Batteries containing soft materials based on boron compounds

Abstract

To provide electrochemical cells with improved solid-state electrolytes, which have conductivity comparable to the conductivity of OIPC-based electrolytes but do not depend on a phase transition with attendant limitations.SOLUTION: Electrochemical cells have soft solid state electrolyte compositions, including a metal salt dispersed or doped in a soft solid matrix. The matrix includes an organic cation and a first boron cluster anion. The metal salt has a metal cation and an anion. The electrolyte compositions are soft, and functionally molded at pressure lower than those required by competing solid electrolytes, and show high ionic conductivity relative to competing electrolytes.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates generally to soft solid electrolytes and boron cluster chemistries for use in secondary batteries. [Background technology]

[0002] background Solid-state electrolytes offer many advantages in the design of secondary batteries, including mechanical stability, non-volatility, and ease of construction. Existing inorganic solid-state electrolytes that exhibit high ionic conductivity are usually hard materials that cannot maintain appreciable contact with electrode materials during battery cycling. Organic solid-state electrolytes, such as polymers, can overcome this problem due to their low hardness, but suffer from low ionic conductivity.

[0003] Such solid electrolytes with appreciable ionic conductivity are generally based on organic ionic liquid crystals (OIPCs). The high conductivity of such materials depends on a solid-solid phase transition. OIPC-based materials can have problems such as low melting points and / or low temperature ranges of the conductive phase, limiting their applicability. Summary of the Invention [Problem to be solved by the invention]

[0004] It would therefore be desirable to provide electrochemical cells with improved solid-state electrolytes that have conductivity comparable to that of OIPC-based electrolytes, but that do not rely on limiting phase transitions. [Means for solving the problem]

[0005] overview This section provides a general summary of the disclosure, but it is not an exhaustive disclosure of the entire scope or all features of the disclosure.

[0006] In one embodiment, an electrochemical cell is disclosed having a solid electrolyte composition for use in a secondary battery. The electrolyte composition has the formula G p The electrolyte composition includes a soft solid matrix of A, where G is an organic cation from a set of possible cations, p is 1 or 2, and A is a boron cluster anion. The electrolyte composition further includes a metal salt having a metal cation and an anion. The anion of the metal salt can optionally be the same or different boron cluster anion as A, the boron cluster anion of the soft solid matrix. The electrolyte composition is generally in a solid state at the steady state operating temperature of the electrochemical cell.

[0007] In some implementations, the boron cluster anion, A, of the soft solid matrix has the anionic formula [B y H (y-z-i) R z X i ] 2- , [CB( y-1 )H (y-z-i) R z X i ] - , [C 2 B (y-2) H (y-t-j-1) R t X j ] - , [C 2 B (y-3) H (y-t-j) R t X j ] - , or [C 2 B (y-3) H (y-t-j-1) R t X j ] 2-In various implementations, y can be an integer ranging from 6 to 12, (z+i) can be an integer ranging from 0 to y, (t+j) can be an integer ranging from 0 to (y-1), and X can be F, Cl, Br, I, or a combination thereof. R can be an organic substituent, hydrogen, or a combination thereof. In various implementations, the boron cluster anion of the metal salt, if present, can be independently defined by any of the formulas set forth above.

[0008] In a further aspect, an electrochemical cell is disclosed having a solid electrolyte composition for use in a secondary battery. The electrolyte composition has the formula G p The electrolyte composition comprises a soft solid matrix of A, where G is an organic cation from a set of possible cations, p is 1 or 2, and A is a boron cluster anion as defined above. The electrolyte composition further comprises a metal salt having a metal cation and an anion. The anion of the metal salt may optionally be a boron cluster anion that is the same or different from A, the boron cluster anion of the soft solid matrix. The electrolyte composition generally has a hardness (elastic modulus) of less than about 10 gigapascals.

[0009] These and other features of the method for forming a soft solid electrolyte and an electrochemical cell having the same will become apparent from a reading of the following detailed description and the drawings and examples, which are intended to be illustrative and non-exclusive.

