Electrolytes and cells employing them

Abstract

Provided are electrolytes suitable for use in secondary cells, optionally lithium-ion secondary cells wherein the electrolytes provide excellent cycle life optionally in NMC based lithium-ion cells that are initially formed with a charge cutoff voltage of >4.3 V and subsequently cycled with a charge cutoff of ≤4.65 V during cell operation. The electrolyte optionally excludes ethylene carbonate and / or additives toxic to humans at the concentration used in the electrolyte.

Description

ELECTROLYTES AND CELLS EMPLOYING THEMCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application depends from and claims priority to U.S. Provisional Application No: 63 / 550,394 filed February 6, 2024 and U.S. Provisional Application No: 63 / 647,199 filed May 14, 2024, the entire contents of each of which are incorporated herein by reference.FIELD

[0002] The present disclosure is directed to electrolytes for lithium-ion batteries.BACKGROUND

[0003] Nickel Manganese Cobalt (NMC) cathodes offer several advantages in lithium- ion batteries, making them popular choices for various applications. NMC cathodes provide a good balance between energy density and power output. They offer higher energy density than other comparable cost cathodes such as lithium iron phosphate, allowing for increased energy storage in batteries, which is crucial for applications demanding long runtimes or high capacities. Compared to some other high energy cathode materials, such as lithium nickel oxide, NMC offers improved thermal and structural stability, which contributes to the overall safety and reliability of the battery, especially in high-drain and high-temperature environments. NMC cathodes can endure a high number of charge-discharge cycles, providing longevity and durability in applications such as electric vehicles and grid storage systems. NMC cathodes are commercially viable due to their relatively low raw material and manufacturing cost and enabling their widespread use in various industries. NMC cathodes often contain fewer hazardous materials compared to some other cathode chemistries, aligning with environmental considerations for sustainable battery technologies.

[0004] The ability to tune the ratio of nickel, manganese, and cobalt in NMC cathodes allows manufacturers to tailor the performance characteristics of the battery. For instance, variations in composition can optimize energy density, stability, and cost-effectiveness for specific applications.

[0005] Overall, the advantages of NMC cathodes make them a preferred choice for many applications, balancing high energy density, stability, safety, and cost-effectiveness in lithium-ion batteries. Researchers continue to refine and innovate NMC formulations tofurther enhance their performance and applicability across various industries.

[0006] The energy storage capacity of NMC cathodes can be significantly increased by raising the charging or delithiation voltage, for example to greater than 4.3V. Higher cathode voltages translate into increased energy storage, enabling electric vehicles to cover longer distances on a single charge. This extended range is critical for the adoption and acceptance of electric vehicles in the market.

[0007] Higher operating voltages also can enhance power output capabilities of NMC batteries. This is beneficial in applications where high power delivery is necessary, such as power tools or electric vehicles requiring quick acceleration. Further, higher voltage NMC cathodes allow for the design of battery systems with fewer cells in series to achieve the desired voltage, potentially simplifying the battery pack and reducing overall system complexity and cost.

[0008] It is crucial, however, to consider potential challenges and risks associated with operating NMC cathodes at higher voltages, including safety concerns, increased degradation rates, and potential material instability. A particular problem is loss of capacity following charge-discharge cycling otherwise known as capacity fade. Manufacturers and researchers address these challenges by introducing various cathode chemical modifications such as dopants and coatings, optimizing electrode structures, and refining electrolyte compositions to ensure the safety and longevity of batteries while maximizing their performance at higher voltage.

[0009] Electrolytes are also a key battery component that can affect the lifetime of NMC cathodes operating at a high charge voltage. The function of a lithium-ion cell electrolyte is to transport lithium ions between the cathode and anode of a lithium ion cell while substantially blocking electrons and impurities created by electrochemical decomposition during cycling. Ideally the electrolyte is also: 1) electrochemically and chemically stable at the anode and cathode interface; or 2) electrochemically or chemically reactive with the anode and / or cathode but creating a passivation layer at the el ectrode / electrolyte interface that inhibits further chemical reaction while maintaining Li-ion transport and blocking electrons as well as limiting creation of electrode decomposition products. The passivation layer otherwise known as the stable solid-electrolyte interface (SEI) can be composed of a mixture of organic compounds and inorganic compounds such as carbonates, oxides and fluorides and effectively seal the underlying electrode from direct contact with the electrolyte.

