CYAN-CONTAINING ORGANOFLUORBORATE ADDITIVES FOR LITHIUM ION BATTERIES

Abstract

Electrolyte fluid comprising at least 0.01 wt% of an additive selected from a compound of formula (I), formula (II), formula (III) and formula (IV): wherein, if the additive is the compound of formula (I), m is an integer equal to or greater than 1 and equal to or less than 9, and M+ is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion; if the additive is the compound of formula (II), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, and M+ is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion;and if the additive is the compound of formula (III), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, and M+ is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion, and a quaternary phosphonium ion; and if the additive is the compound of formula (IV), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, q is an integer equal to or greater than 1 and equal to or less than 9, and M+ is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion, and a quaternary phosphonium ion.

Description

AREA

[0001] This disclosure relates generally to battery cells and in particular to electrolyte additives for use in lithium-ion battery cells. US GOVERNMENT LICENSE RIGHTS

[0002] This invention was made with U.S. government support under WFO application no. 85C85. The present invention was made under CRADA 1500801 between Apple Inc. and Argonne National Laboratory, which is operated for the U.S. Department of Energy. The U.S. government has certain rights in the invention. BACKGROUND

[0003] Lithium-ion batteries are frequently used as power sources in consumer electronics. Consumer electronics require lithium-ion batteries that deliver higher volumetric energy densities and can withstand more discharge-charge cycles. A lithium-ion battery typically operates at a voltage of up to 4.45 V (full cell voltage).

[0004] A battery's lifespan can deteriorate due to instability of the cathode structure and electrolyte degradation. The stability of the cathode material can be improved by modifying LiCoO2, such as doping and surface coating. Limited progress has been made in developing electrolytes capable of delivering both high volumetric energy densities and long battery life. Most existing electrolytes exhibit poor ability to form stable cathode electrolyte interphases (CEI) and / or solid electrolyte interphases (SEI), resulting in rapid interfacial impedance growth and capacity degradation. SUMMARY

[0005] In a first respect, the disclosure relates to an electrolyte fluid comprising at least 0.01 wt% of an additive selected from a compound of formula (I), formula (II), formula (III) and formula (IV).

[0006] In a second aspect, the disclosure relates to an electrolyte fluid comprising at least 0.01 wt% of an additive selected from a compound of formula (I), formula (II), and formula (III). The electrolyte fluid may comprise at least 0.01 wt% of a compound of formula (I). The electrolyte fluid may comprise at least 0.01 wt% of a compound of formula (II). The electrolyte fluid may comprise at least 0.01 wt% of a compound of formula (III). The electrolyte fluid may comprise at least 0.01 wt% of a compound of formula (IV).

[0007] If the additive is the combination of formula (I), then m is an integer equal to or greater than 1 and equal to or less than 9, and M + is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion.

[0008] If the additive is the combination of formula (II), then m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, and M + is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion.

[0009] If the additive is the combination of formula (III), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, and M + is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion.

[0010] If the additive is the combination of formula (IV), then m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, q is an integer equal to or greater than 1 and equal to or less than 9, and M + is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion.

[0011] In some variations, the additive is the potassium organotrifluoroborate compound potassium (cyanomethyl)trifluoroborate (PCTFB). In some variations, the additive is the organotrifluoroborate lithium (cyanomethyl)trifluoroborate (LiCTFB).

[0012] In some variations, the electrolyte fluid can be an electrolyte salt consisting of LiPF6, LiBF4, LiClO4, LiSO3CF3, LiN(SO2F)2, LiN(SO2CF3)2, LiBC4O8, Li[PF3(C2CF5) 3], LiC(SO2CF3)3 and a combination thereof is selected.

[0013] In some variations, the electrolyte fluid may include a solvent selected from ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl propionate (EP), butyl butyrate (BB), methyl acetate (MA), methyl butyrate (MB), methyl propionate (MP), propylene carbonate (PC), ethyl acetate (EA), propyl propionate (PP), butyl propionate (BP), propyl acetate (PA), butyl acetate (BA) and a combination thereof.

[0014] In some variations, the electrolyte fluid may include an additive selected from (LiDFOB), pro-1-ene-1,3-sultone (PES), methylenemethanedisulfonate (MMDS), vinylethylene carbonate (VEC), propane sultone (PS), fluoroethylene carbonate (FEC), succinonitrile (SN), vinyl carbonate (VC), adiponitrile (ADN), ethylene glycol bis(2-cyanoethyl) ether (EGPN), 1,3,6-hexanetricarbonitrile (HTCN) and a combination thereof.

[0015] In some variations, the disclosure relates to a battery cell. The battery cell may include a cathode with a cathode-active material arranged on a cathode current collector, and an anode with an anode-active material arranged on an anode current collector. The anode is oriented towards the cathode such that the anode-active material faces the cathode-active material. A separator is arranged between the cathode-active material and the anode-active material. An electrolyte fluid, as described herein, is arranged between the cathode and the anode. List of characters

[0016] The revelation is easily understood through the following detailed description in conjunction with the accompanying drawings, where identical reference numbers denote identical structural elements, and in which: Fig.1. A top view of a lithium battery cell according to an illustrative embodiment; and Fig. 2 a perspective view of a battery cell according to an illustrative embodiment; Fig. 3 shows a cycle power energy retention at cycle 201 for a battery operating at 45 °C of the control electrolyte, compared to the control including 0.5 wt.% PCTFB according to an illustrative embodiment; Fig. 4 shows the RSS at cycle 201 for a battery operating at 45 °C of the control electrolyte, compared to the control, including 0.5 wt% PCTFB according to an illustrative embodiment; Fig. Figure 5 shows a representation of the cycle power energy retention at cycle 200 at 45 °C of the control electrolyte compared to the control including 0.5 wt.% PCTFB according to an illustrative embodiment; Fig.6 RSS as a function of the battery cycle counter at 45 °C for a battery with a spreading electrolyte and an electrolyte including 0.5 wt.% PCTFB according to an illustrative embodiment; Fig. 7. The capacity recovery of different electrolyte compositions containing HTCN and optionally LiCTFB after 8 hours of battery storage at 85 °C according to an illustrative embodiment; Fig. 8 represents an improved lithium plating of different electrolyte compositions containing HTCN and optionally LiCTFB after battery operation at -3 °C according to an illustrative embodiment; and Fig. 9 represents the formation of a solid electrolyte boundary layer according to an illustrative embodiment. DETAILED DESCRIPTION

[0017] Reference is now made in detail to representative embodiments, which are illustrated in the accompanying drawings. It is understood that the following descriptions are not intended to limit the embodiments to a single preferred embodiment. On the contrary, the intention is to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of protection of the described embodiments as defined by the attached claims.