[0010] Various aspects and advantages of the present invention will become apparent and may be more readily understood from the following description of the embodiments and the accompanying drawings. [Brief description of the drawings]

[0011] [Figure 1A] FIG. 1 is a schematic perspective view of a representative boron cluster anion, closo-[B12H12]2-, according to the present disclosure. [Figure 1B]FIG. 1 is a schematic perspective view of the boron cluster anion closo-[CB11H12]- according to the present disclosure. [Figure 1C] FIG. 1 is a schematic perspective view of the boron cluster anion closo-[C2B10H11]- according to the present disclosure. [Figure 2A] 1 is a plot of differential scanning calorimetry (DSC) data for a soft solid matrix (solid matrix) of N-methyl-N-butylpyrrolidinium closo-[CB11H12]-, an electrolyte according to the teachings of the present invention. [Figure 2B] 1 is a plot of differential scanning calorimetry (DSC) data for triethylhexylphosphonium closo-[CB11H12]- doped with LiCB11H12, a solid matrix according to the teachings of the present invention. [Diagram 3] 1 is a plot of the ionic conductivity of several solid matrices, each having the closo-[CB11H12]- anion, in accordance with the teachings of the present invention. [Figure 4] 1 is a plot showing the conductivity of a solid matrix according to the present teachings as a function of temperature when subjected to two different pressures. [Diagram 5] FIG. 1 shows a plot of ionic conductivity in N-methyl-N-butylpyrrolidinium CB11H12 doped with LiCB11H12, with the inset being a photographic image of the soft electrolyte. [Figure 6] 1 is a plot of ionic conductivity for various soft electrolytes having a 1:1 molar ratio of LiCB9H10:LiCB11H12 to N-methyl-N-butylpyrrolidinium CB9H10 or N-methyl-N-butylpyrrolidinium CB11H12 in accordance with the teachings of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Detailed Description The teachings of the present invention provide electrochemical cells having soft electrolyte compositions similar to organic ionic liquid crystals (OIPCs), which are typically solid at battery operating temperatures, but have unusually high ionic conductivity due to their high-entropy, plastic-like molecular structure.

[0013] An electrochemical cell according to the teachings of the present invention includes a novel soft electrolyte composition. The electrolyte composition has a metal boron cluster salt and a soft solid matrix doped with the salt. The solid matrix includes boron cluster anions and organic cations with flexible and / or asymmetric substituents. The resulting electrolyte forms a soft solid with a plastic-like or glass-like, high-entropy molecular structure that results in high ionic mobility and conductivity.

[0014] Thus, a soft solid electrolyte composition (hereinafter simply referred to as the "electrolyte composition") for use in a secondary battery is disclosed. The electrolyte composition has the formula G p The solid matrix includes a solid matrix having a structure A, where G is an organic cation, A is a boron cluster anion, and p is either 1 or 2. In some implementations, the organic cation may include at least one of an ammonium and a phosphonium cation, such as examples shown below as Structures 1-4.

[0015] [ka]

[0016] wherein R, and, when R', R'', and R''', are present, R', R'', and R''', are each independently a substituent belonging to the group (i) which is a linear, branched, or cyclic C1-C8 alkyl or fluoroalkyl group, the group (ii) which is a C6-C9 aryl or fluoroaryl group, the group (iii) which is a linear, branched, or cyclic C1-C8 alkoxy or fluoroalkoxy group, the group (iv) which is a C6-C9 aryloxy or fluoroaryloxy group, the group (v) which is an amino, and the group (vi) which is a substituent containing two or more moieties as defined by any two or more of the groups (i)-(v). The substituents R, R', and, when R'' and R'''', are present, R'' and R'''', may hereinafter alternatively be referred to as "multiple organic substituents". In general, organic cations may have some degree of asymmetry with respect to the size and distribution of the substituents. Thus, at least one of R, R', R'', and R''' may be different from the others, and the cation preferably may not contain two pairs of substituents.

