Electrolytes for lithium-ion batteries with micro-sized silicon anode and methods thereof

Abstract

This present disclosure is directed to electrolyte compositions for lithium-ion batteries comprising novel ionic liquids or a molecular solvent novel to electrolyte usage, lithium-ion batteries comprising the electrolyte compositions, and methods of assembly and supplying power thereof.

Description

PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0ELECTROLYTES FOR LITHIUM-ION BATTERIES WITH MICRO-SIZED SILICON ANODE AND METHODS THEREOF by Chunsheng Wang Ai-Min Li Weiran ZhangCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 63 / 684,271, filed on August16, 2024, the contents of which are hereby incorporated by reference in its entirety.STATEMENT OF FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

[0002] This invention was made with government support under DE-EE0009183 awarded by the U.S. Department of Energy. The government has certain rights in the invention.FIELD OF THE INVENTION

[0003] The field of the invention relates generally to batteries and battery technology, in particular to lithium-ion batteries and methods thereof. More particularly, the invention relates to electrolyte compositions for lithium-ion batteries.BACKGROUND

[0004] This background information is provided for the purpose of making information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should it be construed, that any of the information disclosed herein constitutes prior art against the present invention.

[0005] Lithium-ion batteries (LIBs) that combine the intercalation transition-metal-oxide cathodes and graphite (Gr) anode are approaching their energy density limit. Li metal batteries (LMBs) using high energy LiNio.sMno.iCoo.i (NMC811) cathode can enhance the batteries' energy density up to 450 Wh kg'1. However, the low cycle Coulombic efficiency (CE) and Li dendrite growth remain unresolved challenges. Alternatively, high-capacity alloying anodes, such as silicon (Si), Tin (Sn), and Aluminum (Al) do not have Li dendrite issues but still havePCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT03-9 times higher capacities than Gr, which can improve the energy density of the LIBs without compromising the safety. However, these alloying anodes, especially in their micro-sized forms, will experience substantial volumetric and structural changes during lithiation / delithiation cycles, resulting in particle cracks and pulverization. Since the organic solid electrolyte interphase (SEI) formed in commercial carbonate electrolytes is strongly bonded to alloying particles, the SEI will experience the same volume change as micro-sized alloying anodes and cracks along with pulverization of alloying particles. The cracked SEI and alloys allow the electrolytes to penetrate the pulverized particles and form new SEI, which isolates the pulverized particles (loss of electric contact) and dries the electrolytes out (loss of ionic conductivity), resulting in a low cycling CE (<95%) and poor cycle life (<50 cycles). One successful strategy is to reduce the particle size of the alloying anodes to nano-scale region and / or integrate them into graphite (Gr) forming Gr-M (M = Si, Sn, Al, or Bi) composite anodes, which can migrate the alloying pulverization. However, nano-sized alloying anodes are expensive due to the high material synthesis cost and pre-lithiation requirements, and the use of nano-sized anodes also reduces cell calendar life and electrode tapping density. Therefore, large-sized (>5 pm) alloying anodes are desired for high-energy LIBs, yet the capacity decay issues cannot be resolved with currently known electrolytes (Tables 1-2).

[0006] The pulverization of micro-sized alloying particles (LixM, M = Si, Sn, Al, or Bi) cannot be avoided when a high capacity is utilized. A solution to this problem lies in the fact that, if the electrolyte does not penetrate the pulverized alloying particles to form SEI in cracked particles, the yet-cracked particles still provide capacity, as they are still electronically connected. Therefore, a problem to be solved by the present invention pertains to preventing the SEI shell from cracking even if the inner alloy core cracks during the volume contraction (delithiation). LiF SEI has higher interfacial energy (Eint) and weaker bonding to alloying phases than the organic SEI (Fig. 1A), and the weak bonding ensures the LiF SEI shellPCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 maintains its integrity when the inner LixM experiences large volume changes (Fig. 1A). Therefore, LiF SEI enables micro-sized alloying anode to achieve a long cycle life, which is evidenced by minimized electrode swelling during the long-term cycling (Fig. 1C, magenta). In contrast, the strong bonding between organic SEI and LixM phases makes the SEI cracks along the pulverization of micro-LixM particles (Fig. IB). The cracks of organic SEI allow electrolytes to penetrate the SEI shell, forming redundant SEI in the pulverized LixM particles, resulting in huge electrode swellings (Fig. 1C, blue), which causes electrolyte depletion and fast cell capacity decay.

[0007] To achieve a long cycle life of alloying LixM anodes, the content of LixM-phobic inorganic LiF in the SEI should be high and the LixM-philic organic components have to be minimized. To reduce the organic components and increase inorganic LiF in SEI, low- reduction ether solvents and concentrated F-rich salts are used in the electrolytes, which enhance the cycle life of alloying anodes. Amongst common fluorinated lithium salts (LiPFe, LiFSI, and LiTFSI), the reduction of FSF and TFSI' anions may also generate organic species, like LiSCLFx and C-Fxcompounds besides the inorganic LiF / Li2O. However, the reduction of PFe' anion only forms LiF-rich inorganic SEI, which is beneficial for the alloying anodes. As for ether solvents, fluorination of ether solvents enables to formation LiF, but it also promotes the formation of organic SEI, which limits the cell cycle performance (cycle life of<200) even at a low capacity utilization (<1200 mAh g'1for Si). To transcend the intrinsic solvent limitations, solvent-free room-temperature ionic liquids (RTILs) electrolytes are promising for alloying anodes. However, the cation in RTILs can also be reduced to form organic SEI. For example, the imidazolium and ammonium cations can match with PFe' anion forming RTILs. However, these cations have relatively high reduction potentials (>0.7 V vs Li / Li+, Fig. 2A), which will form organic SEIs on the alloying anodes, reducing cell cyclability. Although pyrrolidinium-based ILs have a substantially lower reduction potential of ~0.2 V (vs Li / Li+),PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 they generally are solid at room temperature with PFe' anion (Fig. 2A). The RTILs with sulfonyl imide anions (FSF, TFSF) are liquid with less viscosity due to their electron- delocalized structure, but the reduction of FSF, TFSF could form organic-rich SEI. Presently, all known RTIL electrolytes show a low-capacity utilization and limited cycle life of <200 cycles for micro-sized alloying anodes due to the formation of organic-inorganic SEIs from the degradation of either cations (imidazolium, tetraalkylammonium) or organic anions (TFSI, FSI) (Supplementary Table 1). A solution to these problems resides in RTILs with low- reduction cations and high-reduction PFe' anions.

[0008] The inventors surprisingly discovered that the electrolyte compositions disclosed herein provide a solution for these recognized problems.BRIEF DESCRIPTION OF THE FIGURES

[0009] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

[0010] FIG. 1. Figure 1 displays a schematic of the cycled micro-sized M anodes LixM (M = Si, Sn, Al, and Bi) with a thin inorganic LiF (magenta) and a thick organic-rich (blue) SEI. In the top panel, the LiF SEI has weak bonding to the LixM phases, which keeps it intact during lithiation / delithiation cycles, enabling long cycling of micro-sized alloying anodes with restrained particle pulverization and reduced electrode swelling. In the middle panel, the organic SEI has a strong bonding to the LixM phases and cracks easily along the contraction of alloying particles, leading to electrolyte penetration and further SEI formation and alloying particle pulverization with huge electrode swelling (thickness growth). In the bottom panel, the electrode thickness evolution along the long cycle of the alloying anodes with LiF (magenta) and organic (blue) SEI.PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0

[0011] FIG. 2. Figure 2 displays a schematic showing the electrolyte design and solvation structure of the NMEP51 electrolyte, particularly the [PFe']-based room temperature ionic liquid design strategy for micro-sized alloying anodes.

[0012] FIGS. 3A-3B. Figure 3 displays LiF and lithium carbonate distribution in the SEI formed with NMEP51 (Figure 3 A) and LP30 (Figure 3B) electrolytes (50 cycles) by EELS imaging. For the HR-TEM images, the colored dots represent the area of corresponding EELS spectra near the surface of the pSi particles.

[0013] FIGS. 4A-4E. Figure 4 displays the electrochemical performance and postmortem analysis of pSi electrodes cycled in different electrolytes. Figure 4A displays a graph depicting the cycling stability and CEs of pSi electrodes at C / 8 (447 mA g'1) in NMEP51 (violet), LP30 (orange), and GenF (1.2 M LiPFe-EC / EMC (3 / 7 w / w) + 10 wt% FEC) (pink) electrolytes. The pSi electrodes were activated at a rate of C / 20 (179 mA g'1) for one cycle and then cycled at C / 8 (447 mA g'1). Figure 4B displays a graph depicting the thickness evolution of pSi electrodes during charge / discharge cycles in NMEP51 and LP30 electrolytes, particularly the pSi electrode thickness growth compared to the pristine state along different cycles. Figures 4C-4E depict a series of SEM images collected for pSi electrode changes before and after cycling in NMEP51 and LP30 electrolytes (50 cycles). Ion beam milling (IBM) cross-sectional views of the pSi electrodes (2.0 mAh cm’2) are shown on the left and top views of these electrodes are shown on the right with different magnifications.