[0018] Fig.Figure 1 shows a top view of a battery cell 100 according to one embodiment. The battery cell 100 can be a lithium-ion or lithium-polymer battery cell used to power a device used in a consumer, medical, aerospace, defense, and / or transportation application. The battery cell 100 incorporates a stack 102 with a number of layers, including a cathode with a cathode-active coating, a separator, and an anode with an anode-active coating. More specifically, the stack 102 can include a strip of cathode-active material (e.g., aluminum foil coated with a lithium compound) and a strip of anode-active material (e.g., carbon-coated copper foil). The stack 102 also includes a strip of separator material (e.g.,a microporous polymer membrane or a non-woven mat) is positioned between one strip of cathode-active material and one strip of anode-active material. The cathode, anode, and separator layers can be left flat in a planar configuration or wound in a coiled configuration (e.g., "jelly roll"). An electrolyte solution is placed between each cathode and anode.

[0019] During the assembly of the battery cell 100, the stack 102 can be enclosed in a bag or container. The stack 102 can be in a planar or coiled configuration, although other configurations are also possible. In some variations, the bag is formed by folding a flexible film along a fold line 112. In some cases, the flexible film is made of aluminum with a polymer film, such as polypropylene. After the flexible film is folded, it can be sealed, for example, by applying heat along a side seal 110 and a terrace seal 108. The flexible bag can be less than or approximately 120 µm thick to improve the packaging efficiency of the battery cell 100, the density of the battery cell 100, or both.

[0020] The stack 102 can also include a set of conductive tabs 106 coupled to the cathode and anode. The conductive tabs 106 can extend through seals in the bag (e.g., formed using sealing tape 104) to provide terminals for the battery cell 100. The conductive tabs 106 can then be used to electrically couple the battery cell 100 to one or more other battery cells to form a battery pack. For example, the battery pack can be formed by coupling the battery cells in a series, parallel, or series-and-parallel configuration.Such coupled cells may be enclosed in a hard-shell housing to complete the battery pack, or may be embedded in the housing of a portable electronic device, such as a laptop computer, tablet computer, mobile phone, personal digital assistant (PDA), digital camera and / or portable media playback device.

[0021] Fig. Figure 2 shows a perspective view of a battery cell 200 (e.g., battery cell 100 from Fig.1) according to the disclosed embodiments. The battery includes a cathode 202, which includes a current collector 204 and a cathode-active material 206, and an anode 210, which includes an anode current collector 212 and an anode-active material 214. A separator 208 is arranged between the cathode 202 and the anode 210. Electrolyte fluid 216 is arranged between the cathode 202 and the anode 210 and is in contact with the separator 208. To create the battery cell, the cathode 202, the separator 208, and the anode 210 can be stacked in a planar configuration or stacked and then wound into a coiled configuration. The electrolyte fluid 216 can then be added. Before assembly of the battery cell, the set of layers can correspond to a cell stack.

[0022] The cathode current collector, the cathode-active material, the anode current collector, the anode-active material, and the separator can be any material known in the prior art. In some variations, the cathode current collector can be an aluminum foil, and the anode current collector can be a copper foil. The cathode-active material can be any material described, for example, in 14 / 206654, 15 / 458604, 15 / 458612, 15 / 709961, 15 / 710540, 15 / 804186, 16 / 531883, 16 / 529545, 16 / 999307, 16 / 999328, and 16 / 999265, each of which is incorporated herein in its entirety by reference.

[0023] The separator can enclose a microporous polymer membrane or a nonwoven mat. Non-restrictive examples of microporous polymer membranes or nonwoven mats include those made of polyethylene (PE), polypropylene (PP), polyamide (PA), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyester, and polyvinylidene fluoride (PVdF). However, other microporous polymer membranes or nonwoven mats are possible (e.g., gel polymer electrolytes).

[0024] In general, separators are structures within a battery, such as interlayers, that prevent physical contact between the cathode and anode while allowing ions to flow between them. Separators are made of materials with pores that provide channels for ion transport, potentially including the absorption of an electrolyte fluid containing the ions. Separator materials can be selected based on chemical stability, porosity, pore size, permeability, wettability, mechanical strength, dimensional stability, softening temperature, and heat shrinkage. These parameters can affect battery performance and operational safety.

[0025] In general, the electrolyte fluid can act as a conductive path for the movement of cations, which migrate from the negative to the positive electrode during discharge. The electrolyte fluid includes an electrolyte salt, electrolyte solvent, and one or more electrolyte additives.

[0026] The electrolyte fluid includes an electrolyte solvent. The electrolyte solvent can be any type of electrolyte solvent suitable for battery cells. Non-restrictive examples of electrolyte solvents include propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl propionate (EP), butyl butyrate (BB), methyl acetate (MA), methyl butyrate (MB), methyl propionate (MP), propylene carbonate (PC), ethyl acetate (EA), propyl propionate (PP), butyl propionate (BP), propyl acetate (PA), butyl acetate (BA), or combinations thereof.

[0027] The electrolyte fluid also contains one or more dissolved electrolyte salts. The salt can be any type suitable for battery cells. For example, and without limitation, salts for a lithium-ion battery cell include LiPF6, LiBF4, LiClO4, LiSO3CF3, LiN(SO2F)2, LiN(SO2CF3)2, LiBC4O8, Li[PF3(C2CF5)3], and LiC(SO2CF3)3. Other salts are possible, including combinations of salts.

[0028] In some variations, the salt concentration is at least 0.1 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.2 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.3 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.4 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.5 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.6 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.7 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.8 M in the total electrolyte fluid. In some variations, the salt concentration is at least 0.9 M in the total electrolyte fluid. In some variations, the salt concentration is at least 1.0 M in the total electrolyte fluid. In some variations, the salt concentration is at least 1.3 M in the total electrolyte fluid.In some variations, the salt concentration is at least 1.6 M in the total electrolyte fluid. In some variations, the salt concentration is at least 1.9 M in the total electrolyte fluid.

