Anode and battery using same

Abstract

An anode and a battery, which have a high capacity and can improve battery characteristics such as large current discharge characteristics and low temperature discharge characteristics are provided. An anode has an anode current collector and an anode active material layer provided on the anode current collector. The density of the anode active material layer is in the range from 1.5 g/cm 3 to 1.8 g/cm 3 . Further, the anode active material layer contains a granulated graphite material which is obtained by granulating a flat graphite particle in nodular shape and mesocarbon microbeads. Thereby, the granulated graphite material is prevented from being destroyed, and diffusion path of lithium ions is secured.

1 . (canceled) 
     
     
         2 . An anode active material comprising:
 a plurality of particles of granulated graphite material; and   mesocarbon microbeads,   wherein a density of the anode active material is in a range from 1.65 g/cm 3  to 1.8 g/cm 3 .   
     
     
         3 . The anode active material according to  claim 1 , wherein the plurality of particles of granulated graphite material is obtained by granulating flat graphite particles in nodular shape. 
     
     
         4 . The anode active material according to  claim 1 , wherein the plurality of particles of granulated graphite material includes a plurality of flat graphite particles. 
     
     
         5 . The anode active material according to  claim 1 , wherein a weight ratio of the mesocarbon microbeads to a total of the granulated graphite material and the mesocarbon microbeads (mesocarbon microbeads/granulated graphite material+the mesocarbon microbeads) is in a range from 10% to 50%. 
     
     
         6 . The anode active material according to  claim 1 , wherein an average particle diameter of each particle of the granulated graphite material measured by a laser diffraction method is in a range from 10 microns to 30 microns. 
     
     
         7 . The anode active material according to  claim 1 , wherein an average particle diameter of the mesocarbon microbeads measured by a laser diffraction method is in a range from 20 microns to 30 microns. 
     
     
         8 . A battery comprising:
 a cathode;   an anode; and   an electrolyte,   wherein the anode has an anode active material,   the anode active material comprises a plurality of particles of granulated graphite material and mesocarbon microbeads, and   a density of the anode active material is in a range from 1.65 g/cm 3  to 1.8 g/cm 3 .   
     
     
         9 . The battery according to  claim 7 , wherein the plurality of particles of granulated graphite material is obtained by granulating flat graphite particles in nodular shape. 
     
     
         10 . The battery according to  claim 7 , wherein the plurality of particles of granulated graphite material includes a plurality of flat graphite particles. 
     
     
         11 . The battery according to  claim 7 , wherein a weight ratio of the mesocarbon microbeads to a total of the granulated graphite material and the mesocarbon microbeads (mesocarbon microbeads/granulated graphite material+the mesocarbon microbeads) is in a range from 10% to 50%. 
     
     
         12 . The battery according to  claim 7 , wherein an average particle diameter of each particle of the granulated graphite material measured by a laser diffraction method is in a range from 10 microns to 30 microns. 
     
     
         13 . The battery according to  claim 7 , wherein an average particle diameter of the mesocarbon microbeads measured by a laser diffraction method is in a range from 20 microns to 30 microns. 
     
     
         14 . The battery according to  claim 7 , wherein the cathode has a cathode active material, and
 the anode active material comprises a lithium complex oxide expressed by a general formula Li x MIO 2  or an interlayer compound containing lithium.   
     
     
         15 . The battery according to  claim 13 , wherein the MI is at least one of cobalt (Co), nickel, manganese (Mn), iron (Fe), aluminum, vanadium (v), and titanium (Ti). 
     
     
         16 . The battery according to  claim 7 , wherein the electrolyte comprises at least one, as a solvent, selected from a group consisting of propylene carbonate, ethylene carbonate, butylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, y-butyrolactone, 1,2-dimethoxy ethane, 1,2-diethoxy ethane, tetrahydrofuran, 2-methyl tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxonane, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, propionitrile, ester acetate, ester butyrate, ester propionate. 
     
     
         17 . The battery according to  claim 7 , wherein the electrolyte comprises a cyclic ester carbonate of an unsaturated compound as a solvent. 
     
     
         18 . The battery according to  claim 16 , wherein the cyclic ester carbonate of an unsaturated compound is 1,3-dioxole-2-one, 4-vinyl-1,3-dioxolane-2-one, or derivatives thereof. 
     
     
         19 . The battery according to  claim 7 , wherein the electrolyte comprises a lithium salt and a content (concentration) of the lithium salt in an electrolytic solution is in a range from 0.1 mol/l to 2.0 mol/l, or in a range from 0.1 mol/kg to 2.0 mol/kg. 
     
     
         20 . The battery according to  claim 7  further comprises a separator, and the separator comprises a ceramics porous film. 
     
     
         21 . The battery according to  claim 7  further comprises a package member made of a laminated film, a high molecular weight film, or a metal film.