[0010] In most instances the electrolyte is of the type to produce a passivation layer onan electrode / electrolyte interface. In the most common commercial Li-ion cells containing a graphitic anode and nickelate cathode, the electrolyte includes a mixture of lithium salts and organic carbonate solvents, for example LiPFe in a mixture of ethylene carbonate (EC) and longer chain carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC). Different solvent combinations offer various properties like conductivity, stability, and temperature performance.

[0011] Additives are often included to enhance specific properties of the electrolyte, such as improving the battery’s safety, performance, or stability over multiple chargedischarge cycles. Additives in EC based electrolytes as an example may include conductive salts, flame retardants, stabilizers, or other proprietary compounds aimed at improving battery performance and safety. Additives play crucial roles in high voltage cathodes for lithium-ion cells, offering several benefits that contribute to the overall performance, safety, and longevity of the battery. Some of the key purposes of additives in high voltage cathodes include: a. Stabilizing Electrolyte: Additives are often included to stabilize the electrolyte at higher voltages. High voltage cathodes can cause electrolyte degradation, and additives help mitigate this by forming a stable SEI layer on the electrode surface that resists dissolution during battery operation or storage. This layer protects the electrolyte from further decomposition and promotes uniform electrode charge / discharge cycling by inhibiting localized high or low lithium concentrations. b. Suppressing Side Reactions: High voltage operation can trigger unwanted side reactions within the battery, leading to capacity fade and reduced performance over time. Additives are designed to suppress these side reactions, preserving the integrity of the cathode material, and improving the battery's cycling stability. c. Enhancing Safety: Some additives are specifically formulated to enhance the safety of high voltage cathodes. They can inhibit the formation of dendrites, which are tiny conductive filaments that can grow during charging and potentially cause short circuits, leading to safety hazards. By reducing dendrite formation, additives contribute to the safety of the battery. d. Improving Cycling Stability: Additives can aid in maintaining the structural integrity of the cathode material, reducing degradation overrepeated charge-discharge cycles. This improves the battery’s long-term cycling stability and helps retain its capacity over time. e. Optimizing Performance: Certain additives are engineered to optimize the electrochemical performance of the cathode material. They can enhance the specific capacity, rate capability, and overall efficiency of the battery, allowing for improved energy output and longer lifespan. f. Customizing Cathode Characteristics: Additives offer a means to tailor the characteristics of the high voltage cathode material, allowing manufacturers to optimize the battery for specific applications, whether it’s focusing on energy density, power output, or temperature stability.

[0012] Additives are generally used at low concentration, for example less than 10 wt%. Examples of useful additives include fluorocarbonates, vinylene carbonate, organic sulfates, organic sultones, lithium difluoro(oxalato)borate, lithium (oxalato)borate, tris(trimethylsilyl)borate tri s(trimethyl silyl) phosphate, tris(trimethylsilyl) phosphite, and others. Some of these additives, however, such as organic sulfates and organic sultones, have health concerns.

[0013] The amount of additive can also be limited to the amount required to passivate the electrode / electrolyte interface during the initial electrochemical formation of the cell during manufacture. In this instance, the additive is completely consumed and not available for further passivation of fresh electrode interfaces created due to particle fracturing that can occur during subsequent cell cycling. The nature of these passivation layers is complex and can include both organic and inorganic mixtures.

[0014] As stated previously, the energy density of lithium ion cells containing certain cathodes such a nickelates and cobaltates, can be increased by increasing the charging voltage above 4.3 V that provides further cathode delithiation. This can be challenging to electrolyte stability due to oxidation, particularly catalytic oxidation, at the cathode interface. For example, the LiNio.8Mno.1Coo.1O2 (NMC811) / graphite cell is expected to support charging voltage greater than or equal to 4.5 volts, thus the electrolyte must be substantially stable, either intrinsically or by cathode passivation, at these high voltages.

