CA2181973A1 - Non-aqueous electrolyte and lithium secondary battery - Google Patents
Non-aqueous electrolyte and lithium secondary batteryInfo
- Publication number
- CA2181973A1 CA2181973A1 CA002181973A CA2181973A CA2181973A1 CA 2181973 A1 CA2181973 A1 CA 2181973A1 CA 002181973 A CA002181973 A CA 002181973A CA 2181973 A CA2181973 A CA 2181973A CA 2181973 A1 CA2181973 A1 CA 2181973A1
- Authority
- CA
- Canada
- Prior art keywords
- carbonate
- aqueous electrolyte
- electrolyte according
- halogen
- lithium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
- H01M6/14—Cells with non-aqueous electrolyte
- H01M6/16—Cells with non-aqueous electrolyte with organic electrolyte
- H01M6/162—Cells with non-aqueous electrolyte with organic electrolyte characterised by the electrolyte
- H01M6/164—Cells with non-aqueous electrolyte with organic electrolyte characterised by the electrolyte by the solvent
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/20—Semi-lead accumulators, i.e. accumulators in which only one electrode contains lead
- H01M10/22—Selection of materials as electrolytes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0569—Liquid materials characterised by the solvents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
- H01M2300/0028—Organic electrolyte characterised by the solvent
- H01M2300/0034—Fluorinated solvents
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Secondary Cells (AREA)
Abstract
It is provided a non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt, said non-aqueous electrolyte containing a halogen-substituted ether compound represented by the general formula [I]:
R1-O-R2 [I]
(wherein R1 is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms) and at least one sort of a compound in which a mixed solvent as the non-aqueous solvent obtained by adding the compound to the halogen-substituted ether compound is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/litter, and a lithium secondary battery comprising a cathode that can be doped/undoped with lithium ions, an anode of a lithium metal or alloy or an anode that can be doped/undoped with lithium ions and the non-aqueous electrolyte described above.
A lithium secondary battery using the non-aqueous electrolyte above is superior in cycle life, for repeating charging/discharging and low-temperature capacity, particularly superior in high-rate capacity, and causes little deterioration of high-rate capacity due to cycles.
R1-O-R2 [I]
(wherein R1 is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms) and at least one sort of a compound in which a mixed solvent as the non-aqueous solvent obtained by adding the compound to the halogen-substituted ether compound is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/litter, and a lithium secondary battery comprising a cathode that can be doped/undoped with lithium ions, an anode of a lithium metal or alloy or an anode that can be doped/undoped with lithium ions and the non-aqueous electrolyte described above.
A lithium secondary battery using the non-aqueous electrolyte above is superior in cycle life, for repeating charging/discharging and low-temperature capacity, particularly superior in high-rate capacity, and causes little deterioration of high-rate capacity due to cycles.
Description
~--- 21~1~73 NON-AQUEOUS ELECTROLYTE AND LITHIUM SECONDARY BATTERY
FIEI.D OF T~E INVENTION
The present invention relates to a non-aqueous electrolyte, and a lithium secondary battery using the same.
BA~ ~uuNL~ OF TE~E INVENTION
Recently, portable information apparatuses including lap-top computers, portable telephones, personal digital assistants, etc. have come into wide use. These apparatuses for multimedia demand a lot of functions, then they need portable and light-weight batteries having large capacity and high energy density as their power sources.
It is one method for accomplishing a high energy density of a battery to increase the voltage of the battery.
A lithium secondary battery attaining an average voltage of 3 . 6 V can be obtained by using a lithiated transition metal dioxide ( e . g . lithiated nickel dioxide, lithiated cobalt dioxide, etc. ) as an active material for a cathode and a . iqrhrl~A~ PQ~Ic material that can be doped/undoped with lithium ions as an active material for an anode.
The above active material has a very high electro~ h-omi-~l activity, and is reactive on the `-- 2181~73 electrolyte. The lithiated metal dioxide such as lithiated cobalt dioxide, lithiated niclcel dioxide, etc. has a high redox potential when lithium is charged/discharged. That is, it has a strong oxidation power and, therefore, the stability against oxidation is requested for the electrolyte .
The r~rhnn~reous material that can be doped/undoped with lithium ions has low redox potential when lithium is charged/discharged. That is, it has a strong reduction power and, therefore, the reduction resistance is requested to the electrolyte .
Since the redox potential for charging/discharging lithium of the above carbonaceous material is lower than that of l~ydL.,Je~l, water or a protic solvent can not be used as the solYent for electrolyte and, therefore, an aprotic solvent is used. In case of the electrolyte using water, the conductivity reaches about lS/cm. ~owever, when using the aprotic solvent, the conductivity is several tens mS/cm at most, and it is a large problem of the lithium battery that the internal resistance of the battery becomes large.
The latest electronic apparatuses such as lap-top computers, cam-corders, portable t~lprhnn~c~ etc. frequently have been used outside as a portable. Therefore, batteries `-- 218~973 for the apparatuses are required to operate over wide ~ ~- C.LuLe range. And, at the same time, batteries are required to be able to pulse discharge at high rate because of the digitization of these electronic appratuses. Under these circumstances, the lithium secondary battery was not n~C~ccarily sufficient in high-rate capacity and low-t aLuL~ capacity, n~C~-ss~rily, in comparison with a battery using an aqueous electrolyte.
An object of the present invention is to provide a non-aqueous electrolyte which is improved in cycle life for repeating charging/discharging and low-temperature capacity, particularly superior in high-rate capacity, and causes little deterioration of high-rate capacity due to cycles, and a lithium secondary battery using the same.
SUMMA~Y OF TEIE INVENTIO~
The present inventors have intensively studied to solve the problems mentioned above. As a result, it has been found that the above problems can be solved by using a specific halogen-substituted ether as an organic solvent of a non-aqueous electrolyte, and the present invention has been accomplished .
That is, the present invention relates to the ~ 2181973 f ollowings:
( 1 ) A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt, said non-aqueous solvent containing a halogen-substituted ether ~ ~ollnd represented by the general formula [I]:
Rl-O-R2 [ I ]
(wherein Rl is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms and at least one sort of a compound, in which a mixed solvent as the non-aqueous solvent obtained by adding the compound to the halogen-substituted ether compound is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/l; and (2~ A lithium se~on(l~ry battery comprising a cathode that can be doped/undoped with lithium ions, an anode of a lithium metal, a lithium alloy or a material that can be doped/undoped with lithium ions, and a non-aqueous electrolyte described in the above-mentioned paragraph ( 1~ .
nT:T~TT.Fn DESCRIPTION OF T~E INVENTION
The present invention will be ~r~ ~; n~d in detail, hereinafter.
FIEI.D OF T~E INVENTION
The present invention relates to a non-aqueous electrolyte, and a lithium secondary battery using the same.
BA~ ~uuNL~ OF TE~E INVENTION
Recently, portable information apparatuses including lap-top computers, portable telephones, personal digital assistants, etc. have come into wide use. These apparatuses for multimedia demand a lot of functions, then they need portable and light-weight batteries having large capacity and high energy density as their power sources.
It is one method for accomplishing a high energy density of a battery to increase the voltage of the battery.
A lithium secondary battery attaining an average voltage of 3 . 6 V can be obtained by using a lithiated transition metal dioxide ( e . g . lithiated nickel dioxide, lithiated cobalt dioxide, etc. ) as an active material for a cathode and a . iqrhrl~A~ PQ~Ic material that can be doped/undoped with lithium ions as an active material for an anode.
The above active material has a very high electro~ h-omi-~l activity, and is reactive on the `-- 2181~73 electrolyte. The lithiated metal dioxide such as lithiated cobalt dioxide, lithiated niclcel dioxide, etc. has a high redox potential when lithium is charged/discharged. That is, it has a strong oxidation power and, therefore, the stability against oxidation is requested for the electrolyte .
The r~rhnn~reous material that can be doped/undoped with lithium ions has low redox potential when lithium is charged/discharged. That is, it has a strong reduction power and, therefore, the reduction resistance is requested to the electrolyte .
Since the redox potential for charging/discharging lithium of the above carbonaceous material is lower than that of l~ydL.,Je~l, water or a protic solvent can not be used as the solYent for electrolyte and, therefore, an aprotic solvent is used. In case of the electrolyte using water, the conductivity reaches about lS/cm. ~owever, when using the aprotic solvent, the conductivity is several tens mS/cm at most, and it is a large problem of the lithium battery that the internal resistance of the battery becomes large.
The latest electronic apparatuses such as lap-top computers, cam-corders, portable t~lprhnn~c~ etc. frequently have been used outside as a portable. Therefore, batteries `-- 218~973 for the apparatuses are required to operate over wide ~ ~- C.LuLe range. And, at the same time, batteries are required to be able to pulse discharge at high rate because of the digitization of these electronic appratuses. Under these circumstances, the lithium secondary battery was not n~C~ccarily sufficient in high-rate capacity and low-t aLuL~ capacity, n~C~-ss~rily, in comparison with a battery using an aqueous electrolyte.
An object of the present invention is to provide a non-aqueous electrolyte which is improved in cycle life for repeating charging/discharging and low-temperature capacity, particularly superior in high-rate capacity, and causes little deterioration of high-rate capacity due to cycles, and a lithium secondary battery using the same.
SUMMA~Y OF TEIE INVENTIO~
The present inventors have intensively studied to solve the problems mentioned above. As a result, it has been found that the above problems can be solved by using a specific halogen-substituted ether as an organic solvent of a non-aqueous electrolyte, and the present invention has been accomplished .
That is, the present invention relates to the ~ 2181973 f ollowings:
( 1 ) A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt, said non-aqueous solvent containing a halogen-substituted ether ~ ~ollnd represented by the general formula [I]:
Rl-O-R2 [ I ]
(wherein Rl is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms and at least one sort of a compound, in which a mixed solvent as the non-aqueous solvent obtained by adding the compound to the halogen-substituted ether compound is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/l; and (2~ A lithium se~on(l~ry battery comprising a cathode that can be doped/undoped with lithium ions, an anode of a lithium metal, a lithium alloy or a material that can be doped/undoped with lithium ions, and a non-aqueous electrolyte described in the above-mentioned paragraph ( 1~ .
nT:T~TT.Fn DESCRIPTION OF T~E INVENTION
The present invention will be ~r~ ~; n~d in detail, hereinafter.
2~81973 A non-agueous electrolyte of the present invention comprises a halogen-sub6tituted ether compound represented by tha general ~ormula [ I 3 as a non-aqueou5 solvent s and u~ing a lithliml sælt.
With the halosen-substit~ted ether compound, P~l in the ~or~u}a is an alkyl or halogen-substituted alkyl group has~i~g 2 or le~ carbon atom~, pre~e_~bly m~thyl group. ~hen the number of carbon atoms of Rl exceeds ~, the solubility o~ the lithi~ ~lt in the cther compound beconles lo~, a~d it i5 not preferred. ~2 in the formula is a h~logen-substituted allcyl group having 2 to 10 carbon atom~, p~e~erably 3 to 5 carbon ~toms. When the numbc~ o~ carbon atoms of ~2 exc~Yds 13, the vis~osity of the ether coGlpound beco~e~ larg~, and it is not pre~err d.
~ t is preferred that the ether ~ompound shows a 1GW
v~por pressure within the operatihg tempe ature range o~ the battç-ry . ~hen R2 ~ n the formula ~ s preferably hdlogen-~u5stituted alkyi grOUp h~vihg 2 or morc c2rbon ato;ns, more pr~ferably haloge~-~ubstitute~ ~lkyl group h~ving 3 or more carbon ato~s, ~ecause the molelcular weight or polarity be~omes l~r~e.
~ xamples of ~2 in the general ~ormula t I ] in~lude the group~ sho~n ~ n the f ormulae [ I II ] - r x ~ .
`-- - 2~81~73 C~3-(CF2~-CHz . IIII]
( n is integer of 1,~,3,4 or 5) HCl?2-(CF2)l.-C~I
( n is integer of 1,2,3,4 Or 5) CF~-~CFz)~-CHF-~CF~)n-C~12 [~1 (m and r. are esch; ~ ly irlteger of 0,1,2, 3 or 4; ~+~ co 3 HcF2-~cFz)~-cIIF-(cF2~n-cHz-(r~ and n ar~ each ind.,"~ ly irlteger of 0,1,2,3 or 4; mtnCO ) (CFa)Y-CF-(CF~)= CHr ( n ib integer of 0,1,2,3 or 43 ~C~2)z CF-~CF2)~-C~'2- [VIII
( ~ is integer of 0,1,2,3 or 4) CFa-CF2-C(CF~F-(CF2).~-CH2-( n is integer of 0,1 or 2) HCFz CFz-C(CFa)F-(CF~D-CHa ~7 integer of 0,1 or 2) ~al~,gen-substituted etber ~ _ '- having the ~2 gr~ups above are ~ el .I becz~use of t~eir gOod high-rate property due to cycles.
Sp~ciSic exa~ple~s o~ t~e h~lg-~n-6ubstituted ether co~pounds include 3, 3, 3, 2 r 2-penta~luoropropyl methyl ether, 3, 3, 3, 71 2-pr3ntaf lu~ropropyl -1 o~ethyl ether, 3, 3, 3, 2, 2-~e ~.
