Fluoroalkylphosphate salt electrolytes

Details Fluoroalkylphosphate salt electrolytes Fluoroalkylphosphate salt electrolytes

2001-11-09

2004-09-21

Ruthkosky, Mark (Department: 1745)

Chemistry: electrical current producing apparatus, product, and

Current producing cell, elements, subcombinations and...

Include electrolyte chemically specified and method

C429S305000, C429S307000, C429S322000, C429S203000, C252S062200, C423S301000, C423S323000

Reexamination Certificate

active

06794083

ABSTRACT:

The present invention relates to mixtures of fluoroalkylphosphate salts and polymers, methods of producing same, and their use in electrolytes, batteries, capacitors, supercapacitors and galvanic cells.
In recent years, the spreading of portable electronic devices such as laptop and palmtop computers, cell telephones, or video cameras and thus, the demand for light-weight and high-performance batteries has dramatically increased worldwide.
In view of such rapidly increasing demand for batteries and the associated ecological problems, the development of rechargeable batteries having long service life and high performance has become more and more important.
More specifically, the quality of the electrolyte has an enormous effect on the service life and performance of the batteries, and the past therefore has seen numerous attempts of continuously improving the electrolyte.
Conventionally, the well-known electrolyte systems have been divided in liquid and solid electrolytes, and solid electrolytes comprise both polymer electrolytes and gel or hybrid electrolytes.
Battery cells based on liquid electrolytes generally have relatively good ionic conductivities, but are liable to leakage, giving rise to liberation of liquids which represent a potential hazard to man and environment. In addition, the production of such battery cells is restricted with respect to feasible sizes and shapes of these cells.
Polymer electrolytes normally are based on an optionally crosslinked polymer and a conducting salt. However, conventional polymer electrolytes frequently have low ionic conductivities which do not comply with the high demands to be met by modern batteries.
Gel or hybrid electrolytes are understood to be electrolyte systems including a solvent in addition to an optionally crosslinked polymer and a conducting salt. These polymers frequently are crosslinked at relatively high temperatures in the presence of the conducting salts. For this reason, appropriate conducting salts must have a relatively high thermal stability in solution because otherwise, they might undergo decomposition and in consequence, the ionic conductivity of the resulting gel electrolyte might be reduced.
DE 196 41 138 discloses lithium fluorophosphates having preferably per-fluorinated or partially fluorinated ethyl and isopropyl groups and their use as conducting salts in batteries. Use of these salts as conducting salts in polymer electrolytes has not been described. The German patent application, file number 100 08 955, describes lithium fluoroalkylphosphates and their use as conducting salts in batteries, capacitors, supercapacitors, and galvanic cells. There is no disclosure as to polymer electrolytes based on these salts.
The basic object of the present invention is to provide electrolytes which, in addition to high ionic conductivity, would have high thermal and electrochemical stability.
Another object of the present invention is to improve the service life and enhance the performance of batteries, capacitors, supercapacitors, and galvanic cells.
Surprisingly, these objects have been accomplished by providing mixtures including
a) at least one fluoroalkylphosphate salt of general formula (I)
M
n+
([PF
x
(C
y
F
2y+1-z
H
z
)
6-x
]
−
)
n
  (I)
 wherein
M
n+
is a univalent, bivalent, or trivalent cation,
1≦x≦5,
1≦y≦8, and
0≦z≦2y+1, n=1, 2 or 3, and the ligands (C
y
F
2y+1-z
H
z
) each are the same or different, and
b) at least one polymer.
Mixtures in the meaning of the present invention include pure mixtures of components a) and b), mixtures wherein the salt of component a) is included in the polymer of component b), and mixtures wherein chemical and/or physical bonds exist between the salt of component a) and the polymer of component b).