[0017] In certain specific implementations, the organic cation is selected from the group consisting of N-methyl-N-propylpyrrolidinium (hereinafter referred to as "Pyr13"); N-methyl-N,N-diethyl-N-propylammonium (N1223); N,N-diethyl-N-methyl-N-(2-methoxyethyl)-ammonium (DEME); N-methyl-N-propylpiperidinium (hereinafter referred to as "Pip13"); N-methyl-N-(2-methoxyethyl)-pyrrolidinium (Pyr12 O 1); Trimethylisopropylphosphonium (P111 i4); methyltriethylphosphonium (P1222); methyltributylphosphonium (P1444); N-methyl-N-ethylpyrrolidinium (Pyr12); N-methyl-N-butylpyrrolidinium (Pyr14); N,N,N-triethyl-N-hexylammonium (N2226); triethylhexylphosphonium (P2226); and N-ethyl-N,N-dimethyl-N-butylammonium (N4211). It is understood that in some implementations, G may include more than one of the cations described above. It is understood that when p is 2, the two organic cations contained in the stoichiometric unit solid matrix may be the same cation or two different cations.

[0018] The phrase "boron cluster anion" as used herein generally refers to any of the following anionic forms: boranes having 6-12 boron atoms with a net charge of -2; carboranes having 1 carbon atom and 5-11 boron atoms in the cluster structure with a net charge of -1; and carboranes having 2 carbon atoms and 4-10 boron atoms in the cluster structure with a net charge of -1 or -2. In some variations, the boron cluster anion may be unsubstituted, and may contain only hydrogen atoms in addition to those described above. In some variations, the boron cluster anion may be substituted, with one or more hydrogen atoms replaced with one or more halogens, or one or more hydrogen atoms replaced with one or more organic substituents, or combinations thereof.

[0019] In some implementations, the boron cluster anion can be an anion having any of the following formulas:

[0020] [ka]

[0021] In the formula, y is an integer ranging from 6 to 12, (z+i) is an integer ranging from 0 to y, (t+j) is an integer ranging from 0 to (y-1), and X is F, Cl, Br, I, or a combination thereof. The substituent R in the anionic formulas I to V may be any organic substituent or hydrogen.

[0022] It is understood that X may be F, Cl, Br, I, or a combination thereof, which indicates that multiple halogen substituents are present when i is an integer ranging from 2 to y, or when j is an integer ranging from 2 to (y-1). In such a situation, the multiple halogen substituents may include F, Cl, Br, I, or any combination thereof. For example, for a boron cluster anion having three halogen substituents (i.e., when i or j is 3), the three halogen substituents may be three fluorine substituents, one chlorine substituent, one bromine substituent, one iodine substituent, or any other combination.

[0023] In many implementations, the boron cluster anion may include any substituted or unsubstituted closo-boron cluster anion. In some implementations, the boron cluster anion is closo-[B 6 H 6 ] 2- , closo-[B 12 H 12 ] 2- , closo-[CB 11 H 12 ] - , or closo-[C 2 B 10 H 11 ] - The anion may be a closo-boron cluster anion, such as:

[0024] 1A-1C show structures of exemplary unsubstituted boron cluster anions according to anionic formulas I-V, respectively. 12 H 12 ]2- , closo-[CB 11 H 12 ] - , closo-[C 2 B 10 H 11 ] - and the anion formula III is an exemplary closo-[C 2 B 10 H 11 ] - The anions are shown as 1,2-dicarba species, however, it will be understood that such closo-icosahedral dicarba species may alternatively be 1,7- or 1,12-dicarba. More generally, it will be understood that the required carbon atoms of anionic formulas III, IV, and V may occupy any available position in the boron cluster framework. It will also be understood that non-hydrogen substituents, if present on the boron cluster anion, may be attached, where possible, to any position in the boron cluster framework, including vertices occupied by either boron or carbon.

[0025] In some implementations, the electrolyte composition does not exhibit a phase transition below 80° C. and standard pressure as determined by DSC.

[0026] The electrolyte composition further comprises a metal salt having a metal cation and an anion. The anion associated with and / or derived from the metal salt may hereinafter be referred to as the "metal salt anion." The metal salt may generally be selected based on the electrochemistry of the battery in which the electrolyte composition is to be used. In a different variation, the metal cation is Li + , Na + , Mg 2+ , Ca 2+ , or any other electrochemically suitable cation.

