Electrolyte for Lithium Ion Batteries

Abstract

The disclosure relates to an electrolyte for an energy store comprising a conducting salt and a solvent. The solvent comprises at least one compound according to the general formula (1), as indicated in the following: wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are, identically or independently of each other, selected from the group comprising linear or branched C.sub.1-6-alkyl, C.sub.2-6-alkenyl C.sub.3-6-cycloalkyl and/or phenyl, each unsubstituted or mono- or polysubstituted by a substituent selected from the group comprising F, CN and/or C.sub.1-2-alkyl, mono- or polysubstituted with fluorine.

Claims

1. An electrolyte for an energy store, comprising an electrolyte salt and a solvent, wherein the solvent comprises at least one compound of the general formula (1) as indicated below: ##STR00004## where: R.sup.1, R.sup.2, R.sup.3, R.sup.4 are identical or different and selected independently from the group comprising linear or branched C.sub.1-6-alkyl, C.sub.2-6-alkenyl, C.sub.2-6-alkynyl, C.sub.3-6-cycloalkyl and phenyl, in each case unsubstituted or singly or multiply substituted by a substituent selected from the group comprising F, CN and C.sub.1-2-alkyl singly or multiply substituted with fluorine.

2. The electrolyte as claimed in claim 1, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are identical or different and selected independently from the group comprising unsubstituted C.sub.1-C.sub.5-alkyl or phenyl and C.sub.1-C.sub.5-alkyl or phenyl singly or multiply substituted by fluorine, CN or CF.sub.3.

3. The electrolyte as claimed in claim 1, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are identical or different and selected independently from the group comprising methyl, ethyl, n-propyl and isopropyl.

4. The electrolyte as claimed in claim 1, wherein the compound of the general formula (1) is selected from the group comprising 1,1,2,2-tetramethoxyethane and 1,1,2,2-tetraethoxyethane.

5. The electrolyte as claimed in claim 1, wherein the solvent comprises the compound of the formula (1) in an amount of from ≥0.1% by weight to ≤100% by weight, preferably in an amount of from ≥10% by weight to ≤80% by weight, more preferably in an amount of from ≥20% by weight to ≤50% by weight, particularly preferably in an amount of from ≥30% by weight to ≤50% by weight, based on the total weight of the electrolyte solvent.

6. The electrolyte as claimed in claim 1, wherein the electrolyte comprises an organic solvent selected from the group comprising ethylene carbonate, ethyl methyl carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, acetonitrile, propionitrile, 3-methoxypropionitrile, glutaronitrile, adiponitrile, pimelonitrile, gamma-butyrolactone, gamma-valerolactone, dimethoxyethane, 1,3-dioxolan, methyl acetate, ethyl acetate, ethyl methanesulfonate, dimethyl methylphosphonate, linear or cyclic sulfone, symmetrical or unsymmetrical alkyl phosphates and mixtures thereof.

7. The electrolyte as claimed in claim 6, wherein the solvent is selected from the group comprising propylene carbonate, ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate and mixtures thereof.

8. An energy store, in particular electrochemical energy store selected from the group comprising lithium battery, lithium ion battery, rechargeable lithium ion battery, lithium polymer battery, lithium ion capacitor or supercapacitor, comprising an electrolyte as claimed in claim 1.

9. A method for forming a solid electrolyte interphase on an electrode of an electrochemical cell comprising an anode, a cathode and an electrolyte, wherein the cell is operated using an electrolyte as claimed in claim 1.

10. The use of a compound of the general formula (1) as indicated below: ##STR00005## where: R.sup.1, R.sup.2, R.sup.3, R.sup.4 are identical or different and are selected independently from the group comprising linear or branched C.sub.1-6-alkyl, C.sub.1-6-alkenyl, C.sub.1-6-alkynyl, C.sub.3-6-cycloalkyl and phenyl, in each case unsubstituted or singly or multiply substituted by a substituent selected from the group comprising F, CN and C.sub.1-2-alkyl singly or multiply substituted by fluorine, in an energy store, in particular an electrochemical energy store selected from the group comprising lithium battery, lithium ion battery, rechargeable lithium ion battery, lithium polymer battery, lithium ion capacitor and a supercapacitor.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0039] Examples and figures which serve to illustrate the present disclosure are presented below.

