GB2606746A

GB2606746A - Compound

Info

Publication number: GB2606746A
Application number: GB2107162.6A
Authority: GB
Inventors: Kugler Thomas; Attanzio Antonio
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2021-05-19
Filing date: 2021-05-19
Publication date: 2022-11-23
Also published as: GB202107162D0; GB202204673D0

Abstract

A compound of formula (I) wherein X is Al or B; R1 is a substituent, where two groups may be linked to form a ring; M+ is a cation. Each R1 may be a C1-20 alkyl, wherein one or more non-adjacent C atoms are replaced with O, S, CO, or COO, and one or more H atoms of the alkyl group may be replaced with F. Each R1 may be the same, or it may have at least 2 different R1 groups. Each pair of R1 groups may be linked, so that the R1 group is a divalent organic group. M+ may be an alkali metal ion, and may be a lithium ion, and may be solvated, and the solvent may eb selected from solvents comprising an ether group. A method is given comprising reacting XH4-M+ with at least one of R1-OH or R2(OH)2, and R1-OH may be monohydric alcohols or mono-carboxylic acids, and R2(OH)2 may be diols or di-carboxylic acids. Also provided in a polymer where one R1 group is replaced with the repeating group of a polymer. Also provided is a metal (ion) battery comprising an anode, cathode and the compound/polymer disposed between the anode and the cathode.

Description

COMPOUND BACKGROUND

Ionic liquids are known for use in lithium ion batteries.

CN101771166 discloses an ionic liquid electrolyte composed of certain organic lithium borate 5 or lithium aluminate compounds and certain organic compound containing an amido functional group.

JP2004265785 discloses an ionic electrolyte material of formula (I): JP 2006/107793 discloses an ion having a fluorinated alkoxy group coordinated to a metallic 10 element.

JP03409852 discloses compounds of formula: US8394539 discloses lithium salts with fluorinated chelated orthoborate anions used as electrolytes or electrolyte additives in lithium-ion batteries. The lithium salts have two chelate 15 rings formed by the coordination of two bidentate ligands to a single boron atom.

E. Zygadlo-Monikowska et al, "Lithium conducting ionic liquids based on lithium borate salts", Journal of Power Sources 195 (2010) 6055-6061, discloses reaction of trialkoxyborates with butyllithium to form Li{ ECH3(00-1/CH2)nObBe4H9).

Michael Rohde et al, -1_1[B(OCH2CF3)4]: Synthesis, Characterization and Electrochemical Application as a Conducting Salt for LiSB Batteries", ChemPhysChem 2015, 16, 666 -675 discloses formation of Ei[B(OCH2CF3)4] by reaction of lithium borohydride with excess 2,2,2-trilluorethanol R Tao et al, "Enhancement of ionic conductivity by mixing lithium borate with lithium aluminate", discloses compounds of formula:

SUMMARY

In some embodiments, the present disclosure provides a compound of formula (I): (I) wherein X is Al or B; RI in each occurrence is independently a substituent; and two RI groups may be linked to form a ring; and W is a cation.

In some embodiments, none of the R groups are linked. According to these embodiments, optionally each RI is independently a Chno alkyl group wherein one or more non-adjacent C atoms of the alkyl group may be replaced with 0, S. CO or COO and one or more H atoms of the alkyl group may be replaced with F. kAt:

OR

S"k Bon tw 11 S Optionally each RI is independently selected from alkyl and alkyl ether groups wherein one or more H atoms may be replaced with F. In some embodiments, each RI is the same.

In some embodiments, the compound of formula (I) contains at least 2 different R1 groups.

In some embodiments, R1 groups of formula (I) are linked and the compound of formula (I) has formula (la): M÷ (Ta) wherein R2 in each occurrence is independently a divalent organic group.

Optionally, 1\4* of the compound of formula (I) is an alkali metal ion, optionally a lithium ion.

Optionally, 1\4* is a solvated cation.

Optionally the solvent of the solvate is selected from solvents comprising at least one ether group.

In some embodiments, the present disclosure provides a method of forming a compound of formula (I) comprising reacting a compound of formula (II) and at least one compound selected from formulae (Illa) and (111b): XH4-M± R1-0H (111b) Optionally, the compounds of formula (111a) are selected from monohydric alcohols and mono-carboxylic acids and the compounds of formula (Illb) are selected from diols and di-carboxylic acids.

Optionally, Ne of the compound of formula (I) is solvated and the reaction is carried out in a reaction mixture comprising the solvent of the solvate.

