Non-aqueous liquid electrolyte and non-aqueous liquid electrolyte secondary battery

Abstract

A non-aqueous liquid electrolyte secondary battery using negative-electrode active material having Si, Sn and/or Pb, with high charge-capacity, superior characteristics including discharge-capacity retention rate over long is provided. Its non-aqueous liquid electrolyte contains carbonate having unsaturated bond and/or halogen and compounds like LiPF 6 and/or LiBF 4 (first lithium salt) and lithium salt different from said first one, represented by formula below (second lithium salt). Li l (α m X a n )

1 . A non-aqueous liquid electrolyte to be used for a non-aqueous liquid electrolyte secondary battery comprising a negative electrode and a positive electrode, capable of intercalating and deintercalating lithium ions, and the non-aqueous liquid electrolyte, the negative electrode containing a negative-electrode active material having at least one kind of atom selected from the group consisting of Si atom, Sn atom and Pb atom,
 wherein said non-aqueous liquid electrolyte contains, at least, a carbonate having at least either an unsaturated bond or a halogen atom, and at least one kind selected from the group consisting of (A), (B), (C), (D) and (E) below,   (A) at least one lithium salt of LiPF 6  and LiBF 4  (hereinafter referred to as “first lithium salt”) and at least one kind of lithium salt, which is different from said first lithium salt, represented by the formula (A-1) below (hereinafter referred to as “second lithium salt”),
   [Chemical Formula 1] 
   Li 1 (α m X a   n )   (A-1) 
   
       in the formula (A-1), 
       l represents an integer of 1 or larger and 10 or smaller, 
       m represents an integer of 1 or larger and 100 or smaller, 
       and n represents an integer of 1 or larger and 200 or smaller, 
       α represents any atom selected from the group consisting of boron atom, carbon atom, nitrogen atom, oxygen atom and phosphorus atom; when m is 2 or larger, the two or more of α may be the same as or different from each other, 
       X a  represents a functional group having at least one kind of atom selected from 14 group to 17 group of the periodic table at its binding position to the α, when n is 2 or larger, the two or more of X a  may be the same or different from each other, in addition, two or more X a  may be connected to each other to form a ring structure, 
       except such a compound that α is boron atom and X a  is represented by
   (C i H 2(i-2) O 4 )(C j H 2(i-2) O 4 ) 
 
       (in this context, i and j each represent, independently of each other, an integer of 2 or larger,)
 (B) at least one kind of compound represented by the formula (B-1) below, 
 
       
         
           
           
               
               
           
         
       
       (in the formula (B-1), R b1  and R b2  represent, independently of each other, a hydrocarbon group, which may have a substituent, with carbon number of 15 or smaller, R b1  and R b2  may be connected to each other to form a ring structure,)
 (C) at least one kind of chain compound having one or more sulfur-containing functional groups represented by the formula (C-1) below,
   [Chemical Formula 3] 
   O m S(═O) y  x O n    (C-1) 
 
 
       (in the formula (C-1), 
       m and n represent, independently of each other, an integer of 0 or 1, 
       x represents an integer of 1 or 2, and 
       y represents an integer of 0 or larger and 2 or smaller,
 (D) at least one kind of organic phosphorous compound represented by the formula (D-1) below, 
 
       
         
           
           
               
               
           
         
       
       (in the formula (D-1), 
       p and q represent, independently of each other, an integer of 0 or 1, and 
       R d1 , R d2  and R d3  represent, independently of each other, a hydrocarbon group, which may have a halogen atom, with carbon number of 1 or larger and 20 or smaller, any two of R d1 , R d2  and R d3  may be connected to each other to form a ring structure,)
 (E) a least one kind of compound represented by the formula (E-1) below, 
 
       
         
           
           
               
               
           
         
       
       (in the formula (E-1), 
       X e  represents a halogen atom, alkyl group or aryl group hen X e  is an alkyl group or aryl group, it may be further substituted with a halogen atom, alkyl group or aryl group, 
       n represents an integer of 1 or larger and 6 or smaller, 
       when n is 2 or larger, the two or more of X e  may be the same or different from each other, in addition, two or more X e  may be connected to each other to form a ring structure or a cage structure. 
     
     
         2 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in the above formula (A-1),   α is boron atom or phosphorus atom, and   X a  is a substituent selected from the group consisting of fluorine atom, hydrocarbon group, substituted carbonyloxy group, alkoxy group, substituted sulfinyloxy group and substituted sulfonyloxy group (in this context, when X a  is a hydrocarbon group, substituted carbonyloxy group, alkoxy group, substituted sulfinyloxy group or substituted sulfonyloxy group, a part or all of the hydrogen atoms may be substituted with a fluorine atom, in addition, when X a  exists plurally, they may be different from or the same as each other and may be connected to each other to form a ring structure).   
     
     
         3 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in the above formula (A-1),   α is carbon atom, nitrogen atom or oxygen atom, and   X a  is a group represented by —SO 2 R a0  (in this context, R a0  represents fluorine atom or a hydrocarbon group when R a0  is a hydrocarbon group, a part or all of the hydrogen atoms may be substituted with a fluorine atom, in addition, when the number of X a  is two or more, the two or more of R a0  may be the same or different from each other and further, the two or more of R a0  may be connected to each other to form a ring structure).   
     