[0015] EC can provide good passivation in lithium ion cells that may be charged to a voltage greater than 4.3V. EC serves several crucial functions within the electrolyte system. a. EC acts as a solvent for lithium salts, such as lithium hexafluorophosphate (LiPFe) or Lithium Bis(fluorosulfonyl)imide (LiFSi), allowing these saltsto dissolve and ionize within the electrolyte. This ionization is essential for facilitating the movement of lithium ions between the battery electrodes during charging and discharging. b. Due to its relatively high dielectric strength, EC enhances the ionic conductivity of the electrolyte solution. This increased conductivity enables more efficient movement of lithium ions within the battery, contributing to improved performance and faster charge discharge rates. c. When the battery is initially charged, EC participates in the formation of a stable and protective solid-electrolyte interface (SEI) layer on the surface of the anode. This SEI layer helps prevent further electrolyte decomposition and ensures stable battery operation over multiple cycles. d. EC helps improve the electrolyte’s stability at both high and low temperatures. This characteristic is crucial for maintaining the battery's performance and safety across a range of operating conditions.

[0016] By forming a stable SEI layer and enhancing the electrolyte’s conductivity, EC can reduce undesirable side reactions between the electrolyte and electrode materials contributing to longer battery lifespan and improved cycling stability. It is important to note, however, that while EC provides many beneficial functions, it can also contribute to potential drawbacks in certain conditions, such as its tendency to form an excessively thick solid layer on the surface of the graphite anode, potentially affecting the battery’s performance over time. As such, new electrolyte formulations that do not require the presence of EC are needed.SUMMARY

[0017] Provided in this disclosure are electrolytes that render a desirable cycle life of lithium-ion cells, particularly in cells that employ NMC cathodes with a Mn content of greater than 45 at%. In some aspects as provided herein, an electrolyte renders a desirable cycle life of NMC / graphite lithium-ion cells when initially cycled with a charge cutoff voltage of >4.3 V during cell formation and subsequently cycled with a charge cut off of 4.3 V or greater, optionally about 4.65 V.

[0018] Also provided are electrolytes that do not contain possibly carcinogenic organic sultones or organic sulfate additives.

[0019] An electrolyte as provided herein optionally does not contain ethylene carbonate. Optionally, the electrolyte includes LiPFe salt, dimethylcarbonate solvent, <10%fluoroethylene carbonate, <10% difluoro-ethylene carbonate, <3% Tri s(trimethyl silyl) malonate and <3% Tris(trimethylsilyl)phosphate and <2% Lithium bis(oxalato)borate. In other aspects, the electrolyte includes LiPFe salt, dimethylcarbonate solvent, <10% fluoroethylene carbonate, <10% difluoro-ethylene carbonate, <3% Tris(trimethylsilyl)malonate, <3% Tris(trimethylsilyl)phosphite, and <2% Lithium bis(oxalato)borate. In other aspects, the electrolyte includes LiPFe salt, dimethylcarbonate solvent, <10% fluoroethylene carbonate, <10% difluoro-ethylene carbonate, <3% Tri s(trimethylsilyl)mal onate, and <2% Lithium bis(oxalato)borate. In other aspects, the electrolyte includes LiPFe salt, dimethylcarbonate solvent, <10% fluoroethylene carbonate, <10% difluoro-ethylene carbonate, <2% Lithium bis(oxalato)borate. In yet other aspects, the electrolyte includes LiPFe salt, dimethylcarbonate solvent, <10% fluoroethylene carbonate, <10% difluoro-ethylene carbonate, <3% Tris(trimethylsilyl)phosphite, and <2% Lithium bis(oxalato)borate. In some aspects, the electrolyte includes LiPFe salt, dimethylcarbonate solvent, <10% fluoroethylene carbonate, <10% difluoro-ethylene carbonate, and <3% Lithium difluoro(oxalato)borate. In other aspects, the electrolyte includes >1.5M LiPFe salt, dimethylcarbonate solvent, <10% fluoroethylene carbonate, and <3% Lithium difluoro(oxalato)borate. In some aspects as provided herein or of any of the foregoing, a concentration of LiPFe in an electrolyte is >1.5 M.