[0027] In some implementations, the metal salt anion can be any of the types of boron cluster anions described above. In some such implementations of the electrolyte, the boron cluster anion of the metal salt can be the same as the boron cluster anion of the soft solid electrolyte, and in some implementations, the two boron cluster anions can be different. In other variations, the metal salt anion can be any of the boron cluster anions such as TFSI, BF 4 , P.F. 6 The anion may be any anion suitable for use in battery chemistries, such as FSI or FSI.

[0028] The solid matrix may generally be doped with a metal salt to form the electrolyte composition. Doping may be performed by intimate contact of the matrix salt with the doping salt. One method to accomplish this is to dissolve the dopant salt in a molten organic salt matrix (melt infusion). Another method is to dissolve all the elements in a solvent, mix, and remove the solvent to obtain a solid material. It is noted that hand grinding or ball milling may be used to condition the material before or after melt infusion.

[0029] In some implementations, the electrolyte composition may include a metal salt present in a molar ratio to the solid matrix ranging from about 1:100 to about 100: 1. More preferably, in some implementations, the electrolyte composition may include a metal salt present in a molar ratio to the solid matrix ranging from about 5:100 to about 1:1.

[0030] In some implementations, the electrolyte composition has a solid-state ionic conductivity of 10 -10 S / cm. Moreover, it may be noted that the soft solid electrolytes according to the teachings of the present invention are substantially softer than most of the current state-of-the-art solid electrolytes. For example, the elastic modulus of a typical sulfide solid electrolyte is about 26 gigapascals (GPa). On the other hand, Pyr14:CB 9 H 10and a 1:1 molar ratio of LiCB 9 H 10 :LiCB 11 H 12 The elastic modulus (an index of hardness) of a soft solid electrolyte containing 80% metal salt of Pyr14:CB is low at 0.214 GPa. 11 H 12 The solid matrix is ​​LiCB 11 H 12 The soft solid-state electrolyte with 45% metal salt also has a low elastic modulus of 2.36 GPa. Thus, in some implementations, the soft solid-state electrolyte according to the present teachings may have an elastic modulus of less than about 10 GPa, or less than about 1 GPa, or less than about 0.5 GPa.

[0031] 2A and 2B show a Pyr14:CB soft solid matrix (solid matrix) according to the teachings of the present invention. 11 H 12 and P2226:CB 11 H 12 1A and 1B are plots of differential scanning calorimetry (DSC) data for (a) and (b) of (b). Note the absence of phase transitions below 100° C. and 95° C., respectively.

[0032] FIG. 3 is a schematic diagram of a closo-[CB 11 H 12 ] - The results in Figure 3, together with those in Figures 2A and 2B, establish that such materials have appreciable ionic conductivity below 95°C, even though they have no phase transition below that temperature.

[0033] Figure 4 shows the results of LiCB under two different pressures at different temperatures. 11 H 12 N2224:CB doped with 11 H 121 is a plot showing the conductivity of 0.1 to 0.25% of the electrolyte composition. It is noted that the disclosed electrolyte compositions are soft solids, and that their "softness" is quantified based on the amount of pressure required to obtain maximum ionic conductivity (i.e., it is generally believed that harder materials require higher pressures to achieve maximum conductivity). By now it will be appreciated that solid electrolytes are typically formed into a desired shape by compressing granules or powders of the solid electrolyte, such as with a dye press. It is believed that harder materials require higher pressures to achieve proper compression and grain contact, while softer materials are properly compressed at lower pressures.

[0034] The results in FIG. 4 show that the cell with electrolyte pressurized at 1 ton pressure shows stable data at all temperatures for two cycles. When 3 ton pressure is applied, the conductivity in the second cycle is slightly less than that in the first cycle. These results show that a low pressure of 1 ton is sufficient to obtain good grain-to-grain contact for optimal conductivity and demonstrate the flexibility of the disclosed electrolyte composition. For comparison, 1 ton pressure is about 1 / 4 of the pressure required to obtain good contact for state-of-the-art Li-sulfide solid electrolytes.