[0014] FIGS. 5A-5F. Figure 5 displays the electrochemical performance of pSi-based full cells using NMC811 or SPAN cathodes. Figures 5 A and 5B display graphs of the performance of pSi||NMC811 coin cells for efficiency and capacity, with an areal capacity of 4.5 mAh cm’2(N / P =1.4). Figure 5C displays a graph a graph of the efficiency and capacity of 90 mAh pSi||NMC811 pouch cells. Figures 5D and 5E displays graphs of the performance ofPCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0Li375Si||SPAN coin cells for efficiency and capacity, with an areal capacity of 3.5 mAh cm'2(N / P =1.8). Figure 5F displays a graph a graph of the efficiency and capacity 70 mAh Li375Si||SPAN pouch cells. The inset shows the actual pressure device (0.1 MPa) with the cell displayed on the right. All the cells are cycled at C / 8 before one formation cycle at C / 20.

[0015] FIGS. 6A-6C. Figure 6 depicts practical considerations of NMEP51 electrolyte design. Figure 6A displays a schematic of the asymmetric molecular design strategy. The introduction of the “DME” fragment into 1-methyl-pyrrolidinium cation breaks the symmetry of the “DME”, facilitating the compatibility between “DME” and LiPFe salt, therefore the formulation of NMEP51 electrolytes. This concept also applies to small molecules as illustrated in EME, making the EME / LiPFe electrolytes possible for application in micro-sized silicon anodes. Figure 6B displays a graph depicting the long cycle performance of pSi||NMC811 (4.5 mAh cm'2, N / P =1.1, 2.8-4.2V) cells in 2.0 M EME / LiPFe electrolytes. The cells were activated at a rate of C / 10 (20 mA g'1) for one cycle and then cycled at C / 3 (67 mA g'1), the temperature was controlled at 25 °C. The cycle CE is labeled on the left y-axis and capacity retention is on the righty-axis. Figure 6C displays the charge / discharge profiles of the pSi||NMC811 full cells at selected cycles.

[0016] FIG. 7. Figure 7 displays an 'H-NMR of pure NMEP ionic liquid (400 MHz, co-axis C6D6, 25 °C, 5 / ppm): 2.16 (m, 4H), 2.99 (s, 3H), 3.30 (s, 3H), 3.52 (m, 4H), 3.89 (m, 4H), 4.56 (s, 2H).

[0017] FIG. 8. Figure 8 displays a13C-NMR of pure NMEP ionic liquid (400 MHz, co-axis C6D6, 25 °C, 5 / ppm): 20.87, 45.31, 57.89, 60.21, 69.62, 71.80, 89.78.

[0018] FIG. 9. Figure 9 displays a19F-NMR of pure NMEP ionic liquid (400 MHz, co-axis C6D6, 25 °C, 5 / ppm): -71.96, -70.07.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0019] FIGS. 10A-10B. Figure 10 displays flammability testing images for two electrolytes, LP30 (figure 10A) and NMEP51 (Figure 10B), respectively.

[0020] FIGS. 11A-11F. Figure 11 displays the electrochemical performance of pAl, pSn, and pBi electrodes with an areal capacity of ~2.0 mAh cm'2. Figures 11A-11C depict the capacity retention and CE of the micro-sized pAl (Figure 11 A), pSn (Figure 11B), and pBi electrodes (Figure 11C). All cells were charged / discharged at C / 20 in the formation cycle and the current was increased to C / 8 in the following cycles. Figures 11D-11F display the charge / discharge voltage profiles of pAl (11D), pSn (HE), and pBi (1 IF) electrodes with labeled alloying / de- alloying reactions.

[0021] Particular non-limiting embodiments of the present invention will now be described with reference to accompanying drawings.DESCRIPTION

[0022] Definitions

[0023] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to certain embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and alterations and modifications in the illustrated invention, and further applications of the principles of the invention as illustrated therein are herein contemplated as would normally occur to one skilled in the art to which the invention relates.

[0024] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] For the purpose of interpreting this specification, the following definitions will apply and whenever appropriate, terms used in the singular will also include the plural and vice versa. In the event that any definition set forth below conflicts with the usage of that word in anyPCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 other document, including any document incorporated herein by reference, the definition set forth below shall always control for purposes of interpreting this specification and its associated claims unless a contrary meaning is clearly intended (for example in the document where the term is originally used).

[0026] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling with the range, unless otherwise indicated, herein, and each separate value is incorporated into the specification as if it were individually recited herein. Any ranges given either in absolute terms or in approximate terms are intended to encompass both, and any definitions used herein are intended to be clarifying and not limiting. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges (including all fractional and whole values) subsumed therein.

[0027] The use of “or” means “and / or” unless stated otherwise.

[0028] The use of “a” or “an” herein means “one or more” unless stated otherwise or where the use of “one or more” is clearly inappropriate.

[0029] The use of “comprise,” “comprises,” “comprising,” “include,” “includes,” and “including” are interchangeable and not intended to be limiting. Furthermore, where the description of one or more embodiments uses the term “comprising,” those skilled in the art would understand that, in some specific instances, the embodiment or embodiments can be alternatively described using the language “consisting essentially of’ and / or “consisting of.”

[0030] As used herein, the term “about” refers to a ±10% variation from the nominal value. It is to be understood that such a variation is always included in any given value provided herein, whether or not it is specifically referred to.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0031] The term “ionic liquid”, as used herein, refers to a salt comprising a cation and an anion, wherein said salt remains in the liquid state at ambient conditions (e.g., about 20 °C). Said cation and said anion may be inorganic or organic. In some embodiments, said cation is organic and said anion is inorganic.

[0032] The term “molecular solvent”, as used herein, refers to a electrically neutral solvent (i.e., having no charge). This is contrast to ionic liquids. Examples include l-ethoxy-2- m ethoxy ethane, cyclopentyl methyl ether, 1,2-dimethoxypropane, or combinations thereof.

[0033] The term “microsized” as used herein, refers to a material having a particle size of > 1 pm, or about 1 pm to about 10 pm.

[0034] The term “hard carbon”, as used herein, refers to char, or non-graphitizing carbon.

[0035] The term “soft carbon”, as used herein, refers to carbon materials having tunable physical properties.

[0036] The term “asymmetric electrolyte composition”, as used herein, refers to a composition comprises at least one salt and one or more solvating agents (ionic liquids or molecular solvents) having an asymmetric molecular configuration. In some embodiments, the cation of the ionic liquid has an asymmetric molecular configuration. The asymmetric electrolyte compositions disclosed herein involves an electrolyte system where the chemical and / or physical properties differ across the anode and cathode compartments of a battery or electrochemical device. Without wishing to be limited to any particular theory, this asymmetry facilitates optimized performance for each electrode, addressing specific requirements like ionic conductivity, stability, and reaction kinetics. The term “asymmetric molecular configuration,” refers to a molecule that lacks symmetry and cannot be superimposed on its mirror image.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0037] The term “liquid phase”, as used herein, refers to a electrolyte composition disclosed herein being in the liquid state. The term “liquid state” is well known in the chemical arts and as used herein refers said electrolyte composition being in a state of matter between solid and gas.

[0038] One aspect of the invention pertains to an asymmetric electrolyte composition for lithium-ion batteries comprising a liquid and at least one lithium salt. The liquid may be an ionic liquid or a molecular solvent. In some embodiments, when the liquid is an ionic liquid, the ionic liquid comprises a cationic component and an anionic component. The cationic component may be of Formula I:Formula I wherein R1is chosen from H, Ci-4 alkyl, or C104 alkyl ether, and R2is an oxyethylene derivative.

[0039] In some embodiments, the anionic component is PFe' or BF4'. In other embodiments, the anionic component os PFe'. R1may be chosen from H, methyl, and methyl ether. In other embodiments, R1is methyl.

[0040] In some embodiments, R2is chosen from -(CH2)[O(CH2)2O]nCH3 or - (CH2)O(CH2)nOCH3, where n is greater than or equal to 1. When n is equal to one, R2may be -(CH2)[O(CH2)2O]CH3.

[0041] In some embodiments, the at least one lithium salt is chosen from LiPFe, LiFSI, LiBF4, and LiDFOB, or combinations thereof. In other embodiments, the at least one lithium salt is LiPFe. The electrolyte composition may maintain a liquid phase over a temperaturePCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 range from about -18 °C to about 200 °C. When combined, the liquid and the at least one lithium salt may also be free of polymerization products.

