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), the 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.

What is claimed is: 
     
         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),   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.   
     
     
         2 . The non-aqueous electrolyte secondary battery according to  claim 1 , wherein weight loss starts in thermogravimetry of the composite particle (C) at a temperature of not higher than 600° C. at the first stage and at a temperature of higher than 600° C. at the second stage. 
     
     
         3 . The non-aqueous electrolyte secondary battery according to  claim 1 , wherein the proportion of weight loss to the weight prior to the temperature rise in thermogravimetry of the composite particle (C) is within a range of 3 to 30 wt. % at the first stage and 5 to 65 wt. % at the second stage. 
     
     
         4 . The non-aqueous electrolyte secondary battery according to  claim 2 , wherein the proportion of weight loss to the weight prior to the temperature rise in thermogravimetry of the composite particle (C) is within a range of 3 to 30 wt. % at the first stage and 5 to 65 wt. % at the second stage. 
     
     
         5 . The non-aqueous electrolyte secondary battery according to  claim 1 , wherein weight loss starts in thermogravimetry of the negative active material at a temperature of not lower than 350° C. at the first stage and at a temperature of not higher than 800° C. at the second stage. 
     
     
         6 . The non-aqueous electrolyte secondary battery according to  claim 2 , wherein weight loss starts in thermogravimetry of the negative active material at a temperature of not lower than 350° C. at the first stage and at a temperature of not higher than 800° C. at the second stage. 
     
     
         7 . The non-aqueous electrolyte secondary battery according to  claim 3 , wherein weight loss starts in thermogravimetry of the negative active material at a temperature of not lower than 350° C. at the first stage and at a temperature of not higher than 800° C. at the second stage. 
     
     
         8 . The non-aqueous electrolyte secondary battery according to  claim 4 , wherein weight loss starts in thermogravimetry of the negative active material at a temperature of not lower than 350° C. at the first stage and at a temperature of not higher than 800° C. at the second stage.