Abstract: 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 LiMn2O4. The coating portion is made of a conductive oxide such as ITO (indium tin oxide) or SnO2. The quantity of the coating portion is 0.001 mol to 0.1 mol per 1 mol of the center portion.

Abstract: A graphite powder suitable for a negative electrode material of a lithium ion secondary battery which assures a high discharging capacity not lower than 320 mAh/g is to be manufactured at a lower cost. Specifically, a graphite powder containing 0.01 to 5.0 wt % of boron and having a looped closure structure at an end of a graphite c-planar layer on the surface of a powder, with the density of the interstitial planar sections between neighboring closure structures being not less than 100/&mgr;m and not more than 1500/&mgr;m, and with d002 being preferably not larger than 3.3650 Å, is manufactured by (1) heat-treating a carbon material pulverized at an elevated speed before or after carbonization for graphization at temperature exceeding 1500° C. or by (2) heat-treating the carbon material pulverized before or after carbonization at a temperature exceeding 1500° C.

Abstract: Carbon fiber having cross sectional shape which satisfies area replenishment rate of 0.8 or more is used as anode material for non-aqueous electrolyte secondary battery. Alternatively, since value of fractal dimension of cross section high order structure of the random radial type carbon fiber can be utilized as material parameter for evaluating the cross sectional structure, carbon fiber in which the value of the fractal dimension is caused to fall within the range from 1.1 to 1.8 and the crystallinity has been controlled such that it falls within reasonable range is used as anode material for non-aqueous electrolyte secondary battery. Further, carbon fiber having cross section high order structure such that the central portion is radial type structure and the surface layer portion is random radial type structure is used as anode material for non-aqueous electrolyte secondary battery. Furthermore, it is also effective to use carbon fiber having notch structure at the cross section.

Abstract: Carbon fiber having cross sectional shape which satisfies area replenishment rate of 0.8 or more is used as anode material for non-aqueous electrolyte secondary battery. Alternatively, since value of fractal dimension of cross section high order structure of the random radial type carbon fiber can be utilized as material parameter for evaluating the cross sectional structure, carbon fiber in which the value of the fractal dimension is caused to fall within the range from 1.1 to 1.8 and the crystallinity has been controlled such that it falls within reasonable range is used as anode material for non-aqueous electrolyte secondary battery. Further, carbon fiber having cross section high order structure such that the central portion is radial type structure and the surface layer portion is random radial type structure is used as anode material for non-aqueous electrolyte secondary battery. Furthermore, it is also effective to use carbon fiber having notch structure at the cross section.

Abstract: In a non-aqueous electrolyte secondary battery including anode and cathode consisting of material capable of doping/undoping of lithium, and non-aqueous electrolytic solution in which electrolyte is dissolved in non-aqueous solvent, flaky graphite having high crystallinity and high electron conductivity is added as conductive agent into the anode and the cathode. Further, granulated carbon or carbon black having specific material property is added as conductive agent in addition to the flaky graphite. Thus, non-aqueous electrolyte secondary battery having long cycle life time and high reliability can be obtained.

Abstract: In a non-aqueous electrolyte secondary cell, it is possible to control the irreversible capacity degradation which is caused when it is preserved under the condition of charging. The non-aqueous electrolyte secondary cell includes a positive electrode that is capable of doping and dedoping lithium and a negative electrode and non-aqueous electrolyte. Specifically, a monomethoxy benzene class compound is added to the non-aqueous electrolyte at a concentration ranging from 0.005 M to 0.5 M.

Abstract: Hydrogen lithium titanate prepared by an acid process of lithium titanate and having pH of 11.2 or smaller or hydrogen lithium titanate expressed by general formula H.sub.x Li.sub.y-x Ti.sub.z O.sub.4 (where y.gtoreq.x>0 0.8.ltoreq.y.ltoreq.2.7 and 1.3.ltoreq.z.ltoreq.2.2) is disclosed. Hydrogen lithium titanate may be employed as active materials of positive and negative electrodes of a non-aqueous electrolyte secondary battery thereby realizing a charging capacity greater than a theoretical capacity. It is preferable that hydrogen lithium titanate is formed into a particle shape and includes voids in the particles. It is preferable that the largest particle size is 0.1 .mu.m to 50 .mu.m and the specific surface area is 0.01 m.sup.2 /g to 300 m.sup.2 /g. Hydrogen lithium titanate of the foregoing type can be manufactured by bringing lithium titanate into contact with an acid, such as acetic acid, to substitute protons for lithium ions.

Abstract: A non-aqueous electrolyte secondary battery is disclosed in which hydrogen lithium titanate prepared by an acid process of lithium titanate and having pH of 11.2 or smaller or hydrogen lithium titanate expressed by general formula H.sub.x Li.sub.y-x Ti.sub.z O.sub.4 (where y.gtoreq.x>0, 0.8.ltoreq.y.ltoreq.2.7 and 1.3.ltoreq.z.ltoreq.2.2) is employed as an active material for an electrode. Hydrogen lithium titanate may be employed as an active material for a positive electrode or a negative electrode. Thus, a charging capacity greater than a theoretical capacity is realized. It is preferable that hydrogen lithium titanate is formed into a particle shape and includes voids in the particles. It is preferable that the largest particle size is 0.1 .mu.m to 50 .mu.m and the specific surface area is 0.01 m.sup.2 /g to 300 m.sup.2 /g.