[0042] In some embodiments, when the electrolyte composition comprises a molecular solvent, the molecular solvent is chosen from 1 -ethoxy-2-methoxy ethane, cyclopentyl methyl ether, 1,2-dimethoxypropane, or combinations thereof. In other embodiments, the molecular solvent is l-ethoxy-2-m ethoxy ethane.

[0043] In further embodiments, the electrolyte composition comprises a co-solvent. The cosolvent may be chosen from 1,3 -di oxolane, 2-methyl-l,3-dioxolane, 4-methyl-l,3,- di oxolane, 1,4 dioxane, 2-methyl-l,4 dioxane, tetrahydropyran, 2-methyltetrahydropyran, 3- methyltetrahydropyran, and 4-methyltetrahydropyran, or combinations thereof.

[0044] In some embodiments, wherein said liquid is an ionic liquid, wherein R1is methyl, R2is -(CH2)[O(CH2)2O]CH3, when n is 1, said anionic component is PFe’, and said at least one lithium salt is LiPFe. In further embodiments, the amount of ionic liquid present in the electrolyte composition compared to the amount of the at least one lithium salt is about 5 to about 1 of ionic liquid to lithium salt.

[0045] Another aspect of the invention pertains to a lithium-ion battery, said lithium-ion battery comprising the electrolyte composition as described previously, a cathode, and an anode. In some embodiments, the anode comprises a microsized anode material or a microsized anode material / carbon composite. In other embodiments, the microsized anode material comprises microsized Si, microsized Al, microsized Sn, microsized Bi, or carbon composites thereof. In further embodiments, the anode comprises microsized Si. The carbon composite may comprises graphite, hard carbon, soft carbon, or combinations thereof. The cathode may be chosen from NMC811, lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA),PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 and sulfurized polyacrylonitrile (SPAN). In some embodiments, the cathode comprises NMC811.

[0046] In some embodiments, the lithium-ion battery as described above comprises a cathode, an anode, and an electrolyte composition, wherein the cathode is NMC811, the anode is microsized Si, and the electrolyte composition is the electrolyte composition as previously described, wherein the liquid is an ionic liquid of Formula I, wherein R1is methyl, R2is -(CH2)[O(CH2)2O]CH3, when n is 1, said anionic component is PFe’, and said at least one lithium salt is LiPFe.

[0047] An additional aspect of the invention pertains to a method of assembling a lithium- ion battery as previously described, the method comprising layering a cathode, an electrolyte composition, and an anode to obtain multiple layers. In some embodiments, the cathode is layered first, followed by the electrolyte composition, followed by the anode. In other embodiments, the cathode, electrolyte composition, and cathode are sealed (e.g., mechanically sealed) in a battery casing. The battery casing may be a coin cell or a pouch cell.

[0048] Another aspect of the invention pertains to a method of supplying power, using the lithium-ion battery as described previously, to supply a voltage upon discharging. In some embodiments, the voltage is about 3.3 V.LIST OF EMBODIMENTS

[0049] The following is a list of non-limiting embodiments:1. An asymmetric electrolyte composition for lithium-ion batteries, said electrolyte composition comprising a liquid and at least one lithium salt; wherein said liquid is an ionic liquid or a molecular solvent; wherein said ionic liquid comprises an anionic component and a cationic component; andPCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 wherein said cationic component is a cation of Formula I:Formula I wherein R1is chosen from H, C1-4 alkyl, and C1-4 alkyl ether; andR2is an oxyethylene derivative.In some embodiments, embodiment 1 encompasses a electrolyte composition comprising a liquid and at least one lithium salt; wherein said liquid is an ionic liquid; wherein said ionic liquid comprises an anionic component and a cationic component; and wherein said cationic component is a cation of Formula I:Formula I wherein R1is chosen from H, Ci-4 alkyl, and Ci-4 alkyl ether; andR2is an oxyethylene derivative.In further embodiments, embodiment 1 encompasses a electrolyte composition comprising a liquid and at least one lithium salt; wherein said liquid is a molecular solvent; wherein said ionic liquid comprises an anionic component and a cationic component;PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 wherein said cationic component is a cation of Formula I:Formula I wherein R1is chosen from H, C1-4 alkyl, and C1-4 alkyl ether; andR2is an oxyethylene derivative.2. The asymmetric electrolyte composition of embodiment 1, wherein said anionic component is chosen from PFe' or BF4'.3. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said anionic component is PFe'.4. The asymmetric electrolyte composition of any of the preceding embodiments, wherein R1is chosen from H, methyl, and methyl ether.5. The asymmetric electrolyte composition of any of the preceding embodiments, wherein R1is methyl.6. The asymmetric electrolyte composition of any of the preceding embodiments, wherein R2is chosen from -(CH2)[O(CH2)2O]nCH3 or -(CH2)O(CH2)nOCH3, wherein n is greater than or equal to 1.7. The asymmetric electrolyte composition of any of the preceding embodiments wherein R2is -(CH2)[O(CH2)2O]CH3, when n is 1.8. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said at least one lithium salt is chosen from LiPFe, LiFSI, LiBF4, and LiDFOB, or combinations thereof.PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT09. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said at least one lithium salt is LiPFe.10. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said electrolyte composition is in a liquid phase over a temperature range from about -18 °C to about 200 °C.11. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said liquid and said at least one lithium salt are free of polymerization products upon combination.12. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said molecular solvent is chosen from l-ethoxy-2-m ethoxy ethane, cyclopentyl methyl ether, 1,2-dimethoxypropane, or combinations thereof.13. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said molecular solvent is l-ethoxy-2-methoxy ethane.14. The asymmetric electrolyte composition of any of the preceding embodiments, further comprising a co-solvent, wherein said co-solvent is chosen from 1,3-dioxolane, 2- m ethyl- 1,3 -di oxolane, 4-methyl-l, 3, -dioxolane, 1,4 dioxane, 2-methyl-l,4 dioxane, tetrahydropyran, 2-methyltetrahydropyran, 3 -methyltetrahydropyran, and 4- methyltetrahydropyran, or combinations thereof.15. The asymmetric electrolyte composition of any of the preceding embodiments, wherein said liquid is an ionic liquid, wherein R1is methyl, R2is -(CH2)[O(CH2)2O]CH3, when n is 1, said anionic component is PFe’, and said at least one lithium salt is LiPFe'.16. The asymmetric electrolyte of any of the preceding embodiments, wherein said ionic liquid and said at least one lithium salt are present at a concentration of about 5 to about 1.PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT017. A lithium-ion battery, said battery comprising a cathode, an anode, and the electrolyte composition of any of the preceding embodiments.18. The lithium-ion battery of embodiment 17, wherein said anode comprises a microsized anode material or a microsized anode material / carbon composite.19. The lithium-ion battery of any of the preceding embodiments, wherein said microsized anode material comprises microsized Si, microsized Al, microsized Sn, microsized Bi, or carbon composites thereof.20. The lithium-ion battery of any of the preceding embodiments, wherein said microsized anode comprises microsized Si.21. The lithium-ion battery of any of the preceding embodiments, wherein said carbon composite comprises graphite, hard carbon, or soft carbon, and combinations thereof.22. The lithium-ion battery of any of the preceding embodiments, wherein said cathode is chosen from NMC811, lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA), and sulfurized polyacrylonitrile (SPAN).23. The lithium-ion battery of any of the preceding embodiments, wherein said cathode is NMC811.24. The lithium-ion battery of any of the preceding embodiments, wherein said cathode is NMC811, said anode is microsized Si, and said electrolyte is the asymmetric electrolyte composition of claim 15.25. A method of assembling a lithium-ion battery of any of the preceding embodiments, said method comprising layering a cathode, an electrolyte composition of any of the preceding embodiments, and an anode to obtain multiple layers.26. The method of embodiment 25, wherein said layering comprises first layering a cathode, then said electrolyte composition, then said anode.PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT027. The method of any of the preceding embodiments, wherein said cathode, said electrolyte composition, and said anode are sealed in a battery casing.28. The method of any of the preceding embodiments, wherein said battery casing is a coin cell or a pouch cell.29. A method of supplying power, said method comprising using the battery of any of the preceding embodiments to supply a voltage upon discharging.30. The method of embodiment 29, wherein said voltage is about 3.3 V. EXAMPLES

[0050] The following examples are provided solely to illustrate the present invention and are not intended to limit the scope of the invention, described herein.

