Sony Corporation

Junji Kuyama

Masayuki Nagamine

Yuzuru Fukushima

Mamoru Hosoya

Koichi Tanaka

Katsuya Shirai

Atsuo Omaru

Kenji Katori

Hideki Sakai

Yoshikatsu Yamamoto

Kiyoshi Yamaura

Hiroaki Tanizaki

Minehisa Imazato

Hisashi Tsujimoto

Tsuyoshi Okawa

Yosuke Hosoya

Keizou Koga

The present invention enables to obtain both of a cycle characteristic and a high load characteristic. The present invention discloses a positive electrode active material containing lithium composite manganese oxide having a spinel structure for a non-aqueous electrolyte cell and a non-aqueous electrolyte cell using this material. The lithium composite manganese oxide having spinel structure has its primary particle diameter not less than 0.05 &#x3bc;m and not greater than 10 &#x3bc;m, forming an aggregate, and a specific surface measured by the BET method in a range not less than 0.2 m/g and not greater than 2 m/g.

Positive electrode active material for a non-aqueous electrode cell and non-aqueous electrode cell using the same

A gas diffusing electrode, an electrochemical device, such as fuel cell, employing same and methods of manufacturing same are provided. The gas diffusing electrode at least includes layers made of at least electro-conductive carbon powder or granule and sputtered platinum layers made of platinum laid alternately to form a multilayer structure. The electrochemical device can be down-sized while maintaining a relatively high power generating capacity.

Gas diffusing electrode body, method of manufacturing the same and electrochemical device

A gas diffusive electrode, an electrochemical device employing same, and methods of manufacturing and using same are provided. The gas diffusive electrode includes platinum powder and carbon powder or grain, to which carbon powder or grain whose particles are provided with a water-repellent film is further mixed. The gas diffusive electrode maintains an enhanced gas permeability.

Gas diffusive electrode body and method of manufacturing the same as well as electrochemical device

A cell in which liquid leakage or destruction may be prevented as the apparent energy density per unit volume of the cell is maintained. The cell uses, as a cathode active material, a compound of an olivinic crystal structure having the formula LiFeMPO, where M is at least one selected from the group of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, with 0.05&#x2266;x&#x2266;1.2 and 0&#x2266;y&#x2266;0.8. By adjusting the amount of the electrolyte solution, the amount of the void in the container is set so as to be not less than 0.14 cc and not more than 0.3 cc per 1 Ah of the cell capacity.

Non-aqueous electrolyte secondary cell with a lithium metal phosphate cathode

Disclosed is a non-aqueous electrolyte secondary battery having an excellent preservation characteristic at a high temperature and charging/discharging cycle characteristic. A rolled body in which a strip-shape positive electrode and negative electrode are rolled with a separator in-between is provided inside a battery can. The positive electrode contains LiMnMaO(where, Ma is at least one element selected from the group consisting of metal elements other than Mn, and B) and LiNiMbO(where, Mb is at least one element selected from the group consisting of metal elements other than Ni, and B). By replacing part of Mn and Ni with other elements, the crystal structure can be stabilized. Thereby, the capacity retention ratio after preservation at a high temperature, and a heavy load discharging power under a high electric potential cutoff can be improved. The mean particle size of particles of the above-mentioned oxides are preferable to be 30 &#x3bc;m and below so that an excellent charging/discharging cycle characteristic can be obtained.

Material for positive electrode and secondary battery

A non-aqueous electrolyte cell having high discharge capacity, an improved capacity upkeep ratio and optimum cyclic characteristics. The non-aqueous electrolyte cell has a cell device including a strip-shaped cathode material and a strip-shaped anode material, layered and together via a separator and coiled a plural number of times, a non-aqueous electrolyte solution, and a cell can for accommodating cell device and the non-aqueous electrolyte solution. The cathode employs a cathode active material containing a compound of the olivinic structure represented by the general formula LiFeMPO, where M is at least one selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, with 0.05&#x2266;x&#x2266;1.2 and 0&#x2266;y&#x2266;0.8, with the compound being used either singly or in combination with other materials. The ratio of an inner diameter d to an outer diameter D of cell device is selected so that 0.05&#x3c;d/D&#x3c;0.5.

Non-aqueous electrolyte cell

A method for producing a cathode active material having superior cell characteristics through single-phase synthesis of a composite material composed of a compound represented by the general formula Li Fe M PO and a carbon material positively and a method for producing a non-aqueous electrolyte cell employing the so produced cathode active material. To this end, the cathode active material is prepared by a step of mixing the starting materials for synthesis of the compound represented by the general formula Li Fe M PO , a step of milling a mixture obtained by the mixing step, a step of compressing the mixture obtained by the mixing step to a preset density and a step of sintering the mixture obtained by the compressing step. A carbon material is added in any one of the above steps prior to the sintering step. The density of the mixture in the compressing step is set to not less than 1.71 g/cm and not larger than 2.45 g/cm .

Method for producing cathode active material and method for producing non-aqueous electrolyte cell

A non-aqueous electrolyte secondary cell containing a compound of an olivinic structure as a cathode active material is to be improved in load characteristics and cell capacity. To this end, there is provided a non-aqueous electrolyte secondary cell including a cathode having a layer of a cathode active material containing a compound represented by the general formula Li Fe M PO , where M is at least one selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, with 0.05&lE;x&lE;1.2 and 0&lE;y&lE;0.8, an anode having a layer of a cathode active material containing the anode active material and a non-aqueous electrolyte, wherein the layer of the cathode active material has a film thickness in a range from 25 to 110 &mgr;m. If a layer of a cathode active material is provided on each surface of a cathode current collector, the sum of the film thicknesses of the layers of the cathode active material ranges between 50 and 220 &mgr;m. The non-aqueous electrolyte may be a liquid-based electrolyte or a polymer electrolyte.

Non-aqueous electrolyte secondary cell

Disclosed is a positive electrode material having improved charging/discharging cycle characteristic, shelf stability, and discharge load characteristic, and a secondary battery using the material. A rolled electrode body obtained by rolling strip-shaped positive and negative electrodes with a separator inbetween is provided on the inside of a battery can. The separator is impregnated with an electrolytic solution. The positive electrode contains a positive electrode material in which a coating portion is provided on the surface of a center portion made of a lithium composite oxide such as LiMn O . The coating portion is made of a conductive oxide such as ITO (indium tin oxide) or SnO . The quantity of the coating portion is 0.001 mol to 0.1 mol per 1 mol of the center portion. By the technique, while assuring conductivity, elution of the positive electrode material into the electrolytic solution can be suppressed and a reaction product can be prevented from being deposited on the surface of the positive electrode.

Growing community of inventors

Kanagawa, Japan

Junji Kuyama