[0020] Also provided herein are electrochemical cells that include an electrolyte as provided herein. Optionally, an electrochemical cell is a NMC (cathode) / Graphite (anode) cell containing the electrolyte as provided herein, where the electrochemical cell has undergone or is intended to undergo an initially cycling at > 4.3 V and subsequently cycled at < 4.7 V. Also provided are NMC / Graphite cells containing the electrolyte as provided herein wherein the electrochemical cell is cycled at > 4.3 V or is intended to cycle at > 4.3 V.

[0021] Optionally, the electrolyte as provided herein excludes organic sulfates or organic sultones.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The aspects set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative aspects can be understood when read in conjunction with the following drawings.

[0023] FIG. 1 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0024] FIG. 2 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0025] FIG. 3 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0026] FIG. 4 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0027] FIG. 5 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0028] FIG. 6 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0029] FIG. 7 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0030] FIG. 8 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0031] FIG. 9 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0032] FIG. 10 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0033] FIG. 11 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0034] FIG. 12 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0035] FIG. 13 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0036] FIG. 14 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0037] FIG. 15 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.

[0038] FIG. 16 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte

[0039] FIG. 17 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0040] FIG. 18 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0041] FIG. 19 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0042] FIG. 20 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0043] FIG. 21 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0044] FIG. 22 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0045] FIG. 23 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0046] FIG. 24 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using a comparative electrolyte.

[0047] FIG. 25 illustrates improved cycle life of using an electrolyte as in Example 14 compared to an EDEVI control in a cell with an NMC cathode including 40:56:4 at% Ni:Mn:Co.

[0048] FIG. 26 illustrates cycle life of cells with an NCA (91 :6:3) cathode and graphite anode employing the electrolyte of Example 1, 5, and 6 relative to a cell with an EDEVI electrolyte control when charged to 4.6 V and discharged to 2.5 V at 45 °C.

[0049] FIG. 27 illustrates cycle life of cells with an NMCA (90:2:6:2) cathode and graphite anode employing the electrolyte of Example 1, 5, and 6 relative to a cell with an EDEVI electrolyte control when charged to 4.6 V and discharged to 2.5 V at 45 °C.

[0050] FIG. 28 illustrates to a 100 mAh / g cutoff the cycle capacities of an electrochemical cell using an exemplary electrolyte as provided herein.DETAILED DESCRIPTION

[0051] When seeking cell chemistries that would be suitably functional when cycling at greater than 4.3 Volts (V), it was found that ethylene carbonate (EC) containing electrolyte contributes to rapid capacity fade of lithium ion cells, particularly NMC (NiCoMn) cathode / graphite anode cells. It was unexpectedly found that replacing EC with dimethylcarbonate (DMC) together with a combination of select additives, the cycle life of NMC cathode containing lithium ion cells can be significantly improved when charged to greater than 4.3 V. This suggested that, unlike what is expected, the absenceof EC did not prevent the graphite SEI formation when the other electrolyte components of the herein provided electrolytes were present.

[0052] As such, as provided herein are electrolytes that include DMC and one or more other additives or co-solvents and exclude EC. In some aspects, an electrolyte includes DMC, LiPFe, and one or more other additives, and optionally excluding EC. Optionally, an electrolyte includes DMC and two additives, optionally three additives, optionally four additives, optionally 5 additives. Optionally, an electrolyte includes DMC, LiPFe, and two additional additives, optionally three additional additives, optionally four additional additives, optionally 5 additional additives.

[0053] Further, the select additives in an electrolyte as provided herein are less possibly carcinogenic (e.g. less toxic) than organic sulfate and sultone type additives. As such, an electrolyte as provided herein optionally excludes organic sulfate and sultone type additives. Illustrative examples of additives for use in an electrolyte as provided herein include but are not limited to fluoroethylene carbonate (FEC), difluoroethylene carbonate (F2EC), tris(trimethylsilyl)malonate (TMSM), tris(trimethylsilyl)phosphite (TMSPi), tris(trimethylsilyl)phosphate (TMSPO4), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB) and the co-solvent 1,1,2,2-tetrafluoroethyl 2, 2,3,3- tetrafluoropropyl ether (TFETFPE). In some aspects, additives optionally include combinations of fluoroethylene carbonate, difluoroethylene carbonate, and lithium difluoro(oxalato)borate. In some other aspects, additives optionally include combinations of fluoroethylene carbonate, difluoroethylene carbonate, and lithium bi s(oxal ato)b orate .