In some embodiment, the present disclosure provides a method in which W of the compound of formula (I) is solvated, the method comprising at least partially replacing the solvent of the solvate with another solvent.

In some embodiments, the present disclosure provides a polymer comprising a repeat unit of formula (IV): +7)-R30-T-0 R3 OR3 (IV) wherein RU is a repeating group of the polymer; R3 is a substituent; and X and W are as described above.

In some embodiments, the present disclosure provides a metal battery or metal ion battery comprising an anode, a cathode and a compound of formula (I) or polymer as described herein disposed between the anode and the cathode.

Optionally, the battery is a metal battery comprising an anode protection layer comprising the compound or polymer disposed between the anode and cathode.

DESCRIPTION OF DRAWINGS

Figure 1 is a schematic illustration of a battery according to some embodiments of the present disclosure having a separator comprising a compound as described herein; Figure 2 is a schematic illustration of a battery according to some embodiments of the present disclosure having an anode protection layer comprising a compound as described herein; Figure 3 is a NMR spectrum of a compound according to an embodiment of the present disclosure; Figure 4 is the cyclic voltammetry plot for the compound of Figure 3 in which the compound was disposed between a copper foil working electrode and a lithium foil counter electrode; Figure 5 is an image of lithium deposited on the copper foil described in Figure 4; and Figure 6 is a Nyquist plot of the compound of Figure 3.

The drawings are not drawn to scale and have various viewpoints and perspectives. The drawings are some implementations and examples. While the technology is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the technology to the particular implementations described. On the contrary, the technology is intended to cover all modifications, equivalents, and alternatives falling within the scope of the technology as defined by the appended claims.

DETAILED DESCRIPTION

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to." Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number may also include the plural or singular number respectively.

The word "or," in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. References to a layer "over" another layer when used in this application means that the layers may be in direct contact or one or more intervening layers are may be present. References to a layer "on" another layer when used in this application means that the layers are in direct contact. References to an element of the Periodic Table include any isotopes of that element.

The teachings of the technology provided herein can be applied to other systems, not necessarily the system described below. The elements and acts of the various examples described below can be combined to provide further implementations of the technology. Some alternative implementations of the technology may include not only additional elements to those implementations noted below, but also may include fewer elements.

These and other changes can be made to the technology in light of the following detailed description. While the description describes certain examples of the technology, and describes the best mode contemplated, no matter how detailed the description appears, the technology can he practiced in many ways. As noted above, particular terminology used when describing certain features or aspects of the technology should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the technology to the specific examples disclosed in the specification, unless the Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the technology encompasses not only the disclosed examples, hut also all equivalent ways of practicing or implementing the technology under the claims.

To reduce the number of claims, certain aspects of the technology are presented below in certain claim forms, but the applicant contemplates the various aspects of the technology in any number of claim forms.

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that embodiments of the disclosed technology may be practiced without some of these specific details.

In some embodiments, the present disclosure provides compounds of formula (I): yR1 R10 f-oR1 oR1 (I) NA+ X is Al or B. RI in each occurrence is independently a substituent and two RI groups may be linked to form a ring.

W is a cation.

In some preferred embodiments, none of the RI groups are linked. Optionally according to these embodiments, each RI is independently a C1_20 alkyl group wherein one or more non-adjacent C atoms of die alkyl group may be replaced with 0, S. CO or COO and one or more H atoms of the alkyl group may be replaced with F. Preferred le groups include CI --)0 alkyl wherein one or more C atoms other than the C atom bound to 0 of OR' or a terminal C atom may be replaced with 0, and one or more H atoms 10 may be replaced by F. By "terminal C atom" of an alkyl group as used herein is meant the C atom of the methyl group or methyl groups at the chain end or chain ends of a linear or branched alkyl, respectively.

In some embodiments, each RI is the same.

In some embodiments, the compound contains two or more different RI groups.

In some embodiments. RI groups of formula (I) are linked and the compound of formula (I) has formula (Ia): /0 x - -R2 0 m+ N z R2 0 / 0 (Ia) wherein R2 in each occurrence is independently a divalent organic group.

Optionally, R2 is selected from a Cork) arylene group, e.2. 1,2-phenylene, which may be unsubstituted or substituted with one or more substituents; a hi-arylene group, for example 2,2'-linked biphenylene; ethylene; and propylene, each of which may be unsubstituted or substituted with one or more substituents. Optionally, substituents are selected from F alkyl wherein one or more non-terminal C atoms of the C1_12 alkyl may be replaced with F and one or more C atoms of the C 1_12 alkyl may be replaced with 0.