[0051] Example 1. NMEP / LiPFe electrolyte design and solvation investigation

[0052] The room-temperature NMEP ionic liquid was synthesized using a typical quaternization and anion-metathesis approach (Figs. 7-9). Details of the synthetic procedures are given in the supplementary materials. The introduction of the DME group into pyrrolidinium-based IL inherits the merits from pyrrolidinium-based IL and DME solvent but migrates the inferiorities of both (Fig. 2A): (1) DME reduces the viscosity of the IL to RTIL; (2) the oxygen atoms in NMEP cation can solvate to the Li+cation, forming fine-tuned solvation structure and enhancing Li+transferring; (3) NMEP / LiPFe electrolytes have high anodic stability of >5.0 V (vs Li / Li+) due to the ionic nature, much higher than the ether-based electrolytes; and (4) the bulky pyrrolidinium group avoids the polymerization of DME when mixed with LiPFe salt, making the DME-LiPFe-RTIL electrolytes unique for high-energy micro-sized alloying anodes. The ionic conductivities and transference numbers of NMEP / LiPFe electrolytes increase with LiPFe concentrations, reaching a maximum ionic conductivity of 1.91 mS cm'2and maximum transference number of 0.57 at an NMEP / LiPFe ratio of 5: 1.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0053] The solvation structure of the NMEP51 electrolytes was explored using ID multinuclear7Li-, and19F- NMR as well as 2D Heteronuclear Overhauser Effect Spectroscopy (HOESY), and compared to the structure of commercial carbonate electrolytes 1.0 M LiPFe / EC-DMC (LP30). The7Li-NMR chemical shift ofNMEP51 electrolytes upfield to -1.39 ppm compared to -0.45 ppm of LP30, indicating a higher ion-pair association in NMEP51 electrolytes, which can also be validated by the downfield shift of19F-NMR in NMEP51 (- 70.01 / -71.90 ppm) compared to LP30 (-72.45 / -74.33 ppm). To understand the fast Li+transport mechanism, the NMEP51 electrolyte was characterized by the heteronuclear coupling through 2D {JH-7Li}, and {JH-19F} HOSEY experiments. The observed cross peaks indicate the closerange interactions (in the range of 5 A) between 'H- and7Li-,19F- nuclei. Protons at position 3 on the terminal DME fragment have the strongest connection to Li+, followed by protons 1 and 4 on the pyrrolidinium ring. The interaction between protons 5 and Li+is very weak, suggesting that the DME side chain interacts with Li+through the terminal ether oxygen. The dipolar interaction between Li+and the bulky cation show high selectivity of Li+cation toward proton 3. Based on the contour plots of both HOESY spectra of the NMEP51 electrolytes, a solvation structure of NMEP51 is proposed where two terminal DME oxygen atoms participate in the solvation shell with four F-atoms from PFe' anions completing the six coordination sphere of Li+cation. This solvation structure is also verified in the Raman spectra, where the symbolic PFe' signal at 737 cm'1in pure NMEP IL gets broadened and blueshifts to 748 cm'1in NMEP51 electrolytes due to the Li+solvation, while the DME peak at 846 cm'1and 912 cm'1keeps around the same position with less change. The larger blueshifts of the PFe' signal in the NMEP51 (748 cm'1) compared to the LP30 electrolytes (740 cm'1) indicates more PFe' anion solvated to the Li+center, which agrees well with the NMR analysis. The high solvation degree of PFe salt anions promotes the reduction of solvated salt anions forming LiF SEI. In addition, the oligoether-supported solvation in the designed IL electrolytes changes the electromigrationPCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 of Li+and its cationic solvating species under an electrical field, which leads to increased coordinated transport and thus Li+transport.

[0054] Example 2. NMEP51 properties and SEI formation

[0055] The asymmetric molecular design with DME fragment reduced the freezing and melting point of NMEP51 electrolytes to -18 °C and 3 °C, respectively. The RTIL electrolytes maintained in a liquid state until a high temperature of 200 °C, which ensures a safer cell operation compared to the ether and carbonate electrolytes. The NMEP51 electrolytes also showed high anti-oxidation stability up to 5 V via anodic linear sweep voltammetry (LSV), while the carbonate LP30 electrolytes displayed a less oxidation stability of 4.5 V. The high anodic stability allows NMEP51 electrolytes to support high-voltage NMC811 cathodes. The cathodic stability of NMEP51 and LP30 electrolytes was also examined using cyclic voltammetry (CV). For NMEP51 electrolytes, a broad peak (0.4 V-0.8 V) centered at 0.62 V in the initial scan is ascribed to the reduction of the PFe' anion (from the dissociation of LiPFe salt) and the little bump at 0.37 V is the reduction of DME fragment. The prior reduction of PFe' anion to DME fragment ensures the formation of LiF-rich SEI. In contrast, the LP30 electrolytes showed a large current density of >6 pA cm'2in the range of 0.9 V to 1.6 V, corresponding to the massive decomposition of EC / DMC solvents, which promotes the organic SEI. In the second cathodic scan, the reduction current density was reduced in NMEP51 (<4.2 pA cm'2) compared to that of LP30 electrolytes (>10.7 pA cm'2), demonstrating the effective passivation of the LiF-rich SEI. In addition, the ionic NMEP51 electrolytes also showed low flammability with a self-extinguished time of <2 s, in sharp contrast to the highly flammable (self-extinguished time of >12 s) LP30 electrolytes (Figs. 10A and 10B), which improves battery operation safety.PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0

[0056] The SEI composition on the pSi electrode surface after 50 continuous lithiation / delithiation cycles in NMEP51 and LP30 electrolytes was examined through high- resolution X-ray photoelectron spectroscopy (HRXPS) with an Ar+sputtering depth profiling. The surface of SEI formed in NMEP51 electrolytes was found rich in inorganic species with a high F-ratio of 28.4%, compared to 2.7% found in LP30. On the other hand, the carbon ratio, an indicator of organic components, dominated the SEI surface in LP30 electrolytes (37.2%) but it was only in a minority of 22.1% in NMEP51. The carbon content in NMEP51-SEI decreased rapidly with increasing sputtering time and dropped to less than 10% after 120 s, reaching the noise level (180 s) at the SEI-Si interface. Meanwhile, the F signal was found strong in NMEP51-SEI and increased with sputtering time. Therefore, the pSi particle surface in NMEP51 electrolytes only has LiF-rich SEI with negligible organic components on the SEI surface. Differences were observed in LP30 electrolytes, where the almost constant C (~ 35%), F (~ 5%), and O (~ 22%) ratios existed in all SEI thicknesses, indicating the formation of organic-inorganic SEI. The uniform LiF-SEI coating of Si particles was further verified by electron energy loss spectroscopy (EELS) spectral imaging. The small valence plasmon peak of 25 eV with a sharp shoulder around 15 eV was assigned as LiF. LiF signal sustained through the surface to the inner layer of NMEP51-SEI (Fig. 3 A), which is in good agreement with the XPS atomic distribution. For SEI formed in LP30 electrolytes, the broad peak centered around 26 eV is ascribed to lithium carbonate organics and LixSiOysignal, which overlapped with the weak LiF peaks (Fig. 3B), validating the formation of organic-inorganic mixed SEI. The thickness of the LiF-rich SEI after 400 cycles in NMEP51 electrolytes was also examined by scanning transmission electron microscopy (STEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and determined to be ~3 nm. The crystalline LiF on pSi electrodes cycled in NMEP51 was also validated with bulk powder X-ray diffraction (PXRD), while the negligible signals for Li2O, Li2COs, and organic components indicate their amorphousPCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 presence. Therefore, the characteristic SEI components of crystalline LiF (c-LiF), amorphous LiF (a-LiF), Li2O (a-Li2O), Li2CO3 (a-Li2CO3), and LiOCChCEE (a-LMC) were selected and calculated for their work of Separation (WoS) towards LixSi phases using density functional theory (DFT). Both crystalline and amorphous LiF showed a weaker bonding to the LixSi phases than that of the amorphous Li2O, Li2CO3, and LMC. The LiF SEI formed in NMEP51 electrolytes with high interfacial energy (low WoS) and strong modulus allows the alloying anodes to achieve a high CE and long cycle life, while the organic-rich SEI formed in LP30 electrolytes has low interfacial energy (high WoS) and strong bonding to the alloying phases, which will break during the volume changes of the alloying particles, resulting in electrolyte penetration and fast cell capacity decay.