21~973 nt~luoropro~yl difl~-o,~ LL~l ether, 3,3,3,2,~-pentafluorop royyl trifluoro~ethyl ether, 3,3,3,2,2-pentafluoropropyl ethyl ether, 3, 3, 3, 2, 2 -pentaf lu3ropropyl 2, 2, 2 -trif luoroethyl ether, 4, 4, 4, 3, 3, Z, 2 -heptaCluorobutyl m0thyl ether, ~, 4, 4, 3, 3, 2, 2-hep~af l~orobutyl f luoro~e~hyl ether, 4,4,4,3,3,2,2-hRpt~lUoLo~uLil di~luorortlethyl ether, 4, 4, ~, 3, 3, 2, 2 -heptaf luorobutyl t r i f 1 uvromethyl ether, 4,4,4,3,3,2,2-heptafluorobutyl cthyl _ther, 4,4,4,3,3,2,2-he ptafluorobutyl 2,2,2-trifluoroethyl ether, 5,5,5,4,4,3,3,2,2 -nr~ni~ f I ~ rop~ntyl methyl ether, ~, 5, ~, 4, 4, 3, 3, 2, 2 -nonaf luoro pentyl f 1uoro~ethy1 ether, 5, 5, 5, 4, 4, 3, 3, 2, 2-nonaf luoropenty 1 dif luoromethyl ether, ~, S, 5, 4, 4, 3, 3, 2, 2 -nona~luoropentyl trifluoromethyl ether, 5,5,5,4,4,3,3,2,2-nonafluoropentyl ethyl ether, 5,5,5,4,4,3,3,2,2-non2fluoIo~,a..L~l 2,2,2-trifluoroethyl ether, 3,3,2,2-tetrafluoropropyl meth~l ~ther, 3,3,2,2-tetra~luoropropyl fluoromethyl ether, 3,3,2,2-te~rRfl-~o)vp~u~yl di~luoromethyl ether, 3,3,2,2-t~trafluu~ yl trifluoromethyl ether, 3,3,2,2-tetrafl~-,Lv~-oy~l ethyl ether, 3, 3, 2, 2-tetra~luoropropyl 2, 2, 2-tri f luoroethyl ether 4,4,3,3,2,2-hPY~ r robutyl methy~ ether, 4,4,3,3,2,2-hexa~l uorobutyl fluo~o~ethyl ~ther, 4,4,3,3,2,2-hexafl~lûro~utyl difluorcmethyl ether, 4,4,3,3, ,~-hexa~ o~vl.L-Lyl 21~ ~73 , trif Luoror~ethy I ethe~, 4, 4, 3, 3, 2, 2 -hexa~luorobutyl ethyl r2thr~r, 4, 4, 3, 3, 2, 2-hr~Y~ f 1~ robutyl Z, 2, 2-tri~'luoroethyl ether 5, 5, 4, 4, 3, 3, 2, 2-octadf luoropentyl m~thyl ether, ~,5,4,4,3,3,2j-2-oct~ fluorc,ye.~yl fluoromethyl ether, ~,5,4,4,3,3,2,2-octaafluoLv}~llLyl difluoro~ethyl eth~r, 5,5,4,4,3,3,2,2-octa~flll~,L~ Lyl trLfluoro~ethyl ether, 5,5,4,4,3,3,2,2-oct~afl,~ x,~ Lyl ethyl ather, S,5,4,4,3,3,2 , 2 -oct a a f 1 u~oroper~ty 1 2, 2, 2 -tri f luoroet hyl ~th~, 3,3,3,2-tetrafLuoro-2-trifluoromethylp ropyl ~nethy1 ~ther, 3,3,3,2-tetra~luoro-2-trifluoromethylpropyl ~luoromethyl ~ther, 3, 3, 3, 2-tetra~luoro-2-tri~luoromethylpropyl ~if luoromethyl eth er, 3, 3, 3, 2 -tetra f luoro-2 -tri ~ luoromethylp ropyl trifluoro~ethyl ether, 3,3,3,2-tetra~luoro-2-trlfluoro methylpropyl et~y1 ~ther, 3, 3, 3,2-tetra~luoro-2-tri~luoromet hylpropyl 2,2,2-~rif~ roethyl ether, 4,4,4,3,2,2-hexa~luoro -3-trifluoromtthylbutyl methy} ether, 4,4,4,3,2,2-hex~luoro -3-tri~luoromethylbutyl ~luoromethyl eth~r, 4,4,4,3,2,2-hex~
fluoro-3-trifluoromethylbutyl di~luoromethyl etherr 4, 4, 4, 3, 2, 2-hexaf luoro-3-tri~luoromethylbutyl trifluoro~ethyl ethsr, 4,4,4,3,2,2-h~xa~luoro-3-trifluoroD;et hylbutyl ethyl ~ther, 4,4,4,3,2,2-hexa~luoro-3-tri~luoro~neth ylbutyl-2,2,2-tri~luoroethyl ether, 3, 3, 3, 2-tetrA~luoropropyl m~thyl ether .
218~97~
3, 3, 3, 2 -tetraf luoropropyl f lu oro!nethyl et he r, 3, 3, 3, 2 -te~ra~luoropropyl dif luoromethyl ether, 3, 3, 3, 2 -tetraf luoropropyl tri~luoromethyl ether r 3, 3, 3, 2-tetraf-luoropropyl ethyl ether, 3,3,3,2-t~tra~luolu~L~,~yl 2,2,2-trifluoroethyl ether, 4, 4, 4, 3, Z, a -hexaf luoro~utyl methyl ether, 4, 4, 4, 3, 2, 2-hexaf 1 uoro~utyl fluoL~ yl ether, 4,4,4,3,2,2-hexafluoro~utyl difluoror~thyl ~ther, 4,4,4,3,2,2-h~ fl~nrobutyl trif luoromethyl ether, 4, 4, 4, 3, 2, 2 -hr-k ~ f 1 1 orobutyl ethyL
ether, 4,4,4,3,2,2-hex~fluorobutyl 2,2,2-trifluoroethyl ether, 5, 5, 5, ~, 3, 3, 2, 2 -o ct :~ f luo ropenty l me thyl ether, 5, 5, 5, 4, 3, 3, 2, 2 -oct~f luoropentyl f luoromethyl ether, 5,5,5,4,3,3,2,2-octa~luoLu~.Lyl difluoromethyl ether, 5, 5, 5, 4, 3, 3, 2, 2 -octaf luoropentyl trif luorometb~-l ether, 5,5,5,4,3,3,2,2-octafluoropentyl ethyl ether, S,5,5,4,3,3,2, 2-octa~luoropentyl 2, 2, 2-trif luoroethyl ether 3, 3, 2 -trif luoropropyl methyl ether, 3, 3, 2 -trif lu~ ~rc yy l ~luoro}oethyl ether, 3, 3, 2-trifluorop~opyl difluoromethyl ~ther, 3,3,2-trifluoropropyl tri~luorom~thyl ether, 3,3,2-t~if~ V~Or~l ethyl ~ther, 3,3,2-tri~lucr~
2, 2, 2-tr1f 1uoroethy1 ether, 4, 4, 3, 2, 2-pentaf luorobutyl m2thyl ether, 4, 4, 3, 2, 2 -per~tAf luoro~utyl f luoromethyl ether 4, 4, 3, 2, 2 -pentaf luoro~utyl di f l uoromethy l ether, _ ~ _ .~ 2181~73 4 ~ 4 r 3, 2, ~ -penta~luorobutyl tri~luoromsthyl ether, ~, 4, 3, 2, 2 -po~ta~ orobutyl ethyl ether, 4, 4, 3, 2, 2 -pentaf luoro~utyl 2,2,2-trifluoroethyl ~ther, 5,5,~,3,3,2,2-heptafluoropenty meth~-l ether, -~,5,4,3,3,2,~-hept~luorop~ntyl fluoromet~yl ether, S, ~, 4, 3, 3, 2, 2-he~t~f luoropentyl dif luorQmethyl ether, 5,~,4,3,3,2,~-hc~tafluulu~-eslLyl trifluo~onLethyl ether, 5,5,4,3,3,2,2-hept~luoropentyl ethyl ether, 5,5,4,3,3,2,2-h eptafluoropenty1 2,2,2-trifluoroethyl ethcr.
Tho co~t~t o~ the ~luorine-substitutad ether compound in ~he mlxed ~olv~nt i~ preferably from S to gO ~ by volume, ~nd more prefcrably from 20 to 70 ~ by volume, When the content of the i~luorine-~ubstituted ether co~pound i8 less then 5 ~ by volu~e or greater then 90 ~ by volume, the high-rate capacity are deteriorated.
It ~eco~es essential for the fluorine-hubstituted ether co~pound r~t,L~ ,-cnLed by the s~eneral ~or~ula tI~ to use a8 a ixed ~olv~nt wherein a co~pound h~Ying ~ high solubility of a lithium salt iE~ added, bec~use o~ the low ~olubility of the lithiu~ salt in thQ ether compound. On practical use, it efe~ d that the electrûlyte ~ubstantially h~s a salt concentration of not l~ss than 0.~ mol/litter, a ~o~pound iJ
~d:led to the halogen-~u~stituted ether compound to obtairL a mixed ~slvent which is c21pable o~ dissslving the lithium 2~1373 ~alt in an amount of not lhs~ than D. 5 mol~litter.
Accng the ~ '~ added, ~ carbon~tc compGund is particul~rly preferred because the reactivity between the carbonzlte compound ~nd ~ctive materi~l of the battery i~
low .
~ 7z~nples ~ the carbonate c~mpound incl~ide acyclic c~rbonate ~lch aa dimethyl cf~rhon~te~ diethy~ carbonate, ethyl methyl c~rbonate, methyl propyl carbon~te, i30propyl methyl ~arbonate, ethyl propyl ~arbonate, i~obutyl :nethyl c~rbonate, etc; and cyclic carbonate such aB ethylene carbonate ~1,3-dioxol~ne-2-one), vinylene carbonate (l~3-~in~nl~n~-2-one~ propylene carbonate (4-D~ethyl-1,3-d~o xo~ane-2-one ~, 1 , 2 -butylene c~rbonA te 1 4 -ethy l- 1 , 3 -dioxolane -2-one ), 2, 3 -butylr ne carbon~te l 4, 5 -din~ethyl -1, 3--l ~ nYc~
2-one~, isobutylene c rbonate ~g,4-dirl~thyl-1,3-dioxolane-~-one~, etc. . The5e c~rbonate u-, ~o~ may be used aloner or 2 or ~or- sorts o~ them may be optionally used ln combination .
~ hen usiny the mixed soLYont s~ith ~ke ~cyclic carbonate such a~ dimethyl carbonate, dlethyl carbona~e, etc., it is preferred bec~us~ the r~ultant electroly~e has excellent hi~h-rate properti~ . A mixed solvent ~ith d isLcthyl r~rhn~ e is particularly preferred.
-- - 2`~8~g7~
It h~s hitherto b~en. considered that the presence of cyclic carbonates such a~ propylene c2rbonat-, ethylene carbona~e, etc. is ~ssential for maintaining cycla properties when using ~ carbon~ceous materi~l that can be doped/undoped with lithium ion~ as an artive material for anode. E~owever, it has been found that excelent cycle properties can ~e maintained ~ithout ci~nt~-nie~ the~e cyclic carbonates when using the electrolyte of the pre3ent inv~ntion, su~prisingly .
When cyclic car~onatea such a~ e~hylene carbonate, vinyl~ne carbonate, etc. ~re added to the above solvent, the initial di~charge capacity is improved. Wh~-n using a sraphite material ~s ~n ~node-~ctive aubstance, ethylene carbonate i~ p~rticularly preferred. Since the high-rate c~pacity ~nd ~ow-temperature capa~ity are d~teriorated a~
the content of t~ese cyclic car~on~tes beco31e~ large, ~he content of the cyclic carbon~te is prefera~ly not mor~ than 50 ', by volume, more prefernbly not more than 3C~ by volum~
As the lithiwn ~alt in the non-aqueou5 el~ctroiyte of the pr~sent i~v~2ntion, th~re can be used any on~ which has hitherto been 1cnown, and eYa~le~ thereof include at least one sort of LiAsF6, LiPF6, Li3~4, LiC104 and LiC~3S03. Among them, LiPF6 is pr~3~erred kecAu-e ~he ionic conductivity of -- 2181~
th~ r~sllltant non-agueous electrolyte i5 large.
In the non-aq~eous electrolyte of the pra~ent invent~on, the lithium s~lt ~onc~n~ration is preferably from O.S to 2 mol/litter, ~o~e prefQrably ~ro~ 0.7 to 1.5 mol/litter bccause of large ionic conductivity.
In thc r~on-aqueou~ electrolyte o~ the present inv~ntion, it is pre~erred that the water cont~nt in th~ solvent be~ore tix~olving the electrolyte i~ not mose than 100~ ppm because the capacity and cycle life of the~ ~attery ~re qood when using i~ for the lithium battery.
