Nonaqueous electrolyte and nonaqueous-electrolyte battery

Abstract

A nonaqueous electrolyte includes an organic solvent and a lithium salt dissolved in the organic solvent, and a quaternary ammonium salt in an amount of 0.06 mol/L or greater and 0.5 mol/L or less, the quaternary ammonium salt having a structure represented by (chemical formula 3): wherein R is an organic linking group or an organic linking group forming an aromatic ring, the organic linking groups each having a main chain which has 4-5 atoms and is constituted of at least one member selected from carbon, oxygen, nitrogen, sulfur, and phosphorus and having one single-bond end and one double-bond end; R1 is an alkyl group having 1-6 carbon atoms or an alkyl group in which at least one of the hydrogen atoms has been replaced by a fluorine atom; and X − is a fluorine-containing anion.

1 . A nonaqueous electrolyte, comprising:
 an organic solvent and a lithium salt dissolved in the organic solvent; and   a quaternary ammonium salt in an amount of 0.06 mol/L or greater and 0.5 mol/L or less, the quaternary ammonium salt having a structure represented by (chemical formula 3):   
     
       
         
         
             
             
         
       
     
     wherein R is an organic linking group or an organic linking group forming an aromatic ring, the organic linking groups each having a main chain which has 4-5 atoms and is constituted of at least one member selected from carbon, oxygen, nitrogen, sulfur, and phosphorus and having one single-bond end and one double-bond end; R1 is an alkyl group having 1-6 carbon atoms or an alkyl group in which at least one of the hydrogen atoms has been replaced by a fluorine atom; and X −  is a fluorine-containing anion. 
   
   
       2 . The nonaqueous electrolyte of  claim 1 , wherein said organic solvent comprises one or more organic solvents selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, and γ-valerolactone. 
   
   
       3 . The nonaqueous electrolyte of  claim 1 , wherein the nonaqueous electrolyte comprises one or more members selected from the group consisting of BF 4   − , PF 6   − , CF 3 SO 3   − , N(CF 3 SO 2 ) 2   − , N(C 2 F 5 SO 2 ) 2   − , N(CF 3 SO 2 ) (C 4 F 9 SO 2 ) − , C(CF 3 SO 2 ) 3   − , and C(C 2 F 5 SO 2 ) 3   − . 
   
   
       4 . A nonaqueous-electrolyte battery, comprising:
 a positive electrode, a negative electrode, and a nonaqueous electrolyte according to  claim 1 .   
   
   
       5 . The nonaqueous-electrolyte battery of  claim 4 , wherein the negative electrode comprises a graphite. 
   
   
       6 . The nonaqueous-electrolyte battery of  claim 4 , further comprising:
 a sheath formed over said positive and negative electrodes and said electrolyte, said sheath comprising a metal/resin composite material.   
   
   
       7 . A nonaqueous-electrolyte battery which comprises a positive electrode, a negative electrode, and a nonaqueous electrolyte according to  claim 2 . 
   
   
       8 . A nonaqueous-electrolyte battery which comprises a positive electrode, a negative electrode, and a nonaqueous electrolyte according to  claim 3 . 
   
   
       9 . The nonaqueous electrolyte of  claim 1 , wherein said organic solvent comprises a member selected from the group consisting of propylene carbonate and butylene carbonate. 
   
   
       10 . The nonaqueous electrolyte of  claim 1 , wherein the quaternary ammonium salt represented by chemical formula 3 comprises a combination of an anion and a member selected from the group consisting of an imidazolium cation, pyrazolium cation, pyrrolinium cation, and pyridinium cation. 
   
   
       11 . The nonaqueous electrolyte of  claim 10 , wherein the imidazolium cation comprises a member selected from the group consisting of a 1,3-dimethylimidazolium ion, 1-ethyl-3-methylimidazolium ion, 1-butyl-3-methylimidazolium ion, 1,2,3-trimethylimidazolium ion, 1,2-dimethyl-3-ethylimidazolium ion, 1,2-dimethyl-3-propylimidazolium ion, and 1-butyl-2,3-dimethylimidazolium ion,
 wherein the pyrazolium cation comprises a member selected from the group consisting of a 1,2-dimethylpyrazolium ion, 1-ethyl-2-methylpyrazolium ion, 1-propyl-2-methylpyrazolium ion, and 1-butyl-2-methylpyrazolium ion,   wherein the pyrrolinium cation comprises a member selected from the group consisting of a 1,2-dimethylpyrrolinium ion, 1-ethyl-2-methylpyrrolinium ion, 1-propyl-2-methylpyrrolinium ion, and 1-butyl-2-methylpyrrolinium ion, and   wherein the pyridinium cation comprises a member selected from the group consisting of an N-methylpyridinium ion, N-ethylpyridinium ion, N-propylpyridinium ion, N-butylpyridinium ion, 1-ethyl-2-methylpyridinium, 1-butyl-4-methylpyridinium, and 1-butyl-2,4-dimethyl-pyridinium.   
   
   
       12 . The nonaqueous electrolyte of  claim 10 , wherein the anion comprises a member selected from the group consisting of a chlorine anion, bromine anion, ClO 4  anion, BF 4  anion, PF 6  anion, CF 3 SO 3  anion, N(CF 3 SO 2 ) 2  anion, N(C 2 F 5 SO 2 ) 2  anion, N(CF 3 SO 2 ) (C 4 F 9 SO 2 ) anion, C(CF 3 SO 2 ) 3  anion, and C(C 2 F 5 SO 2 ) 3  anion. 
   
   
       13 . The nonaqueous electrolyte of  claim 1 , wherein said amount of said quaternary ammonium salt is 0.1 mol/L or greater and 0.35 mol/L or less. 
   
   
       14 . The nonaqueous electrolyte of  claim 1 , wherein said lithium salt comprises a member selected from the group consisting of LiBF 4 , LiPF 6 , LiCF 3 SO 3 , LiN(CF 3 SO 2 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) (C 4 F 9 SO 2 ), LiC(CF 3 SO 2 ) 3 , and LiC(C 2 F 5 SO 2 ) 3 . 
   
   
       15 . A nonaqueous-electrolyte battery, comprising:
 a power generating unit comprising a positive electrode, a negative electrode, and a separator interposed between said positive and negative electrodes; and   a nonaqueous electrolyte impregnated into said power generating unit, said nonaqueous electrolyte comprising:
 an organic solvent and a lithium salt dissolved in the organic solvent; and 
 a quaternary ammonium salt in an amount of 0.06 mol/L or greater and 0.5 mol/L or less, the quaternary ammonium salt having a structure represented by (chemical formula 3): 
   
     
       
         
         
             
             
         
       
       wherein R is an organic linking group or an organic linking group forming an aromatic ring, the organic linking groups each having a main chain which has 4-5 atoms and is constituted of at least one member selected from carbon, oxygen, nitrogen, sulfur, and phosphorus and having one single-bond end and one double-bond end; R1 is an alkyl group having 1-6 carbon atoms or an alkyl group in which at least one of the hydrogen atoms has been replaced by a fluorine atom; and X −  is a fluorine-containing anion.