[0057] Example 3. Electrochemical performance of micro-sized alloying anodes

[0058] The electrochemical performance of the Li||pSi half cells with NMEP51 and LP30 electrolytes was evaluated. The pSi powder (-325 mesh, Sigma, US) was used as-received and the crystallite size of the pSi particles was determined to be -350 nm through Scherrer’s equation. The Li||pSi half cells have a Si mass loading of -2.2 mg cm2and was charged / discharged between 0.05 V and 1.0 V at a current density of C / 20 (179 mA g'1) for the first activation cycle and then cycled at C / 8 (447 mA g'1). The pSi electrodes in the formation cycle with NMEP51 electrolytes delivered a high capacity of 3,137 mAh g'1with an z'CE of 88.7% (C / 20, 1C = 3,579 mA g'1) (Fig. 4A, violet). The CE quickly increased to 99.9% in the 5thcycle with an average CE (aCE) of >99.9% from the 2ndto 400thcycles. The pSi in the NMEP51 electrolytes delivered a high capacity of -2900 mAh g'1at C / 8 (447 mA g'1) with a high-capacity retention of >87% after 400 cycles (Fig. 4A). The capacity of 2537 mAh g'1at the 400thcycle is still more than 6-fold than the graphite theoretical capacity (372 mAh g'1). In contrast, the same Si electrodes in commercial LP30 electrolytes only provided -2937 mAh g'1capacity during the formation cycle with a lower iCE of 83.6%, and the capacity quicklyPCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 dropped to <50% of its initial value within 100 cycles (Fig. 4A) with a low aCE of <98.0% (2ndto 150th). GenF (1.2 MLiPFe-EC / EMC (3 / 7 w / w) + 10 wt% FEC) electrolytes with the addition of fluoroethylene carbonate (FEC) could improve the cycle performance because the reduction of FEC will contribute more LiF in the SEI (Fig. 4A,). However, the inevitable organic SEI from the organic solvent degradation in GenF electrolytes still makes the SEI crack along pSi volume contraction, the cell capacity decreased fast after 50 cycles and eventually dropped to <65% in 100 cycles. The rate performance of NMEP51 electrolytes was also evaluated in the Li||pSi (6.3 mAh cm’2) half cells at room temperature, delivering a discharge capacity of 2865, 2252, 1858, and 1276 mAh g'1at a cycle rate of C / 10 (358 mA g'1), C / 3 (1193 mA g'1), C / 2 (1790 mA g'1), and 1 C (3579 mA g'1), respectively. At a high mass loading of 80% pSi, the NMEP51 electrolytes still enabled the Li||pSi half cells to deliver a high specific capacity of >2300 mAh g'1for 50 cycles, validating the effectiveness of NMEP51 electrolytes in high- loading pSi electrodes.

[0059] The asymmetric design of solvent-free ionic liquid electrolytes provides a simple strategy to stabilize pSi electrodes without using complicated strategies, which can drop in existing LIB manufacturing by simply replacing carbonate electrolytes and graphite anodes with NMEP51 electrolytes and pSi anodes, respectively. The “crack-less” morphology of the pSi particles with self-healing LiF SEI in NMEP51 electrolytes was confirmed by SEM image after 50 cycles (Fig. 4D), which is similar to the crack-free pristine pSi (Fig. 4C). In contrast, the organic-inorganic SEI formed in LP30 electrolytes strongly bonds to pSi particles and cracks along Si pulverization, allowing electrolytes to penetrate cracked particles and form additional SEIs (Fig. IB). The SEIs separated the cracked Si, resulting in the isolation of pulverized Si with huge crack (Fig. 4E), which further leads to the depletion of LP30 electrolytes, thus low-capacity utilization and rapid cell capacity decay. The cyclability of thePCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 pSi electrodes in NMEP51 and LP30 electrolytes (Fig. 4A) is correlated with the SEI analysis (Figs. 3D-E) and p Si cracks (Figs. 4D-E), which strongly supports the pSi capacity degradation mechanism (Figs. 1A-B). The higher stability of LiF-rich SEI than organic SEI was also supported by the restrained pSi electrode thickness growth after 150 cycles in different electrolytes (33 pm for NMEP51, 72 pm for LP30) (Fig. 4B). Moreover, the thickness evolution trend of the pSi electrodes in NMEP51 and LP30 electrolytes (Fig. 4B) is in agreement with the thickness evolution depicted in Fig. 1C, which validated the mechanism of how the Si-phobic LiF SEI and Si-philic organic SEI affect the cycle performance on pSi electrodes. The NMEP51 electrolytes apply also to alloying anodes with large particle sizes, including Al, Sn, and Bi, because the LiF-rich SEI has a weak bonding to all alloying phases LixM (M = Al, Sn, Bi). NMEP51 electrolytes enabled over 300 cycles for Li||pM (2.0 mAh cm’2, M = Al, Sn, Bi) half cells with no obvious capacity decay and a high aCE of >99.9% (Fig. H).

[0060] Example 4. Electrochemical performance of full cells

[0061] The high anodic stability of NMEP51 electrolytes and its superior capacity reversibility on different micro-sized alloying anodes (Fig. 4A, Fig. 11) enables the evaluation of the full cell performance using the high-voltage NMC811 cathodes. The pSi electrode is first used as the representative anode to evaluate the pSi||NMC811 full cell (4.5 mAh. cm'2, N / P = 1.4) performance. The cycling stability and CE between 2.8 to 4.4 V are shown in Figs. 5A-5B. The high cut-off voltage of 4.4 V enables the NMC811 cathodes to have the 03 to 01 phase transition at around 4.1V, enhancing the discharge capacity to 200 mAh g'1(Fig. 5B). The 4.1 V phase transition plateau was well-preserved in NMEP51 (Fig. 5B), but gradually disappeared in LP30 electrolytes, indicating that the pSi||NMC811 cells remained stable in NMEP51 electrolytes but decayed fast in LP30 during cycling. The capacity of pSi||NMC811 full cellsPCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 cycled in NMEP51 electrolytes has a high reservation of >85% at the 200thcycle with an aCE of >99.9%, but the cell capacity in LP30 electrolytes quickly dropped in 20 cycles with a low full cell aCE of <97% (Fig. 5 A). The NMEP51 electrolytes also enabled good cyclability for the 4.5 mAh cm'2pSi||NMC811 full cells at a low N / P ratio of 1.1, delivering a high discharge capacity of 186, 153, 125, and 86 mAh g'1at a cycle rate of C / 10 (20 mA g'1), C / 3 (67 mA g'J), C / 2 (100 mA g-1)and 1 C (200 mA g'1), respectively. The rate performance can be further improved when using low-loading electrodes (2.0 mAh cm'2, porosity of 62.6%). The pSi||NMC811 full cells (1.8 mAh cm'2, N / P = 1.1) delivered a discharge capacity of 88 mAh g'1at 3C at room temperature, and this value can be further improved to 120 mAh g'1at an elevated temperature of 40 °C, demonstrating the potential of NMEP51 electrolytes for higher rate cell cycling. In addition, the high-voltage stability of NMEP51 electrolytes also enabled the successful cycle of 4.8 V pSi||Lii.2Nio.i3Coo.i3Mno.5402(LRM) full cells (2.0 mAh cm'2, N / P = 1.1) with a capacity retention of >96.6% for 50 cycles. The full cells using pAl, pSn, or pBi anodes and NMC811 cathode show high cycling stability in NMEP51 electrolytes. Under a practical N / P ratio of 1.1, the pM (M = Al, Sn, Bi)||NMC811 (1.8 mAh cm'2, N / P = 1.1) full cells demonstrated superior cyclability for >150 cycles with a high capacity retention of >90%.

[0062] To test the stability of the electrolyte under more realistic conditions, the 90 mAh pSi||NMC811 (4.5 mAh cm'2) pouch cells with lean NMEP51 electrolytes (E / C ratio of ~3 g Ah'1) and low N / P ratio (~1.4) were fabricated. The electrochemical performance of the 90 mAh pSi||NMC811 pouch cells was evaluated between 2.8 V and 4.4 V at a low external pressure of 0.1 MPa (Fig. 5C). The pSi||NMC811 pouch cells demonstrated >72% capacity retention after 200 cycles at C / 8 (25 mA g'1) (Fig. 5C). The NMEP51 electrolyte is the only electrolyte that enables LIBs with micro-sized alloying anodes and NMC811 cathode to achieve a long cycle life of >200 under such conditions (lean electrolytes of 3gE Ah'1, low N / PPCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 ratio of 1.4, low external pressure of 0.1 MPa). All other state-of-the-art electrolytes can only support nano-LixSi||NMC811 full cells that require pre-lithiation for nano-Si anodes, suffering a high cost and low calendar life (Tables 1-2). In addition, the surface chemistry on NMC811 cathodes after 50 consecutive cycles (2.8V - 4.4 V) in both NMEP51 and LP30 electrolytes was investigated using HRXPS and scanning transmission electron microscope (STEM), where a thin layer (3 nm) of LiF-rich cathode electrolyte interphase (CEI) was found for NMEP51- cycled NMC811 electrodes, in comparison with a thick (5 nm) organic-rich CEI in LP30 electrolytes, which is found responsible for the long cycle performance in pM (M = Si, AL, Sn, Bi)||NMC811 full cells.