The lithiu~ s~condary ~attery co~pri5es a cathode t~at can be doped~undopPd with lithiur~ ion~, an anote of 3 lithium met~l or alloy or ~n anode thct ~an be doped~undoped with lithiu~ ionc and ~he above non-aquecu~ *lectroly~.
In the lithiu~ condary ~attery of the present invention, it i2~ pre~red to use a lithicted m tal dioxide rrJntAi7-ing t l~ast one scrt of 1l lithiated transitlon metal dioxide as an active material ~or cathode because the charge voltage i8 high 21nd the ~nergy density o~ the battery can 3: e inore~et .
~ xartlples of the lithiated metal dioxide conta~ nLnq llt least one sort of 8 tran~tion met~l in the cathode include l~thiated metal dioxide r~ntAin;n~ at least one sor~ o~
tr~niition metals such 15 vanadium, ~ g~n~e, iron, ccbalt, .-- 2181~7~
nickel, etc. Among t~em, laminar lithiated metal dioxide conta~ning cob~lt, nickel, etc. havlng ~ Q-~a~ei~2 typ~?
~I~LU~_LU e or lithiat~d metal dioxide comprising manganese, etc. h~Ying a ~pinel type structure are particularly fe, ~ b causc the aYerage disch~rge potential is high.
A~ong them, the laminar lithiated metel dioxide (e.g., lithiated nic)cel dioxide) is p~rticularly pLerel ~ d because of ~he eYr~ n~ CyClR life.
With thc cathode in the lith~um secondary battery u8ing the non-aqueoufi electrolyte of the pres~nt inYention, a lithiated metal dioxid~ containing at lea~t one sort o~ a ~ran6ition snet~l is used as the ~ctive m2t~rial. Specific exe~ s of thc cathode include those obtained by uniformly m~cing active material powder of the lithiated metal dioxide And auxili~ry conductive ~ot--rial powder with a ~inder for ~irding ~hese powder~, followed by pressure mol ding, or those obtnined ~y formin~ th~Re powder3 in~o a pastt! using a solvent, ~pplying t31e paste on a curr~nt collector sheet, followed by drying and further pres~ing to ~tick on the colle~tor ~heot.
hR auxili~ry conductive material powder used for the ~Athode ~ay ~e those whicb have a condu~tive e~fec~, a resistance to the non-~queous electrolyte used and a _ 14 --2181~73 resi~tance to the electroth~ l reaction 2t th~ cathode, and ~x~pleQ thereof include gr~phite powder, carbon bl~ck, cokes powder~ conductive poly~er, etc.
An amount~ of the auxiliary conductivr material is pre~er~bly about 1 to 20 parts by weight based on lO~ p~rts by weigllt of the ~ctiv~ sub~tAnce powder u6ed.
In the lithium second~ry battery o~ the pre~ent invention, the active ~naterial o~ the ~ode may comprise ~atural or artificiAl graphite or ~ cok~s a~ a ~ingle Lngredient or a maill inqredient ~ecaus~ Or good charge~discharg~ cycle charac~r~ c. It i8 also pos~ible to u~e a lithLum metal or alloy a3 the ~ctive ~terial for an aDode.
When 1 natural or arti~icial qr~phite or a cokes is u~ed as elctive ~at~rial for an anode, the anode cJ~n contain a pol~ner having a c~r~o~-te ~tructure L~ L~3e.l~ed by the g~ner~ ormula ~ II ] and number average n.ol~culnr weight of 30~ or more --O C~--O-- ~ L[ 3 5he binder used for the cathode or anode ~ay be tho~e which have a binding ei~fect, ~ r~Gi~tanCe to the non-a~ueous -2~ 73 . .
electrolyte used and a resistance to the el~ctrQchemicai reaction at the c~thode or nnode, and exa~ples thereof include fluoror~sin~ such a~ polytetra~luo~oethylene ~h.ereinafter re~erred to as "PT~S"~, po'yvinylidens fluoride (hereinafter referred ~o as "PVdF" ~, etc ., and polyethylene p~lypropylene .
An an~ount Q~ the binder i~ pref~rably about 1 tO ;~0 part~; by weight ba~ed on ~00 parts by ~eight of the active ~ubstance powder us-d.
The current collector used for the aooYe c~thode or a~ode may be those which have a re~ i st2nce to the ~on-agueous electrolyte u~d and a resistance to the ~lectrochemic~l r~action at the cathode or 2nods, and examples thereof iacl,ude nickel, titaaium, stainless steel, alu~inum, cop~ r etc.
It is pr-?~arred tb2t ~ thicJ~ness Qf the current collector is as ~mall a~ poYsiole so far as the strength is maintained, beca~se the vol~me ener~y donsity of the hattery iacrease~. 'rhe thickness is pr~ferably a3~out ~ to 100 ~Lm.
A~ the current collector of the cathode, an aluminum ~oil i~ pr~f~rred :~ecause it i5 e~sily ~ormed into a thin filn~ ~md is ch~tlp. As the curr~nt collector of the anode, a ~opper foil i5 preferre~ be~ause it hardly form an alloy .
.~ 2181973 with lithium and is easily formed into A thin iil:n.
~ n the lithium secondary b~ttery using the non-agueou~
electrolyte of the present inYention, th~ s~parator ~ay be those which ~revent contact between ~oth electrodes and have insula~ing ~roperties, ~nd which retain the non-aqueous electrolyte and ~ave a ~unction c~pabl~ of penetrating lithiu~L ions, a resistance to the r~on ?'r""~'lC electrolyte used and a resi~tance to the ~lecrrochPm~c~l reaction at the cathode or ~node, and example~ thereof include non~roven and wov~n ~abric~ of olefin resinY (e.q. fluororesin~, polyethylene, polypropylene, etc. ) and nylon.
It i~ preferred that a t~;Ck-~q5 of the ~ap~rator ls a~
small ~s pos~ible ~o far a~ the s~eci~ic ener~y density of ~he battery increA~es ~nd internal resi~tance d~creas~s. ~he ~hir~n~ is pr~ferably ~bout 10 to 200 ,Um.
EXal~L.
The ~ollowing Exa~ple~ further illnstrate ti~ p~esent iIlvention in det~ ut are not to b~ ccn~tr~ed t~ limit the cope thereof.
~ 1~ Spt-'5;ca1-;os of lithium seconda~y bat~ery test~d:
The c~thode of the l~thiu~ secondary l~ttery te~ted W28 ol~tained by Qethod de~crib~d hereina~ter.
--- - 2i8~973 A~ D cathoda active mz~terial, ~owder of lithiated nickel dioxid~ containing gallium w~ prepared by mixing lithiu~ nitrate, nickel carbon~-te alld g~llium nitr~e and f irin~ ~he mLxture in an oxygen stream at 660 C for l~
hours. To 81~ by weigh of the cathode active m~te~ial powter, 1~ by weight of acetylene black having a r,umber average prima~y parti~le size of 4a nm ~manufactured by Denki X~gaku l~ogyo 1~h~Ch~l~i Kai~ha., trade r.a31e: DYnka black, ~% pr~ed protuctl and 99~ by weisht of scaly artif iclAl gr~phite having a weight average ~rticle ~ize of 7.2 ~/m tmanufactured by ~onz~ Co.~ trade name: RS151, 3~ by wei~ht o~ PVdF ~manu~actured by Rureha Chen~ic2~l Industry ~o., Led., trade name: ~F#1300; in N-methylpyrrolidone as solvent was added a~ a bind~r, follo~ed by ~ufficiently kneading to form ~ p~ste.
It was confiri;~ed by X-r~y powder dif~raction that the Above lithi~ted nLckel dioxide ha~ a~ cY-Na~eO2 type structure .
After ehe pasee ~ras co~ted on ~n ~1 foil h~ving a i~ 4S~ of 20 ~ D~ the current collector, the ~oated ~oil wa~ drled a~d pr~set to ~orn~ into a sheet, whlch wa Cllt into small pieces ir~ ~ize of 1.3 x 1.8 cm to o~tain cathods~. The weight of active material of e~ch of the~Q
2~ 8~ 97~
cathodes ls fro~ 4G to 45 mg.
Thc anode of the lithium second~ry battery tested w~
obtained }~y 2nethod described her~ina~ter.
The carcon powder for the anode was obtained usinc natural graphite powder, pseude-graphitic ~arbon bl~ck powder, and ~ilane coupling agent, by the method described hereil~after. The naturAl ~raphlte powder u~td occurred in MA~ Rt!r~r, which was heat-treated ~t 3000 'C, and have ;
specific ~ur~ce area of ~ m'/g according to a nitrogen ~dsorption method, a number-zv~r~ge particle si2e of 10 ~, true density o~ 2.25, an interlayter ~pacing d~C2 of 3.35 ~ngstrom in X-ray powder di~fraction and an ash content of a. os~ by weight: The P3~ hite ce!rbon bl~ck powder l~nUiaCtured by ~ok~i C~rbon Co., Ltd., trade nam~:
rs3aO~], ~7hich was graphiti2ed at 2~0~ C, and h~ve a specific surfac~ ~rea of 30 n~2tg according to a nitro~en ~dsorpti~n ~cthod, ~ tnle specific gravity of 2.0g and a number average primary particle stize of 66 nl:l. To 95 parts by weight of the natural çraphite powder, 5 part:i by weight of the p~eudo-graphLtic c~rbon black powder ~ s added a~d mix~d to o~t~in a mixed rArhr~n~reo1-s material. To the mixed r~rhnn~reo~ terial, 1 part by weight of a solutlon prep~red by p~eviously d~spersing ~ilane coupling agent _ 19 --~, 21~973 tmanuf actured by ~ippon Yunic~r Co ., Lt~ O, tr~de name: P.l a6 ]
which w~ previoY~ly disper~ed in pure water was added, fol~owed by ~uf~iciently mixing and further vacuum-drying at 150 C to obt~in carbon powder treated with the silane coupling a~ent.
Ihen, 10' by weight of PVdF in ~-;nethylpyrrolidone binder w~s ~dded to 90~ by weight of the a~ove silane col~pling agent-tr~tHd c~rbon powder, aY A ~olv~nL, followed by suf~i~iently kneading to form a pnste.
After the pa~te w~ coated on ~ copper foil having a 1 hielrn~ of 20 /~m as the current collecto~, th~ ~oil was dr$ed arld pr~ed to fo~n into d she~t, ~hich was cut $nto small pieceq in si~e of 1. 5 x 2 cs~ to obt2in anode~ .
A~ t~e Geparator, a micro-~orou~ polypropylene ~
[manu~ctured by Daisel Chemical Indust~ies, Ltd., trade nn2~: ~T~TT~-T~T~n ~24 J0~ W~l~ used.
(II~ Cycle yL~/y~Lty test condition With ~he ~ycl~ efficiency o~ the diYch~rge cap~city of the battery, the ~ollowing conditions ~1 ) clnd ( 2 ) were alternatively reE~eated four times and, finally, the condition ~ one time) ~nd only first ~ycle of the conditior~ ~2) were conducted, that i8, tot21 91 times of thc chnryeldi~ch~rge cycle~ were repeated, 2nd then the cycle _ ~0 ---21gl973 ef ~iciency and high rate ef f iciency were examined .
~ 1 ) A const~lnt-current 2nd voltage chargir.g was conducted under the condition of a current of 7 . 7 mA, a charge maxi~:m voltage of 4.24 V and a charge tima o~ 3 hours, and then discllarging was conducted under the condition ~f ~ current of 1.5~ ~A and ~ final v~lt~ge o~
2.75 ~/. Thi~ ch~rging~di5charginq i5 conducted consecutively two times ~referred to as A low-curr~nt discharge condition ~ .
~ 2) A cDn8~4~ L and volt~ge charging was conducted under the condition of ~ char~e current of 7.7 mA, a chArge alaximum volta~e of i 4 . 24 Y and ~ charge time o~ one hour, and then di~charging W~15 conducted under the condition uf a discharge current oi 7 . 7 mA and ~ f inal voltage of 2 . 75 V. ~his cycle is conducted consecutiv~y 20 ti3tes ~ref~rred to aC a larg~-current di~chelrge condition ) .
'rhe cycle efficiency are evaluat~d by a capacity retention of a discharge ~ap~city }n the g7th charging~discharglng to th~t in the second charginq~di~charging. The higher the cycle ef ~iciency, the longer the cycl~ lif~ .
The high rat~ efficiency is evaluated by a c~pacity retention of the first disch~rge c~pacity under the large curren~ di~ch~rge condition to the fiecond discharqe cap~city .
~- 2~81~73 und~r the low current. discharge condition. The initi~l high rate efficiency corre~pont to the proportion o~ the dlscharge capacity of the third cycle t~ thAt of tSe second cycle, nnd the high r~te ~fficiency ~er cycles CO~L. 5~Vnd to the ~roportion o~ th~ disCharge capacity of the 91st cycle to thAt of t~e 90th cycle.