[0029] In some variations, the salt concentration is at least 2.0 M in the total electrolyte fluid. In some variations, the salt concentration is less than or equal to 1.9 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 1.6 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 1.3 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 1.1 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 1.0 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 0.9 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 0.8 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 0.7 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 0.6 M in the electrolyte fluid. In some variations, the salt concentration in the electrolyte fluid is less than or equal to 0.5 M.In some variations, the salt concentration is less than or equal to 0.4 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 0.3 M in the electrolyte fluid. In some variations, the salt concentration is less than or equal to 0.2 M in the electrolyte fluid.

[0030] In some variations, the disclosure is directed to electrolyte fluids that include one or more cyanide-containing organotrifluoroborate additives selected from the compound of formula (I), (II), (III) or (IV).

[0031] In one variation, the electrolyte solution includes an additive with the structure of formula (I), where m is non-zero. In some variations, increasing the value of m to extend the carbon chain of the boron increases the likelihood that the cyano functionality can come into contact with the cathode.

[0032] In some variations, m is 1. In some variations, m is 2. In some variations, m is 3. In some variations, m is 4. In some variations, m is 5. In some variations, m is 6. In some variations, m is 7. In some variations, m is 8. In some variations, m is 9.

[0033] In some variations, m ranges from 1 to 9. In other variations, m ranges from 1 to 3. In still other variations, m ranges from 1 to 2.

[0034] In some variations, m is 1 or greater. In some variations, m is 2 or greater. In some variations, m is 3 or greater. In some variations, m is 4 or greater. In some variations, m is 5 or greater. In some variations, m is 6 or greater. In some variations, m is 7 or greater. In some variations, m is 8 or greater. In some variations, m is 9 or less. In some variations, m is 8 or less. In some variations, m is 7 or less. In some variations, m is 6 or less. In some variations, m is 5 or less. In some variations, m is 4 or less. In some variations, m is 3 or less. In some variations, m is 2 or less.

[0035] As used herein, the variable m denotes the number of carbons. In other words, the structurally described alkyl group can be saturated or unsaturated, branched, or straight-chain. The term "alkyl" is specifically intended to include groups exhibiting any level or degree of saturation, i.e., groups with exclusively single carbon-carbon bonds, groups with one or more double carbon-carbon bonds, groups with one or more triple carbon-carbon bonds, and groups with mixtures of single, double, and triple carbon-carbon bonds.

[0036] If a specific degree of saturation is desired, the terms "alkanyl", "alkenyl" and "alkynyl" can be used.

[0037] "Alkanyl" refers to a saturated, branched, straight-chain, or cyclic alkyl radical derived by the removal of a hydrogen atom from a single carbon atom of a parent alkane. Typical alkanyl groups include, but are not limited to, methanyl; ethanol; propanyles such as propan-1-yl, propan-2-yl (isopropyl), cyclopropan-1-yl, etc.; butanyles such as butan-1-yl, butan-2-yl (sec-butyl), 2-methylpropan-1-yl (isobutyl), 2-methylpropan-2-yl (t-butyl), cyclobutan-1-yl, etc., and the like.

[0038] "Alkenyl" refers to an unsaturated, branched, straight-chain or cyclic alkyl radical with at least one carbon-carbon double bond, derived by the removal of a hydrogen atom from a single carbon atom of a parent alkene. The group can be either the cis or trans conformation across the double bond(s). Common alkenyl groups include, but are not limited to, ethenyl; propenyls such as prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl (allyl), prop-2-en-2-yl, cycloprop-1-en-1-yl; cycloprop-2-en-1-yl; Butenyls such as but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl, but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl, cyclobut-1-en-1-yl, Cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl, etc. and the like.

[0039] "Alkynyl" refers to an unsaturated, branched, straight-chain or cyclic alkyl radical with at least one carbon-carbon triple bond, derived by the removal of a hydrogen atom from a single carbon atom of a parent alkyne. Common alkynyl groups include, but are not limited to, ethynyl; propynyls such as prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butynyls such as but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.

[0040] The defined alkyl group is substituted by one or more cyanide groups. In some variations, a cyanide group substitutes a hydrogen atom at the terminal carbon of the alkyl group. In some variations, the terminal carbon of the alkyl group can have one, two, or three cyanide substitutions. For example, if n is 1 and the alkyl group is methyl, the carbon can be the terminal carbon, monosubstituted with a cyanide group (forming an acetonitrile moiety), disubstituted with a cyanide group (forming a malononitrile moiety), or trisubstituted with a cyanide group (forming a methanetricarbonitrile moiety). Likewise, each carbon atom in the alkyl chain can have one or more substituted hydrogen atoms.

[0041] Well-defined multiple carbons in the alkyl group can be cyano-substituted.

[0042] The cation M +The cation of formula (I), (II) or (III) can be any cation known in the prior art. In some variations, the cation is lithium (Li). + ) and / or potassium (K + In some variations, the cation is Li. + In some variations, the cation K + .

[0043] In one variation, the electrolyte solution includes an additive with the structure of formula (II).

[0044] The variables m and n can vary independently of each other and in any combination, as detailed below.

[0045] Increasing the value of m ensures that the carbon chain of the boron is extended for a greater probability than the cyano functionality can come into contact with the cathode.

[0046] In some variations, m is 1. In some variations, m is 2. In some variations, m is 3. In some variations, m is 4. In some variations, m is 5. In some variations, m is 6. In some variations, m is 7. In some variations, m is 8. In some variations, m is 9.

[0047] In some variations, m ranges from 1 to 9. In other variations, m ranges from 1 to 3. In still other variations, m ranges from 1 to 2.

[0048] In some variations, m is 1 or greater. In some variations, m is 2 or greater. In some variations, m is 3 or greater. In some variations, m is 4 or greater.

[0049] In some variations, m is 5 or greater. In some variations, m is 6 or greater. In some variations, m is 7 or greater. In some variations, m is 8 or greater. In some variations, m is 9 or less. In some variations, m is 8 or less. In some variations, m is 7 or less. In some variations, m is 6 or less. In some variations, m is 5 or less. In some variations, m is 4 or less. In some variations, m is 3 or less. In some variations, m is 2 or less.

[0050] Increasing the value of m and / or n increases the probability that the carbon chain of the boron will be extended, making it more likely that the cyano functionality can come into contact with the cathode.