     
         4 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in said non-aqueous liquid electrolyte, the concentration of said first lithium salt is 0.5 mol/liter or higher and 2.5 mol/liter or lower,   in said non-aqueous liquid electrolyte, the concentration of said second lithium salt is 0.001 mol/liter or higher and I mol/liter or lower, and   the molar ratio of said second lithium salt relative to the first lithium salt is 1 or smaller.   
     
     
         5 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 said compound represented by the above formula (B-1) is a compound in which R b1  and R b2  are connected to each other directly to form a ring structure.   
     
     
         6 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in said non-aqueous liquid electrolyte, the concentration of said compound represented by the above formula (B-1) is 0.01 weight % or higher and 5 weight % or lower.   
     
     
         7 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 said chain compound having said sulfur-containing functional group represented by the above formula (C-1) is a compound represented by the formula (C-2) below,
   [Chemical Formula 6] 
   R c1 -A c -R c2    (C-2) 
   
       (In the formula (C-2), 
       A c  represents a sulfur-containing functional group represented by the above formula (C-1), and 
       R c1  and R c2  represent, independently of each other, a hydrocarbon group, which may have a halogen atom, with carbon number of 1 or larger and 20 or smaller.) 
     
     
         8 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 said chain compound having said sulfur-containing functional group represented by the above formula (C-1) is a compound represented by the formula (C-3) below.
   [Chemical Formula 7] 
   (R c3 -A c  z —R c4    (C-3) 
   
       (in the formula (C-3), 
       R c3  represents a hydrocarbon group, which may have a halogen atom, with carbon number of 1 or larger and 20 or smaller, 
       A c  represents a sulfur-containing functional group represented by the above formula (C-1), 
       z represents an integer of 2 or larger and 4 or smaller, and 
       R c4  represents a hydrocarbon group, which may have a halogen atom, with z number of connection parts and with carbon number of 1 or larger and 20 or smaller; in this context, the z number of R c3  and A c  may be the same or different from each other, respectively.) 
     
     
         9 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 said sulfur-containing functional group represented by the above formula (C-1) is any one of functional groups represented by the formulae (C-4) to (C-10) below,   
       
         
           
           
               
               
           
         
       
     
     
         10 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in said non-aqueous liquid electrolyte, the concentration of said chain compound having said sulfur-containing functional group represented by the above formula (C-1) is 0.01 weight % or higher and 10 weight % or lower.   
     
     
         11 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in the above formula (D-1), p+q is equal to 1 or 2.   
     
     
         12 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in the above formula (D-1), p+q is equal to 0.   
     
     
         13 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in said non-aqueous liquid electrolyte, the concentration of said compound represented by the above formula (D-1) is 0.01 weight % or higher and 10 weight % or lower.   
     
     
         14 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 said compound represented by the above formula (E-1) is the compound represented by the formula (E-2) below;   
       
         
           
           
               
               
           
         
       
       (In the formula (E-2), 
       R e1 , R e2  and R e3  represent, independently of each other, hydrogen atom, or an alkyl group that may be substituted with a halogen atom; in addition, two or three of R e1 , R e2  and R e3  may be connected to each other to form a ring structure or cage structure; however, none of or one of R e1 , R e2  and R e3  is hydrogen atom. 
       Y e  represents a halogen atom, alkyl group or aryl group, when Y e  is an alkyl group or aryl group, it may be further substituted with a halogen atom, alkyl group or aryl group; 
       m represents an integer of 0 or larger and 5 or smaller; when m is 2 or larger, the two or more of Y e  may be the same or different from each other; in addition, two or more Y e  may be connected to each other to form a ring structure or cage structure.) 
     
     
         15 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in the above formula (E-1), at least one of X e  is halogen atom, or an aryl group that may be substituted with a halogen atom.   
     
     
         16 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in said non-aqueous liquid electrolyte, the concentration of said compound represented by the above formula (E-1) is 0.01 weight % or higher and 10 weight % or lower.   
     
     
         17 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 in said non-aqueous liquid electrolyte, the concentration of said carbonate having at least either an unsaturated bond or a halogen atom is 0.01 weight % or higher, and 70 weight % or lower.   
     
     
         18 . A non-aqueous liquid electrolyte according to  claim 1 , wherein
 wherein said carbonate having at least either an unsaturated bond or a halogen atom is one or more kinds of carbonates selected from the group consisting of vinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate and derivatives of these carbonates.   
     
     
         19 . A non-aqueous liquid electrolyte according to  claim 1 ,
 further containing ethylene carbonate and/or propylene carbonate.   
     
     
         20 . A non-aqueous liquid electrolyte according to  claim 1 ,
 further containing at least one carbonate selected from the group consisting of dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, methyl-n-propyl carbonate, ethyl-n-propyl carbonate and di-n-propyl carbonate.   
     
     
         21 . A non-aqueous liquid electrolyte secondary battery comprising a negative electrode and a positive electrode, capable of intercalating and deintercalating lithium ions, and a non-aqueous liquid electrolyte,
 the negative electrode containing a negative-electrode active material having at least one kind of atom selected from the group consisting of Si atom, Sn atom and Pb atom, wherein   said non-aqueous liquid electrolyte is a non-aqueous liquid electrolyte according to  claim 1 .