Carbon-based negative electrode material and secondary battery including negative electrode material

Abstract

To provide a carbon-based negative electrode material which can be used with an electrolyte containing PC as a main ingredient, a carbon-based negative electrode material having a graphene layer structure is crystalline and has pores. That is, the crystal structure of the carbon-based negative electrode material is distorted more significantly than that of graphite. Accordingly, the carbon-based negative electrode material has a larger interlayer distance between graphenes than graphite. It has been shown that such a negative electrode material can be used for a secondary battery which contains an electrolyte containing PC as a main ingredient.

1 . (canceled) 
     
     
         2 . A secondary battery comprising:
 a negative electrode including a carbon-based material having a graphene layer structure; and   an electrolyte,   wherein a main ingredient of a solvent of the electrolyte is propylene carbonate,   wherein the carbon-based material has crystallinity and pores, and   wherein an interlayer distance between graphenes is larger than a size of a solvated lithium ion generated by the electrolyte and a lithium ion.   
     
     
         3 . The secondary battery according to  claim 2 , wherein diameters of the pores of the carbon-based material range from 2 nm to 4 nm. 
     
     
         4 . The secondary battery according to  claim 2 , wherein the solvent of the electrolyte is a single solvent. 
     
     
         5 . The secondary battery according to  claim 2 , wherein the carbon-based material is porous graphite. 
     
     
         6 . The secondary battery according to  claim 2 , wherein a solute of the electrolyte is a lithium salt. 
     
     
         7 . An electric appliance comprising the secondary battery according to  claim 2 . 
     
     
         8 . A secondary battery comprising:
 a negative electrode including a carbon-based material having a graphene layer structure; and   an electrolyte,   wherein a main ingredient of a solvent of the electrolyte is propylene carbonate, and   wherein the carbon-based material has crystallinity and pores,   wherein an interlayer distance between graphenes is larger than a size of a solvated lithium ion generated by the electrolyte and a lithium ion, and   wherein the interlayer distance between graphenes is larger than an interlayer distance of a flake graphite.   
     
     
         9 . The secondary battery according to  claim 8 , wherein diameters of the pores of the carbon-based material range from 2 nm to 4 nm. 
     
     
         10 . The secondary battery according to  claim 8 , wherein the solvent of the electrolyte is a single solvent. 
     
     
         11 . The secondary battery according to  claim 8 , wherein the carbon-based material is porous graphite. 
     
     
         12 . The secondary battery according to  claim 8 , wherein a solute of the electrolyte is a lithium salt. 
     
     
         13 . An electric appliance comprising the secondary battery according to  claim 8 . 
     
     
         14 . A secondary battery comprising:
 a negative electrode including a carbon-based material having a graphene layer structure; and   an electrolyte,   wherein a main ingredient of a solvent of the electrolyte is propylene carbonate, and   wherein the carbon-based material has crystallinity and pores,   wherein an interlayer distance between graphenes is larger than a size of a solvated lithium ion generated by the electrolyte and a lithium ion,   wherein the carbon-based material is porous graphite, and   wherein the porous graphite has a structure in which graphites overlap with each other with a gap interposed therebetween.   
     
     
         15 . The secondary battery according to  claim 14 , wherein the solvent of the electrolyte is a single solvent. 
     
     
         16 . The secondary battery according to  claim 14 , wherein a solute of the electrolyte is a lithium salt. 
     
     
         17 . The secondary battery according to  claim 14 ,
 wherein the solvent of the electrolyte is a single solvent, and   wherein a solute of the electrolyte is a lithium salt.   
     
     
         18 . An electric appliance comprising the secondary battery according to  claim 14 .