[0051] In some variations, n is 1. In some variations, n is 2. In some variations, n is 3. In some variations, n is 4. In some variations, n is 5. In some variations, n is 6. In some variations, n is 7. In some variations, n is 8. In some variations, n is 9.

[0052] In some variations, n ranges from 1 to 9. In other variations, n ranges from 1 to 3. In still other variations, n ranges from 1 to 2.

[0053] In some variations, n is 1 or greater. In some variations, n is 2 or greater. In some variations, n is 3 or greater. In some variations, n is 4 or greater. In some variations, n is 5 or greater. In some variations, n is 6 or greater. In some variations, n is 7 or greater. In some variations, n is 8 or greater. In some variations, n is 9 or less. In some variations, n is 8 or less. In some variations, n is 7 or less. In some variations, n is 6 or less. In some variations, n is 5 or less. In some variations, n is 4 or less. In some variations, n is 3 or less. In some variations, n is 2 or less.

[0054] In one variation, the electrolyte solution includes an additive with the structure of formula (III).

[0055] The variables m, n, and p can vary independently and in any combination, as detailed below. In some variations, increasing the value of m, n, and / or p extends the carbon chains of the boron and can provide a greater probability of the cyano functionality coming into contact with the cathode.

[0056] In some variations, m is 1. In some variations, m is 2. In some variations, m is 3. In some variations, m is 4. In some variations, m is 5. In some variations, m is 6. In some variations, m is 7. In some variations, m is 8. In some variations, m is 9.

[0057] In some variations, m ranges from 1 to 9. In other variations, m ranges from 1 to 3. In still other variations, m ranges from 1 to 2.

[0058] In some variations, m is 1 or greater. In some variations, m is 2 or greater. In some variations, m is 3 or greater. In some variations, m is 4 or greater. In some variations, m is 5 or greater. In some variations, m is 6 or greater. In some variations, m is 7 or greater. In some variations, m is 8 or greater. In some variations, m is 9 or less. In some variations, m is 8 or less. In some variations, m is 7 or less. In some variations, m is 6 or less. In some variations, m is 5 or less. In some variations, m is 4 or less. In some variations, m is 3 or less. In some variations, m is 2 or less.

[0059] Increasing the value of n increases the probability that the carbon chain of the boron will extend, making it more likely that the cyano functionality can come into contact with the cathode.

[0060] In some variations, n is 1. In some variations, n is 2. In some variations, n is 3. In some variations, n is 4. In some variations, n is 5. In some variations, n is 6. In some variations, n is 7. In some variations, n is 8. In some variations, n is 9.

[0061] In some variations, n ranges from 1 to 9. In other variations, n ranges from 1 to 3. In still other variations, n ranges from 1 to 2.

[0062] In some variations, n is 1 or greater. In some variations, n is 2 or greater. In some variations, n is 3 or greater. In some variations, n is 4 or greater. In some variations, n is 5 or greater. In some variations, n is 6 or greater. In some variations, n is 7 or greater. In some variations, n is 8 or greater. In some variations, n is 9 or less. In some variations, n is 8 or less. In some variations, n is 7 or less. In some variations, n is 6 or less.

[0063] In some variations, n is 5 or lower. In some variations, n is 4 or lower. In some variations, n is 3 or lower. In some variations, n is 2 or lower.

[0064] Increasing the value of p ensures that the carbon chain of the boron is extended for a greater probability that the cyano functionality can come into contact with the cathode.

[0065] In some variations, p is 1. In some variations, p is 2. In some variations, p is 3. In some variations, p is 4. In some variations, p is 5. In some variations, p is 6. In some variations, p is 7. In some variations, p is 8. In some variations, p is 9.

[0066] In some variations, p ranges from 1 to 9. In other variations, p ranges from 1 to 3. In still other variations, p ranges from 1 to 2.

[0067] In some variations, p is 1 or greater. In some variations, p is 2 or greater. In some variations, p is 3 or greater. In some variations, p is 4 or greater. In some variations, p is 5 or greater. In some variations, p is 6 or greater. In some variations, p is 7 or greater. In some variations, p is 8 or greater. In some variations, p is 9 or less. In some variations, p is 8 or less. In some variations, p is 7 or less. In some variations, p is 6 or less. In some variations, p is 5 or less. In some variations, p is 4 or less. In some variations, p is 3 or less. In some variations, p is 2 or less.

[0068] In one variation, the electrolyte solution includes an additive with the structure of formula (IV).

[0069] The variables m, n, p, and q can vary independently and in any combination, as detailed below. In some variations, increasing the value of m, n, p, and / or q extends the carbon chains of the boron and can provide a greater probability of the cyano functionality coming into contact with the cathode.

[0070] In some variations, m is 1. In some variations, m is 2. In some variations, m is 3. In some variations, m is 4. In some variations, m is 5. In some variations, m is 6. In some variations, m is 7. In some variations, m is 8. In some variations, m is 9.

[0071] In some variations, m ranges from 1 to 9. In other variations, m ranges from 1 to 3. In still other variations, m ranges from 1 to 2.

[0072] In some variations, m is 1 or greater. In some variations, m is 2 or greater. In some variations, m is 3 or greater. In some variations, m is 4 or greater. In some variations, m is 5 or greater. In some variations, m is 6 or greater. In some variations, m is 7 or greater. In some variations, m is 8 or greater. In some variations, m is 9 or less. In some variations, m is 8 or less. In some variations, m is 7 or less. In some variations, m is 6 or less. In some variations, m is 5 or less. In some variations, m is 4 or less. In some variations, m is 3 or less. In some variations, m is 2 or less.

[0073] Increasing the value of n increases the probability that the carbon chain of the boron will extend, making it more likely that the cyano functionality can come into contact with the cathode.

[0074] In some variations, n is 1. In some variations, n is 2. In some variations, n is 3. In some variations, n is 4. In some variations, n is 5. In some variations, n is 6. In some variations, n is 7. In some variations, n is 8. In some variations, n is 9.

[0075] In some variations, n ranges from 1 to 9. In other variations, n ranges from 1 to 3. In still other variations, n ranges from 1 to 2.

[0076] In some variations, n is 1 or greater. In some variations, n is 2 or greater. In some variations, n is 3 or greater. In some variations, n is 4 or greater. In some variations, n is 5 or greater. In some variations, n is 6 or greater. In some variations, n is 7 or greater. In some variations, n is 8 or greater. In some variations, n is 9 or less. In some variations, n is 8 or less. In some variations, n is 7 or less. In some variations, n is 6 or less. In some variations, n is 5 or less. In some variations, n is 4 or less. In some variations, n is 3 or less. In some variations, n is 2 or less.