[0054] While some of the additives of the electrolytes as provided herein are known to improve the cycle life of li-ion cells, it is surprising that specific combinations of the provided electrolyte components along with the absence of EC can significantly enhance the cycle life of lithium ion cells and more specifically lithium ion cells that include an NMC cathode wherein the Mn content in the cathode active material is greater than 45 mole % and when charged to greater than 4.3 V. Thus, the specifically provided combination of electrolytes that include one or more of the provided additives and exclude EC are uniquely able to support higher charge voltages.

[0055] An electrolyte as provided herein optionally includes DMC. The DMC is optionally present as a solvent meaning that the electrolyte includes DMC at an amount of 100 wt% minus the total wt% of all additives and / or LiPFe if present. Optionally, DMC is present as a predominant. Optionally, DMC is present at about 80% or greater.Optionally DMC is present at about 50 wt% to 99.9 wt%.

[0056] In some aspects, an electrolyte includes LiPFe in addition to the DMC. The LiPFe is optionally present in the electrolyte at a concentration equal to or greater than 0.1 molar (M), optionally 0.5 M, optionally 0.6 M, optionally 0.7 M, optionally 0.8 M, optionally 0.9 M, optionally 1 M, optionally 1.1 M, optionally 1.2 M, optionally 1.3 M, optionally1.4 M optionally 1.5 M, optionally 1.6 M, optionally 1.7 M, optionally 1.8 M, optionally 1.9 M, optionally 2.0 M. Optionally, the LiPFe is present at about 0.1 wt%, optionally about 0.5 wt%, optionally about 1 wt%, optionally about 1.5 wt%, optionally about 2 wt%, optionally about 2.5 wt%, optionally about 3 wt%, optionally about 3.5 wt%, optionally about 4 wt%, optionally about 4.5 wt%, optionally about 5 wt%, optionally about 6 wt%, optionally about 10 wt%, optionally about 15 wt%, optionally about 20 wt%, optionally about 15 wt%, optionally about 30 wt%. In some aspects, the range of LiPFe is from 1.5 wt% to 30 wt%.

[0057] An electrolyte as provided herein optionally includes one or more additives in addition to the DMC and / or LiPFe. An additive optionally excludes a toxic additive, where toxic is toxic to a human at the concentration used. A toxic additive may be an additive that is carcinogenic to a human at or below the concentration at which the additive is used in an electrolyte as provided herein. An additive in an electrolyte as provided herein may be present at less than 10 weight percent (wt%), depending on the additive. Optionally, an additive is present at less than or equal to 5 wt%, optionally 4.5 wt%, optionally 4 wt%, optionally 3.5 wt%, optionally 3 wt%, optionally 2.5 wt%, optionally 2 wt%, optionally 1.5 wt%, optionally 1 wt%, optionally 0.5 wt%, optionally 0.1 wt%.

[0058] Optionally, an additive is present at more than 0.1 wt%, optionally more than 0.5 wt%, optionally more than 1 wt%, optionally more than 1.5 wt%, optionally more than 2 wt%, optionally more than 2.5 wt%, optionally more than 3 wt%, optionally more than3.5 wt%, optionally more than 4 wt%, optionally more than 4.5 wt%, optionally more than 5 wt%.

[0059] Optionally, an electrolyte includes DMC and FEC wherein the FEC is present at more than 0.1 wt%, optionally 0.5 wt%, optionally more than 1 wt%, optionally more than 1.5 wt%, optionally more than 2 wt%, optionally more than 2.5 wt%, optionally more than 3 wt%, optionally more than 3.5 wt%, optionally more than 4 wt%, optionally more than 4.5 wt%, optionally more than 5 wt%, optionally more than 6 wt%. In some aspects, the range of FEC is from 1.5 wt% to 6 wt%, optionally from 2 wt% to 5 wt%.