Preferably, W is an alkali metal cation, more preferably a lithium cation. Preferably. W is a solvated cation.

Preferably, the solvent of the solvate is selected from solvents comprising at least one ether group.

Preferably, the solvent contains two or more groups capable of coordinating to the metal cation.

The solvent may be selected from linear and cyclic compounds containing one or more ether groups and, optionally one or more groups selected from hydroxyl and carboxylate groups.

Exemplary solvents include, without limitation, tetrahydrofuran, dimethoxyethane, diglyme (diethylene glycol ditnethyl ether), triglyme (triethylene glycol di methyl ether), tetraglyme (tetraethylene glycol dimethyl ether) and crown ethers, for example 12-Crown-4 and 1-aza-12-Crown-4.

The compound may contain more than one solvent of a solvate.

The compound of formula (I) may be formed by reacting a compound of formula (II) and at least one compound selected from formulae (Ilia) and (tub): XF14-M+ R1-0H,-OH

RLOH

(ha) (Mb) It will be understood that the compounds of formulae (Ina) and (Mb) may be selected according to the desired RI and R2 groups of formula (I).

Exemplary compounds of formula (I) include, without limitation, lithium aluminium hydride (LiA1H4), lithium borohydride (Li BH4) Exemplary compounds of formula (Ma) include, without limitation: C1_20 alkyl monohydric alcohols which may be non-fluorinated or wherein one or more, optionally all, H atoms of the CI_20 alkyl may be replaced with F, for example ethanol, isopropanol, 1H,1H,5H-octafluoro-1 -pentanol and pentadecafluoro-1 -octanol; ether monohydric alcohols which may be non-fluorinated, partially fluorinated or peril uorinated for example 2-ethoxyethanol, diethylene glycol monoethyl ether, 1 H, 1 H-perfluoro-3,6-dioxaheptan-1 -ol, 1H, 1 H-perfluoro-3,6,9-trioxadecan-1 -01, 1 Hi H-perfluoro3,6-dioxadecan-1 -ol and 1 H,1H-perfluoro-3,6,9-trioxatridecan-1 -ol; and mono-carboxylic acid compounds, for example C1_20 alkyl carboxylic acids wherein one or more non-adjacent C atoms other than terminal C atoms or the C atom adjacent to the carboxylic acid group may be replaced with 0 and one or more H atoms may be replaced with F. Examples include, without limitation: perfluoroalkyl carboxylic acids, for example trifluoroacetic acid; perfluoroalkyl ether carboxylic acids; and alkyl ether carboxylic acids.

Exemplary compounds of formula (Mb) include alkane diols wherein one or more nonadjacent, non terminal C atoms other than the C atom bound to 0 of R2-0 may be replaced with 0; aromatic diols; dicarboxylic acids; and compounds having one hydroxyl and one carboxylic acid group, each of which may be unsubstituted or substituted with one or more substituents, optionally non-fluorinated, partially fluorinated or perfluorinated.

Exemplary compounds of formula (Illb) include ethylene glycol, catechol ( 1,2-dihydroxybenzene), oxalic acid and fluorinated derivatives thereof.

In some embodiments, the reaction is carried out with only one compound selected from compounds of formulae (111a) and (111b). According to these embodiments, the RI groups (and, therefore, each R2 group in the case of compounds of formula (II)) are all the same.

In some embodiments, the reaction is carried out with two or more compounds selected from 25 compounds of formulae (HRa) and (Mb). According to these embodiments, the R1 groups may be different. The ratio of different RI groups may be selected according the ratio of the compounds of formulae (Ina) and (IIIb) and their relative reactivity.

If the metal cation 1\4* is a solvated cation then in some embodiments the solvent of the solvate 30 is present in the reaction mixture containing the compound of formula (II) and the compound of formula (Ma) and / or (Mb).

In some embodiments, the solvent of a compound of formula (I) containing a solvated cation may be replaced with a different solvent. Methods of changing the solvent of a solvate include, without limitation, driving off a solvent of a compound of formula (I) by heat treatment and replacing it with another solvent capable of solvating the cation; and contacting a compound of formula (I) with a solvent which coordinates more strongly to the cation than an existing solvating solvent, for example by treating a compound of formula (I) having a monodentate solvate solvent with a hi-dentate or higher-dentate ligand.