[0077] Increasing the value of p ensures that the carbon chain of the boron is extended for a greater probability that the cyano functionality can come into contact with the cathode.

[0078] In some variations, p is 1. In some variations, p is 2. In some variations, p is 3. In some variations, p is 4. In some variations, p is 5. In some variations, p is 6. In some variations, p is 7. In some variations, p is 8. In some variations, p is 9.

[0079] In some variations, p ranges from 1 to 9. In other variations, p ranges from 1 to 3. In still other variations, p ranges from 1 to 2.

[0080] In some variations, p is 1 or greater. In some variations, p is 2 or greater. In some variations, p is 3 or greater. In some variations, p is 4 or greater. In some variations, p is 5 or greater. In some variations, p is 6 or greater. In some variations, p is 7 or greater. In some variations, p is 8 or greater. In some variations, p is 9 or less. In some variations, p is 8 or less. In some variations, p is 7 or less. In some variations, p is 6 or less. In some variations, p is 5 or less. In some variations, p is 4 or less. In some variations, p is 3 or less. In some variations, p is 2 or less.

[0081] Increasing the value of q ensures that the carbon chain of the boron is extended for a greater probability that the cyano functionality can come into contact with the cathode.

[0082] In some variations, q is 1. In some variations, q is 2. In some variations, q is 3. In some variations, q is 4. In some variations, q is 5. In some variations, q is 6. In some variations, q is 7. In some variations, q is 8. In some variations, q is 9.

[0083] In some variations, q ranges from 1 to 9. In other variations, q ranges from 1 to 3. In still other variations, q ranges from 1 to 2.

[0084] In some variations, q is 1 or greater. In some variations, q is 2 or greater. In some variations, q is 3 or greater. In some variations, q is 4 or greater. In some variations, q is 5 or greater. In some variations, q is 6 or greater. In some variations, q is 7 or greater. In some variations, q is 8 or greater. In some variations, q is 9 or less. In some variations, q is 8 or less. In some variations, q is 7 or less. In some variations, q is 6 or less.

[0085] In some variations, q 5 or lower. In some variations, q 4 or lower. In some variations, q 3 or lower. In some variations, q 2 or lower.

[0086] If the additive is the combination of formula (IV), then m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, q is an integer equal to or greater than 1 and equal to or less than 9, and M + is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion and a quaternary phosphonium ion.

[0087] In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 0.01 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 0.03 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 0.05 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 0.07 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formula (I), formula (II), formula (III) and formula (IV) is present in an amount of at least 0.10 wt.-% of the electrolyte fluid. In some variations, the additive, selected from a compound of formula (I), formula (II), formula (III), and formula (IV), is present in an amount of at least 0.20 wt% of the electrolyte fluid. In some variations, the additive, selected from a compound of formula (I), formula (II), formula (III), and formula (IV), is present in an amount of at least 0.30 wt% of the electrolyte fluid. In some variations, the additive, selected from a compound of formula (I), formula (II), formula (III), and formula (IV), is present in an amount of at least 0.50 wt% of the electrolyte fluid. In some variations, the additive, selected from a compound of formula (I), formula (II), formula (III), and formula (IV), is present in an amount of at least 0.75 wt% of the electrolyte fluid.In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 1.0 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 1.25 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 1.50% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 1.75 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formula (I), formula (II), formula (III) and formula (IV) is present in an amount of at least 2.00 wt.-% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 2.25 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 2.50 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 2.75 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 3.0 wt% of the electrolyte fluid.In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 3.25 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 3.50 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 3.75 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount of at least 4.00 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formula (I), formula (II), formula (III) and formula (IV) is present in an amount of at least 4.25 wt.-% of the electrolyte fluid. In some variations, the additive, selected from a compound of formula (I), formula (II), formula (III), and formula (IV), is present in an amount of at least 4.50 wt% of the electrolyte fluid. In some variations, the additive, selected from a compound of formula (I), formula (II), formula (III), and formula (IV), is present in an amount of at least 4.75 wt% of the electrolyte fluid.

[0088] In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 5.0 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 4.75 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 4.50 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 4.25 wt% of the electrolyte fluid.In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 4.00 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 3.75 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 3.50 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 3.25 wt% of the electrolyte fluid.In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 3.00 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 2.75 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 2.50 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 2.25 wt% of the electrolyte fluid.In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 2.00 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 1.75 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 1.50 wt% of the electrolyte fluid. In some variations, the additive selected from a compound of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 1.25 wt% of the electrolyte fluid.In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 1.00 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.75 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.50 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.30 wt% of the electrolyte fluid.In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.20 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.10 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.08 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formulas (I), (II), (III), and (IV) is present in an amount equal to or less than 0.06 wt% of the electrolyte fluid.In some variations, the additive selected from a combination of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 0.04 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 0.03 wt% of the electrolyte fluid. In some variations, the additive selected from a combination of formula (I), formula (II), formula (III), and formula (IV) is present in an amount equal to or less than 0.02 wt% of the electrolyte fluid.

[0089] In some variations, the electrolyte fluid may include one or more additives. From various perspectives, the additives may include lithium difluoro(oxalate)borate (LiDFOB), pro-1-ene-1,3-sultone (PES), methylenemethanedisulfonate (MMDS), vinylethylene carbonate (VEC), propane sultone (PS), fluoroethylene carbonate (FEC), succinonitrile (SN), vinyl carbonate (VC), adiponitrile (ADN), ethylene glycol bis(2-cyanoethyl) ether (EGPN), and / or 1,3,6-hexanetricarbonitrile (HTCN) in any combination and in ranges of amounts.

[0090] In some variations, LiDFOB constitutes at least 0.1 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.2 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.3 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.4 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.5 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.6 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.7 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.8 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 0.9 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 1.0 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 1.3 wt% of the total electrolyte fluid.In some variations, LiDFOB constitutes at least 1.6 wt% of the total electrolyte fluid. In some variations, LiDFOB constitutes at least 1.9 wt% of the total electrolyte fluid.