[0060] Optionally, an electrolyte includes DMC and F2EC wherein the F2EC is present at more than 0.1 wt%, optionally 0.5 wt%, optionally more than 1 wt%, optionally more than 1.5 wt%, optionally more than 2 wt%, optionally more than 2.5 wt%, optionally more than 3 wt%, optionally more than 3.5 wt%, optionally more than 4 wt%, optionally more than 4.5 wt%, optionally more than 5 wt%. In some aspects, the range of F2EC is from 1.5 wt% to 6 wt%, optionally from 2 wt% to 5 wt%.

[0061] In some aspects, an electrolyte includes DMC and TMSPCh wherein the TMSPCh is present less than 5 weight percent (wt%). Optionally, TMSPO4 is present at less than or equal to 5 wt%, optionally 4.5 wt%, optionally 4 wt%, optionally 3.5 wt%, optionally 3 wt%, optionally 2.5 wt%, optionally 2 wt%, optionally 1.5 wt%, optionally 1 wt%, optionally 0.5 wt%, optionally 0.1 wt%. In some aspects, the range of TMSPO4 is from 0.1 wt% to 3 wt%, optionally from 0.5 wt% to 2 wt%.

[0062] In some aspects, an electrolyte includes DMC and TMSM wherein the TMSM is present less than 5 weight percent (wt%). Optionally, TMSM is present at less than or equal to 5 wt%, optionally 4.5 wt%, optionally 4 wt%, optionally 3.5 wt%, optionally 3 wt%, optionally 2.5 wt%, optionally 2 wt%, optionally 1.5 wt%, optionally 1 wt%, optionally 0.5 wt%, optionally 0.1 wt%. In some aspects, the range of TMSM is from 0.1 wt% to 3 wt%, optionally from 0.5 wt% to 2 wt%.

[0063] In some aspects, an electrolyte includes DMC and TMSPi wherein the TMSPi is present less than 5 weight percent (wt%). Optionally, TMSPi is present at less than or equal to 5 wt%, optionally 4.5 wt%, optionally 4 wt%, optionally 3.5 wt%, optionally 3 wt%, optionally 2.5 wt%, optionally 2 wt%, optionally 1.5 wt%, optionally 1 wt%, optionally 0.5 wt%, optionally 0.1 wt%. In some aspects, the range of TMSPi is from 0.1 wt% to 3 wt%, optionally from 0.5 wt% to 2 wt%.

[0064] In some aspects, an electrolyte includes DMC and the co-solvent TFETFPE wherein the TFETFPE is present less than 20 weight percent (wt%) depending on the additive. Optionally, the TFETFPE is present at less than or equal to 15 wt%, optionally 10 wt%. In some aspects, the TFETFPE is present at 1 wt% to 20 wt% or any value or range therebetween, optionally 2 wt% to 10 wt%.

[0065] The concentration of LiPFe when present is optionally equal to or greater than 1.0 M, optionally at or greater than 1.3 M or 2.0 M. With certain additives, for example fluoroethylene carbonate and lithium difluoro(oxalato)borate, the higher concentration of LiPFe, for example 2 M LiPFe, improves cycle life relative to 1.3 M LiPFe present in the electrolyte.

[0066] An electrolyte as provided herein promotes improved cycle life, particularly, but not limited to cells with a graphite anode and Ni based (e.g. greater than 50 wt% Ni) cathode, optionally an NMC cathode. When cycling a cell including an electrolyte as provided herein at about 2.5 V to greater than or equal to about 4.3 V, optionally about 2.5 V to about 4.65 V, optionally about 2.5 V to about 4.8 V, a cell optionally has a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. In some aspects, the capacity retention at 100 cycles is equal to or greater than or equal to 65%, optionally 66%, optionally 67%, optionally 68%, optionally 69%, optionally 70%, optionally 71%, optionally 72%, optionally 73%, optionally 74%. optionally 75%, optionally 76%, optionally 77%, optionally 78%, optionally 79%. optionally 80%, optionally 81%, optionally 82%, optionally 83%, optionally 84% optionally 85%, optionally 86%, optionally 87%, optionally 88%, optionally 89% optionally 90%. In any of the foregoing, an electrolyte optionally does not undergo a shuttling reaction as otherwise described herein.