[0040] Here, the figures show:

[0041] FIG. 1 the reductive stability window of an electrolyte containing 1 M LiTFSI in a mixture of 1,1,2,2-tetramethoxyethane (TME) and propylene carbonate (PC) in FIG. 1a) and the reductive stability window of an electrolyte containing 1 M LiTFSI in a mixture of 1,1,2,2-tetraethoxyethane (TEE) and propylene carbonate in FIG. 1b). In each case, the current is plotted against the potential.

[0042] FIG. 2 the oxidative stability window in Pt/Li half cells of electrolytes each containing 1 M LiTFSI in mixtures of 1,1,2,2-tetraethoxyethane or 1,1,2,2-tetramethoxyethane and propylene carbonate and of 1 M LiFSI in a mixture of PC and 1,1,2,2-tetramethoxyethane. The current density is plotted against the potential.

[0043] FIG. 3 the oxidative stability window in an LiMn.sub.2O.sub.4/Li half cell for an electrolyte containing 1 M LiFSI in a mixture of propylene carbonate and 1,1,2,2-tetraethoxyethane.

[0044] FIG. 4 the charging and discharging capacity (left-hand ordinate axis) and Coulombic efficiency (right-hand ordinate axis) versus the number of charging/discharging cycles for an electrolyte containing 1 M LiTFSI in a 1:1 mixture of propylene carbonate and 1,1,2,2-tetraethoxyethane for a graphite/Li cell.

[0045] FIG. 5 the charging and discharging capacity and Coulombic efficiency versus the number of charging/discharging cycles for an electrolyte containing 1 M LiTFSI in a 1:1 mixture of propylene carbonate and 1,1,2,2-tetraethoxyethane in an LFP/graphite full cell.

[0046] FIG. 6 the charging and discharging capacity and Coulombic efficiency versus the number of charging/discharging cycles for an electrolyte containing 1 M LiFSI in a 1:1 mixture of propylene carbonate and 1,1,2,2-tetraethoxyethane in an NMC/graphite full cell.

[0047] FIG. 7 in FIG. 7a), the course of the cell voltage versus the capacity of the first cycle for an electrolyte containing 1 M LiTFSI in a 1:1 mixture of propylene carbonate and 1,1,2,2-tetraethoxyethane. FIG. 7b) shows a scanning electron micrograph of the cross section of secondary graphite particles of the surface after one cycle in this electrolyte.

[0048] FIG. 8 in FIG. 8a), the course of the cell voltage versus the time of the first cycle for an electrolyte containing 1 M LiPF.sub.6 in propylene carbonate containing 2% by weight of FEC. FIG. 8b) shows a scanning electron micrograph of the graphite surface after one cycle in the electrolyte.

DETAILED DESCRIPTION

Example 1

Determination of the Conductivity of 1,1,2,2-Tetraethoxyethane in Various Electrolytes

[0049] The conductivity of a 1 M solution of LiTFSI (lithium bis(trifluoromethanesulfonyl)imide (LiN(SO.sub.2CF.sub.3).sub.2) was determined in 1,1,2,2-tetraethoxyethane and in mixtures of 1,1,2,2-tetraethoxyethane (TEE), propylene carbonate (PC) and dimethyl carbonate (DMC).

[0050] To produce the electrolytes, 1,1,2,2-tetraethoxyethane, a mixture of 50% by weight of 1,1,2,2-tetraethoxyethane and 50% by weight of propylene carbonate or a mixture of 1,1,2,2-tetraethoxyethane, propylene carbonate and dimethyl carbonate in a weight ratio of 1:1:1 were initially charged. The respective required amount of LiTFSI or LiFSI (LiN(SO.sub.2F).sub.2) was dissolved in these so that a concentration of 1 M of the lithium salt was obtained. In the same way, comparative electrolytes containing 1 M LiTFSI or LiPF.sub.6 in propylene carbonate were produced.

[0051] The conductivity of the electrolytes was examined in a temperature range from −35° C. to +60° C. using a 2-electrode conductivity measurement cell (RHD Instruments, GC/Pt). For this purpose, the conductivity measurement cells were firstly heated to 60° C. and cooled in temperature steps of 10° C. to −30° C. and subsequently to −35° C. Table 1 below shows the conductivity in the temperature range from −35° C. to +60° C. in the corresponding solvent mixtures.