~3xample 1 U~Lng a non-~queous ~l~ctr~lyt~ preFared ~y dissol~ing 11~F6 as the lithiu~ salt in A mixed solven~ c~f pentafluvLv~,.Lv~l ~ethyl ~ther thereinaf~er referred ~o as ~PFP~ nd di ethyl carbonat* (hereinAfter referrRd to a6 ~D~Cn) (volume ratio: lsl) as a ~olvent for non-2queous electrolyte to 1 ~ol/liter The above cathoàQ and the ~node were ~andwiched uith a s~par~tor. The non-A~ueous electrolyte and the ~andwiched electrods with separator ~_re put in` ~ t~n~r made of ;t~inless steel to produc~ a battery Al.
~ he obs~rved l:esults of the cycle F.ffi~iPn~y and high rate effi~iency 2r~ ~hown in ~able 1.
~x*lr.ple 2 According to the same ~nner a~ that d~R~`J'; h~ in _ ~2 --2~8~ ~73 Fxa~ple 1 excf~pt ~or u~in~ a mixed s~lven~ of ethylene t-:-rhor ~P (hereina~tQr re~er~ed to a~ "EC" ~, D~C and ~FP~3 vol~me ratio: 10:45:~5 and 30:3~:35~ as a golvent fo~
~on-aqueous ~lectro}yte, b~tteries A2 and A3 were produced, respectively. The charg~/di~charge test wa~ conducted accorting to th~ s~n~ manner as that descri}~ed in Exa~.ple 1.
The ~served re~ults of the cycle e~ficiency and high rate e~icit~ncy are ~own in Table 1.
Ca~Dparative Example 1 Aocordint~ to the ~ame ~anner a5 that de~cribed in ~x~pl~ 1 ex~ept for u~ing only ~C, a mixed ~olvent o~ D~fC
~nd ethyl ~ethyl carbonate lher~ina~ter referred to 2S
"EMC~ ~volume ratio: 5C:503 ~nd a mixed golvent o~ D~C, ~C
~nd E~5C tvolum~ ratio: 30:35:35) as the ~olvent ~vr non-agueouS ~lectrolytt~, batteries R1, R2 and ~3 wer~
producèd, resp~ctiv~ly. The ch.~rge~d~scharge ~est W2~5 conduct~d according to the sa~e ~ann~ar a~ th~t de~cribed in x~le 1 .
I`he observed result~ o~ the cyclta ef ~iciency and high rat~ e~iciency are shown in Table 1.
218197~
Crable l> ..
Bath~ C~posit;o~ of l:~itial Cy~ rat~ e~ficiency solv~t ~isch~rge e~CieDCy capacity l~idal After cvcl~s mple 1 Al D~C:PFPME- 6.3 0.~4 Q74 D.80 50:50 A2 EC:DMC;PFPMi- 7.~ 0.84 0.74 0.80 e 2 10 45:45 A3 ~C:DMC:PF~ME- 7.~ 0.80 ~.63 0.56 30:3~:3S
Rl D~fC 0.79 0.~8 O.5û
Colmpas tive ~2 505J0 0.78 0.47 û33 DMC:EMC= 0.77 0 63 0.57 30:35:35 As is a~parent ~r4~L ~able l, the battery ~1 o~ the present inv~ntion is superior to the batterie~ ~l, R2 and R3, which contain no PFP~:, in cycle e~ficie~.cies, particul~rly sup~rior in higll rat~ ~ficiencies. ~emarkably, the high rate efficiencies ~f the batteri~s ~1 ~nc~ P~2, ~hi~h contain ~o PFP!~E:, are draçtically deteriorated w~en the chargcJdisch~rge cycle~ are re~eated, whereas no deterior~tion i8 reco~niz~d in the high-rate eJf;C1--ncie th~ ttery oî the pre~ent inve~tLon even i th~
charge~di~charge cycles are repeated. There~ore, the batte~r o~ the pr~sent invention i~ re~narkably superior in cyclc 218~73 .--effi~-ien~ies o~ the hiqh rate e~icieneie~.
Further~ore, surprisingly, the ~atterieS A2 and P.3, ~hich contain EC, of the pre~ent invention are rc~arkably :~Qperior to the ~At~ery ~3, whlch ha~ hitherto been ~uggested~ using a n~ixed non-~lqueous electrolrte o~ a cyclic carbonate and an acyciic carbonat~ ir~ cycle e~ficiency. -- ~
She batterie~ A2 and ~3, ~hich contain E:C, o~ t~e present invention were i~provQd in initial di ~h~rge capacity in co~np~rison wLth the battery Al ~nt~ini-g no EC.
~owever, the high r~te ~iciencie~ werc ~ h~ly deterior~ted with respect to the battery A3 having a ~:C
content of 3Q~ br volu~e. That is, it hAs been found that the 3~;C content is ~refera~ly 30~ by volu31e ~t most.
~xa~ple 3 With the ba~tery A2 obtain~d in Ex~mple 2, con~t~ntcurrent and voltage chargi~g was conduct~d ~t 20 C
under the conditio~ o~ ~ current of 7.7 ~, a charqe maximum voltage of 4.24 V And a charge tirae of 3 hours, and then d~ schargin~ ~a~ conducted at -2Q C under the condition o~ a current of 1.54 ID~ and a final voltage o~ 2.75 V. The lo-temperAture e~fi~ie~ s are e~aluated by the plo~ortion of the di~charge capacl ty on low-ter~perature discharging to . .
21819~3 that on rooltt tem~eratllre disch~rging.
The resultant lo~ temperature e~icencies are ~hown in Table 2.
~, .
Comparative Example 2 According to the aAne manner Ag th~t described in Example 3, the low-temperature efficencies o~ th~ b~tteries ~l und R~
produced in Comp~rative Example 1 w~re measured. The resultant low-te~er~tur~ R~ e:~ciee. are shown in Tuble 2.
<~ble 2~
Test Ba~tely r , ~ of so~vent L4w t"~,ll,,".~, e~lcicncy mpie 3 A2 EC:DMC:PFPME=10:45:45 73%
C~omp~ative Rl DMC Impossible to E~lmple 2 discharge becallsc of ~2 DMC:EMC=~0:50 2n~
A~ is apparent from Table 2, the ~ttery R2 o~ the present invention showfi excellent low-t~ Lure effice~cies in co~r.pcri~or~ with the battery ~2 ~ontaining no PFPME .
~x~mple 4 i~ith th~ b~tteries A2 l~nd A3 obt~ined in ~camp1e 2, cOnsL~ntcurrent and voltage charglng was conducted at 20 C
. .
21~1973 under the condition of a current of 7.7 mP~, A ch~rge maxi~
volt~ge o~ 4.24 V and ~ charge ti~e of 3 hours and, a~ter di~charging at 6C ~C onder the t:ondition ~ ~ current o~
1.54 mA and a ~final voltage o~ 2 . 75 V, the c~arge~discharge te6t waJ conducted at room ~ , dture again. As ~ result, it WAS possible to conduct charging/di~h~rging, Exa~le S
The ~lAsh points of the electrolytes obtained in ~xample 1 and 2 were loeasur-d accordiDg to a test method by t~g clolied test~r. The results obt~ned ~r~ ~hown in Ta3:le 3.
Tho flash point of the ~lectrolyte obtainet in Comparative Exa~rple 1 was meaS~red accordiDg to the test method by t~ colsed tester. The r~sult obt~ined i~ shown in '~ble 3.
~ecrolyte Composition of el*ctrolyte ~l~sh point Salt Solvent ~-C~
I:Al lN LiPF~ EC:DMC:PPP~ 45:45 ~4~
~:~1 1~ LiPF, EC:I~HC:PP~.~E=30:35:3~ 22 Ta~?le 3 show~ that the electrolyte used in the battery of this inv~ntio~ ha~ increasi~gly hlgh fl~sh point and the ~nfene~s of it i~ greatly ialproved. rt ~an be posi ibl~ t~
lower the d~nger o~ fl~shiDg by leaking of the electrolyte, -- 27 _ .
218~73 and to i~prove the productivLty in the production pr~ces~.
Ex~pl~ 6 Using 2l- ~on-aSrueous electrolyte pre~ared by dissolvin~
LiPF6 ~g th~ lithium s~lt Ln a ~nixed solvent f luorin~ted ether ~nd D~C ~hown in Table ~ (vol~me ratio~ 9 a solv~nt for n~n-~queous e~ectrolyte to 1 mol~liter, cAthode ~nd anode obtained ~s described ai:?ove werc ~andw- ~hed with tor. The non-agueous electrolyte and the ~andwiched electrod~s with a aepar~tor were ~ut in a container ~ade of Yt~inless 6teel to produce batteries 81-sll. q~h~
chArgefdischarqe t~st w2~ cor1dnc~ed i!~ccordin to the ~a~Le manner ~s that describsd ~n Ex~mple 1.
~ he observed re~ults of the cy~le eff~ nci~ d high rate e~l cien-;es ~r~ ~hown in Table q .
~ 218~g7C~
g i}igh-rat-D~ttery r]llr,r1n~ ther Initlal ~ icicucy ch~rq~ e~ ien c~p~oity cy Initial ~t~r [ ~Ah ] C~ cl~s 2 2~3 3-Bl tétrailu.JL~,y~ yl 6.1 0.89 0.60 0.68 hyl ther B2 2 ~ 2, 3 ~ 3 ~ 3- 6 . 4 0 . B 8 0 5 3 0 ~ 7 ~,1,2,2-~trA f 1~ roethy ether 2,2,3,4,4_ i33 r~rltA~ ^rooutyl 6.7 0.81 0.~2 0.55 di~luo~ ~ LL~l ether 2,2 3,3,3-B4 p~;A~ oropropyl 6.4 û.9~ 0.64 o.84 di~luoro~ethyl eti er 1 -tri ~luoro~_thyl-Z,2,2-tri~luoroethyl 7 4 0.68 0 7tl 0.57 ether 1,1,2,2-B6 tetra~ oroethyl 7.2 0 ~32 Q 69 0 75 e'chy~ ethe~
1,1,2,2-B7 rl.tr/lJllloroethyl 6.0 0.80 0.~1 0.4a -2, 2, 2-trif luoroethyl ether 2,2,3,3-~38 tetrail~ lvL,, ,~l 5~3 0~75 0.6~ 0.61 thyl ct~er 2,2,3,3.q.q~
B9 h~.~J~ .r~-h~ rl 7.0 0.84 0 61 0 -:g metbyl ether ~x~mplQ 7 O oi ~y weight of polyethylene car}~onat~ (nu~ber verage moleculer weight 50~00 ~reinafter rl3~erred t~
,, 21~1g7~ ' 'PEC") in ~-met~ylpyrro~idon~ ~nt 2.4 % by weight of PVd~ in ~-methylpyrroLidone as ~he binder were added to ~7% by weight o the a~ove ~ilane coupling agent-tr~ted materi~l, followed ~y s~icient kneading to form a pa~te.
Aft~r the pa~te wa6 coatet on a copper foil having a thirl~n~Cs 0~ 20,~Lm a~ th~ ~urrent collector, the foil waS
dried and pres~d to form into ~ sheet, which WAS ~ut into small pie~es in size of 1. 5 x 2 c~ to o}~t~in anodes cr.t ~ ; n i n g PE:C .
Except using th~ anod~ obtaind a},ove, and al the non-~queou~ ~lectroiyte, the mixed solvent ~f PFPNE:~Dr~C
~volusLe ratio 1:1~ or 2,2,3,3-tetr,lfluoropropyl di~luo~o2nethyl ether ( hereinaf ter re~erred to a~
~T~PDE-')JD~C ~volume ratio 1~ tteries P1 and ~2 wer~
produced, and the ch~rge/discharge t~sts were condu~ted according to the same manner as that d~rr~h~' in ~xapmtil 1.
rhe initial discharge capacitieS s~ere 6 . 5 mAh ~nd ~ . 6mAh, re6pectively .
Above r~ lt shows that the initial capaclty is incre~Aed by u~ing an anode containing polyethylene car~onato without using EC.
Therc can be o~tained a lithio~n secondary batter~ which operate~ within the ~ide temporature range ~rom -20 to ~ C
` - 2~8197~
and c~u~e6 little deterioration of the di~ch~rge cap~city by repe~ted cnarqingJdivcharging, and w~ich i~ particularly supcrior in high-r~te capacity and cause~ little deterioratioh D~ the hish-rate capa~ity due to the cycles.
The lit~iu~ ~econdary battery has a very l~rg~
indu~trial value for ~pplicati~ns ~uch ~s pcrta~le ~E~PZ~rAtu5es, tr~n~ports aDd n achine tools, which rc~uire l~rge current and ~ l~rgo capacity.
-
With the halosen-substit~ted ether compound, P~l in the ~or~u}a is an alkyl or halogen-substituted alkyl group has~i~g 2 or le~ carbon atom~, pre~e_~bly m~thyl group. ~hen the number of carbon atoms of Rl exceeds ~, the solubility o~ the lithi~ ~lt in the cther compound beconles lo~, a~d it i5 not preferred. ~2 in the formula is a h~logen-substituted allcyl group having 2 to 10 carbon atom~, p~e~erably 3 to 5 carbon ~toms. When the numbc~ o~ carbon atoms of ~2 exc~Yds 13, the vis~osity of the ether coGlpound beco~e~ larg~, and it is not pre~err d.