[0035] Figure 5 shows the LiCB 11 H 12 Pyr14:CB doped with 11 H 125 plots ionic conductivity at 125° C. for 15 minutes, with the inset being a photographic image of the soft electrolyte. The electrolyte composition of FIG. 5 is prepared by mixing the elements at 125° C. for 15 minutes, followed by cooling to room temperature to obtain a solid material. The solid material is then hand-ground using a mortar and pestle. The solid powder obtained by this procedure is pressed at 3 tons in a die press into a circular pellet (shown in the inset of FIG. 5). The results show that very high ionic conductivity can be obtained using the electrolyte composition according to the teachings of the present invention without the need for a phase transition. In addition to the high Li conductivity, the absence of grain boundaries is shown as evidenced by the transparency of the sample. A very high lithium ion transport number of 0.86 was also measured for this material (data not shown), which is significantly higher than the lithium ion transport numbers of all known soft materials, such as polymers and all other OIPC type materials (<0.5).

[0036] FIG. 6 shows LiCB as the Li salt in accordance with the teachings of the present invention. 9 H 10 :LiCB 11 H 12 and Pyr14:CB 9 H 10 or Pyr14:CB 11 H 12 6 plots the ionic conductivity of various soft electrolytes with a 1:1 molar ratio of 0.1% to 0.1%. The composition of FIG. 6 is prepared by mixing the elements by hand grinding, followed by mixing in the molten state for 24 hours, followed by cooling to room temperature to obtain a solid material. This solid material is hand ground with a mortar and pestle to obtain a solid powder. Pressed at 3 tons in a die press to form the electrolyte. It may be noted that the conductivity of the resulting material is high compared to the state-of-the-art solid electrolyte, lithium phosphide sulfide (LPS). It may also be noted that a pressure of at least 4 tons is required for the LPS grains to achieve useful conductivity, further demonstrating the flexibility of the electrolyte composition according to the teachings of the present invention.

[0037] Further provided herein is an electrochemical cell comprising the electrolyte composition described above. The electrochemical cell may generally be a secondary battery in which a reduction / oxidation reaction occurs with an active material such as lithium, sodium, calcium, magnesium, dual ion systems, or any other suitable electrochemical system of a secondary battery.

[0038] An electrochemical cell according to the teachings of the present invention may generally have an anode, a cathode, and an electrolyte disposed such that the anode and cathode are in ionic communication with each other. The electrolyte may be a solid electrolyte composition as described above. As used herein, the term "anode" is understood to refer to the electrode at which oxidation of magnesium occurs during cell discharge and reduction of magnesium occurs during cell charge. Similarly, the term "cathode" is understood to refer to the electrode at which reduction of the cathode material occurs during cell discharge and oxidation of the cathode material occurs during cell charge in such implementations.

[0039] It is understood that an electrochemical cell according to the teachings of the present invention generates heat during operation and may generally have a steady-state operating temperature or temperature range (referred to herein as "battery operating temperature"). This refers to the temperature of the electrochemical cell, particularly the electrolyte, when the battery has been operated for a sufficient time under normal operating conditions to reach the steady-state temperature. The electrochemical cell may also have a maximum operating temperature, i.e., the maximum temperature (particularly the electrolyte temperature) at which the electrochemical cell is designed to operate. In many implementations, the soft solid-state electrolyte of the electrochemical cell may have a melting point high enough to remain solid at battery operating temperatures, including the maximum operating temperature. This differs from many state-of-the-art electrolytes, which may be solid at room temperature, but are designed to melt at battery operating temperatures because they achieve suitable conductivity only in the molten state. As discussed above, it can be understood that the soft solid-state electrolyte according to the teachings of the present invention has a very high solid-state ionic conductivity, allowing the electrolyte to remain solid and the electrochemical cell to operate.

[0040] The electrochemical cell may further include at least one external conductor configured to allow electrical communication between the anode and the cathode.

[0041] The anode may include any material or combination of materials effective to participate in the electrochemical oxidation of an active material (e.g., lithium) during cell discharge. This may alternatively be described as the anode being configured to incorporate and / or release active material. Similarly, the anode may include any material or combination of materials effective to participate in the electrochemical reduction of active cations during cell charging and incorporate reduced active material. In some implementations, the anode may consist essentially of elemental active material (e.g., lithium metal) or may include at least one surface layer of elemental active material. In other implementations, the anode may include alloy-type anodes, such as tin or silicon, bismuth-type anodes, intercalation-type materials that contain active material in a composite or alloy with other materials to the extent that the cell can be charged.

