Nonaqueous electrolyte, capacitor device using same, and carboxylic acid ester compound used in same

Abstract

The present invention provides a nonaqueous electrolytic solution capable of improving electrochemical characteristics in the case of using an energy storage device at a high temperature and at a high voltage and further capable of inhibiting the gas generation while maintaining a capacity retention rate after storage at a high temperature and at a high voltage and also provides an energy storage device using the same. Disclosed is a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution containing a carboxylic acid ester compound represented by the following general formula (I). In the formula, each of R 1 and R 2 independently represents a hydrogen atom, a —C(═O)—OR 4 group, or the like, and R 1 and R 2 may be bonded to each other to form a ring structure. R 3 represents a hydrogen atom or the like, and n represents an integer of 1 to 3. When n is 1, then L and R 4 represent an alkyl group having 1 to 6 carbon atoms or the like; and when n is 2 or 3, then L represents an n-valent connecting group, X represents a —C(═O)— group, an —S(═O)— group, an —S(═O) 2 — group, an —S(═O) 2 —R 5 —S(═O) 2 — group or a CR 6 R 7 group, R 5 represents an alkylene group having 1 to 4 carbon atoms, and each of R 6 and R 7 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

1 : A nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution comprising from 0.001 to 10% by mass of a carboxylic acid ester compound represented by the following general formula (I): 
       
         
           
           
               
               
           
         
         wherein: 
         each of R 1  and R 2  independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a —C(═O)—OR 4  group, and when R 1  and R 2  are each an alkyl group, then R 1  and R 2  may be bonded to each other to form a ring structure; R 3  represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms; n represents an integer of 1 to 3; 
         when n is 1, then L and R 4  may be the same as or different from each other and represent an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and when n is 2 or 3, then L represents an n-valent connecting group constituted of a carbon atom and a hydrogen atom, which may contain an ether bond, a thioether bond, or an SO 2  bond and R 4  is the same as described above; and 
         X represents a —C(═O)— group, an —S(═O)— group, an —S(═O) 2 — group, an —S(═O) 2 —R 5 —S(═O) 2 — group or a CR 6 R 7  group, R 5  represents an alkylene group having 1 to 4 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom or an alkyl group having 1 to 4 carbon atoms, and each of R 6  and R 7  independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, 
         when X is a —C(═O)— group, R 1  and/or R 2  is a —C(═O)—OR 4  group, and 
         wherein at least one hydrogen atom of the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 3 to 6 carbon atoms, the alkenyl group having 2 to 6 carbon atoms, the alkynyl group having 3 to 6 carbon atoms, the alkoxyalkyl group having 2 to 6 carbon atoms, the cyanoalkyl group having 2 to 6 carbon atoms, the aralkyl group having 7 to 13 carbon atoms, or the aryl group having 6 to 12 carbon atoms as R 1 , R 2 , R 4 , or L, may be substituted with a halogen atom; and 
         further comprising 0.07 to 7% by volume of one or more selected from vinylene carbonate, vinyl ethylene carbonate and 4-ethynyl-1,3-dioxolan-2-one, relative to a total volume of the nonaqueous solvent. 
       
     
     
         2 : The nonaqueous electrolytic solution according to  claim 1 , wherein in the general formula (I), X is a —C(═O)— group, and n is an integer of 1 to 3. 
     
     
         3 . (canceled) 
     
     
         4 : The nonaqueous electrolytic solution according to  claim 1 , wherein in the general formula (I), X is an —S(═O)— group, an —S(═O) 2 — group, or a —CR 6 R 7  group, and n is 1. 
     
     
         5 : The nonaqueous electrolytic solution according to  claim 4 , wherein in the general formula (I), the compound wherein X is an —S(═O)— group, an —S(═O) 2 — group, or a —CR 6 R 7  group is a carboxylic acid ester compound represented by the following general formula (I-2): 
       
         
           
           
               
               
           
         
         wherein: 
         each of R 21  and R 22  independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, an aryl group having 6 to 12 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, or a —C(═O)—OR 25  group, and when R 21  and R 22  are each an alkyl group, then R 21  and R 22  may be bonded to each other to form a ring structure; 
         R 23  represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms; 
         R 24  and R 25  may be the same as or different from each other and represent an alkyl group having 1 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, a cycloalkyl group having 3 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, an alkenyl group having 2 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, an alkynyl group having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, or an aryl group having 6 to 12 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom; and 
         X 1  represents an —S(═O) group, an —S(═O) 2  group, or a —CR 26 R 27  group and each of R 26  and R 27  independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom. 
       
     
     
         6 : The nonaqueous electrolytic solution according to  claim 1 , wherein in the general formula (I), X is an —S(═O) 2 —R 5 —S(═O) 2 — group, and n is 1 or 2. 
     