[0063] Sulfurized polyacrylonitrile (SPAN) has a higher energy density and lower cost than NMC811, making it a promising cathode for high-energy Li batteries. However, the large volume change of SPAN particles limits its electrochemical cycle performance. NMEP51 electrolytes can form LiF-rich CEI on both SPAN and S cathodes, which enables SPAN and S particles to expand / contract inside the LiF-CEI core-shell without cracking the LiF SEI, thus extending the cycle life of SPAN and S. The Li3.7sSi||SPAN (3.5 mAh cm’2, N / P =1.8) full cells exhibited an excellent initial discharge capacity of -1000 mAh g1in NMEP51 electrolytes (900 mAh g'1in LP30) with a high iCE of 83.5% (78.2% in LP30) and high capacity retention of 80.7% was achieved in NMEP51 electrolytes after 250 cycles (50% capacity in 50 cycles for LP30) (Figs. 5D-5E). Moreover, the 70 mAh Li3.7sSi||SPAN pouch cells (lean NMEP51 electrolytes of -3 gE Ah'1, low N / P ratio of 1.8, and low operating pressure of 0. IMPa) showed an ultra-stable cycle performance for 400 cycles with >85.3% capacity retention (>690 mAh g'1at 400thcycle) between 1.0 V and 3.0 V at C / 8 (100 mA g'1) (Fig. 5F). Based on the Betz’s model, the specific (Wh kg'1) and volumetric (Wh L'1) energy density for pSi||NMC811, Li3.75Si||SPAN, and pSi||LRM in 18650-type cells is projected to be 341 / 840, 245 / 501, andPCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0 165 / 403, respectively, which is poised to increase the energy density and reduce the cost of current LIBs. The calculated specific and volumetric energy density for the 90 mAh pSi||NMC811 and 70 mAh Li3.7sSi||SPAN single-layer pouch cells is 189 / 321 and 68 / 124, respectively.

[0064] Example 5. Practical Considerations

[0065] The successful integration of the “DME” fragment into the methylpyrrolidinium cation through asymmetric design allows the NMEP / LiPFe electrolytes to be used on micro-sized alloying anodes, achieving high CE of >99.9% for pSi, pSn, pBi, and pAl anodes and high cycle performance for pM (M = Si, AL, Sn, Bi)||NMC811, pSi||LRM, Li3.7sSi||SPAN full cells at a cycle rate of C / 8. To meet the practical requirements for potential commercialization and maximize the energy density of the pSi||NMC811 cells, the electrolytes should be able to deliver a high-rate performance with high-loading, low-porosity electrodes at room temperature. Therefore, the asymmetric design of NMEP51 ionic liquid electrolytes was updated by using asymmetric small molecules. As shown in Fig. 6A, the asymmetric design of the 1 -ethoxy -2-methoxy ethane (EME) molecule also resolves the polymerization issues of oxyethylene / LiPFe and allows the compatibility between LiPFe salt and small molecule EME, which enables high performance on pSi anodes. HRXPS and post-mortem analysis on cycled pSi electrodes using EME / LiPFe electrolytes revealed the formation of LiF SEI and restrained electrode swelling, which is in high consistency with the NMEP51-cycled ones. That is, the asymmetric molecular design enables the compatibility between low-reduction ether solvents and LiPFe salt, which will promote LiF-rich SEI on the alloying anodes (Fig. 6A).

[0066] The EME / LiPFe electrolytes enabled a high-rate performance on both Li| | pSi half cells (5.0 mAh cm’2, 5C, >1100 mAh g'1) and pSi||NMC811 full cells (4.5 mAh cm’2, N / P = 1.1, 5C, >127 mAh g'1) at room temperature, promising for fast charging LIBs. A long cycle life of 400PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 cycles was achieved in the Li||pSi half cells at C / 3 rate with a high capacity retention of >86%.The EME / LiPFe electrolytes also enabled the pSi||NMC811 full cells (4.5 mAh cm'2, N / P = 1.1) to achieve 200 cycles performance with a capacity retention of >90% at C / 3 (1C = 200 mA g'1) (Figs. 6B-C), projecting high commercialization potential for pSi||NMC811 batteries.

[0067] Example 6. General Methods

[0068] Lithium hexafluorophosphate (LiPFe, >99.99%) salt was purchased from Gotion Company. N-methylpyrrolidine (>98%), 2-methoxyethoxymethyl chloride (technical grade), 1 -ethoxy -2-methoxy ethane (EME) and sodium hexafluorophosphate (NaPFe, 98%) were purchased from Sigma-Aldrich, US. Solvents diethyl ether (>99%), acetonitrile (>99%), N- m ethyl- 1,2-pyrrolidone (>99%), di chloromethane, and acetone (99%) were purchased through the Chem-store of Chemistry Department, University of Maryland, College Park, and used as received without further purification. The DME-doped RTILs were synthesized through a two- step reaction with synthetic details and characterization is shown in Figures 7-9.

[0069] Example 7. Electrolytes and Electrode Preparation

[0070] Electrolyte solutions of NMEP and LiPFe with different ratios were prepared by dissolving LiPFe salt into dried NMEP ionic liquids in a plastic vial in an argon-filled glovebox at 25 °C with moisture and oxygen level less than 0.1 ppm. Homogeneous and clear solutions were obtained by a careful magnetic stirring of the mixture overnight. Commercial carbonate LP30 (1.0 M LiPFe in EC / DMC=50 / 50 (wt / wt)) electrolytes were used as obtained from Sigma-Aldrich, US. The EME / LiPFe electrolytes were prepared by dissolving LiPFe salt in commercially obtained EME solvent (dried over molecular sieves before usage, other weak solvated solvents can be used to optimize the solvation structure, i.e., 1,2-dimethoxy propane, cyclopentyl methyl ether, et al.). The Li chips with a thickness of 250 pm were purchased from MTI Corporation.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0071] For the SiMP electrodes, a slurry was prepared by dispersing pSi particles (-325 mesh,Sigma, US, as-received, particle confirmed by SEM), lithium polyacrylate binder (10 wt% aqueous solutions) and Ketjen black in water with a weight ratio of 6:2:2 or 8: 1 : 1. The slurry was cast onto a copper (Cu) foil, dried at room temperature for 24 h and further dried at 90 °C overnight under vacuum. The pSi electrodes with an areal loading of 2.2 / 1.7 / 0.70 mg cm'2(corresponding to 6.3 / 5.0 / 2.0 mAh cm'2from a practical capacity release of -2900 mAh gsi'1) were obtained. The pSi electrode processing is the same as that of commercial graphite electrodes without any additional pretreatments. For the A1MP, SnMP, and BiMP electrodes, a similar protocol was applied for the electrode preparation, except to change the active materials (A1MP, SnMP, and BiMP), binder, and carbon black weight ratio to 8: 1 : 1. The active materials were controlled to reach an areal loading of -2.0 mAh cm'2for A1MP, SnMP, and BiMP electrodes.

[0072] The LiNio.8Coo.1Mno.1O2 (NMC811) cathodes coated on Al foil with areal loadings of -1.8 and 4.5 mAh cm'2were kindly provided by Saft America Inc. The SPAN materials were prepared by ball-milling polyacrylonitrile (Sigma- Aldrich, Mw = 150,000) and elemental sulfur (Sigma-Aldrich) with a mass ratio of 1 :4 for three hours. The mixed powders were then heated in an argon-filled tube furnace at 350 °C for 12 hours with a ramp rate of 2 °C min-1, cooled down naturally afterward. The SPAN cathode was prepared by mixing the synthesized SPAN powder, Super-P, and PVDF in a mass ratio of 80: 10:10 with N-methyl pyrrolidinone as the solvent, then hand-casting on carbon-coated Al foil and drying overnight in a vacuum oven at 60 °C. The mass loading of the electrode is -3.5 mg cm'2, corresponding to an areal capacity of 3.5 mAh cm'2, given the largest capacity release of -1000 mAh g'1. The S cathode was cast by mixing the S-C composite (75 wt% S) : C65 : PVDF in a mass ratio of 84:8:8 with N-methyl pyrrolidinone as the solvent, then hand-casted on carbon-coated Al foil and dried overnight in a vacuum oven at 60 °C. The mass loading of the S electrode is -5.0 mg cm'2. ThePCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0Li-rich material Li1.2Nio.13Coo.13Mno.54O2 (LRM) was purchased from MTI Corporation. The LRM was mixed with polyvinylidene fluoride (PVDF) and carbon black (C65) in a mass ratio of 8: 1 : 1 with N-Methyl-2-pyrrolidone (NMP) as the solvent. Then hand-casted onto Al foil with a doctor-blade and vacuum-dried at 120 °C. The mass loading of the LRM cathode was about 6.5 mg cm’2, and the dried electrode was cut into 12 cm diameter discs for further use.