In some embodiments, the present disclosure provides a polymer comprising a repeat unit of formula (IV): -EF1G)-R3.--OR3 oR3 (IV) wherein RG is a repeating group of the polymer; R3 is a substituent; and X and M* are as described above.

R' may be a polymeric chain or a substituent RI as described above.

The polymer may be formed by reacting a compound of formula (II) as described above with a starting polymer having a backbone repeating group substituted with a hydroxyl or carboxylic acid group. The reaction may be performed in the presence of a compound of formula (Ma) or (Mb); the ratio of polymer: non-polymer groups may be selected according to the ratio of the starting polymer to the compounds of formula (111a) and / or (Mb) and their relative reactivities.

The polymer may be formed by reacting a compound of formula (I) as described above with a starting polymer.

The starting polymer may be, for example, cellulose, optionally in a power or fibrous form. Applications A single ion conducting compound of formula (I) as described herein may be provided in a battery. The battery may be, without limitation, a metal battery or a metal ion battery, for example a lithium battery or a lithium ion battery.

The compound of formula (I) may be a component of a composite comprising one or more additional materials, for example one or more polymers. A composition comprising a compound of formula u) and a polymer may form a gel.

A layer comprising or consisting of the compound of formula (I) may be formed by depositing a formulation containing the material dissolved or dispersed in a solvent or solvent mixture followed by evaporation of the solvent or solvents.

The formulation may comprise a polymer additional material dissolved in the solvent or solvents.

Figure 1 illustrates a battery comprising an anode current collector 101 carrying an anode 103 on a surface thereof; a cathode current collector 109 having a cathode 107 disposed on a surface thereof; and a separator 105 disposed between the anode and cathode. The separator comprises or consists of a compound of formula (I).

The battery may be a metal battery. The battery may be a metal ion battery.

In the case of a metal battery, the anode is a layer of metal (e.g. lithium) which is formed over the anode current collector during charging of the battery and which is stripped during discharge of the battery.

In the case of a metal ion battery, the anode comprises an active material, e.g. graphite, for absorption of the metal ions.

The cathode may be selected from any cathode known to the skilled person.

The anode and cathode cut-rent collectors may be any suitable conductive material known to the skilled person, e.g. one or more layers of metal or metal alloy such as aluminium or copper.

Figure 1 illustrates a battery in which the anode and cathode are separated only by a separator.

In other embodiments, one or more further layers may be disposed between the anode and the separator and / or the cathode and the separator.

Figure 2 illustrates a battery, preferably a metal battery, comprising an anode current collector 101 carrying an anode 103 on a surface thereof; a cathode current collector 109 having a cathode 107 disposed on a surface thereof; a separator 105 disposed between the anode and cathode; and an anode protection layer 111 disposed between anode and the separator. The separator may comprise or consist of a compound as described herein or may be any other separator known to the skilled person, for example a porous polymer having a liquid electrolyte absorbed therein. The anode protection layer comprises or consist of a compound of formula (I) as described herein. The anode protection layer may prevent or retard formation of lithium metal dendrites of a metal battery.

Examples

Compound Example 1

Compound Example 1 was prepared according to Scheme 1.

2.15 ml of a solution of LiA1H4 in THE (1 M) was added clropwise to a stirred solution of 1.19 ml of 2,2,3,3,4,4,5,5-octalluoropentan-1 -ol (OFP) in dry THE' (2 ml). The solution bubbled during the addition. The rate of addition was controlled to prevent excess bubbling and heating.

The mixture was then stirred at room temperature for 2 hours.

The excess solvent was then removed under reduced pressure (3.0x10-2 mbar for 30 mins). During this time the mixture was stirred to disperse the bubbles formed by the evaporating solvent. The mixture slowly concentrated into a thick oil, and then into a viscous liquid, stopping the stirrer bar. The sample was left under vacuum for 5 more minutes, before the evacuated flask was sealed and transferred to the glovebox.

LiAIH4 THF

F F

HO

F FE F

Compound Example 1

Scheme 1 The NMR spectrum of the product in deuterated THF is shown in Figure 3. The spectrum shows that there are potentially two product species containing OFP units (6.2-6.8 and 4.2 ppm) and that about 10% of unreacted OFP is still present in the mixture (5.1 and 4 ppm).

From integration of NMR peaks, it was calculated that for four molecules of OFP in the products mixture there is one molecule of THF present as residual solvent, at least some of which is believed to form part of a solvate.

