performance and has also been effective in enhancing of battery performance, such as improvement to cycle characteristics.

Lithium ion secondary battery and process for manufacturing the same

A conventional, multilayer, all-solid-state, lithium ion secondary battery where an electrode layer and an electrolyte layer are stacked has a problem that it has a high interface resistance between the electrode layer and the electrolyte layer and has a difficulty in increasing the capacity of the battery. A battery has been manufactured by applying pastes of a mixture of an active material and a solid electrolyte to form electrode layers and baking a laminate of electrode layers and electrolyte layers at a time. As a result, a matrix structure including the active material and the solid electrolyte has been formed in the electrode layers, so that a battery with a large capacity and a reduced interface resistance between the electrode layer and the electrolyte layer has been successfully achieved.

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Niigata, Japan

Shoichi Iwaya