[0091] In some variations, LiDFOB is less than or equal to 2.0 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 1.9 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 1.3 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 1.3 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 1.1 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 1.0 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.9 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.8 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.7 wt% of the total electrolyte fluid.In some variations, LiDFOB is less than or equal to 0.6 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.5 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.4 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.3 wt% of the total electrolyte fluid. In some variations, LiDFOB is less than or equal to 0.2 wt% of the total electrolyte fluid.

[0092] In some variations, the amount of PES is at least 0.5 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 0.6 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 0.9 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 1.3 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 1.6 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 1.9 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 2.2 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 2.5 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 2.8 wt% of the total electrolyte fluid. In some variations, the amount of PES is at least 3.1 wt.-% of the total electrolyte fluid.

[0093] In some variations, the amount of PES is less than or equal to 3.5 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 3.1 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 2.8 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 2.5 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 2.2 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 1.9 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 1.6 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 1.3 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 1.1 wt.-% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 0.9 wt% of the total electrolyte fluid. In some variations, the amount of PES is less than or equal to 0.6 wt% of the total electrolyte fluid.

[0094] In some variations, the amount of MMDS is at least 0.1 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.2 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.3 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.4 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.5 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.6 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.7 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.8 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 0.9 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 1.0 wt.-% of the total electrolyte fluid. In some variations, the amount of MMDS is at least 1.1% by weight of the total electrolyte fluid. In some variations, the amount of MMDS is at least 1.2% by weight of the total electrolyte fluid. In some variations, the amount of MMDS is at least 1.3% by weight of the total electrolyte fluid. In some variations, the amount of MMDS is at least 1.4% by weight of the total electrolyte fluid.

[0095] In some variations, the amount of MMDS is less than or equal to 1.5 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 1.4 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 1.3 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 1.2 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 1.1 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 1.0 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.9 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.8 wt% of the total electrolyte fluid.In some variations, the amount of MMDS is less than or equal to 0.7 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.6 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.5 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.4 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.3 wt% of the total electrolyte fluid. In some variations, the amount of MMDS is less than or equal to 0.2 wt% of the total electrolyte fluid.

[0096] In some variations, the amount of VEC is at least 0.1 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.2 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.3 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.4 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.5 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.6 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.7 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.8 wt% of the total electrolyte fluid. In some variations, the amount of VEC is at least 0.9 wt% of the total electrolyte fluid.

[0097] In some variations, the amount of VEC is less than or equal to 0.9 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.8 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.7 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.6 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.5 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.4 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.3 wt% of the total electrolyte fluid. In some variations, the amount of VEC is less than or equal to 0.2 wt% of the total electrolyte fluid.

[0098] In some variations, the amount of FEC is at least 2% by weight of the total electrolyte fluid. In some variations, the amount of FEC is at least 4% by weight of the total electrolyte fluid. In some variations, the amount of FEC is at least 6% by weight of the total electrolyte fluid. In some variations, the amount of FEC is at least 8% by weight of the total electrolyte fluid. In some variations, the amount of FEC is less than or equal to 10% by weight of the total electrolyte fluid. In some variations, the amount of FEC is less than or equal to 8% by weight of the total electrolyte fluid. In some variations, the amount of FEC is less than or equal to 6% by weight of the total electrolyte fluid. In some variations, the amount of FEC is less than or equal to 4% by weight of the total electrolyte fluid.

[0099] In some variations, the amount of PS is at least 0.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is at least 1.0 wt% of the total electrolyte fluid. In some variations, the amount of PS is at least 1.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is at least 2.0 wt% of the total electrolyte fluid. In some variations, the amount of PS is at least 2.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is at least 3.0 wt% of the total electrolyte fluid.

[0100] In some variations, the amount of PS is at least 3.5% by weight of the total electrolyte fluid. In some variations, the amount of PS is at least 4.0% by weight of the total electrolyte fluid. In some variations, the amount of PS is at least 4.5% by weight of the total electrolyte fluid. In some variations, the amount of PS is at least 5.0% by weight of the total electrolyte fluid.

[0101] In some variations, the amount of PS is less than or equal to 6.0 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 5.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 5.0 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 4.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 4.0 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 3.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 3.0 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 2.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 2.0 wt% of the total electrolyte fluid.-% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 1.5 wt% of the total electrolyte fluid. In some variations, the amount of PS is less than or equal to 1.0 wt% of the total electrolyte fluid.

[0102] In some variations, the amount of SN is at least 0.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 1.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 1.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 2.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 2.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 3.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 3.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 4.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 4.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is at least 5.0 wt% of the total electrolyte fluid.

[0103] In some variations, the amount of SN is less than or equal to 6.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 5.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 5.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 4.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 4.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 3.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 3.0 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 2.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 2.0 wt% of the total electrolyte fluid.-% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 1.5 wt% of the total electrolyte fluid. In some variations, the amount of SN is less than or equal to 1.0 wt% of the total electrolyte fluid.

[0104] In some variations, the amount of HTCN is at least 0.01% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 0.1% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 0.5% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 1.0% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 1.5% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 2.0% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 2.5% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 3.0% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 3.5% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 4.0 wt.-% of the total electrolyte fluid. In some variations, the amount of HTCN is at least 4.5% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 5.0% by weight of the total electrolyte fluid. In some variations, the amount of HTCN is at least 5.5% by weight of the total electrolyte fluid.

[0105] In some variations, the amount of HTCN is less than or equal to 6.0 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 5.5 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 5.0 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 4.5 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 4.0 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 3.5 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 3.0 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 2.5 wt% of the total electrolyte fluid.In some variations, the amount of HTCN is less than or equal to 2.0 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 1.5 wt% of the total electrolyte fluid. In some variations, the amount of HTCN is less than or equal to 1.0 wt% of the total electrolyte fluid.