TABLE-US-00001 TABLE 1 Conductivity of 1M LiTFSI and LiFSI in various mixtures containing 1,1,2,2-tetraethoxyethane (TEE) LiTFSI in LiTFSI in LiFSI in LiTFSI in TEE:PC TEE:PC:DMC TEE:PC T TEE (1:1 w/w) (1:1:1 w/w) (1:1 w/w) [° C.] [σ/mS cm.sup.−1] [σ/mS cm.sup.−1] [σ/mS cm.sup.−1] [σ/mS cm.sup.−1] −35 0.3 0.3 0.8 0.3 −30 0.4 0.5 1.0 0.5 −20 0.7 0.8 1.6 0.9 −10 1.0 1.3 2.3 1.5 0 1.4 1.9 3.2 2.2 10 1.8 2.6 4.1 3.1 20 2.2 3.4 5.1 4.1 30 2.7 4.2 6.1 5.2 40 3.2 5.2 7.1 6.5 50 3.7 6.2 8.2 7.7 60 4.2 7.2 9.3 9.0

[0052] As can be seen from table 1, 1 M LiTFSI in 1,1,2,2-tetraethoxyethane (TEE) as sole solvent displays a conductivity at 20° C. of 2.2 mS cm.sup.−1, which is below the comparative value of 4.1 mS cm.sup.−1 in propylene carbonate. An addition of propylene carbonate led to a significant increase in the conductivity, while a mixture of TEE, PC and DMC displayed a conductivity which even slightly exceeded that of the comparative system 1 M LiPF.sub.6 in PC of 5.0 mS cm.sup.−1.

Example 2

Determination of the Conductivity of 1,1,2,2-Tetramethoxyethane in Various Electrolytes

[0053] The conductivity of electrolytes containing 1,1,2,2-tetramethoxyethane (TME) was examined in a temperature range from −35° C. to +60° C. as described in example 1 using a 2-electrode conductivity measurement cell (RHD Instruments, GC/Pt).

[0054] The conductivity of a 1 M solution of LiTFSI in 1,1,2,2-tetramethoxyethane (TME) and in mixtures of in each case 50% by weight of TME and PC and also mixtures of TME, PC and DMC in a weight ratio of 1:1:1 and 1:2:2 was determined. Table 2 below shows the conductivity in the temperature range from −35° C. to +60° C. in the corresponding solvents.

TABLE-US-00002 TABLE 2 Conductivity of 1M LiTFSI in various mixtures containing 1,1,2,2-tetramethoxyethane (TME) LiTFSI in LiTFSI in LiTFSI in LiTFSI in TME:PC TME:PC:DMC TME:PC:DMC T TME (1:1 w/w) (1:1:1 w/w) (1:2:2 w/w) [° C.] [σ/mS cm.sup.−1] [σ/mS cm.sup.−1] [σ/mS cm.sup.−1] [σ/mS cm.sup.−1] −35 0.2 0.4 0.8 1.0 −30 0.3 0.6 1.1 1.5 −20 0.5 1.1 1.7 2.3 −10 0.8 1.7 2.6 3.2 0 1.1 2.4 3.6 4.3 10 1.4 3.3 4.6 5.5 20 1.8 4.4 5.8 6.8 30 2.3 5.5 6.9 8.1 40 2.8 6.7 8.2 9.4 50 3.3 8.0 9.5 10.7 60 3.8 9.4 10.9 12.0

[0055] As can be seen from table 2, 1 M LiTFSI in 1,1,2,2-tetramethoxyethane (TME) as sole solvent displays a conductivity at 20° C. of 1.8 mS cm.sup.−1, which is somewhat lower than the conductivity of 1,1,2,2-tetraethoxyethane. An addition of propylene carbonate and DMC led to a significant increase in the conductivity.

Example 3

Determination of the Reductive Electrochemical Stability and Cyclability of 1,1,2,2-Tetramethoxyethane and 1,1,2,2-Tetraethoxyethane Using a Graphite Electrode

[0056] The determination of the stability of the electrolytes in half cells was carried out by means of cyclic voltammetry. In this method, the electrode voltage is continuously changed cyclically. A three-electrode cell (Swagelok® type) having a graphite composite electrode (96%, 350 mAh/g; 1.1 mAh cm.sup.−2) as working electrode and lithium foil as counterelectrode and reference electrode was used for this purpose. A glass fiber nonwoven was used as separator.