Electrochemical characterisation The characterisation of the ionic liquid was performed on a 2-electrode cell having a Cu foil (Advent) as the working electrode and a Li foil as the counter electrode/reference electrode, respectively. The ionic liquid was manually deposited between the two electrodes that were connected to a potentiostat (CHI). Cyclic voltammetry measurements were performed to determine the current passing in the cell as a function of applied potential difference at the electrodes. The experiment was performed in an Ar-filled glovebox (MBRAUN). The potential of the Cu electrode was scanned between -2 V and +2 V vs. Li electrode and the cyclic voltammetry plot is shown in Figure 4. Visual confirmation of Li metal deposition on Cu foil was obtained with a digital picture of the substrate (Figure 5), in which the darkened area of the image is lithium metal.

Electrochemical impedance spectroscopy (EIS) EIS measurements were conducted on 2032-type coin cell devices (casings purchased from Cambridge Energy Solutions) having a stainless steel disk (SS), a spacer, made with four layers of Kapton tapes (final thickness 260 microns) which was punched in the middle with a circular hole with a diameter of 0.6 cm. The material containing Compound Example I was spread to cover the hole. Two more stainless steel disks were placed on top of the stack. The symmetrical cell was assembled in a rigorously dry and oxygen-free Ar-filled MBraun glovebox.

EIS measurements were conducted at room temperature. The EIS measurements were taken over a frequency range of 1Hz to 1 MHz with an amplitude of 5 mV.

Conductivity was calculated using the following formula: where 1 is the thickness of the material between the two stainless disks which corresponds to the Kapton spacer thickness (260 microns), A is the area of the hole were the material was deposited (diameter 0.6 cm) and R is the impedance. The impedance of the cell was determined by calculating the difference between the second x-axis intercept and the first x-axis intercept in the Nyquist plot (Figure 6), where real impedance (7, Ohm) is plotted on the x-axis and the negative imaginary impedance (-Z". Ohm) is plotted on the y-axis, giving a conductivity of 4.5 x 10-6 S/cm.

Claims

CLAIMS1. A compound of formula (I): R1 R10 -0 R1 0 R1 (I) wherein X is M or B; 121 in each occurrence is independently a substituent; and two 121 groups may be linked to form a ring; and N4* is a cation.
2. The compound according to claim I wherein none of the R1 groups arc linked.
3. The compound according to claim 2 wherein each I21 is independently a C1,20 alkyl group wherein one or more non-adjacent C atoms of the alkyl group may be replaced with 0, S, CO or COO and one or more H atoms of the alkyl group may be replaced with F.
4. The compound according to claim 3 wherein each 121 is independently selected from alkyl and alkyl ether groups wherein one or more H atoms may be replaced with F.
5. The compound according to any one of claims 2-4 wherein each 121 is the same.
6. The compound according to any one of claims 1-4 wherein the compound contains at least 2 different RI groups.
7. The compound according to claim 1 wherein le groups of formula (I) are linked and the compound of formula (I) has formula (Ta): NA+ o /°NNR2 x R2 0 0 wherein R2 in each occurrence is independently a divalent organic group.
8. The compound according to any one of the preceding claims wherein W is an alkali metal ion.
9. The compound according to claim 8 wherein W is a lithium ion.
10. The compound according to any one of the preceding claims wherein W is a solvated cation
11. The compound according to claim 10 wherein the solvate of the solvent is selected from solvents comprising at least one ether group.
12. A method of forming a compound according to any one of the preceding claims comprising reacting a compound of formula (II) and at least one compound selected from formulae (lila) and (Illb): M+ R1-0H OH R2 ThoH (Illa) (1M)
13. The method according to claim 12 wherein the compounds of formula (Ma) are selected from monohythic alcohols and mono-carboxylic acids and wherein the compounds of formula (11ffi) are selected from diols and di-carboxylic acids.
14. The method according to claim 12 or 13 wherein the reaction is carried out in a reaction mixture comprising the solvent of the solvate according to claim 10 or 11. M+
15. A method comprising at least partially replacing the solvent of the solvate of the compound according to claim 10 or 11 with another solvent.
16. A polymer comprising a repeat unit of formula (IV): R301-0R3 oR3 (IV) wherein RG is a repeating group of the polymer; R3 is a substituent; X is Al or B; and M+ is a cation.
17. A metal battery or metal ion battery comprising an anode, a cathode and a compound according to any one of claims 1-11 or a polymer according to claim 16 disposed between the anode and the cathode.
18. A metal battery according to claim 17 comprising an anode protection layer comprising the compound or polymer disposed between the anode and cathode. M+