Classifications

• • 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
  • H01M10/0568—Liquid materials characterised by the solutes
• • 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
• • 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
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • 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
  • H01M2300/002—Inorganic electrolyte
• • 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

Definitions

• the invention relates to lithium borate complex salts, their preparation and their use as electrolytes in galvanic cells, in particular as conductive salts in lithium ion batteries.
• LiPF ⁇ lithium hexafluorophosphate
• LiPF 6 has serious disadvantages, which can mainly be attributed to its lack of thermal stability (decomposition above approx. 130 ° C).
• corrosive and toxic hydrogen fluoride is released on contact with moisture, which on the one hand makes handling difficult and on the other hand battery components, e.g. B. the cathode, attacks and damages.
• lithium trifluoromethanesulfonate (“Li triflate”)
• lithium imides lithium bis (perfluoroalkylsulfonyl) imides
• lithium methides lithium tris (perfluoroalkylsulfonyl) methide). All of these salts require relatively complex manufacturing processes, are therefore relatively expensive and have other disadvantages, such as corrosiveness to aluminum or poor conductivity.
• Lithium organoborates have been investigated as a further class of compounds for use as conductive salt in rechargeable lithium batteries. However, because of their low oxidation stability and safety concerns when handling triorganoboranes, they are ruled out for commercial systems.
• the lithium complex salts of the ABL 2 type proposed in EP 698301 for use in galvanic cells represent a significant advance (where A is lithium or a quaternary ammonium ion, B boron and L is a bidentate ligand which is bonded to the boron atom via two oxygen atoms)
• the proposed salts whose ligands contain at least one aromatic radical, only have sufficient electrochemical stability if the aromatic is substituted with electron-withdrawing radicals, typically fluorine, or has at least one nitrogen atom in the ring.
• Such chelate compounds are not commercially available and can only be produced at high costs. The proposed products could therefore not prevail on the market.
• the lithium bis (oxalato) borate (LiBOB) described for the first time in DE 19829030 is the first boron-centered complex salt described for use as an electrolyte, which uses a dicarboxylic acid (in this case oxalic acid) as the chelate component.
• the connection is easy to produce, non-toxic and electrochemically stable up to about 4.5 V, which enables it to be used in lithium-ion batteries.
• it is disadvantageous that it can hardly be used in new battery systems with cell voltages> 3 V.
• Such electrochemical stores require salts with stabilities> approximately 5 V.
• Another disadvantage is that lithium bis (oxalato) borate does not allow structural variations without destroying the basic structure.
• EP 1035612 describes additives of the formula
• Particularly preferred additives are lithium bis [1, 2-benzenediolato (2-) O, 0 '] borate (1-), lithium bis [3-fluoro-1, 2-benzenediolato (2-) 0.0 '] borate (1-),
• R 1 , R 2 independently of one another H, alkyl (with 1 to 5 C -Atoms), aryl, silyl or a polymer, and one of the alkyl radicals R 1 or R 2 can be linked to a further chelatoborate radical, b -
• liquid electrolytes which contain only one of the mixed borchelate complex salts disclosed in DE 10108592 cannot be used for high-performance high-performance batteries.
• the undesired ⁇ o / no compounds have different physicochemical properties, especially an electrochemical stability different from the mixed compound; they must therefore be separated by recrystallization or a similar purification process, which is relatively complex.
• WO 01/99209 also discloses the preparation of mixed lithium borate salts such as lithium (malonatooxalato) borate (Examples 6 and 7). Two synthesis options are described, both of which give the desired salt as the main product, but contamination by ⁇ omo complex compounds cannot be avoided (Example 6: 4.5% lithium bis (oxalato) borate).
• EP 1095942 describes complex salts of the formula
• Li + B- (OR 1 ) m (OR 2 ) p described (for the meaning of R 1 , R 2 , m and p see above in EP 1035612). They serve as conductive salts in electrolytes for electrochemical cells. They can also be used in proportions between 1 and 99% in combination with other conductive salts. Conductive salts from the group LiPF 6 , LiBF 4 , LiCI0 4 , LiAsF 6 , LiCF 3 S0 3 , LiN (CF 3 S0 2 ) 2 or LiC (CF 3 S0 2 ) 3 and mixtures thereof are suitable. These are all fluorinated conductive salts.
