Non-aqueous electrolyte secondary battery

Abstract

The present invention provides a non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode having a negative active material, and a non-aqueous electrolyte; characterized in that the negative active material contains composite particle (C), which has silicon-containing particle (A) and electronic conductive additive (B), and carbon material (D), wherein the weight of the electronic conductive additive (B) falls within the range of 0.5 wt. % to 60 wt. % to the weight of the composite particle (C). The negative active material contains silicon which is capable of performing high discharge capacity, so that a non-aqueous electrolyte secondary battery having a large discharge capacity can be obtained. In addition, since the negative active material contains the electronic conductive additive (B) and the carbon material (D), the contact conductivity between the silicon-containing particle (A) or between the negative active material improves and, as a result, a non-aqueous electrolyte secondary battery having satisfactory cycle performance can be attained.

1 . A non-aqueous electrolyte secondary battery comprising:
 a positive electrode;   a negative electrode having a negative active material; and   a non-aqueous electrolyte;   characterized in that   said negative active material contains composite particle (C), which has silicon-containing particle (A) and electronic conductive additive (B), and carbon material (D), and   the weight of said electronic conductive additive (B) falls within the range of 0.5 wt. % to 60 wt. % to the weight of said composite particle (C).   
     
     
         2 . The non-aqueous electrolyte secondary battery according to  claim 1 , characterized in that
 said silicon-containing particle (A) has a content of carbon, and   said composite particle (C) is configured by coating said silicon-containing particle (A) with said electronic conductive additive (B).   
     
     
         3 . The non-aqueous electrolyte secondary battery according to  claim 1 , characterized in that the proportion of the weight of said composite particle (C) to the total weight of said composite particle (C) and said carbon material (D) falls within the range of 60 wt. % to 99.5 wt. %. 
     
     
         4 . The non-aqueous electrolyte secondary battery according to  claim 2 , characterized in that the proportion of the weight of said composite particle (C) to the total weight of said composite particle (C) and said carbon material (D) falls within the range of 60 wt. % to 99.5 wt. %. 
     
     
         5 . The non-aqueous electrolyte secondary battery according to  claim 1 , characterized in that said silicon-containing particle (A) has a content of silicon oxide SiO x  (where 0<X≦2). 
     
     
         6 . The non-aqueous electrolyte secondary battery according to  claim 2 , characterized in that said silicon-containing particle (A) has a content of silicon oxide SiO x  (where 0<X≦2). 
     
     
         7 . The non-aqueous electrolyte secondary battery according to  claim 5 , characterized in that the proportion of the weight of said composite particle (C) to the total weight of said composite particle (C) and said carbon material (D) falls within the range of 1 wt. % to 30 wt. %. 
     
     
         8 . The non-aqueous electrolyte secondary battery according to  claim 6 , characterized in that the proportion of the weight of said composite particle (C) to the total weight of said composite particle (C) and said carbon material (D) falls within the range of 1 wt. % to 30 wt. %. 
     
     
         9 . A non-aqueous electrolyte secondary battery comprising:
 a positive electrode;   a negative electrode having a negative active material; and   a non-aqueous electrolyte;   characterized in that   said negative active material has silicon-containing particle (A), and   said silicon-containing particle (A) contains silicon oxide SiO x  (where 0<X≦2) and carbon.   
     
     
         10 . A non-aqueous electrolyte secondary battery comprising:
 a positive electrode;   a negative electrode having a negative active material; and   a non-aqueous electrolyte;   characterized in that   said negative active material contains composite particle (C), which has silicon-containing particle (A) and electronic conductive additive (B),   said silicon-containing particle (A) has a content of carbon, and when measured at a temperature rising rate of 10±2° C./min by thermogravimetry, said composite particle (C) exhibits two stages of weight loss in the range of 30 to 1000° C.