     
         7 : The nonaqueous electrolytic solution according to  claim 6 , wherein in the general formula (I), the compound wherein X is an —S(═O) 2 —R 5 —S(═O) 2 — group, and n is 1 or 2 is a carboxylic acid ester compound represented by the following general formula (I-3): 
       
         
           
           
               
               
           
         
         wherein: 
         each of R 31  and R 32  independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, an aryl group having 6 to 12 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, or a —C(═O)—OR 34  group; R 33  represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms; m represents 1 or 2; 
         when m is 1, then L 3  and R 34  may be the same as or different from each other and represent an alkyl group having 1 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, a cycloalkyl group having 3 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, an alkenyl group having 2 to 6 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, an alkynyl group having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, or an aryl group having 6 to 12 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom, and when m is 2, then L 3  represents an alkylene group having 2 to 8 carbon atoms, an alkenylene group having 4 to 8 carbon atoms, or an alkynylene group having 4 to 8 carbon atoms, and at least one hydrogen atom of L 3  may be substituted with a halogen atom and R 34  is the same as described above; and 
         X 2  represents an —S(═O) 2 —R 35 —S(═O) 2 — group and R 35  represents an alkylene group having 1 to 4 carbon atoms, in which at least one hydrogen atom may be substituted with a halogen atom or an alkyl group having 1 to 4 carbon atoms. 
       
     
     
         8 . (canceled) 
     
     
         9 : The nonaqueous electrolytic solution according to  claim 1 , wherein the nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent comprises 0.01 to 5% by mass of the carboxylic acid ester compound represented by the general formula (I). 
     
     
         10 : The nonaqueous electrolytic solution according to  claim 1 , wherein the nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent comprises the carboxylic acid ester compound represented by the general formula (I) and further comprises LiPF 6  as an electrolyte salt. 
     
     
         11 : An energy storage device comprising a positive electrode, a negative electrode, and a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution comprising the nonaqueous electrolytic solution according to  claim 1 . 
     
     
         12 : The energy storage device according to  claim 11 , wherein the positive electrode comprises, as a positive electrode active material, a complex metal oxide containing lithium and one or more selected from cobalt, manganese, and nickel, or a lithium-containing olivine-type phosphate. 
     
     
         13 : The energy storage device according to  claim 11 , wherein the negative electrode comprises, as a negative electrode active material, one or more selected from lithium metal, a lithium alloy, a carbon material capable of absorbing and releasing lithium, tin, a tin compound, silicon, a silicon compound, and a lithium titanate compound. 
     
     
         14 - 15 . (canceled) 
     
     
         16 : The nonaqueous electrolytic solution according to  claim 1 , wherein the carboxylic acid ester compound represented by the formula (I) is at least one selected from 2-propenyl 2-oxo-1,3-dioxolane-4-carboxylate, 2-propynyl 2-oxo-1,3-dioxolane-4-carboxylate, 2-propynyl 5-fluoro-2-oxo-1,3-dioxolane-4-carboxylate, 2-propynyl 4-fluoro-2-oxo-1,3-dioxolane-4-carboxylate, dimethyl 2-oxo-1,3-dioxolane-4,5-dicarboxylate, diethyl 2-oxo-1,3-dioxolane-4,5-dicarboxylate, diisopropyl 2-oxo-1,3-dioxolane-4,5-dicarboxylate, dicyclohexyl 2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(2-propenyl) 2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(2-propynyl) 2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(trifluoroethyl) 2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(tetrafluorophenyl) 2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(pentafluorophenyl) 2-oxo-1,3-dioxolane-4,5-dicarboxylate, 2-butene-1,4-diyl bis(2-oxo-1,3-dioxolane-4-carboxylate), and 2-butyne-1,4-diyl bis(2-oxo-1,3-dioxolane-4-carboxylate). 
     
     
         17 : The nonaqueous electrolytic solution according to  claim 5 , wherein the carboxylic acid ester compound represented by the formula (I-2) is at least one selected from methyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide, ethyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide, 2-propenyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide, 2-propynyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide, 2,2,2-trifluoroethyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide, methyl 5-fluoro1-1,3,2-dioxathiolane-4-carboxylate 2-oxide, dimethyl 1,3,2-dioxathiolane-4,5-dicarboxylate 2-oxide, diethyl 1,3,2-dioxathiolane-4,5-dicarboxylate 2-oxide, methyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, ethyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, 2-propenyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide), 2-propynyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, 2,2,2-trifluoroethyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, methyl 5-fluoro-1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, dimethyl 1,3,2-dioxathiolane-4,5-dicarboxylate 2,2-dioxide, diethyl 1,3,2-dioxathiolane-4,5-dicarboxylate 2,2-dioxide, methyl 1,3-dioxolane-4-carboxylate, ethyl 1,3-dioxolane-4-carboxylate, 2-propenyl 1,3-dioxolane-4-carboxylate, 2-propynyl 1,3-dioxolane-4-carboxylate, 2,2,2-trifluoroethyl 1,3-dioxolane-4-carboxylate, methyl 5-fluoro-1,3-dioxolane-4-carboxylate, dimethyl 1,3-dioxolane-4,5-dicarboxylate, diethyl 1,3-dioxolane-4,5-dicarboxylate, methyl 2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate and dimethyl 2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate. 
     
     
         18 : The nonaqueous electrolytic solution according to  claim 7 , wherein the carboxylic acid ester compound represented by the formula (I-3) is at least one selected from methyl 1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide, ethyl 1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide, 2-propenyl 1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide, 2-propynyl 1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide, 2,2,2-trifluoroethyl 1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide, methyl 1,5,2,4-dioxadithiepane-7-fluoro-6-carboxylate 2,2,4,4-tetraoxide, dimethyl 1,5,2,4-dioxadithiepane-6,7-dicarboxylate 2,2,4,4-tetraoxide, and diethyl 1,5,2,4-dioxadithiepane-6,7-dicarboxylate 2,2,4,4-tetraoxide.