~ t is preferred that the ether ~ompound shows a 1GW
v~por pressure within the operatihg tempe ature range o~ the battç-ry . ~hen R2 ~ n the formula ~ s preferably hdlogen-~u5stituted alkyi grOUp h~vihg 2 or morc c2rbon ato;ns, more pr~ferably haloge~-~ubstitute~ ~lkyl group h~ving 3 or more carbon ato~s, ~ecause the molelcular weight or polarity be~omes l~r~e.
~ xamples of ~2 in the general ~ormula t I ] in~lude the group~ sho~n ~ n the f ormulae [ I II ] - r x ~ .
`-- - 2~81~73 C~3-(CF2~-CHz . IIII]
( n is integer of 1,~,3,4 or 5) HCl?2-(CF2)l.-C~I
( n is integer of 1,2,3,4 Or 5) CF~-~CFz)~-CHF-~CF~)n-C~12 [~1 (m and r. are esch; ~ ly irlteger of 0,1,2, 3 or 4; ~+~ co 3 HcF2-~cFz)~-cIIF-(cF2~n-cHz-(r~ and n ar~ each ind.,"~ ly irlteger of 0,1,2,3 or 4; mtnCO ) (CFa)Y-CF-(CF~)= CHr ( n ib integer of 0,1,2,3 or 43 ~C~2)z CF-~CF2)~-C~'2- [VIII
( ~ is integer of 0,1,2,3 or 4) CFa-CF2-C(CF~F-(CF2).~-CH2-( n is integer of 0,1 or 2) HCFz CFz-C(CFa)F-(CF~D-CHa ~7 integer of 0,1 or 2) ~al~,gen-substituted etber ~ _ '- having the ~2 gr~ups above are ~ el .I becz~use of t~eir gOod high-rate property due to cycles.
Sp~ciSic exa~ple~s o~ t~e h~lg-~n-6ubstituted ether co~pounds include 3, 3, 3, 2 r 2-penta~luoropropyl methyl ether, 3, 3, 3, 71 2-pr3ntaf lu~ropropyl -1 o~ethyl ether, 3, 3, 3, 2, 2-~e ~.
21~973 nt~luoropro~yl difl~-o,~ LL~l ether, 3,3,3,2,~-pentafluorop royyl trifluoro~ethyl ether, 3,3,3,2,2-pentafluoropropyl ethyl ether, 3, 3, 3, 2, 2 -pentaf lu3ropropyl 2, 2, 2 -trif luoroethyl ether, 4, 4, 4, 3, 3, Z, 2 -heptaCluorobutyl m0thyl ether, ~, 4, 4, 3, 3, 2, 2-hep~af l~orobutyl f luoro~e~hyl ether, 4,4,4,3,3,2,2-hRpt~lUoLo~uLil di~luorortlethyl ether, 4, 4, ~, 3, 3, 2, 2 -heptaf luorobutyl t r i f 1 uvromethyl ether, 4,4,4,3,3,2,2-heptafluorobutyl cthyl _ther, 4,4,4,3,3,2,2-he ptafluorobutyl 2,2,2-trifluoroethyl ether, 5,5,5,4,4,3,3,2,2 -nr~ni~ f I ~ rop~ntyl methyl ether, ~, 5, ~, 4, 4, 3, 3, 2, 2 -nonaf luoro pentyl f 1uoro~ethy1 ether, 5, 5, 5, 4, 4, 3, 3, 2, 2-nonaf luoropenty 1 dif luoromethyl ether, ~, S, 5, 4, 4, 3, 3, 2, 2 -nona~luoropentyl trifluoromethyl ether, 5,5,5,4,4,3,3,2,2-nonafluoropentyl ethyl ether, 5,5,5,4,4,3,3,2,2-non2fluoIo~,a..L~l 2,2,2-trifluoroethyl ether, 3,3,2,2-tetrafluoropropyl meth~l ~ther, 3,3,2,2-tetra~luoropropyl fluoromethyl ether, 3,3,2,2-te~rRfl-~o)vp~u~yl di~luoromethyl ether, 3,3,2,2-t~trafluu~ yl trifluoromethyl ether, 3,3,2,2-tetrafl~-,Lv~-oy~l ethyl ether, 3, 3, 2, 2-tetra~luoropropyl 2, 2, 2-tri f luoroethyl ether 4,4,3,3,2,2-hPY~ r robutyl methy~ ether, 4,4,3,3,2,2-hexa~l uorobutyl fluo~o~ethyl ~ther, 4,4,3,3,2,2-hexafl~lûro~utyl difluorcmethyl ether, 4,4,3,3, ,~-hexa~ o~vl.L-Lyl 21~ ~73 , trif Luoror~ethy I ethe~, 4, 4, 3, 3, 2, 2 -hexa~luorobutyl ethyl r2thr~r, 4, 4, 3, 3, 2, 2-hr~Y~ f 1~ robutyl Z, 2, 2-tri~'luoroethyl ether 5, 5, 4, 4, 3, 3, 2, 2-octadf luoropentyl m~thyl ether, ~,5,4,4,3,3,2j-2-oct~ fluorc,ye.~yl fluoromethyl ether, ~,5,4,4,3,3,2,2-octaafluoLv}~llLyl difluoro~ethyl eth~r, 5,5,4,4,3,3,2,2-octa~flll~,L~ Lyl trLfluoro~ethyl ether, 5,5,4,4,3,3,2,2-oct~afl,~ x,~ Lyl ethyl ather, S,5,4,4,3,3,2 , 2 -oct a a f 1 u~oroper~ty 1 2, 2, 2 -tri f luoroet hyl ~th~, 3,3,3,2-tetrafLuoro-2-trifluoromethylp ropyl ~nethy1 ~ther, 3,3,3,2-tetra~luoro-2-trifluoromethylpropyl ~luoromethyl ~ther, 3, 3, 3, 2-tetra~luoro-2-tri~luoromethylpropyl ~if luoromethyl eth er, 3, 3, 3, 2 -tetra f luoro-2 -tri ~ luoromethylp ropyl trifluoro~ethyl ether, 3,3,3,2-tetra~luoro-2-trlfluoro methylpropyl et~y1 ~ther, 3, 3, 3,2-tetra~luoro-2-tri~luoromet hylpropyl 2,2,2-~rif~ roethyl ether, 4,4,4,3,2,2-hexa~luoro -3-trifluoromtthylbutyl methy} ether, 4,4,4,3,2,2-hex~luoro -3-tri~luoromethylbutyl ~luoromethyl eth~r, 4,4,4,3,2,2-hex~
fluoro-3-trifluoromethylbutyl di~luoromethyl etherr 4, 4, 4, 3, 2, 2-hexaf luoro-3-tri~luoromethylbutyl trifluoro~ethyl ethsr, 4,4,4,3,2,2-h~xa~luoro-3-trifluoroD;et hylbutyl ethyl ~ther, 4,4,4,3,2,2-hexa~luoro-3-tri~luoro~neth ylbutyl-2,2,2-tri~luoroethyl ether, 3, 3, 3, 2-tetrA~luoropropyl m~thyl ether .
218~97~
3, 3, 3, 2 -tetraf luoropropyl f lu oro!nethyl et he r, 3, 3, 3, 2 -te~ra~luoropropyl dif luoromethyl ether, 3, 3, 3, 2 -tetraf luoropropyl tri~luoromethyl ether r 3, 3, 3, 2-tetraf-luoropropyl ethyl ether, 3,3,3,2-t~tra~luolu~L~,~yl 2,2,2-trifluoroethyl ether, 4, 4, 4, 3, Z, a -hexaf luoro~utyl methyl ether, 4, 4, 4, 3, 2, 2-hexaf 1 uoro~utyl fluoL~ yl ether, 4,4,4,3,2,2-hexafluoro~utyl difluoror~thyl ~ther, 4,4,4,3,2,2-h~ fl~nrobutyl trif luoromethyl ether, 4, 4, 4, 3, 2, 2 -hr-k ~ f 1 1 orobutyl ethyL
ether, 4,4,4,3,2,2-hex~fluorobutyl 2,2,2-trifluoroethyl ether, 5, 5, 5, ~, 3, 3, 2, 2 -o ct :~ f luo ropenty l me thyl ether, 5, 5, 5, 4, 3, 3, 2, 2 -oct~f luoropentyl f luoromethyl ether, 5,5,5,4,3,3,2,2-octa~luoLu~.Lyl difluoromethyl ether, 5, 5, 5, 4, 3, 3, 2, 2 -octaf luoropentyl trif luorometb~-l ether, 5,5,5,4,3,3,2,2-octafluoropentyl ethyl ether, S,5,5,4,3,3,2, 2-octa~luoropentyl 2, 2, 2-trif luoroethyl ether 3, 3, 2 -trif luoropropyl methyl ether, 3, 3, 2 -trif lu~ ~rc yy l ~luoro}oethyl ether, 3, 3, 2-trifluorop~opyl difluoromethyl ~ther, 3,3,2-trifluoropropyl tri~luorom~thyl ether, 3,3,2-t~if~ V~Or~l ethyl ~ther, 3,3,2-tri~lucr~
2, 2, 2-tr1f 1uoroethy1 ether, 4, 4, 3, 2, 2-pentaf luorobutyl m2thyl ether, 4, 4, 3, 2, 2 -per~tAf luoro~utyl f luoromethyl ether 4, 4, 3, 2, 2 -pentaf luoro~utyl di f l uoromethy l ether, _ ~ _ .~ 2181~73 4 ~ 4 r 3, 2, ~ -penta~luorobutyl tri~luoromsthyl ether, ~, 4, 3, 2, 2 -po~ta~ orobutyl ethyl ether, 4, 4, 3, 2, 2 -pentaf luoro~utyl 2,2,2-trifluoroethyl ~ther, 5,5,~,3,3,2,2-heptafluoropenty meth~-l ether, -~,5,4,3,3,2,~-hept~luorop~ntyl fluoromet~yl ether, S, ~, 4, 3, 3, 2, 2-he~t~f luoropentyl dif luorQmethyl ether, 5,~,4,3,3,2,~-hc~tafluulu~-eslLyl trifluo~onLethyl ether, 5,5,4,3,3,2,2-hept~luoropentyl ethyl ether, 5,5,4,3,3,2,2-h eptafluoropenty1 2,2,2-trifluoroethyl ethcr.
Tho co~t~t o~ the ~luorine-substitutad ether compound in ~he mlxed ~olv~nt i~ preferably from S to gO ~ by volume, ~nd more prefcrably from 20 to 70 ~ by volume, When the content of the i~luorine-~ubstituted ether co~pound i8 less then 5 ~ by volu~e or greater then 90 ~ by volume, the high-rate capacity are deteriorated.
It ~eco~es essential for the fluorine-hubstituted ether co~pound r~t,L~ ,-cnLed by the s~eneral ~or~ula tI~ to use a8 a ixed ~olv~nt wherein a co~pound h~Ying ~ high solubility of a lithium salt iE~ added, bec~use o~ the low ~olubility of the lithiu~ salt in thQ ether compound. On practical use, it efe~ d that the electrûlyte ~ubstantially h~s a salt concentration of not l~ss than 0.~ mol/litter, a ~o~pound iJ
~d:led to the halogen-~u~stituted ether compound to obtairL a mixed ~slvent which is c21pable o~ dissslving the lithium 2~1373 ~alt in an amount of not lhs~ than D. 5 mol~litter.
Accng the ~ '~ added, ~ carbon~tc compGund is particul~rly preferred because the reactivity between the carbonzlte compound ~nd ~ctive materi~l of the battery i~
low .
~ 7z~nples ~ the carbonate c~mpound incl~ide acyclic c~rbonate ~lch aa dimethyl cf~rhon~te~ diethy~ carbonate, ethyl methyl c~rbonate, methyl propyl carbon~te, i30propyl methyl ~arbonate, ethyl propyl ~arbonate, i~obutyl :nethyl c~rbonate, etc; and cyclic carbonate such aB ethylene carbonate ~1,3-dioxol~ne-2-one), vinylene carbonate (l~3-~in~nl~n~-2-one~ propylene carbonate (4-D~ethyl-1,3-d~o xo~ane-2-one ~, 1 , 2 -butylene c~rbonA te 1 4 -ethy l- 1 , 3 -dioxolane -2-one ), 2, 3 -butylr ne carbon~te l 4, 5 -din~ethyl -1, 3--l ~ nYc~
2-one~, isobutylene c rbonate ~g,4-dirl~thyl-1,3-dioxolane-~-one~, etc. . The5e c~rbonate u-, ~o~ may be used aloner or 2 or ~or- sorts o~ them may be optionally used ln combination .
~ hen usiny the mixed soLYont s~ith ~ke ~cyclic carbonate such a~ dimethyl carbonate, dlethyl carbona~e, etc., it is preferred bec~us~ the r~ultant electroly~e has excellent hi~h-rate properti~ . A mixed solvent ~ith d isLcthyl r~rhn~ e is particularly preferred.