• the object of the present invention is to overcome the disadvantages of the prior art and in particular to find fluorine-free, simple and inexpensive to produce conductive salts for lithium ion batteries and to show their synthesis. Furthermore, the conductive salts should be able to be adapted to the material and application properties and have a formation and overload protection function.
• LiBOB lithium bis (oxalato) borate
• X in formula (I) is a bridge connected to two oxygen atoms to the boron, which is selected from
• L 2 is, for example, a dicarboxylic acid (not oxalic acid), hydroxycarboxylic acid or salicylic acid (which can also be substituted at most twice). Further possibilities for the chelating agent L 2 are listed below in the description of the connecting part X.
• the reaction is preferably carried out in such a way that the raw material components are suspended in a medium suitable for azeotropic water removal (for example toluene, xylene, methylcyclohexane, perfluorinated hydrocarbons with more than 6 C atoms) and the water is removed azeotropically in a known manner ,
• azeotropic water removal for example toluene, xylene, methylcyclohexane, perfluorinated hydrocarbons with more than 6 C atoms
• reaction media It is also possible to carry out the synthesis in aqueous solution.
• the components are introduced into water in any order and evaporated with stirring, preferably under reduced pressure. After removal of the main amount of water, a solid reaction product forms which, depending on the specific product properties, is finally dried at temperatures between 100 and 180 ° C and reduced pressure (e.g. 10 mbar).
• reduced pressure e.g. 10 mbar
• alcohols and other polar organic solvents are also suitable as reaction media.
• the product can also be produced without the addition of any solvent, ie the commercially available raw materials are mixed and then heated by the application of heat and dewatered under preferably reduced pressure. - y -
• the resulting conductive salt mixture has the advantage over pure LiBOB that a decomposition reaction occurs at the cathode when it is overloaded, which slows down the increase in cell voltage. In this way, dangerous subsequent reactions of the cathode material with constituents of the electrolyte can be avoided or reduced.
• Preferred examples of the connecting part X are 1, 3-dicarboxylic acids, such as malonic acid and alkylmalonic acids (malonic acid, substituted by an alkyl group having preferably 1 to 5 carbon atoms) reduced by two OH groups.
• malonic acid substituted by an alkyl group having preferably 1 to 5 carbon atoms
• alkyl group having preferably 1 to 5 carbon atoms reduced by two OH groups.
• the O atoms binding to the boron are already contained in formula (I), which corresponds to 1, 3 dicarboxylic acids L 2.
• connecting part X are 1, 2- or 1, 3-hydroxycarboxylic acids, such as glycolic acid or lactic acid, which are formally reduced by two OH groups.
• the 1, 2- or 1, 3-hydroxycarboxylic acids correspond to L 2.
• the connecting part X can also preferably be formed by saturated C 2 or C 3 chains, which is formally reduced from 1, 2- by two OH groups or 1, 3-diols can be derived.
• the 1, 2- or 1, 3-diols correspond to L 2.
• connecting part X is 1, 2-bisphenols (such as pyrocatechol) or 1, 2-
• Carboxyphenols such as salicylic acid
• aromatic or heteroaromatic aromatic acids such as salicylic acid
• the remaining solid was comminuted with a nickel spatula under a protective gas atmosphere (argon) and finely ground in a porcelain mortar.
• the powder was then poured back into a round glass flask and finally dried on a rotary evaporator at 150 ° C. and finally 13 mbar.

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• 2004
  • 2004-03-08 DE DE102004011522A patent/DE102004011522A1/de not_active Withdrawn
• 2005
  • 2005-03-08 DE DE502005003737T patent/DE502005003737D1/de active Active
  • 2005-03-08 JP JP2007502277A patent/JP5150248B2/ja active Active
  • 2005-03-08 US US10/591,509 patent/US8945778B2/en active Active
  • 2005-03-08 KR KR1020067020829A patent/KR101156825B1/ko active IP Right Grant
  • 2005-03-08 WO PCT/EP2005/002439 patent/WO2005086274A2/de active IP Right Grant
  • 2005-03-08 CN CN2005800146854A patent/CN1957498B/zh active Active
  • 2005-03-08 AT AT05715835T patent/ATE392723T1/de not_active IP Right Cessation
  • 2005-03-08 EP EP05715835A patent/EP1726061B1/de active Active

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