[0057] To determine the reductive stability and cyclability, the potential between working electrode and reference electrode was firstly lowered from the equilibrium potential (OCP) to 0.025 V vs. Li/Li.sup.+ and subsequently increased again from 0.025 V to 1.5 V vs. Li/Li.sup.+. The cyclic potential change procedure between 0.025 V and 1.5 V vs. Li/Li.sup.+ was repeated twice. The rate of advance was 0.025 mV s.sup.−1.

[0058] Two electrolytes each containing 1 M LiTFSI in mixtures of 1,1,2,2-tetraethoxyethane and propylene carbonate (1 M LiTFSI, PC:TEE (1:1)) or 1,1,2,2-tetramethoxyethane and propylene carbonate (1 M LiTFSI, PC:TME (1:1)) were examined. The electrolytes were produced by dissolving the required amount of LiTFSI in TEE or TME. FIG. 1a) shows the reductive stability window of the electrolyte containing 50% by weight of 1,1,2,2-tetramethoxyethane (TME) and FIG. 1b) shows the reductive stability window of the electrolyte containing 50% by weight of 1,1,2,2-tetraethoxyethane (TEE). The current is in each case plotted against the potential over three cycles. As can be seen from FIGS. 1a) and 1b), the electrolytes containing 50% by weight of propylene carbonate were stable and compatible with graphite electrodes. This shows that effective passivation of graphite can be achieved by means of 1,1,2,2-tetramethoxyethane and 1,1,2,2-tetraethoxyethane even in a 1:1 mixture with propylene carbonate. Reductive decomposition was not discernible for TME and TEE from the cyclic voltammogram.

Example 4

Determination of the Oxidative Electrochemical Stability of 1,1,2,2-Tetramethoxyethane and 1,1,2,2-Tetraethoxyethane Using a Platinum Electrode

[0059] The determination of the oxidative stability of the electrolytes in half cells was carried out by means of linear sweep voltammetry in a three-electrode cell of the Swagelok® type having a platinum electrode (Ø=0.1 cm, eDAQ) as working electrode and lithium foil as counterelectrode and reference electrode. A glass fiber nonwoven was used as separator. To determine the oxidative stability, the potential between working electrode and reference electrode was increased from the open-circuit voltage to 7.0 V vs. Li/Li.sup.+. The rate of advance was 0.1 mV s.sup.−1.

[0060] Three electrolytes each containing 1 M LiTFSI in mixtures of 1,1,2,2-tetraethoxyethane and propylene carbonate (1 M LiTFSI, PC:TEE (1:1)) or 1,1,2,2-tetramethoxyethane and propylene carbonate (1 M LiTFSI, PC:TME (1:1)) and also 1 M LiFSI in a mixture of PC and TME (1:1) were examined. The electrolytes were produced by dissolving the required amount of LiTFSI or LiFSI in TEE or TME. FIG. 2 shows the oxidative stability window of the electrolytes. The current is plotted against the potential. As can be seen from FIG. 2, the electrolytes were stable up to a potential of 5 V vs. Li/Li.sup.+.

Example 5

Determination of the Oxidative Stability of 1,1,2,2-Tetraethoxyethane Using an LMO Electrode

[0061] The oxidative stability of an electrolyte containing 1 M LiFSI in a mixture of 1,1,2,2-tetraethoxyethane and propylene carbonate (1 M LiFSI, PC:TEE (1:1)) was examined using lithium-manganese oxide as working electrode. The determination of the oxidative stability was carried out as described in example 4 by means of linear sweep voltammetry in a three-electrode cell of the Swagelok® type. Lithium foil served as reference electrode and counterelectrode, and the potential between working electrode and reference electrode was increased from the open-circuit voltage to 4.9 V vs. Li/Li.sup.+. The rate of advance of the potential was 0.025 mV s.sup.−1.