-- - 2`~8~g7~
It h~s hitherto b~en. considered that the presence of cyclic carbonates such a~ propylene c2rbonat-, ethylene carbona~e, etc. is ~ssential for maintaining cycla properties when using ~ carbon~ceous materi~l that can be doped/undoped with lithium ion~ as an artive material for anode. E~owever, it has been found that excelent cycle properties can ~e maintained ~ithout ci~nt~-nie~ the~e cyclic carbonates when using the electrolyte of the pre3ent inv~ntion, su~prisingly .
When cyclic car~onatea such a~ e~hylene carbonate, vinyl~ne carbonate, etc. ~re added to the above solvent, the initial di~charge capacity is improved. Wh~-n using a sraphite material ~s ~n ~node-~ctive aubstance, ethylene carbonate i~ p~rticularly preferred. Since the high-rate c~pacity ~nd ~ow-temperature capa~ity are d~teriorated a~
the content of t~ese cyclic car~on~tes beco31e~ large, ~he content of the cyclic carbon~te is prefera~ly not mor~ than 50 ', by volume, more prefernbly not more than 3C~ by volum~
As the lithiwn ~alt in the non-aqueou5 el~ctroiyte of the pr~sent i~v~2ntion, th~re can be used any on~ which has hitherto been 1cnown, and eYa~le~ thereof include at least one sort of LiAsF6, LiPF6, Li3~4, LiC104 and LiC~3S03. Among them, LiPF6 is pr~3~erred kecAu-e ~he ionic conductivity of -- 2181~
th~ r~sllltant non-agueous electrolyte i5 large.
In the non-aq~eous electrolyte of the pra~ent invent~on, the lithium s~lt ~onc~n~ration is preferably from O.S to 2 mol/litter, ~o~e prefQrably ~ro~ 0.7 to 1.5 mol/litter bccause of large ionic conductivity.
In thc r~on-aqueou~ electrolyte o~ the present inv~ntion, it is pre~erred that the water cont~nt in th~ solvent be~ore tix~olving the electrolyte i~ not mose than 100~ ppm because the capacity and cycle life of the~ ~attery ~re qood when using i~ for the lithium battery.
The lithiu~ s~condary ~attery co~pri5es a cathode t~at can be doped~undopPd with lithiur~ ion~, an anote of 3 lithium met~l or alloy or ~n anode thct ~an be doped~undoped with lithiu~ ionc and ~he above non-aquecu~ *lectroly~.
In the lithiu~ condary ~attery of the present invention, it i2~ pre~red to use a lithicted m tal dioxide rrJntAi7-ing t l~ast one scrt of 1l lithiated transitlon metal dioxide as an active material ~or cathode because the charge voltage i8 high 21nd the ~nergy density o~ the battery can 3: e inore~et .
~ xartlples of the lithiated metal dioxide conta~ nLnq llt least one sort of 8 tran~tion met~l in the cathode include l~thiated metal dioxide r~ntAin;n~ at least one sor~ o~
tr~niition metals such 15 vanadium, ~ g~n~e, iron, ccbalt, .-- 2181~7~
nickel, etc. Among t~em, laminar lithiated metal dioxide conta~ning cob~lt, nickel, etc. havlng ~ Q-~a~ei~2 typ~?
~I~LU~_LU e or lithiat~d metal dioxide comprising manganese, etc. h~Ying a ~pinel type structure are particularly fe, ~ b causc the aYerage disch~rge potential is high.
A~ong them, the laminar lithiated metel dioxide (e.g., lithiated nic)cel dioxide) is p~rticularly pLerel ~ d because of ~he eYr~ n~ CyClR life.
With thc cathode in the lith~um secondary battery u8ing the non-aqueoufi electrolyte of the pres~nt inYention, a lithiated metal dioxid~ containing at lea~t one sort o~ a ~ran6ition snet~l is used as the ~ctive m2t~rial. Specific exe~ s of thc cathode include those obtained by uniformly m~cing active material powder of the lithiated metal dioxide And auxili~ry conductive ~ot--rial powder with a ~inder for ~irding ~hese powder~, followed by pressure mol ding, or those obtnined ~y formin~ th~Re powder3 in~o a pastt! using a solvent, ~pplying t31e paste on a curr~nt collector sheet, followed by drying and further pres~ing to ~tick on the colle~tor ~heot.
hR auxili~ry conductive material powder used for the ~Athode ~ay ~e those whicb have a condu~tive e~fec~, a resistance to the non-~queous electrolyte used and a _ 14 --2181~73 resi~tance to the electroth~ l reaction 2t th~ cathode, and ~x~pleQ thereof include gr~phite powder, carbon bl~ck, cokes powder~ conductive poly~er, etc.
An amount~ of the auxiliary conductivr material is pre~er~bly about 1 to 20 parts by weight based on lO~ p~rts by weigllt of the ~ctiv~ sub~tAnce powder u6ed.
In the lithium second~ry battery o~ the pre~ent invention, the active ~naterial o~ the ~ode may comprise ~atural or artificiAl graphite or ~ cok~s a~ a ~ingle Lngredient or a maill inqredient ~ecaus~ Or good charge~discharg~ cycle charac~r~ c. It i8 also pos~ible to u~e a lithLum metal or alloy a3 the ~ctive ~terial for an aDode.
When 1 natural or arti~icial qr~phite or a cokes is u~ed as elctive ~at~rial for an anode, the anode cJ~n contain a pol~ner having a c~r~o~-te ~tructure L~ L~3e.l~ed by the g~ner~ ormula ~ II ] and number average n.ol~culnr weight of 30~ or more --O C~--O-- ~ L[ 3 5he binder used for the cathode or anode ~ay be tho~e which have a binding ei~fect, ~ r~Gi~tanCe to the non-a~ueous -2~ 73 . .
electrolyte used and a resistance to the el~ctrQchemicai reaction at the c~thode or nnode, and exa~ples thereof include fluoror~sin~ such a~ polytetra~luo~oethylene ~h.ereinafter re~erred to as "PT~S"~, po'yvinylidens fluoride (hereinafter referred ~o as "PVdF" ~, etc ., and polyethylene p~lypropylene .
An an~ount Q~ the binder i~ pref~rably about 1 tO ;~0 part~; by weight ba~ed on ~00 parts by ~eight of the active ~ubstance powder us-d.
The current collector used for the aooYe c~thode or a~ode may be those which have a re~ i st2nce to the ~on-agueous electrolyte u~d and a resistance to the ~lectrochemic~l r~action at the cathode or 2nods, and examples thereof iacl,ude nickel, titaaium, stainless steel, alu~inum, cop~ r etc.
It is pr-?~arred tb2t ~ thicJ~ness Qf the current collector is as ~mall a~ poYsiole so far as the strength is maintained, beca~se the vol~me ener~y donsity of the hattery iacrease~. 'rhe thickness is pr~ferably a3~out ~ to 100 ~Lm.
A~ the current collector of the cathode, an aluminum ~oil i~ pr~f~rred :~ecause it i5 e~sily ~ormed into a thin filn~ ~md is ch~tlp. As the curr~nt collector of the anode, a ~opper foil i5 preferre~ be~ause it hardly form an alloy .
.~ 2181973 with lithium and is easily formed into A thin iil:n.
~ n the lithium secondary b~ttery using the non-agueou~
electrolyte of the present inYention, th~ s~parator ~ay be those which ~revent contact between ~oth electrodes and have insula~ing ~roperties, ~nd which retain the non-aqueous electrolyte and ~ave a ~unction c~pabl~ of penetrating lithiu~L ions, a resistance to the r~on ?'r""~'lC electrolyte used and a resi~tance to the ~lecrrochPm~c~l reaction at the cathode or ~node, and example~ thereof include non~roven and wov~n ~abric~ of olefin resinY (e.q. fluororesin~, polyethylene, polypropylene, etc. ) and nylon.
It i~ preferred that a t~;Ck-~q5 of the ~ap~rator ls a~
small ~s pos~ible ~o far a~ the s~eci~ic ener~y density of ~he battery increA~es ~nd internal resi~tance d~creas~s. ~he ~hir~n~ is pr~ferably ~bout 10 to 200 ,Um.
EXal~L.
The ~ollowing Exa~ple~ further illnstrate ti~ p~esent iIlvention in det~ ut are not to b~ ccn~tr~ed t~ limit the cope thereof.
~ 1~ Spt-'5;ca1-;os of lithium seconda~y bat~ery test~d:
The c~thode of the l~thiu~ secondary l~ttery te~ted W28 ol~tained by Qethod de~crib~d hereina~ter.
--- - 2i8~973 A~ D cathoda active mz~terial, ~owder of lithiated nickel dioxid~ containing gallium w~ prepared by mixing lithiu~ nitrate, nickel carbon~-te alld g~llium nitr~e and f irin~ ~he mLxture in an oxygen stream at 660 C for l~
hours. To 81~ by weigh of the cathode active m~te~ial powter, 1~ by weight of acetylene black having a r,umber average prima~y parti~le size of 4a nm ~manufactured by Denki X~gaku l~ogyo 1~h~Ch~l~i Kai~ha., trade r.a31e: DYnka black, ~% pr~ed protuctl and 99~ by weisht of scaly artif iclAl gr~phite having a weight average ~rticle ~ize of 7.2 ~/m tmanufactured by ~onz~ Co.~ trade name: RS151, 3~ by wei~ht o~ PVdF ~manu~actured by Rureha Chen~ic2~l Industry ~o., Led., trade name: ~F#1300; in N-methylpyrrolidone as solvent was added a~ a bind~r, follo~ed by ~ufficiently kneading to form ~ p~ste.
It was confiri;~ed by X-r~y powder dif~raction that the Above lithi~ted nLckel dioxide ha~ a~ cY-Na~eO2 type structure .
After ehe pasee ~ras co~ted on ~n ~1 foil h~ving a i~ 4S~ of 20 ~ D~ the current collector, the ~oated ~oil wa~ drled a~d pr~set to ~orn~ into a sheet, whlch wa Cllt into small pieces ir~ ~ize of 1.3 x 1.8 cm to o~tain cathods~. The weight of active material of e~ch of the~Q
2~ 8~ 97~
cathodes ls fro~ 4G to 45 mg.
Thc anode of the lithium second~ry battery tested w~
obtained }~y 2nethod described her~ina~ter.
The carcon powder for the anode was obtained usinc natural graphite powder, pseude-graphitic ~arbon bl~ck powder, and ~ilane coupling agent, by the method described hereil~after. The naturAl ~raphlte powder u~td occurred in MA~ Rt!r~r, which was heat-treated ~t 3000 'C, and have ;
specific ~ur~ce area of ~ m'/g according to a nitrogen ~dsorption method, a number-zv~r~ge particle si2e of 10 ~, true density o~ 2.25, an interlayter ~pacing d~C2 of 3.35 ~ngstrom in X-ray powder di~fraction and an ash content of a. os~ by weight: The P3~ hite ce!rbon bl~ck powder l~nUiaCtured by ~ok~i C~rbon Co., Ltd., trade nam~:
rs3aO~], ~7hich was graphiti2ed at 2~0~ C, and h~ve a specific surfac~ ~rea of 30 n~2tg according to a nitro~en ~dsorpti~n ~cthod, ~ tnle specific gravity of 2.0g and a number average primary particle stize of 66 nl:l. To 95 parts by weight of the natural çraphite powder, 5 part:i by weight of the p~eudo-graphLtic c~rbon black powder ~ s added a~d mix~d to o~t~in a mixed rArhr~n~reo1-s material. To the mixed r~rhnn~reo~ terial, 1 part by weight of a solutlon prep~red by p~eviously d~spersing ~ilane coupling agent _ 19 --~, 21~973 tmanuf actured by ~ippon Yunic~r Co ., Lt~ O, tr~de name: P.l a6 ]
which w~ previoY~ly disper~ed in pure water was added, fol~owed by ~uf~iciently mixing and further vacuum-drying at 150 C to obt~in carbon powder treated with the silane coupling a~ent.
Ihen, 10' by weight of PVdF in ~-;nethylpyrrolidone binder w~s ~dded to 90~ by weight of the a~ove silane col~pling agent-tr~tHd c~rbon powder, aY A ~olv~nL, followed by suf~i~iently kneading to form a pnste.
After the pa~te w~ coated on ~ copper foil having a 1 hielrn~ of 20 /~m as the current collecto~, th~ ~oil was dr$ed arld pr~ed to fo~n into d she~t, ~hich was cut $nto small pieceq in si~e of 1. 5 x 2 cs~ to obt2in anode~ .
A~ t~e Geparator, a micro-~orou~ polypropylene ~
[manu~ctured by Daisel Chemical Indust~ies, Ltd., trade nn2~: ~T~TT~-T~T~n ~24 J0~ W~l~ used.
(II~ Cycle yL~/y~Lty test condition With ~he ~ycl~ efficiency o~ the diYch~rge cap~city of the battery, the ~ollowing conditions ~1 ) clnd ( 2 ) were alternatively reE~eated four times and, finally, the condition ~ one time) ~nd only first ~ycle of the conditior~ ~2) were conducted, that i8, tot21 91 times of thc chnryeldi~ch~rge cycle~ were repeated, 2nd then the cycle _ ~0 ---21gl973 ef ~iciency and high rate ef f iciency were examined .