[0106] The electrolyte solvent may also contain a dissolved salt. The salt can be any type of salt suitable for battery cells. For example, and without limitation, salts suitable for a lithium-ion battery cell include LiPF6, LiBF4, LiClO4, LiSO3CF3, LiN(SO2CF3)2, LiBC4O8, Li[PF3(C2CF5)3], and LiC(SO2CF3)3. Other salts are possible, including combinations of salts. EXAMPLES

[0107] The examples are provided for illustrative purposes only. These examples are not intended to limit each embodiment disclosed herein to every application or operating theory. Example 1

[0108] Various battery cell properties were tested with the electrolyte fluid, including PCTFB, and compared with a battery cell using a control electrolyte fluid without PCTFB. The composition of the control electrolyte fluid is shown in Table 1. Table 1 Salt M Solvent wt.% Additive wt.% LiPF6 EC PC PP EP PS FEC SN 1,2 20 10 45 25 4 7 3

[0109] Fig.Figure 3 shows the energy retention at cycle 200 for a battery operating at 45 °C of the control electrolyte compared to the control electrolyte, which included 0.5 wt% PCTFB. When the control electrolyte was used without PCTFB, the energy retention at cycle 200 was approximately 60%. With the addition of 0.5 wt% PCTFB, the energy retention at cycle 200 was over 85%. The addition of PCTFB resulted in a significant increase in energy retention at high cycle times. Example 2

[0110] Fig. Figure 4 shows the RSS at cycle 202 for a control electrolyte and the control electrolyte including PCTFB. The battery resistance was significantly higher in the absence of PCTFB. In the absence of 0.5 wt% PCTFB, the resistance at cycle 202 ranged from 200 to 250. When the electrolyte formulation included 0.5 wt% PCTFB, the RSS was less than 75. Example 3

[0111] Fig.Figure 5 shows the energy retention normalized to cycle 25 as a function of cycle count at 45 °C for a battery containing a control electrolyte and an electrolyte including 0.5 wt% PCTFB. The energy retention is roughly similar over 100 cycles. However, in the absence of PCTFB, the energy retention begins to decline sharply. The data show that the presence of PCTFB in electrolytes essentially improves the energy retention in battery cells with increasing cycle count. Example 4

[0112] Fig.Figure 6 shows a plot of the RSS as a function of the battery cycle counter at 45 °C for a battery with a single electrolyte and an electrolyte containing 0.5 wt% PCTFB. Three trials were conducted with and without PCTFB. The RSS of the battery cells with and without PCTFB was approximately similar over 75 cycles. However, energy retention began to increase substantially in the absence of PCTFB. PCTFB in electrolyte fluids substantially decreased the RSS in battery cells with increasing cycle count.

[0113] The recovery capacity after storage was measured for battery cells with a control electrolyte fluid, a control electrolyte fluid containing 0.3 wt% PCTFB, and a control electrolyte fluid containing 0.3 wt% PCTFB. As shown in Table 2, batteries with a control electrolyte fluid had a lower recovery capacity than batteries containing either 0.3 wt% PCTFB or 0.5 wt% PCTFB. Table 2 Alloy ID Remaining Cap. % Recovery capacity % Cycle 1 Cycle 3 2 85,4 + / - 1 90,8 + / - 1 96,9 + / - 0,5 2 + 0.5 wt.% PCTFB 90,4 + / - 6,5 95,7 + / - 2 96,2 + / - 1,6 2 + 0.3 wt.% PCTFB 84,6 + / - 6,4 94,0 + / - 3,4 96,8 + / - 0,8 Example 5

[0114] Fig. Figure 7 shows the capacity recovery of different electrolyte compositions after battery storage at 85 °C. The electrolyte solvent compositions are described in Table 3, and the additive compositions are described in Table 4. Table 3 Electrolyte fluid no. . LiPF6 (mol) EC (wt%) PC (wt%) PP (wt%) EP (wt%) 1 1,2 20 10 45 25 2 1,2 20 10 45 25 3 1,2 20 10 45 25 4 1,2 20 10 45 25 5 1,2 20 10 45 25 Table 4 Electrolyte fluid no. . LiDFOB VEC MMDS SN FEC PS LiCTFB PES HTCN 1 0,7 0,5 2 7 2,5 1,5 3 2 0,5 0,5 2 4 3 3 0,5 2 4 3 4 0,5 2 4 1 5 0,5 2 4 0,2 1

[0115] With reference to Fig. Electrolyte fluids 1, 2, and 3 contain 3.0 wt% HTCN, while electrolyte fluids 4 and 5 contain 1.0 wt% HTCN. Reducing the percentage of HTCN to 1.0 wt% resulted in improved high-temperature recovery capacity. The recovery capacity improved upon the introduction of 0.2 wt% LiCTFB compared to the electrolyte composition without LiCTFB.

[0116] Fig.Figure 8 represents a low-temperature cycle for batteries with electrolyte fluids containing different combinations of additives. At low temperatures, lithium mobility can decrease. The addition of HTCN leads to passivation of the cathode surface, which also increases the internal resistance. Electrolyte fluids containing 3.0 wt% HTCN exhibit a lower internal resistance compared to lower amounts of HTCN. Electrolyte fluids with 1 wt% HTCN show a slight improvement compared to 3.0 wt% HTCN. The addition of 0.2 wt% LiCTFB provides higher capacity at lower temperatures. Example 6

[0117] Without being limited to a specific mechanism or mode of action, cyan functionality can act as a protective agent for the cathode. Fig. 9 represents a cathode-active material interface layer 300 with cobalt oxide or modified cobalt oxide (e.g. LiCoM xO) in the electrolyte 302. Compounds of formula (I), (II), (III) or (IV) can contain two CEI-forming functional groups CN and BF3 in a single structure. When a compound of formula (I), (II), (III) or (IV) is applied to the cathode-active material surface LiCoM x Upon contact with O, the compound can oxidize to generate a CEI 304 on the surface of the cathode-active material 306, thereby passivating the surface of the cathode-active material 306. The cyano functionality can bind cobalt, and the boron functionality can bind oxygen. The presence of the CN functionality and / or BF3 functionality (e.g., LiCoM) bound to cathode-active materials with cobalt oxide or modified cobalt oxide is also a factor. xO) can prevent other electrolyte components from coming into contact with the cathode-active material and may degrade the active cathode-active material. In different variations, compounds of formula (I), (II), (III), or (IV) may have a lesser effect on internal resistance than other passivation compounds. Example 7

[0118] LiCTFB can be synthesized from a potassium cation to a lithium cation. The initial potassium cation compound is used to lithiate the compound of formula (I), (II), (III), or (IV) by combining the compound with LiBF4. The reaction leads to the formation of LiCTFB and KBF4 precipitates.