[0042] The cathode may comprise any material or combination of materials effective to participate in the electrochemical insertion of metal cations during cell discharge. Similarly, the cathode may comprise any material or combination of materials effective to participate in the electrochemical extraction of active material during cell charge. Suitable, non-exclusive examples of such materials include LiCoO 2 , low cobalt oxide cathode, FeSiO 4 , LiFePO 4 , a conversion cathode such as a Li-rich cathode, a spinel oxide cathode, sulfur, an organosulfur compound, air, oxygen, or any other suitable material.

[0043] In one simple implementation, the external conductor may be a single conductor, such as a wire, with one end connected to the anode and the other end connected to the cathode, hi other implementations, the external conductor may include multiple conductors that provide electrical communication between the anode and cathode and other electrical devices configured to supply power to the electrochemical cell during charging and / or arranged to receive power from the electrochemical cell.

[0044] The above description is merely exemplary in nature and is not intended to limit the disclosure or the application or use of the disclosure. As used herein, the expression "at least one (1) of A, B, and C" should be interpreted as meaning "A or B or C" logic using non-exclusive logic "or". It is understood that the principle of the disclosure is not altered even if various steps included in a method are performed in different orders. The disclosure of a range includes the disclosure of each individual range and each subrange included in the entire range.

[0045] The headings (e.g., "Background" and "Summary") and subheadings used herein are intended only to provide a general organization of topics covered within the scope of the disclosure and are not intended to limit the disclosure of the technology or any aspect thereof. The description of embodiments having described features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the described features.

[0046] As used herein, the terms "comprising" and "including" and variations thereof are intended to be non-limiting, and a sequential listing or enumeration of items does not exclude other similar items that may be useful in the devices and methods of the present technology. Similarly, the terms "may" and "may" and variations thereof are intended to be non-limiting, and a description that an embodiment may or may include a particular element or feature does not exclude other embodiments of the present technology that do not include such element or feature.

[0047] The broad teachings of the present disclosure can be implemented in a variety of forms. Thus, while the present disclosure includes specific examples, the true scope of the present disclosure should not be limited to the specific examples contained in the present disclosure, since other modifications will become apparent to those skilled in the art upon studying the specification and the following claims. Reference to an aspect or various aspects herein means that a specific feature, structure, or characteristic described in connection with an embodiment or a specific system is included in at least one embodiment or aspect. When the phrase "in one aspect" (or variations thereof) is used, it does not necessarily refer to the same aspect or embodiment. It should also be understood that the various method steps described herein do not necessarily have to be performed in the same order as described, and that each method step is not required for each aspect or embodiment.

[0048] The above description of the embodiments is provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a specific embodiment are generally not limited to that specific embodiment, and where appropriate, may be interchangeable and used in selected embodiments without specific indication or description. Also, individual elements or features of a specific embodiment may be modified in various ways. Such modifications should not be considered as a departure from the scope of the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. 1. An electrochemical cell comprising: An anode; A cathode; an electrolyte composition disposed in ionic communication with the anode and the cathode; The electrolyte composition has the formula G ｐ A soft solid matrix (solid matrix) of During the ceremony, G comprises at least one organic cation selected from the group consisting of ammonium cations and phosphonium cations represented by the following structures 1 to 4: 【Chemistry 1】 wherein R, R', R'', and R''' are each independently (i) a linear, branched, or cyclic C1-C8 alkyl group; (iii) a straight-chain, branched-chain, or cyclic C1-C8 alkoxy group, and (vi) selected from the group consisting of a combination of two or more of (i) and (iii); p is 1 or 2; A is a boron cluster anion including at least one of closo-[B 6 H 6 ] 2− , closo-[B 12 H 12 ] 2− , closo-[CB 11 H 12 ] − , and closo-[C 2 B 10 H 11 ] − ; The electrolyte composition further comprises a metal salt having a metal cation and a metal salt anion; An electrochemical cell, wherein the electrolyte composition is in a solid state at a steady-state operating temperature of the electrochemical cell.