~ 1 ) A const~lnt-current 2nd voltage chargir.g was conducted under the condition of a current of 7 . 7 mA, a charge maxi~:m voltage of 4.24 V and a charge tima o~ 3 hours, and then discllarging was conducted under the condition ~f ~ current of 1.5~ ~A and ~ final v~lt~ge o~
2.75 ~/. Thi~ ch~rging~di5charginq i5 conducted consecutively two times ~referred to as A low-curr~nt discharge condition ~ .
~ 2) A cDn8~4~ L and volt~ge charging was conducted under the condition of ~ char~e current of 7.7 mA, a chArge alaximum volta~e of i 4 . 24 Y and ~ charge time o~ one hour, and then di~charging W~15 conducted under the condition uf a discharge current oi 7 . 7 mA and ~ f inal voltage of 2 . 75 V. ~his cycle is conducted consecutiv~y 20 ti3tes ~ref~rred to aC a larg~-current di~chelrge condition ) .
'rhe cycle efficiency are evaluat~d by a capacity retention of a discharge ~ap~city }n the g7th charging~discharglng to th~t in the second charginq~di~charging. The higher the cycle ef ~iciency, the longer the cycl~ lif~ .
The high rat~ efficiency is evaluated by a c~pacity retention of the first disch~rge c~pacity under the large curren~ di~ch~rge condition to the fiecond discharqe cap~city .
~- 2~81~73 und~r the low current. discharge condition. The initi~l high rate efficiency corre~pont to the proportion o~ the dlscharge capacity of the third cycle t~ thAt of tSe second cycle, nnd the high r~te ~fficiency ~er cycles CO~L. 5~Vnd to the ~roportion o~ th~ disCharge capacity of the 91st cycle to thAt of t~e 90th cycle.
~3xample 1 U~Lng a non-~queous ~l~ctr~lyt~ preFared ~y dissol~ing 11~F6 as the lithiu~ salt in A mixed solven~ c~f pentafluvLv~,.Lv~l ~ethyl ~ther thereinaf~er referred ~o as ~PFP~ nd di ethyl carbonat* (hereinAfter referrRd to a6 ~D~Cn) (volume ratio: lsl) as a ~olvent for non-2queous electrolyte to 1 ~ol/liter The above cathoàQ and the ~node were ~andwiched uith a s~par~tor. The non-A~ueous electrolyte and the ~andwiched electrods with separator ~_re put in` ~ t~n~r made of ;t~inless steel to produc~ a battery Al.
~ he obs~rved l:esults of the cycle F.ffi~iPn~y and high rate effi~iency 2r~ ~hown in ~able 1.
~x*lr.ple 2 According to the same ~nner a~ that d~R~`J'; h~ in _ ~2 --2~8~ ~73 Fxa~ple 1 excf~pt ~or u~in~ a mixed s~lven~ of ethylene t-:-rhor ~P (hereina~tQr re~er~ed to a~ "EC" ~, D~C and ~FP~3 vol~me ratio: 10:45:~5 and 30:3~:35~ as a golvent fo~
~on-aqueous ~lectro}yte, b~tteries A2 and A3 were produced, respectively. The charg~/di~charge test wa~ conducted accorting to th~ s~n~ manner as that descri}~ed in Exa~.ple 1.
The ~served re~ults of the cycle e~ficiency and high rate e~icit~ncy are ~own in Table 1.
Ca~Dparative Example 1 Aocordint~ to the ~ame ~anner a5 that de~cribed in ~x~pl~ 1 ex~ept for u~ing only ~C, a mixed ~olvent o~ D~fC
~nd ethyl ~ethyl carbonate lher~ina~ter referred to 2S
"EMC~ ~volume ratio: 5C:503 ~nd a mixed golvent o~ D~C, ~C
~nd E~5C tvolum~ ratio: 30:35:35) as the ~olvent ~vr non-agueouS ~lectrolytt~, batteries R1, R2 and ~3 wer~
producèd, resp~ctiv~ly. The ch.~rge~d~scharge ~est W2~5 conduct~d according to the sa~e ~ann~ar a~ th~t de~cribed in x~le 1 .
I`he observed result~ o~ the cyclta ef ~iciency and high rat~ e~iciency are shown in Table 1.
218197~
Crable l> ..
Bath~ C~posit;o~ of l:~itial Cy~ rat~ e~ficiency solv~t ~isch~rge e~CieDCy capacity l~idal After cvcl~s mple 1 Al D~C:PFPME- 6.3 0.~4 Q74 D.80 50:50 A2 EC:DMC;PFPMi- 7.~ 0.84 0.74 0.80 e 2 10 45:45 A3 ~C:DMC:PF~ME- 7.~ 0.80 ~.63 0.56 30:3~:3S
Rl D~fC 0.79 0.~8 O.5û
Colmpas tive ~2 505J0 0.78 0.47 û33 DMC:EMC= 0.77 0 63 0.57 30:35:35 As is a~parent ~r4~L ~able l, the battery ~1 o~ the present inv~ntion is superior to the batterie~ ~l, R2 and R3, which contain no PFP~:, in cycle e~ficie~.cies, particul~rly sup~rior in higll rat~ ~ficiencies. ~emarkably, the high rate efficiencies ~f the batteri~s ~1 ~nc~ P~2, ~hi~h contain ~o PFP!~E:, are draçtically deteriorated w~en the chargcJdisch~rge cycle~ are re~eated, whereas no deterior~tion i8 reco~niz~d in the high-rate eJf;C1--ncie th~ ttery oî the pre~ent inve~tLon even i th~
charge~di~charge cycles are repeated. There~ore, the batte~r o~ the pr~sent invention i~ re~narkably superior in cyclc 218~73 .--effi~-ien~ies o~ the hiqh rate e~icieneie~.
Further~ore, surprisingly, the ~atterieS A2 and P.3, ~hich contain EC, of the pre~ent invention are rc~arkably :~Qperior to the ~At~ery ~3, whlch ha~ hitherto been ~uggested~ using a n~ixed non-~lqueous electrolrte o~ a cyclic carbonate and an acyciic carbonat~ ir~ cycle e~ficiency. -- ~
She batterie~ A2 and ~3, ~hich contain E:C, o~ t~e present invention were i~provQd in initial di ~h~rge capacity in co~np~rison wLth the battery Al ~nt~ini-g no EC.
~owever, the high r~te ~iciencie~ werc ~ h~ly deterior~ted with respect to the battery A3 having a ~:C
content of 3Q~ br volu~e. That is, it hAs been found that the 3~;C content is ~refera~ly 30~ by volu31e ~t most.
~xa~ple 3 With the ba~tery A2 obtain~d in Ex~mple 2, con~t~ntcurrent and voltage chargi~g was conduct~d ~t 20 C
under the conditio~ o~ ~ current of 7.7 ~, a charqe maximum voltage of 4.24 V And a charge tirae of 3 hours, and then d~ schargin~ ~a~ conducted at -2Q C under the condition o~ a current of 1.54 ID~ and a final voltage o~ 2.75 V. The lo-temperAture e~fi~ie~ s are e~aluated by the plo~ortion of the di~charge capacl ty on low-ter~perature discharging to . .
21819~3 that on rooltt tem~eratllre disch~rging.
The resultant lo~ temperature e~icencies are ~hown in Table 2.
~, .
Comparative Example 2 According to the aAne manner Ag th~t described in Example 3, the low-temperature efficencies o~ th~ b~tteries ~l und R~
produced in Comp~rative Example 1 w~re measured. The resultant low-te~er~tur~ R~ e:~ciee. are shown in Tuble 2.
<~ble 2~
Test Ba~tely r , ~ of so~vent L4w t"~,ll,,".~, e~lcicncy mpie 3 A2 EC:DMC:PFPME=10:45:45 73%
C~omp~ative Rl DMC Impossible to E~lmple 2 discharge becallsc of ~2 DMC:EMC=~0:50 2n~
A~ is apparent from Table 2, the ~ttery R2 o~ the present invention showfi excellent low-t~ Lure effice~cies in co~r.pcri~or~ with the battery ~2 ~ontaining no PFPME .
~x~mple 4 i~ith th~ b~tteries A2 l~nd A3 obt~ined in ~camp1e 2, cOnsL~ntcurrent and voltage charglng was conducted at 20 C
. .
21~1973 under the condition of a current of 7.7 mP~, A ch~rge maxi~
volt~ge o~ 4.24 V and ~ charge ti~e of 3 hours and, a~ter di~charging at 6C ~C onder the t:ondition ~ ~ current o~
1.54 mA and a ~final voltage o~ 2 . 75 V, the c~arge~discharge te6t waJ conducted at room ~ , dture again. As ~ result, it WAS possible to conduct charging/di~h~rging, Exa~le S
The ~lAsh points of the electrolytes obtained in ~xample 1 and 2 were loeasur-d accordiDg to a test method by t~g clolied test~r. The results obt~ned ~r~ ~hown in Ta3:le 3.
Tho flash point of the ~lectrolyte obtainet in Comparative Exa~rple 1 was meaS~red accordiDg to the test method by t~ colsed tester. The r~sult obt~ined i~ shown in '~ble 3.
~ecrolyte Composition of el*ctrolyte ~l~sh point Salt Solvent ~-C~
I:Al lN LiPF~ EC:DMC:PPP~ 45:45 ~4~
~:~1 1~ LiPF, EC:I~HC:PP~.~E=30:35:3~ 22 Ta~?le 3 show~ that the electrolyte used in the battery of this inv~ntio~ ha~ increasi~gly hlgh fl~sh point and the ~nfene~s of it i~ greatly ialproved. rt ~an be posi ibl~ t~
lower the d~nger o~ fl~shiDg by leaking of the electrolyte, -- 27 _ .
218~73 and to i~prove the productivLty in the production pr~ces~.
Ex~pl~ 6 Using 2l- ~on-aSrueous electrolyte pre~ared by dissolvin~
LiPF6 ~g th~ lithium s~lt Ln a ~nixed solvent f luorin~ted ether ~nd D~C ~hown in Table ~ (vol~me ratio~ 9 a solv~nt for n~n-~queous e~ectrolyte to 1 mol~liter, cAthode ~nd anode obtained ~s described ai:?ove werc ~andw- ~hed with tor. The non-agueous electrolyte and the ~andwiched electrod~s with a aepar~tor were ~ut in a container ~ade of Yt~inless 6teel to produce batteries 81-sll. q~h~
chArgefdischarqe t~st w2~ cor1dnc~ed i!~ccordin to the ~a~Le manner ~s that describsd ~n Ex~mple 1.
~ he observed re~ults of the cy~le eff~ nci~ d high rate e~l cien-;es ~r~ ~hown in Table q .
~ 218~g7C~
g i}igh-rat-D~ttery r]llr,r1n~ ther Initlal ~ icicucy ch~rq~ e~ ien c~p~oity cy Initial ~t~r [ ~Ah ] C~ cl~s 2 2~3 3-Bl tétrailu.JL~,y~ yl 6.1 0.89 0.60 0.68 hyl ther B2 2 ~ 2, 3 ~ 3 ~ 3- 6 . 4 0 . B 8 0 5 3 0 ~ 7 ~,1,2,2-~trA f 1~ roethy ether 2,2,3,4,4_ i33 r~rltA~ ^rooutyl 6.7 0.81 0.~2 0.55 di~luo~ ~ LL~l ether 2,2 3,3,3-B4 p~;A~ oropropyl 6.4 û.9~ 0.64 o.84 di~luoro~ethyl eti er 1 -tri ~luoro~_thyl-Z,2,2-tri~luoroethyl 7 4 0.68 0 7tl 0.57 ether 1,1,2,2-B6 tetra~ oroethyl 7.2 0 ~32 Q 69 0 75 e'chy~ ethe~
1,1,2,2-B7 rl.tr/lJllloroethyl 6.0 0.80 0.~1 0.4a -2, 2, 2-trif luoroethyl ether 2,2,3,3-~38 tetrail~ lvL,, ,~l 5~3 0~75 0.6~ 0.61 thyl ct~er 2,2,3,3.q.q~
B9 h~.~J~ .r~-h~ rl 7.0 0.84 0 61 0 -:g metbyl ether ~x~mplQ 7 O oi ~y weight of polyethylene car}~onat~ (nu~ber verage moleculer weight 50~00 ~reinafter rl3~erred t~
,, 21~1g7~ ' 'PEC") in ~-met~ylpyrro~idon~ ~nt 2.4 % by weight of PVd~ in ~-methylpyrroLidone as ~he binder were added to ~7% by weight o the a~ove ~ilane coupling agent-tr~ted materi~l, followed ~y s~icient kneading to form a pa~te.
Aft~r the pa~te wa6 coatet on a copper foil having a thirl~n~Cs 0~ 20,~Lm a~ th~ ~urrent collector, the foil waS
dried and pres~d to form into ~ sheet, which WAS ~ut into small pie~es in size of 1. 5 x 2 c~ to o}~t~in anodes cr.t ~ ; n i n g PE:C .