Abstract: A material for a negative electrode of a cell, which is prepared according to a process of the present invention, can provides a cell having a high true specific gravity, a high charging capacity and an excellent cycle characteristic. The process of the present invention comprises the steps of carbonizing an organic compound to form a carbide thereof, pulverizing said carbide to form a powder having an average particle size of 10 .mu.m to 2 mm, and sintering said powder of the carbide at a temperature of 2,000.degree. C. or higher to produce a graphite. In addition, in accordance with the present invention, there is also provided non-aqueous electrolyte secondary cell comprising a negative electrode, which is prepared by carbonizing an organic compound to form a carbide thereof, pulverizing the carbide to form a powder having an average particle size of 10 .mu.m to 2 mm, and sintering the powder of the carbide at a temperature of 2,000.degree. C. to form a graphite.

Abstract: A nonaqueous-electrolyte secondary battery has an electrode assembly having positive and negative electrodes separated from each other by a porous resin separator, and a battery case having a side wall with at least one land projecting inwardly into the battery case or outwardly out of the battery case, the electrode assembly being disposed in the battery case. Alternatively, the battery case may have a plurality of walls and a plurality of round corners each joining adjacent two of the walls.

Abstract: An anode material consisting of non-graphitizable carbon material obtained by baking a carbon precursor is disclosed. In this non-graphitizable carbon material, a ratio by weight of carbon Ps in a stacking structure as determined from diffraction peak originating in a (002) crystal lattice plane and X-ray diffraction spectrum components on the lower angle side with respect to the diffraction peak originating in the (002) crystal lattice plane of X-ray diffraction spectrum is smaller than 0.59, or the stacking index SI thereof is smaller than 0.76. Moreover, an average number of carbon layers n.sub.ave in a stacking structure is smaller than 2.46. Alternatively, when the baking temperature is T.degree.C. and the half width at half maximum of the peak appearing in the vicinity of 1340 cm.sup.-1 in the Raman spectrum is HW, the condition expressed below is satisfied.HW>138-0.06.multidot.

Abstract: A material for a negative electrode of a cell, which is prepared according to a process of the present invention, can provides a cell having a high true specific gravity, a high charging capacity and an excellent cycle characteristic. The process of the present invention comprises the steps of carbonizing an organic compound to form a carbide thereof, pulverizing said carbide to form a powder having an average particle size of 10 .mu.m to 2 mm, and sintering said powder of the carbide at a temperature of 2,000.degree. C. or higher to produce a graphite. In addition, in accordance with the present invention, there is also provided non-aqueous electrolyte secondary cell comprising a negative electrode, which is prepared by carbonizing an organic compound to form a carbide thereof, pulverizing the carbide to form a powder having an average particle size of 10 .mu.m to 2 mm, and sintering the powder of the carbide at a temperature of 2,000.degree. C. to form a graphite.

Abstract: An anode material consisting of non-graphitizable carbon material obtained by baking carbon precursor is disclosed. In this non-graphitizable carbon material, ratio by weight of carbon Ps in stacking structure determined from diffraction peak originating in (002) crystal lattice plane and X-ray diffraction spectrum components on the lower angle side with respect to the diffraction peak originating in the (002) crystal lattice plane of X-ray diffraction spectrum is smaller than 0.59, or stacking index SI thereof is smaller than 0.76. Moreover, average number of carbon layers n.sub.ave in stacking structure is smaller than 2.46. Alternatively, when baking temperature is T.degree. C. and half width at half maximum of peak appearing in the vicinity of 1340 cm.sup.-1 in Raman spectrum is HW, the condition expressed below is satisfied.HW>138-0.06.multidot.

Abstract: A non-aqueous liquid electrolyte secondary battery using a carbon material satisfying predetermined conditions of true density and parameters of crystalline structure as an anode material, a transition metal composite oxide having predetermined ion supply capability as a cathode material, and ethylene carbonate as a non-aqueous solvent, is disclosed. The carbon material has a true density of 2.2 g/cm.sup.3 and greater, an interplanar distance of (002) plane of between 0.375 and 0.338 nm, inclusive a C-axis crystallite size of the (002) plane of 20.0 nm and greater and a G value in Raman spectrum of 2.5 and greater. The transition metal composite oxide contains lithium of an amount equivalent to a charge/discharge capacity of 300 mAh and greater per unit weight of the carbon material. The carbon material forming the anode has a grain diameter of 1 .mu.m and greater. The non-aqueous solvent is a mixed solvent of ethylene carbonate and chain carbonic ester.

Abstract: A non-aqueous liquid electrolyte secondary battery including an anode formed of a carbon material capable of doping and de-doping of lithium, a cathode formed of a lithium-containing transition metal composite oxide and a non-aqueous liquid electrolyte is disclosed. The carbon material for the anode contains graphite and a non-graphitic carbon material formed of at least a non-graphitizable carbon material or a graphitizable carbon material. The non-graphitic carbon material preferably exhibits a discharge capacity per gram 80% or more of that of the graphite, measured in the first cycle of intermittent charging and discharging. The non-graphitic carbon material exhibits a ratio of a discharge capacity up to 0.3 V to a discharge capacity up to 1.5 V which is not smaller than 0.5, measured in the first cycle of intermittent charging and discharging with a standard of a lithium potential. Specifically, the graphite has a true density of 2.1 g/cm.sup.3 or greater, an interplanar distance of (002) of less than 0.

Abstract: A nonaqueous-electrolyte secondary cell is disclosed which comprises a positive and negative electrode and nonaqueous electrolyte. Each of the negative and positive electrode is formed of electrode mix layer comprises a binding agent and active material carrier or active material The electrodes are thus formed to satisfy the intensity ratio (I1/I2) of a first peak (P1) near a diffraction angle of 17.7.degree. to a second peak (P2) near a diffraction angle of 18.5.degree. in an X-ray diffraction pattern obtained with the Cuk.alpha. radiation for the electrode mix layer is from 0.3 to 0.6.