NON-AQUEOUS LIQUID ELECTROLYTE AND NON-AQUEOUS LIQUID ELECTROLYTE SECONDARY BATTERY

• US 20090325065A1
• Filed: 04/27/2007
• Published: 12/31/2009
• Est. Priority Date: 04/27/2006
• Status: Abandoned Application

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: Fujii, Takashi, Kinoshita, Shinichi, Shima, Noriko, Ohashi, Youichi
• Application Number:
  US12/298,440
• Publication Number:
  US 20090325065A1
• Time in Patent Office: Days
• US Class Current: 429/199
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0028 characterised by the solvent
• CPC Class Codes: H01M 2300/0034 Fluorinated solvents
• CPC Class Codes: H01M 2300/0042 Four or more solvents
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/387 Tin or alloys based on tin
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/58 of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

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 LiPF₆ and/or LiBF₄ (first lithium salt) and lithium salt different from said first one, represented by formula below (second lithium salt).

Li_l(α_mX^a_n)

Claims

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 LiPF₆ and LiBF₄ (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]

Li₁(α

_mX^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_iH_2(i-2)O₄)(C_jH_2(i-2)O₄)

(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,

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 —

SO₂R^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;

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.