[0067] Certain combinations of additives create an electrolyte that discolors over time indicating the occurrence of chemical reaction or association or components while other combinations remained color free. Electrolyte discoloration is not necessarily detrimental to cycle-life, however, depending on the nature of the chemical reaction. Nonetheless, also provided are electrolytes that do not undergo discoloration.

[0068] Some additives such as lithium bis(oxalato)borate have limited solubility in DMC solvent for example less than 2 wt%. The additive can be completely consumed during the initial formation stage of li-ion cell production or, if used in a higher concentration, be present during the operational lifetime of the cell.

[0069] In some cases, the electrolyte can create an undesirably high and unstable charging voltage, for example higher than 4.65 V or 4.8 V. While not wanting to be bound by theory, this may be the result of a chemical redox shuttling reaction of a soluble impurity between the cathode and anode. For example, 1.3 M LiPFe DMC with 2 wt% tri s(trimethyl silyl) mal onate has improved cycle life versus EDEVI, however there is also an undesirably high, periodic and unstable charging voltage. We define this behavior as a “high voltage shuttling.” As such, also provided are electrolyte compositions that do not suffer from high voltage shuttling.

[0070] It was found that EC containing electrolytes such those shown in comparative Examples 1-3 have poor capacity and cycle life when used with NMC / graphite cells cycled to 4.65 V. Additionally, there is extensive shuttling type behavior as seen in Figs.16-24.

[0071] Thus, it was found that LiPFe with DMC (without EC) had superior cycle life (measured as capacity retention at 100 cycles as described above) to EC containing electrolytes as seen in comparative example 4 vs comparative example 1-3. However, LiPFe with DMC alone experienced undesirable shuttling reaction as seen in Fig 19.

[0072] When 4% FEC was added to LiPFe with DMC the capacity and cycle life was significantly improved versus LiPFe with DMC alone as seen in comparative example 7 vs comparative example 4; however, there was a shuttling reaction as seen in Fig. 22.

[0073] When 2% TMSM was added to LiPFe with DMC the capacity and cycle life was significantly improved versus LiPFe with DMC as seen in comparative example 5 vs comparative example 4; however, there was a shuttling reaction as seen in Fig. 20.

[0074] When 2% TMSPi was added to LiPFe with DMC the capacity and cycle life was improved versus LiPFe with DMC alone as seen in comparative example 6 vs comparative example 4; however, there was a shuttling reaction as seen in Fig. 21.

[0075] When 4% FEC and 2% TMSM was added to LiPFe with DMC the capacity and cycle life was significantly improved versus LiPFe with DMC as seen in comparative example 8 vs comparative example 4; however, there was a shuttling reaction as seen in Fig. 23.

[0076] When 4% FEC and 2% TMSPi were added to LiPFe with DMC the capacity and cycle life was significantly improved versus LiPFe with DMC as seen in comparative example 9 vs comparative example 4; however, there was a shuttling reaction as seen in Fig. 24.

[0077] It was found that certain combinations of additives and solvents can improve the cycle life of NMC cathodes while also inhibiting shuttling type reactions. While not wanting to be bound by any particular theory, it is believed these combinations of additives are more effective at passivating or modifying the anode / cathode surface and inhibiting electrolyte oxidation, cathode corrosion and chemical shuttling reactions versus both carbonate electrolytes and DMC only electrolytes. This can include creating a denser and thinner SEI layer and / or an SEI that more effectively resists dissolution, cracking or fragmentation.

[0078] As provided herein the combination of LiPFe, DMC, FEC, F2EC, TMSPO4, TMSM and LiBOB improves the capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 1 vs comparative example 4 and Fig. 1 vs Fig 13.

[0079] As provided herein the combination of LiPFe, DMC, FEC, F2EC, TMSPi and TMSM improves both capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 2 vs comparative example 4 and Fig. 2 vs. Fig 13.

[0080] As provided herein the combination of LiPFe, DMC, FEC, F2EC, TMSPi, TMSM and LiBOB improves both capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 3 vs comparative example 4 and Fig. 3 vs Fig. 13.

[0081] As provided herein the combination of LiPFe, DMC, FEC, TMSPi, TMSM and LiBOB improves both capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 4 vs comparative example 4 and Fig. 4 vs Fig. 19.