Conventionally, corresponding mixtures comprised of at least one conducting salt and at least one polymer are also referred to as polymer electrolytes.
The mixtures according to the invention may also include two or more fluoroalkylphosphate salts of general formula (I) as component a) and/or two or more polymers of component b) at a time. Preferably, the mixtures of the invention each include a fluoroalkylphosphate salt of general formula (I) as component a) and a polymer of component b), because particularly good reproducibility of the electrochemical properties can be achieved in this way.
The mixture according to the invention preferably includes fluoroalkylphosphate salts of general formula (I) as component a), wherein M
n+
is a lithium cation, a sodium cation, a potassium cation, a rubidium cation, a cesium cation, a magnesium cation, or an aluminum cation. In a particularly preferred fashion, the mixture of the invention includes those salts as component a) wherein M
n+
represents a lithium cation.
Likewise, the mixture according to the invention preferably includes fluoroalkylphosphate salts of general formula (I) wherein M
n+
represents an organic cation. Preferably, the organic cation a nitrosyl cation, a nitryl cation, a tropylium cation, or a cation of general formula [NR
4
]
+
, [P(NR
2
)
k
R
4−k
]
+
, with 0≦k≦4, [C(NR
2
)
3
]
+
, or [CR
3
]
+
, wherein each of the substituents R, same or different, represents
H,
C
o
F
2o+1-p−q
H
p
A
q
, or
A,
wherein
1≦o≦10, 0≦p≦2o+1, 0≦q≦2o+1, preferably 1≦o≦6, 0≦p≦2o+1, 0≦q≦2o+1, and A represents an aromatic residue optionally having hetero-atoms, or a preferably 5- or 6-membered cycloalkyl residue. The ligands C
o
F
2o+1−p−q
H
p
A
q
may also be at least partially substituted by chlorine and/or bromine, and the residues A may also be at least partially substituted by fluorine, chlorine and/or bromine.
All of the aromatic, heteroaromatic or cycloaliphatic compounds well-known to those skilled in the art and suitable in the preparation of [NR
4
]
+
, [P(NR
2
)
k
R
4−k
]
30
, with 0≦k≦4, [C(NR
2
)
3
]
+
, or [CR
3
]
+
cations can be used as aromatic or cycloaliphatic residue A optionally including heteroatoms.
Preferably, A represents a 5- or 6-membered aromatic or cycloaliphatic residue optionally including nitrogen and/or sulfur and/or oxygen atoms, more preferably a phenyl or pyridine residue.
As component a), the mixtures according to the invention more preferably include fluoroalkylphosphate salts of general formula (I) having perfluorinated ligands, i.e., salts having ligands wherein 1≦x≦5, 1≦y≦8, and z=0.
In a particularly preferred embodiment of the present invention, the mixtures of the invention include one or more fluoroalkylphosphate salts as component a), which are selected from the group consisting of:
Li
+
[F
6−x
P(CF
2
CF
3
)
x
]
−
, with 1≦x≦3,
Li
+
[F
6−x
P(CF
2
CF
2
CF
3
)
x
]
−
, with 1≦x≦3,
Li
+
[F
6−x
P(CF
2
CF
2
CF
2
CF
3
)
x
]
−
, with 1≦x≦3,
Li
+
[F
6−x
P(CF(CF
3
)
2
)
x
]
−
, with x=1 or 2,
[N(C
2
H
5
)
4
][PF
3
(C
2
F
5
)
3
],
[N(CH
3
)
4
][PF
3
(C
4
F
9
)
3
],
[P(N(CH
3
)
2
)
4
][PF
3
(C
2
F
5
)
3
],
[P(N(CH
3
)
2
)
4
][PF
3
(C
4
F
9
)
3
],
[P(CH
3
)
4
][PF
3
(C
2
F
5
)
3
],
[P(C
2
H
5
)
4
][PF
3
(C
2
F
5
)
3
],
[P(CH
3
)
4
][PF
3
(C
4
F
9
)
3
],
[P(C
2
H
5
)
4
][PF
3
(C
4
F
9
)
3
],
[C(N(CH
3
)
2
)
3
][PF
3
(C
2
F
5
)
3
], and
[C(N(CH
3
)
2
)
3
][PF
3
(C
4
F
9
)
3
].
The fluoroalkylphosphate salts of general formula (I) can be obtained using methods according to which at least one compound of general formula (II) to (VII)
H
r
P(C
s
H
2s+1
)
3−r
(II),
OP(C
s
H
2s+1
)
3
(III),
Cl
r
P(C
s
H
2s+1
)
3−r
(IV),
F
r
P(C

Affiliated with

Also associated with

Rating

Fluoroalkylphosphate salt electrolytes does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fluoroalkylphosphate salt electrolytes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluoroalkylphosphate salt electrolytes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3233540