[0062] FIG. 3 shows the oxidative stability window of the electrolyte for a potential vs. Li/Li.sup.+ in the range from 3.2 V to 5 V. As can be seen from FIG. 3, complete delithiation without additional indications of parasitic Faradaic reactions was possible for the electrolyte based on a 1:1 mixture of 1,1,2,2-tetraethoxyethane and propylene carbonate through to a shut-off voltage of 4.3 V vs. Li/Li.sup.+.

Example 6

Examination of the Cycling Stability Using a Graphite Electrode

[0063] The examination of the cycling stability was carried out in a button cell construction (Hohsen Corp., CR2032) using lithium electrodes and graphite electrodes (MCMB). A glass fiber nonwoven was used as separator. Cycling was carried out in a voltage window from 0.025 V to 1.5 V. 3 formation cycles at 0.1 C and also 3 conditioning cycles at 0.25 C and 3 conditioning cycles at 0.5 C were carried out, followed by 41 charging/discharging cycles at 1.0 C. The measurements at constant current were carried out on a battery tester series 4000 (Maccor) at 20.0° C.±0.1° C.

[0064] An electrolyte containing 1 M LiTFSI in a mixture of 50% by weight of each of 1,1,2,2-tetraethoxyethane (TEE) and propylene carbonate (PC) was produced by initially charging the solvent mixture and dissolving the required amount of LiTFSI therein.

[0065] The charging and discharging capacity of the graphite/Li cell and also the Coulombic efficiency versus the number of cycles are shown in FIG. 4. As can be seen from FIG. 4, the electrolyte displayed a high Coulombic efficiency of 87.3% in the first cycle and a small capacity loss and a high Coulombic efficiency of >99.9% over the total period of cycling. This indicates effective passivation of the graphite surface by means of 1,1,2,2-tetraethoxyethane, even without addition of an SEI additive.

[0066] As comparative electrolytes, a solution of 1 M LiTFSI in propylene carbonate and also in propylene carbonate containing 5% by weight of the SEI additive vinylene carbonate were cycled in parallel. As expected, pure propylene carbonate displayed exfoliation of the graphite electrode after the first cycle. Reversible cycling was not possible. The addition of vinylene carbonate made cycling possible, but the cell displayed only a low Coulombic efficiency of 79.6% even in the first cycle and a rapid capacity loss within the first 20 cycles, which indicates that there is not effective passivation by vinylene carbonate. In contrast, the compound according to the disclosure displayed a high and constant Coulombic efficiency of >99.9% over the entire cycling time of 50 cycles examined.

Example 7

Examination of the Long-Term Cycling Stability in an LFP/Graphite Full Cell

[0067] The examination of the long-term cycling stability in full cells was likewise carried out in a button cell construction (Hohsen Corp., CR2032) using lithium iron phosphate (LFP, 83%, 150 mAh/g; 1.0 mAh/cm.sup.−2) and graphite electrodes (96%, 350 mAh/g; 1.1 mAh cm.sup.−2). A polymer nonwoven was used as separator. Cycling was carried out in a voltage window from 2.5 V to 3.6 V. 3 formation cycles at 0.1 C and 3 conditioning cycles at 0.33 C were carried out, followed by 320 charging/discharging cycles at 1.0 C. The measurements were carried out on a battery tester series 4000 (Maccor) at 20.0° C.±0.1° C.

[0068] An electrolyte containing 1 M LiTFSI in a mixture of 50% by weight each of 1,1,2,2-tetraethoxyethane (TEE) and propylene carbonate (PC) was used, with the solvent mixture being initially charged and the required amount of LiTFSI being dissolved therein.

[0069] FIG. 5 shows the discharging and charging capacity and also the Coulombic efficiency of the full cell versus the number of cycles. As can be seen from FIG. 5, the electrolyte displayed a Coulombic efficiency of 88.4% in the first cycle and a high Coulombic efficiency of >99.9% over 300 cycles. Furthermore, this result demonstrates that there is compatibility with LFP cathode material.

Example 8

Examination of the Cycling Stability in an NMC/Graphite Full Cell

[0070] The cycling stability in full cells was repeated as described in example 7 using a lithium-nickel.sub.0.5-manganese.sub.0.3-cobalt.sub.0.2 oxide cathode (NMC532) against graphite over 40 charging/discharging cycles at 1.0 C. Cycling was carried out in a voltage window from 2.8 V to 4.2 V. 1 M LiFSI in a 1:1 mixture of 1,1,2,2-tetraethoxyethane and propylene carbonate was used as electrolyte.