[0073] Example 8. Electrochemical Measurements

[0074] All battery parts used are commercially available and electrochemical tests were carried out in a 2032-type coin-cell or homemade pouch-cell configurations. All cells were fabricated in an argon-filled glovebox (O2 and H2O <0.1 ppm), and one layer of Celgard 3501 (NMEP51) or 2325 (EME / LiPFe) separator was used. The cathodes (NMC811, SPAN) with a diameter of 12.7 mm (1 / 2 inch) were coupled with the same size of pSi electrode as the anode. The N / P ratio was controlled via different areal loadings of the cathodes and anodes. The electrolytes used for the cell assembly were: “NMEP51” - NMEP : LiPFe in a molar ratio of 5: 1, 2.0 M LiPF6in EME and “LP30” - 1.0 M LiPF6in EC / DMC=50 / 50 (wt / wt). All the galvanostatic cells were tested using a Wuhan LAND Electronic Company CT2001A tester. The self-made pouch cells were assembled with an active material size of 4 cm x 5 cm, and the cycle test was carried out on an Arbin battery test station (BT2000, Arbin Instruments). In the galvanostatic Li||pSi half cell tests, the current density was set at 1 / 8 C (447 mA g'1) in the potential range 0.05-1.0 V vs Li / Li+, and one activation cycle with a voltage cutoff of 0.005 V was performed at 1 / 20C (179 mA g'1). The rate performance of the Li| | pSi half cells was evaluated from C / 10 (358 mA g'1), C / 3 (1193 mA g'1), C / 2 (1790 mA g'1), to 1 C (3579 mA g'1), the cells were cycled at a constant rate for six repeated cycles until changed to the next rate. The full cells were charged / discharged at the corresponding voltage range: pSi||NMC811 (2.8 V-4.4 / 4.2 V) and Li3.75Si||SPAN (1.0 V-3.0 V). The rate performance of the pSi||NMC811 full cells was evaluated from C / 10 (20 mA g'1), C / 3 (67 mA g'1), C / 2 (100 mA g'1) to 1 C (200 mA g'1), thePCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 cells were cycled at a constant rate for six repeated cycles until changed to the next rate. All the electrochemical measurements were conducted at room temperature (25 to 27 °C). Li+transference number (LTN), and electrochemical impedance spectroscopy (EIS) were tested on a Gamry 1000E electrochemical workstation (USA) The electrochemical impedance spectroscopy measurements were taken over a frequency range of 1 MHz to 0.1 Hz. Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were conducted on a CHI 600E electrochemical workstation (CH Instruments Inc. USA). The anodic tests LSV were tested over a voltage range of 2.5 to 6 V in Li||Al cells at a scan rate of 0.5 mV.S’1and the SEI formation kinetics were studied in CV test at a scan rate of 0.5 mV. S'1in the voltage range of 0 to 1.5 V in Li||Cu cells.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0Table 1. Comparison of the present disclosure and reported ionic liquid electrolytes on Si anodes. The first 16 rows are nano-Si refs and the remainder are micro-Si refs are highlighted.PCT ApplicationApplicant Ref: 2024-059-02Aty Dkt. No.: UMD-042PCT0Note: * 200 mesh Si was used with ball-milling to downsize the particle to <1 pm based on the electrode SEM; ** Elkem Silgrain® e-Si 400 is used, and the particle size is projected to be ~l-5 pm; *** Si (-325 mesh, Sigma, US) was used as the received, particles confirmed by SEM.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0Table 2. Comparison of the state-of-the-art battery performances using micro-sized silicon as anodes.Note: LP40: 1.0 M LiPFe-EC / DEC (1 : 1 by weight); N / A indicates “not available”; PFM, PR-PAA and HEA-co-DMA are the abbreviations of functional binders used in the corresponding work.PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0

[0075] All publications mentioned herein are incorporated by reference to the extent they support the present invention.

[0076] REFERENCES

[0077] A number of patents and publications are cited above in order to more fully describe and disclose the invention and the state of the art to which the invention pertains. Full citations for these references are provided below. Each of these references is incorporated herein by reference in its entirety into the present disclosure, to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference.[1] Choi, J. W. et al. Promise and reality of post-lithium-ion batteries with high energy densities. Nat. Rev. Mater. 1, 1-16 (2016).[2] Liu, J. et al. Pathways for practical high-energy long-cycling lithium metal batteries. Nat. Energy 4, 180-186 (2019).[3] Albertus, P. et al. A. Status and challenges in enabling the lithium metal electrode for high-energy and low-cost rechargeable batteries. Nat. Energy 3, 16-21 (2017).[4] Obrovac, M. N. et al. Alloy negative electrodes for Li-ion batteries. Chem. Rev. 114, 11444-11502 (2014).[5] He, Y. et al. Progressive growth of the solid-electrolyte interphase towards the Si anode interior causes capacity fading. Nat. Nanotechnol. 16, 1113-1120 (2021).[6] Sung, J. et al. Subnano-sized silicon anode via crystal growth inhibition mechanism and its application in a prototype battery pack. Nat. Energy 6, 1164-1175 (2021).[7] Li, Y. et al. Growth of conformal graphene cages on micrometer-sized silicon particles as stable battery anodes. Nat. Energy 1, 1-9 (2016).[8] Jia, H. et al. Hierarchical porous silicon structures with extraordinary mechanical strength as high-performance lithium-ion battery anodes. Nat. Commun. 11, 1474 (2020).PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0[9] Park, S.-H. etal. High areal capacity battery electrodes enabled by segregated nanotube networks. Nat. Energy 4, 560-567 (2019).

[0010] McBrayer, J. D. el al. Calendar aging of silicon-containing batteries. Nat. Energy 6, 866-872 (2021).

[0011] Kim, N. et al. Issues impeding the commercialization of laboratory innovations for energy-dense Si-containing lithium-ion batteries. Nat. Energy, 9, 921-933 (2023).

[0012] Chen, J. etal. Electrolyte design for LiF-rich solid-electrolyte interfaces to enable high- performance microsized alloy anodes for batteries. Nat. Energy 5, 386-397 (2020).

[0013] Yang, F. etal. Achieving High-Performance Metal Phosphide Anode for Potassium Ion Batteries via Concentrated Electrolyte Chemistry. Adv. Energy Mater. 11, 2003346 (2020).

[0014] Jia, H. et al. High-Performance Silicon Anodes Enabled By Nonflammable LocalizedHigh-Concentration Electrolytes. Adv. Energy Mater. 9, 1900784 (2019).

[0015] Li, X. etal. Understanding steric hindrance effect of solvent molecule in localized high- concentration electrolyte for lithium metal batteries. Carbon Neutrality, 2, 34 (2023).

[0016] Philippe, B. et al. Role of the LiPFe salt for the long-term stability of silicon electrodes in Li-ion batteries-A photoelectron spectroscopy study. Chem. Mater. 25, 394-404 (2013).

[0017] Chen, L. et al. High-Energy Li Metal Battery with Lithiated Host. Joule 3, 732-744 (2019).

[0018] MacFarlane, D. R. et al. Ionic liquids and their solid-state analogues as materials for energy generation and storage. Nat. Rev. Mater. 1, 1-15 (2016).

[0019] Watanabe, M. et al. Application of Ionic Liquids to Energy Storage and ConversionMaterials and Devices. Chem. Rev. 117, 7190-7239 (2017).

[0020] Jiang, S. et al. Viscosity of typical room-temperature ionic liquids: a critical review. JJ. Phys. Chem. Ref. Data 48, 033101 (2019).PCT Application Applicant Ref: 2024-059-02 Atty Dkt. No.: UMD-042PCT0

[0021] Piper, D. M. et al. Stable silicon-ionic liquid interface for next-generation lithium-ion batteries. Nat. Commun. 6, 1-10 (2015).

[0022] Mac Glashan, G. S. et al. Structure of the polymer electrolyte poly (ethylene oxide)e:LiAsF6. Nature 398, 792-794 (1999).

[0023] Kama, M. et al. Preparation and characterization of new low-melting ammonium -based ionic liquids with ether functionality. J. Mol. Struct. 922, 64-76 (2009).

[0024] Sato, T. et al. Electrochemical properties of novel ionic liquids for electric double layer capacitor applications. Electrochim. Acta, 49, 3603-3611 (2004).

[0025] Borodin, O. et al. Li+cation environment, transport, and mechanical properties of theLiTFSI doped N-methyl-N-alkylpyrrolidinium+ TFSI-ionic liquids. J. Phys. Chem. B 110, 16879-16886 (2006).

[0026] Bruce, P.G. et al. Conductivity and transference number measurements on polymer electrolytes. Solid State Ion. 28, 918-922 (1988).

[0027] Qiao, B. et al. Supram olecular Regulation of Anions Enhances Conductivity and Transference Number of Lithium in Liquid Electrolytes. J. Am. Chem. Soc. 140, 10932-10936 (2018).

[0028] Ma, P. et al. Effect of Building Block Connectivity and Ion Solvation on Electrochemical Stability and Ionic Conductivity in Novel Fluoroether Electrolytes. ACS Cent.Sci. 7, 1232-1244 (2021).

[0029] Martin, P. A. et al. Correlating Intermolecular Cross-Relaxation Rates with Distances and Coordination Numbers in Ionic Liquids. J. Phys. Chem. Lett. 9, 7072-7078 (2018).

