Nonaqueous electrolytic solution and nonaqueous-electrolyte battery

Abstract

Disclosed is a nonaqueous electrolytic solution which forms a nonaqueous-electrolyte battery having high capacity and excellent storage characteristics at high temperatures, while sufficiently enhancing safety at the time of overcharge, and a nonaqueous-electrolyte battery using the same. The nonaqueous electrolytic solution has an electrolyte and a nonaqueous solvent with (A) a compound of formula (2): wherein R 7 is an optionally halogenated and/or phenylated alkyl group comprising 1-12 carbon atoms, R 8 to R 12 are independently a hydrogen atom, a halogen atom, an optionally halogenated ether or alkyl group comprising 1-12 carbon atoms, and at least one of R 8 to R 12 is an optionally halogenated alkyl group comprising 2-12 carbon atoms; and/or (B) a carboxylic acid ester with a phenyl group substituted by at least one alkyl group (having 4 or more carbon atoms) that is optionally substituted.

1 . A nonaqueous electrolytic solution, comprising:
 an electrolyte; and   a nonaqueous solvent, and   a carboxylic acid ester comprising a phenyl group substituted by at least one alkyl group that is optionally substituted, wherein the at least one alkyl group by which the phenyl group is substituted comprises 4 or more carbon atoms.   
     
     
         2 . The solution of  claim 1 , which further comprises (2) at least one compound selected from the group consisting of
 (2-i) a cyclic carbonate comprising an unsaturated C═C bond,   (2-ii) a cyclic carbonate comprising a fluorine atom,   (2-iii) a monofluorophosphoric acid salt, and   (2-iv) a difluorophosphoric acid salt.   
     
     
         3 . The solution of  claim 1 , wherein (2-i) a cyclic carbonate comprising an unsaturated C═C bond is present. 
     
     
         4 . The solution of  claim 1 , wherein (2-ii) a cyclic carbonate comprising a fluorine atom is present. 
     
     
         5 . The solution of  claim 1 , wherein (2-iii) a monofluorophosphoric acid salt is present. 
     
     
         6 . The solution of  claim 1 , wherein (2-iv) a difluorophosphoric acid salt is present. 
     
     
         7 . The solution of  claim 1 , wherein the carboxylic acid ester in present in a proportion to the nonaqueous electrolytic solution of 0.001 wt. % or higher but less than 10 wt. %. 
     
     
         8 . The solution of  claim 2 , wherein the compound (2) is present in a proportion to the nonaqueous electrolytic solution of from 0.001 wt. % to 10 wt. %. 
     
     
         9 . The solution of  claim 3 , wherein the compound (2) is present in a proportion to the nonaqueous electrolytic solution of from 0.001 wt. % to 10 wt. %. 
     
     
         10 . The solution of  claim 4 , wherein the compound (2) is present in a proportion to the nonaqueous electrolytic solution of from 0.001 wt. % to 10 wt. %. 
     
     
         11 . The solution of  claim 5 , wherein the compound (2) is present in a proportion to the nonaqueous electrolytic solution of from 0.001 wt. % to 10 wt. %. 
     
     
         12 . The solution of  claim 6 , wherein the compound (2) is present in a proportion to the nonaqueous electrolytic solution of from 0.001 wt. % to 10 wt. %. 
     
     
         13 . The solution of  claim 1 , which further comprises
 (3) a cyclic carbonate selected from the group consisting of ethylene carbonate (3-i), propylene carbonate (3-ii), and a mixture thereof,   (4) an asymmetric chain dialkyl carbonate, and   (5) a symmetric chain dialkyl carbonate.   
     
     
         14 . The solution of  claim 2 , which further comprises
 (3) a cyclic carbonate selected from the group consisting of ethylene carbonate (3-i), propylene carbonate (3-ii), and a mixture thereof,   (4) an asymmetric chain dialkyl carbonate, and   (5) a symmetric chain dialkyl carbonate.   
     
     
         15 . The solution of  claim 2 , which further comprises at least two compounds selected from the group consisting of (2-i), (2-ii), (2-iii), and (2-iv). 
     
     
         16 . The solution of  claim 2 , which further comprises at least three compounds selected from the group consisting of (2-i), (2-ii), (2-iii), and (2-iv). 
     
     
         17 . The solution of  claim 13 , wherein the nonaqueous electrolytic solution comprises (3-i) ethylene carbonate. 
     
     
         18 . The solution of  claim 13 , wherein the nonaqueous electrolytic solution comprises (3-ii) propylene carbonate. 
     
     
         19 . The solution of  claim 13 , wherein the nonaqueous electrolytic solution comprises (3-i) ethylene carbonate and (3-ii) propylene carbonate.