[0119] The electrolyte fluids described herein can be valuable in battery cells, including those used in electronic devices and consumer electronics products. An electronic device herein may refer to any electronic device known in the prior art. For example, the electronic device may be a telephone, such as a mobile phone or a landline telephone, or any communication device, such as a smartphone, including, for example, an iPhone®, or an electronic email sending / receiving device. The electronic device may also be an entertainment device, including a portable DVD player, a conventional DVD player, a Blu-ray disc player, a video game console, a music playback device such as a portable music player (e.g., iPod®), etc.The electronic device can be part of a display, such as a digital display, a television screen, an e-reader, a portable web browser (e.g., iPad®), a watch (e.g., Apple Watch), or a computer monitor. The electronic device can also be part of a device that provides control, such as controlling the streaming of images, videos, or sound (e.g., Apple TV®), or it can be a remote control for an electronic device. Furthermore, the electronic device can be part of a computer or its accessories, such as the hard disk drive tower enclosure or box, a laptop case, a laptop keyboard, a laptop trackpad, a desktop keyboard, a mouse, and a speaker. The anode cells, lithium-metal batteries, and battery packs can also be applied to a device such as a wristwatch or clock.

[0120] The preceding description employed specific nomenclature for explanatory purposes, aiming to provide a complete understanding of the described embodiments. However, it is evident to the person skilled in the art that these specific details are not necessary to carry out the described embodiments. Therefore, the foregoing descriptions of the specific embodiments are presented herefor illustrative and descriptive purposes only. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It is evident to the person skilled in the art that many modifications and variations are possible in light of the foregoing teachings.

Claims

[1] Electrolyte fluid comprising at least 0.01 wt% of an additive selected from a compound of formula (I), formula (II), formula (III) and formula (IV): wherein if the additive is the combination of formula (I), m is an integer equal to or greater than 1 and equal to or less than 9, and M + selected from an alkali metal ion, a quaternary Ammonium ion, an imidazole ion and a quaternary phosphonium ion; if the additive is the combination of formula (II), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, and M + selected from an alkali metal ion, a quaternary ammonium ion, an imidazoline ion and a quaternary phosphonium ion; and if the additive is the combination of formula (III), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, if the additive is the combination of formula (IV), m is an integer equal to or greater than 1 and equal to or less than 9, n is an integer equal to or greater than 1 and equal to or less than 9, p is an integer equal to or greater than 1 and equal to or less than 9, q is an integer equal to or greater than 1 and equal to or less than 9, and M + It is selected from an alkali metal ion, a quaternary ammonium ion, an imidazole ion, and a quaternary phosphonium ion. [2] Electrolyte fluid according to claim 1, wherein m is from 1 to 3. [3] Electrolyte fluid according to any of the preceding claims, wherein m is from 1 to 2. [4] Electrolyte fluid according to any of the preceding claims, wherein the additive is potassium organofluoroborate (PCTFB) or lithium (cyanomethyl) trifluoroborate (LiCTFB). [5] Electrolyte fluid according to any of the preceding claims, wherein n is from 1 to 3. [6] Electrolyte fluid according to any of the preceding claims, wherein n is from 1 to 2. [7] Electrolyte fluid according to any of the preceding claims, wherein p is from 1 to 3. [8] Electrolyte fluid according to any of the preceding claims, wherein p is from 1 to 2. [9] Electrolyte fluid according to any of the preceding claims, wherein q is from 1 to 3. [10] Electrolyte fluid according to any of the preceding claims, wherein q is from 1 to 2. [11] Electrolyte fluid according to any of the preceding claims, comprising an electrolyte salt selected from LiPF6, LiBF4, LiClO4, LiSO3CF3, LiN(SO2F)2, LiN(SO2CF3)2, LiBC4O8, Li[PF3(C2CF5)3], LiC(SO2CF3)3 and a combination thereof. [12] Electrolyte fluid according to claim 11, wherein the salt comprises LiPF6. [13] Electrolyte fluid according to one of claims 11 or 12, wherein the salt is from 0.8 M to 1.6 M. [14] Electrolyte fluid according to any of the preceding claims, comprising a solvent selected from ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl propionate (EP), butyl butyrate (BB), methyl acetate (MA), methyl butyrate (MB), methyl propionate (MP), propylene carbonate (PC), ethyl acetate (EA), propyl propionate (PP), butyl propionate (BP), propyl acetate (PA) and butyl acetate (BA) and a combination thereof. [15] Electrolyte fluid according to claim 14, wherein the solvent is selected from PC, EC, PP, EP and a combination thereof. [16] Electrolyte fluid according to claim 14 or 15, wherein the solvent comprises PC, EC, PP and EP. [17] Electrolyte fluid according to any one of claims 14 to 16, wherein PC is 2 to 20 wt% of the total electrolyte fluid, EC is 5 to 40 wt% of the total electrolyte fluid, PP is 20 to 70 wt% of the total electrolyte fluid and / or EP is 10 to 50 wt% of the total electrolyte fluid. [18] Electrolyte fluid according to any of the preceding claims, comprising an additive selected from lithium difluoro(oxalate)borate (LiDFOB), pro-1-ene-1,3-sultone (PES), methylenemethanedisulfonate (MMDS), propylene carbonate (PC), vinylethylene carbonate (VEC), propane sultone (PS), fluoroethylene carbonate (FEC), succinonitrile (SN), vinyl carbonate (VC), adiponitrile (ADN), ethylene glycol bis(2-cyanoethyl) ether (EGPN), 1,3,6-hexanetricarbonitrile (HTCN) and a combination thereof. [19] Electrolyte fluid according to claim 18, wherein the additive is selected from LiDFOB, PES, MMDS, PS, FEC, SN, HTCN and a combination thereof. [20] Electrolyte fluid according to claim 19, wherein the additive comprises LiDFOB, PES, MMDS, PS, FEC, SN and HTCN. [21] Electrolyte fluid containing 3.5 wt% or less of HTCN. [22] Battery cell, comprising: a cathode comprising a cathode-active material arranged on a cathode current collector; an anode comprising an anode-active material arranged on an anode current collector, wherein the anode is oriented towards the cathode such that the anode-active material faces the cathode-active material; a separator arranged between the anode-active material and the cathode-active material; and an electrolyte fluid according to one of the preceding claims, which is arranged between the cathode and the anode. [23] Battery cell according to claim 22, wherein the energy retention of the battery cell in cycle 200 is increased by more than 10% compared to a battery cell comprising the electrolyte fluid in the absence of the additive. [24] Battery cell according to claim 22 or 23, wherein the RSS of the battery cell in cycle 200 is reduced by at least 50% compared to a battery cell comprising the electrolyte fluid in the absence of the additive.

Images