2. The metal salt anion may be represented by the formula [B ｙ H （ｙ－ｚ－ｉ） R ｚ X ｉ ] ２－ , [CB( ｙ－１ ) H （ｙ－ｚ－ｉ） R ｚ X ｉ ] － [C ２ B （ｙ－２） H （ｙ－ｔ－ｊ－１） R ｔ X ｊ ] － [C ２ B （ｙ－３） H （ｙ－ｔ－ｊ） R ｔ X ｊ ] － , and [C ２ B （ｙ－３） H （ｙ－ｔ－ｊ－１） R ｔ X ｊ ] ２－ [0033] wherein the boron cluster anion has one of the following structures: During the ceremony, y is an integer ranging from 6 to 12; (z+i) is an integer ranging from 0 to y; (t+j) is an integer ranging from 0 to (y-1); X is F, Cl, Br, I, or a combination thereof; 2. The electrochemical cell of claim 1, wherein R comprises any of a linear, branched, or cyclic C1-C18 alkyl or fluoroalkyl group, alkoxy or fluoroalkoxy, and combinations thereof.

3. 3. The electrochemical cell of claim 2 wherein the metal salt anion is a closo-boron cluster anion.

4. 3. The electrochemical cell of claim 2, wherein the boron cluster anion of the soft solid matrix, A, and the boron cluster anion of the metal salt comprise different anions.

5. 3. The electrochemical cell of claim 2, wherein the boron cluster anion of the soft solid matrix, A, and the boron cluster anion of the metal salt comprise the same anion.

6. The metal salt anion is closo-[B ６ H ６ ] ２－ , closo-[B １２ H １２ ] ２－ , closo-[CB １１ H １２ ] － , or closo-[C ２ B １０ H １１ ] － 3. The electrochemical cell of claim 2 comprising at least one of:

7. The metal salt anion is (fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), PF ６ , and B.F. ４ 10. The electrochemical cell of claim 1 comprising at least one of the anions.

8. 1. An electrochemical cell comprising: An anode; A cathode; an electrolyte composition disposed in ionic communication with the anode and the cathode; The electrolyte composition has the formula G ｐ A soft solid matrix (solid matrix) of During the ceremony, G comprises at least one organic cation selected from the group consisting of ammonium cations and phosphonium cations represented by the following structures 1 to 4: 【Chemistry 2】 wherein R, R', R'', and R''' are each independently (i) a linear, branched, or cyclic C1-C8 alkyl group; (iii) a straight-chain, branched-chain, or cyclic C1-C8 alkoxy group, and (vi) selected from the group consisting of a combination of two or more of (i) and (iii); p is 1 or 2; A is a boron-containing cluster anion, which is at least one of closo-[B 6 H 6 ] 2− , closo-[B 12 H 12 ] 2− , closo-[CB 11 H 12 ] − , and closo-[C 2 B 10 H 11 ] − ; The electrolyte composition further comprises a metal salt having a metal cation and a metal salt anion; The electrochemical cell, wherein the electrolyte composition has an elastic modulus of less than 10 gigapascals (GPa).

9. 9. The electrochemical cell of claim 8, wherein the electrolyte composition has an elastic modulus of less than 1 GPa.

10. 9. The electrochemical cell of claim 8, wherein the electrolyte composition has an elastic modulus of less than 0.5 GPa.

11. The metal cation is Li ＋ , Na ＋ , Mg ２＋ , Ca ２＋ 9. The electrochemical cell of claim 8, wherein the electrochemical cell is selected from the group consisting of:

12. The metal salt is Li(CB １１ H １２ 9. The electrochemical cell of claim 8 comprising:

13. 9. The electrochemical cell of claim 8 wherein G comprises an ammonium cation.

14. 9. The electrochemical cell of claim 8 wherein G comprises a phosphonium cation.

15. 9. The electrochemical cell of claim 8, wherein G comprises a pyrrolidinium or piperidinium cation.

16. 9. The electrochemical cell of claim 8, wherein G comprises an N,N-diethyl-N-methyl-N-(2-methoxyethyl)-ammonium cation.

17. 9. The electrochemical cell of claim 8, wherein the metal salt is present in a molar ratio to the solid matrix in the range of 1:100 to 100:1 inclusive.

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