[0030] Han, S.-D. et al. Solvate Structures and Computational / Spectroscopic Characterization of LiPF6 Electrolytes. J. Phys. Chem. C 119, 8492-8500 (2015).PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0031] Zheng, J. etal. 3D visualization of inhomogeneous multi-layered structure and Young's modulus of solid electrolyte interphase (SEI) on silicon anodes for lithium-ion batteries. Phys. Chem. Chem. Phys. 16, 13229-13238, (2014).

[0032] Philippe, B. et al. Improved performances of nanosilicon electrodes using the salt LiFSI: a photoelectron spectroscopy study. J. Am. Chem. Soc. 135, 9829-9842 (2013).

[0033] Philippe, B. et al. Nanosilicon electrodes for lithium-ion batteries: interfacial mechanisms studied by hard and soft X-ray photoelectron spectroscopy. Chem. Mater. 24, 1107-1115 (2012).

[0034] Egerton, R.F. et al. EELS in the TEM. J. Electron Spectros. Relat. Phenomena 143, 43- 50 (2005).

[0035] Danet, J. etal. Valence electron energy-loss spectroscopy of silicon negative electrodes for lithium batteries. Phys. Chem. Chem. Phys. 12, 220-226 (2010).

[0036] Li, A.M. et al. High voltage electrolytes for lithium-ion batteries with micro-sized silicon anodes. Nat. Commun. 15, 1206 (2024).

[0037] Boniface, M. et al. Nanoscale Chemical Evolution of Silicon Negative Electrodes Characterized by Low-Loss STEM-EELS. Nano Lett. 16, 7381-7388 (2016).

[0038] Choi, N.S. et al. Effect of fluoroethylene carbonate additive on interfacial properties of silicon thin-film electrode. J. Power Sources 161, 1254-1259 (2006).

[0039] Park, S. et al. Liquid electrolyte chemistries for solid electrolyte interphase construction on silicon and lithium-metal anodes. Chem. Set. 14, 9996-10024 (2023).

[0040] Kovalenko, I. et al. A major constituent of brown algae for use in high-capacity Li-ion batteries. Science, 334, 75-79 (2011).

[0041] Zhu, T. et al. Formation of hierarchically ordered structures in conductive polymers to enhance the performances of lithium-ion batteries. Nat. Energy 8, 129-137 (2023).PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0

[0042] Choi, S. et al. Highly elastic binders integrating polyrotaxanes for silicon microparticle anodes in lithium-ion batteries. Science, 357, 279-283 (2017).

[0043] Lee, S.W. et al. Fracture of crystalline silicon nanopillars during electrochemical lithium insertion. Proc. Natl. Acad. Sci. USA 109, 4080-4085 (2012).

[0044] Park, H. et. al. Novel design of silicon-based lithium-ion battery anode for highly stable cycling at elevated temperature. J. Mater. Chem. A 3, 1325-1332 (2015).

[0045] Wu, H. et al. Stable cycling of double-walled silicon nanotube battery anodes through solid-electrolyte interphase control. Nat. Nanotechnol. 7, 310-315 (2012).

[0046] Heist, A. et al. Electrochemical Analysis of Factors Affecting the Kinetic Capabilities of an Ionic Liquid Electrolyte. J. Electrochem. Soc. 166, NUSll (2019).

[0047] Betz, J. et al. Theoretical versus practical energy: a plea for more transparency in the energy calculation of different rechargeable battery systems. Adv. Energy Mater. 9, 1803170 (2019).

[0048] Kim, N. et al. Fast-charging high-energy lithium-ion batteries via implantation of amorphous silicon nanolayer in edge-plane activated graphite anodes. Nat. Commun. 8, 812(2017).

[0049] Han, J. G. et al. An electrolyte additive capable of scavenging HF and PF5 enables fast charging of lithium-ion batteries in LiPF6-based electrolytes. J. Power Sources 446, 227366 (2020).

Claims

PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0CLAIMSWe claim:

1. An asymmetric electrolyte composition for lithium-ion batteries, said electrolyte composition comprising a liquid and at least one lithium salt; wherein said liquid is an ionic liquid or a molecular solvent; wherein said ionic liquid comprises an anionic component and a cationic component; and wherein said cationic component is a cation of Formula I:Formula I wherein R1is chosen from H, C1-4 alkyl, and C1-4 alkyl ether; andR2is an oxyethylene derivative.

2. The asymmetric electrolyte composition of claim 1, wherein said anionic component is chosen from PFe' or BF4 .

3. The asymmetric electrolyte composition of any of the preceding claims, wherein said anionic component is PFe'.

4. The asymmetric electrolyte composition of any of the preceding claims, wherein R1is chosen from H, methyl, and methyl ether.

5. The asymmetric electrolyte composition of any of the preceding claims, wherein R1is methyl.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT06. The asymmetric electrolyte composition of any of the preceding claims, wherein R2is chosen from -(CH2)[O(CH2)2O]nCH3 or -(CH2)O(CH2)nOCH3, wherein n is greater than or equal to 1.

7. The asymmetric electrolyte composition of any of the preceding claims wherein R2is -(CH2)[O(CH2)2O]CH3, when n is 1.

8. The asymmetric electrolyte composition of any of the preceding claims, wherein said at least one lithium salt is chosen from LiPFe, LiFSI, LiBF4, and LiDFOB, or combinations thereof.

9. The asymmetric electrolyte composition of any of the preceding claims, wherein said at least one lithium salt is LiPFe.

10. The asymmetric electrolyte composition of any of the preceding claims, wherein said electrolyte composition is in a liquid phase over a temperature range from about -18 °C to about 200 °C.

11. The asymmetric electrolyte composition of any of the preceding claims, wherein said liquid and said at least one lithium salt are free of polymerization products upon combination.

12. The asymmetric electrolyte composition of any of the preceding claims, wherein said molecular solvent is chosen from l-ethoxy-2-m ethoxy ethane, cyclopentyl methyl ether, 1,2-dimethoxypropane, or combinations thereof.

13. The asymmetric electrolyte composition of any of the preceding claims, wherein said molecular solvent is l-ethoxy-2-methoxy ethane.

14. The asymmetric electrolyte composition of any of the preceding claims, further comprising a co-solvent, wherein said co-solvent is chosen from 1,3-dioxolane, 2-methyl-l,3- dioxolane, 4-methyl-l, 3, -dioxolane, 1,4 dioxane, 2-methyl-l,4 dioxane, tetrahydropyran, 2-PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT0 methyltetrahydropyran, 3 -methyltetrahydropyran, and 4-m ethyltetrahydropyran, or combinations thereof.

15. The asymmetric electrolyte composition of any of the preceding claims, wherein said liquid is an ionic liquid, wherein R1is methyl, R2is -(CH2)[O(CH2)2O]CH3, when n is 1, said anionic component is PFe’, and said at least one lithium salt is LiPFe'.

16. The asymmetric electrolyte of any of the preceding claims, wherein said ionic liquid and said at least one lithium salt are present at a concentration of about 5 to about 1.

17. A lithium-ion battery, said battery comprising a cathode, an anode, and the electrolyte composition of any of the preceding claims.

18. The lithium-ion battery of claim 18, wherein said anode comprises a microsized anode material or a microsized anode material / carbon composite.

19. The lithium-ion battery of any of the preceding claims, wherein said microsized anode material comprises microsized Si, microsized Al, microsized Sn, microsized Bi, or carbon composites thereof.

20. The lithium-ion battery of any of the preceding claims, wherein said microsized anode comprises microsized Si.

21. The lithium-ion battery of any of the preceding claims, wherein said carbon composite comprises graphite, hard carbon, or soft carbon, and combinations thereof.

22. The lithium-ion battery of any of the preceding claims, wherein said cathode is chosen from NMC811, lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA), and sulfurized polyacrylonitrile (SPAN).

23. The lithium-ion battery of any of the preceding claims, wherein said cathode isNMC811.PCT ApplicationApplicant Ref: 2024-059-02Atty Dkt. No.: UMD-042PCT024. The lithium-ion battery of any of the preceding claims, wherein said cathode is NMC811, said anode is microsized Si, and said electrolyte is the asymmetric electrolyte composition of claim 15.

25. A method of assembling a lithium-ion battery of any of the preceding claims, said method comprising layering a cathode, an electrolyte composition of any of the preceding claims, and an anode to obtain multiple layers.

26. The method of claim 25, wherein said layering comprises first layering a cathode, then said electrolyte composition, then said anode.

27. The method of any of the preceding claims, wherein said cathode, said electrolyte composition, and said anode are sealed in a battery casing.

28. The method of any of the preceding claims, wherein said battery casing is a coin cell or a pouch cell.

29. A method of supplying power, said method comprising using the battery of any of the preceding claims to supply a voltage upon discharging.

30. The method of claim 29, wherein said voltage is about 3.3 V.

Images