[0071] FIG. 6 shows the discharging and charging capacity and also the Coulombic efficiency of the NMC/graphite full cell versus the number of cycles. As can be seen from FIG. 6, the electrolyte displayed a Coulombic efficiency of 84.5% in the first cycle and a Coulombic efficiency of >99.5% over 40 cycles. This shows that there is also good compatibility with NMC cathode material. The electrolyte of the disclosure can thus also be used with cathode materials at a shut-off voltage of up to 4.2 V.

Example 9

[0072] Examination of the Graphite Surface after Cycling in 1,1,2,2-Tetraethoxyethane Mixtures

[0073] To examine the passivation of the graphite electrode by 1,1,2,2-tetraethoxyethane, the surface of the electrode was examined by scanning electron microscopy after one charging/discharging cycle.

[0074] A graphite anode (96%, 350 mAh/g; 1.1 mAh cm.sup.−2) was cycled against a lithium iron phosphate cathode (LFP) or a lithium-nickel.sub.0.5-manganese.sub.0.3-cobalt.sub.0.2 oxide cathode (NMC532) in a full cell having a button cell construction (Hohsen Corp., CR2032). A polymer nonwoven was used as separator. The charging/discharging cycle was carried out in a voltage window from 2.5 V to 3.6 V (LFP) or from 2.8 V to 4.2 V (NMC532). The measurements were carried out at 250° C.±0.1° C. on a battery tester series 4000 (Maccor).

[0075] 1 M LiTFSI in a 1:1 mixture of 1,1,2,2-tetraethoxyethane and propylene carbonate was used as electrolyte. A solution of 1 M LiPF.sub.6 in propylene carbonate containing 2% by weight of the SEI additive fluoroethylene carbonate (FEC) was used as comparative electrolyte.

[0076] After the charging/discharging cycle had been carried out, the graphite electrodes were in each case removed from the cell and the surfaces were examined by high-resolution scanning electron microscopy (SEM) using a ZEISS Auriga® electron microscope.

[0077] FIG. 7a) shows the course of the cell voltage (graphite/LFP cell) versus the capacity of the first cycle for the electrolyte containing 50% by weight of 1,1,2,2-tetraethoxyethane and PC, and FIG. 7b) shows a scanning electron micrograph of the graphite surface (cross section of the secondary graphite particles). FIG. 7a) shows that a reversible intercalation/deintercalation of the Li.sup.+ ions in the graphite was possible in the first cycle. As can be seen from FIG. 7b), the surface of the graphite electrode was intact after the charging/discharging cycle had been carried out. There were no discernible signs of exfoliation.

[0078] FIG. 8a) shows the cell voltage of the comparative cell (graphite/NMC532, containing 1 M LiPF.sub.6 in propylene carbonate containing 2% by weight of fluoroethylene carbonate as electrolyte) for the first cycle versus time. FIG. 8b) shows a scanning electron micrograph of the graphite surface after the charging/discharging cycle. As can be seen from FIG. 8a), a significantly lower reversibility of the intercalation/deintercalation of Li.sup.+ ions in the graphite is observed. FIG. 8b) clearly shows that the surface of the graphite electrode displayed severe exfoliation after one charging/discharging cycle in propylene carbonate even when using the SEI additive FEC.

[0079] Comparison of FIGS. 7b) and 8b) confirms effective passivation by 1,1,2,2-tetraethoxyethane which displayed significantly better protection of the graphite electrode than the use of a conventional SEI additive.

[0080] Overall, the results show that 1,1,2,2-tetraethoxyethane and 1,1,2,2-tetramethoxyethane can form a passivating protective layer which conducts lithium ions on the surface of graphite. In addition, the two compounds display satisfactory conductivity and good oxidative stability. Furthermore, the compounds were able to be operated stably in lithium ion batteries with good cycling stability over 300 cycles.

[0081] The disclosure forming the basis of the present patent application arose in a project supported by BMBF under the support number 3120034900.

[0082] It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

[0083] As used in this specification and claims, the terms “for example,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.