Except using th~ anod~ obtaind a},ove, and al the non-~queou~ ~lectroiyte, the mixed solvent ~f PFPNE:~Dr~C
~volusLe ratio 1:1~ or 2,2,3,3-tetr,lfluoropropyl di~luo~o2nethyl ether ( hereinaf ter re~erred to a~
~T~PDE-')JD~C ~volume ratio 1~ tteries P1 and ~2 wer~
produced, and the ch~rge/discharge t~sts were condu~ted according to the same manner as that d~rr~h~' in ~xapmtil 1.
rhe initial discharge capacitieS s~ere 6 . 5 mAh ~nd ~ . 6mAh, re6pectively .
Above r~ lt shows that the initial capaclty is incre~Aed by u~ing an anode containing polyethylene car~onato without using EC.
Therc can be o~tained a lithio~n secondary batter~ which operate~ within the ~ide temporature range ~rom -20 to ~ C
` - 2~8197~
and c~u~e6 little deterioration of the di~ch~rge cap~city by repe~ted cnarqingJdivcharging, and w~ich i~ particularly supcrior in high-r~te capacity and cause~ little deterioratioh D~ the hish-rate capa~ity due to the cycles.
The lit~iu~ ~econdary battery has a very l~rg~
indu~trial value for ~pplicati~ns ~uch ~s pcrta~le ~E~PZ~rAtu5es, tr~n~ports aDd n achine tools, which rc~uire l~rge current and ~ l~rgo capacity.
-
Claims (19)
1. A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt, said non-aqueous electrolyte containing a halogen-substituted ether compound represented by the general formula [I]:
R1-O-R2 [I]
(wherein R1 is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms) and at least one sort of a compound in which a mixed solvent obtained by adding the compound to the halogen-substituted ether compound is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/litter, as the non-aqueous solvent.
R1-O-R2 [I]
(wherein R1 is an alkyl or halogen-substituted alkyl group having 2 or less carbon atoms and R2 is a halogen-substituted alkyl group having 2 to 10 carbon atoms) and at least one sort of a compound in which a mixed solvent obtained by adding the compound to the halogen-substituted ether compound is capable of dissolving the lithium salt in an amount of not less than 0.5 mol/litter, as the non-aqueous solvent.
2. A non-aqueous electrolyte according to Claim 1, wherein R1 of the halogen-substituted ether compound in the formula is methyl group, fluoromethyl group, difluoromethylgroup or trifluoromethyl group.
3. A non-aqueous electrolyte according to Claim 1, wherein R2 in the formula is a halogen-substituted alkyl group having 3 to 5 varbon atoms.
4. A non-aqueous electrolyte according to Claim 1, wherein R2 in the formula is a fluorine-substituted alkyl group having 3 to 5 varbon atoms.
5. A non-aqueous electrolyte according to Claim 1, wherein the compound added to the halogen-substituted ether compound is an acyclic carbonate.
6. A non-aqueous electrolyte according to Claim 5, wherein the acyclic carbonate is dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, isopropyl methyl carbonate, ethyl propyl carbonate or isobutylmethyl carbonate.
7. A non-aqueous electrolyte according to Claim 5, wherein the acyclic carbonate is dimethyl carbonate or ethyl methyl carbonate.
8. A non-aqueous electrolyte according to Claim 5, wherein the acyclic carbonate is dimethyl carbonate.
9. A non-aqueous electrolyte according to Claim 1 or 5, wherein the non-aqueous solvent contains a cyclic carbonate.
10. A non-aqueous electrolyte according to Claim 9, wherein the content of the cyclic carbonate in the non-aqueous solvent is 50 % by volume or less.
11. A non-aqueous electrolyte according to Claim 9, wherein the content of the cyclic carbonate in the non-aqueous solvent is 30 % by volume or less.
12. A non-aqueous electrolyte according to Claim 9, wherein the cyclic carbonate is ethylene carbonate (1,3-dioxolane-2-one), vinylene carbonate (1,3-dioxolane-2-one), propylene carbonate (4-methyl-1,3-dioxolane-2-one), 1,2-butylene carbonate (4-ethyl-1,3-dioxolane-2-one), 2,3-butylene carbonate (4,5-dimethyl-1,3-dioxolane-2-one) or isobutylene carbonate (4,4-dimethyl-1,3-dioxolane-2-one).
13. A non-aqueous electrolyte according to Claim 9, wherein the cyclic carbonate is ethylene carbonate (1,3-dioxolane-2-one) or vinylene carbonate.
14. A non-aqueous electrolyte according to Claim 9, wherein the cyclic carbonate is ethylene carbonate (1,3-dioxolane-2-one).
15. A lithium secondary battery comprising a cathode that can be doped/undoped with lithium ions, an anode of a lithium metal or alloy or a material that can be doped/undoped with lithium ions, and a non-aqueous electrolyte according to claim 1.
16. A lithium secondary battery according to claim 15, wherein the anode of the material can be doped/undoped with lithium ions, contains carbonaceous materials comprising a natural or artificial graphite or a coke material as a single ingredient or a main ingredient.
17. A lithium secondary battery according to claim 15 or 16, wherein the cathode comprising a lithiated metal dioxide containing at least one sort of lithiated transition metal dioxide such as vanadium, manganese, iron, cobalt and nickel.
18. A lithium secondary battery according to claim 15 or 16, wherein the cathode comprising a laminar lithiated metal dioxide containing a lithiated nickel dioxide as a main ingredinet.
19. A lithium secondary battery according to any one of claims 15 to 18, wherein the anode contains a polymer having a carbonate structure represented bythe genaral formula [II] and number average molecular weight of 300 or more [II]
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7-189335 | 1995-07-25 | ||
| JP18933595 | 1995-07-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2181973A1 true CA2181973A1 (en) | 1997-01-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002181973A Abandoned CA2181973A1 (en) | 1995-07-25 | 1996-07-24 | Non-aqueous electrolyte and lithium secondary battery |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US5795677A (en) |
| EP (1) | EP0757399B1 (en) |
| KR (1) | KR100439448B1 (en) |
| CN (1) | CN1091956C (en) |
| CA (1) | CA2181973A1 (en) |
| DE (1) | DE69627081T2 (en) |
| TW (1) | TW360987B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19619233A1 (en) * | 1996-05-13 | 1997-11-20 | Hoechst Ag | Fluorine-containing solvents for lithium batteries with increased security |
| US5994000A (en) * | 1997-12-31 | 1999-11-30 | Covalent Associates, Inc. | Asymmetric organic alkyl methyl carbonates for non-aqueous power sources |
| US5986879A (en) * | 1997-12-31 | 1999-11-16 | Covalent Associates | Asymmetric organic alkyl ethyl carbonates for non-aqueous power sources |
| TW434923B (en) * | 1998-02-20 | 2001-05-16 | Hitachi Ltd | Lithium secondary battery and liquid electrolyte for the battery |
| US6136477A (en) * | 1998-10-22 | 2000-10-24 | Wilson Greatbatch Ltd. | Nitrate additives for nonaqueous electrolyte rechargeable cells |
| JP2001085058A (en) * | 1999-09-20 | 2001-03-30 | Hitachi Ltd | Non-aqueous electrolyte, lithium primary battery and lithium secondary battery using the same, electrochemical capacitor, polymer electrolyte, and polymer secondary battery using the same |
| US6562515B2 (en) | 2001-03-21 | 2003-05-13 | Wilson Greatbatch Ltd. | Electrochemical cell having an electrode with a nitrate additive in the electrode active mixture |
| US7229718B2 (en) * | 2002-08-22 | 2007-06-12 | Samsung Sdi Co., Ltd. | Electrolyte for rechargeable lithium battery and rechargeable lithium battery comprising same |
| DE10247675A1 (en) * | 2002-10-12 | 2004-04-22 | Solvay Fluor Und Derivate Gmbh | The use of polyfluoropolyethers and their mixtures as fire resistant solvents for conductive salt mixtures in reusable battery electrolytes increases the safety of the batteries, e.g. decreases the explosion risk |
| DE602004004956T2 (en) | 2003-08-20 | 2007-11-08 | Samsung SDI Co., Ltd., Suwon | Electrolyte for rechargeable lithium battery and rechargeable lithium battery containing the same |
| CN100495774C (en) * | 2003-11-17 | 2009-06-03 | 松下电器产业株式会社 | Non-aqueous electrolyte secondary cell |
| KR100709207B1 (en) * | 2004-06-30 | 2007-04-18 | 삼성에스디아이 주식회사 | Lithium secondary battery |
| JP2006019274A (en) | 2004-06-30 | 2006-01-19 | Samsung Sdi Co Ltd | Lithium secondary battery |
| JP2006049037A (en) * | 2004-08-03 | 2006-02-16 | Three M Innovative Properties Co | Nonaqueous electrolyte for electrochemical energy device |
| WO2006070546A1 (en) | 2004-12-27 | 2006-07-06 | Ube Industries, Ltd. | Nonaqueous electrolyte solution and lithium secondary battery using same |
| JPWO2006115023A1 (en) * | 2005-04-19 | 2008-12-18 | 松下電器産業株式会社 | Non-aqueous electrolyte, electrochemical energy storage device using the same, and non-aqueous electrolyte secondary battery |
| DE102005048802A1 (en) * | 2005-10-10 | 2007-04-12 | Solvay Fluor Gmbh | Fluorinated additives for lithium-ion batteries |
| JP5457429B2 (en) | 2009-02-18 | 2014-04-02 | 旭化成イーマテリアルズ株式会社 | Electrolyte for lithium ion secondary battery and lithium ion secondary battery |
| CN102449842B (en) | 2009-06-10 | 2015-03-04 | 旭化成电子材料株式会社 | Electrolytic solution and lithium ion secondary battery utilizing same |
| JP5704633B2 (en) * | 2009-09-29 | 2015-04-22 | Ｎｅｃエナジーデバイス株式会社 | Secondary battery |
| US20110143217A1 (en) * | 2009-12-15 | 2011-06-16 | E. I. Du Pont De Nemours And Company | Electrochemical cell comprising a separator comprising a nanoweb consisting essentially of nanofibers of fully aromatic polyimide |
| CN102812589B (en) * | 2010-03-26 | 2016-01-13 | Nec能源元器件株式会社 | Nonaqueous electrolytic solution secondary battery |
| JP5582587B2 (en) * | 2010-06-25 | 2014-09-03 | Ｎｅｃエナジーデバイス株式会社 | Lithium ion secondary battery |
| CN103636048B (en) * | 2012-02-29 | 2016-12-14 | 新神户电机株式会社 | Lithium ion battery |
| CN105074995B (en) | 2013-08-21 | 2018-01-02 | 积水化学工业株式会社 | Electrolyte, and lithium-ion secondary battery |
| US12438153B2 (en) * | 2019-07-22 | 2025-10-07 | Lg Energy Solution, Ltd. | Lithium secondary battery |
| CN116023239B (en) * | 2022-11-04 | 2024-05-17 | 华南师范大学 | A preparation method of amphiphilic fluoroether molecules and their application in lithium batteries |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6161369A (en) * | 1984-08-31 | 1986-03-29 | Sanyo Electric Co Ltd | non-aqueous electrolyte battery |
| JPH0665043B2 (en) * | 1985-07-30 | 1994-08-22 | 三洋電機株式会社 | Non-aqueous electrolyte battery |
| JP2555378B2 (en) * | 1987-10-30 | 1996-11-20 | 株式会社ネオス | Synthetic Fluoroalkoxyethanes |
| JPH02207464A (en) * | 1989-02-07 | 1990-08-17 | Showa Denko Kk | secondary battery |
| DE69309861T2 (en) * | 1992-11-18 | 1997-09-11 | Mitsui Petrochemical Ind | Carbonate compounds, non-aqueous electrolyte solutions and batteries containing non-aqueous electrolyte solutions |
| EP0634805B1 (en) * | 1992-12-04 | 1998-07-15 | Sony Corporation | Secondary cell of nonaqueous electrolyte |
| US5529859A (en) * | 1994-04-15 | 1996-06-25 | National Research Council Of Canada | Elecrolyte for a secondary cell |
-
1996
- 1996-07-23 TW TW085108931A patent/TW360987B/en not_active IP Right Cessation
- 1996-07-24 CA CA002181973A patent/CA2181973A1/en not_active Abandoned
- 1996-07-24 DE DE69627081T patent/DE69627081T2/en not_active Expired - Lifetime
- 1996-07-24 EP EP96111941A patent/EP0757399B1/en not_active Expired - Lifetime
- 1996-07-24 US US08/685,666 patent/US5795677A/en not_active Expired - Lifetime
- 1996-07-25 CN CN96112297A patent/CN1091956C/en not_active Expired - Lifetime
- 1996-07-25 KR KR1019960030211A patent/KR100439448B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE69627081D1 (en) | 2003-05-08 |
| DE69627081T2 (en) | 2004-01-29 |
| EP0757399B1 (en) | 2003-04-02 |
| CN1091956C (en) | 2002-10-02 |
| TW360987B (en) | 1999-06-11 |
| EP0757399A1 (en) | 1997-02-05 |
| KR970008713A (en) | 1997-02-24 |
| US5795677A (en) | 1998-08-18 |
| CN1151619A (en) | 1997-06-11 |
| KR100439448B1 (en) | 2004-10-20 |
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