[0082] As provided herein the combination of LiPFe, DMC, FEC and LDFOB improves the capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 5 vs comparative example 4 and Fig. 5 vs Fig. 19.

[0083] As provided herein the combination of LiPFe, DMC, FEC, F2EC, TMSPO4 and TMSM improves both capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 6 vs comparative example 4 and Fig. 6 vs Fig. 19.

[0084] As provided herein the combination of LiPFe, DMC, FEC , F2EC, TMSM and LiBOB improves the capacity and cycle life vs LiPFe with DMC alone and there is no shuttling reaction as seen in example 7 vs comparative example 4 and Fig. 7 vs Fig. 19.

[0085] As provided herein the combination of LiPFe, DMC, FEC and F2EC improve the capacity and cycle life vs LiPFe with DMC and there is no shuttling reaction as seen in example 9 vs comparative example 4 and Fig. 9 vs Fig. 19.

[0086] As provided herein the combination of LiPFe, DMC, FEC, F2EC and LiBOB improves the capacity and cycle life vs LiPFe with DMC and there is no shuttling reaction as seen in example 16 vs comparative example 4 and Fig. 15 vs Fig. 19.

[0087] It was found that that the presence of certain trimethyl silyl compounds such as TMSM and TMSPi and combinations of TMSM with TMSPi or combinations of TMSM or TMSPi with TMSPO4 can result in discoloring of the electrolyte after one week or after two weeks. While discoloration does not necessarily prevent electrolyte functionality it does indicate a chemical reaction which might be undesirable. To address this issue, we found that effective electrolytes that do not contain TMSPi or TMSM compounds remain colorless after at least one month. As such, also provided are electrolytes that exclude TMSPi, TMSM or a combination thereof.

[0088] As such, also provided herein is the combination of LiPFe, DMC, FEC, F2ECand LiDFOB improves the capacity and cycle life vs LiPF6 with DMC and there is no shuttling reaction as illustrated in example 12 and Fig. 28.

[0089] Also provided herein is the combination of LiPFe , DMC, FEC , F2EC, LiDFOB, TFETFPE and TMSPO4 as illustrated in Example 13 and Fig. 12.

[0090] Also provided herein is the combination of LiPFe , DMC, FEC and F2EC as illustrated in Example 9 and Fig. 9.

[0091] Also provided herein is the combination of LiPFe , DMC, FEC , F2EC, TFETFPE and TMSPO4 as illustrated in Example 14 and Fig. 13.

[0092] Also provided herein is the combination of LiPFe , DMC, FEC, LiDFOB, F2EC and TMSPO4 as illustrated in Example 15 and Fig. 14.

[0093] Also provided herein is the combination of LiPF6 , DMC, FEC, F2EC and LiBOB as illustrated in Example 16 and Fig. 15.

[0094] Optionally, an electrolyte as provided herein remains colorless as measured by eye (or as not significantly changing absorbance at any wavelength in the visible spectrum (e.g. 350 nm to 700 nm)) for 1 week or more, optionally 2 weeks or more, optionally 3 weeks or more, optionally 1 month or more, optionally 2 months or more, optionally 3 months or more, optionally 1 year or more.

[0095] Also provided are electrochemical cells that include an electrolyte as provided herein. An electrochemical cell is optionally a lithium electrochemical cell meaning that the electrochemical cell shuttles lithium between the anode and the cathode. The electrochemical cell may be a lithium ion battery, a lithium-polymer battery, or a lithium battery, for example. The electrochemical cell may include a cathode, an anode, and a separator interposed between the cathode and the anode. The separator may be a microporous membrane, and may include a porous film including polypropylene, polyethylene, or a combination thereof, or may be a woven or non-woven material such a glass-fiber mat.

[0096] The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used.

[0097] An electrochemical cell as provided herein includes a cathode that includes one or more cathode electrochemically active materials optionally coated on a current collector as otherwise provided herein, optionally an aluminum foil or copper foil currentcollector.

[0098] A cathode electrochemically active material optionally is defined by Lii+xMCh+y (Formula I) wherein -0.1<x<0.3, -0.3<y<0.3, and wherein M optionally comprises nickel at greater than or equal to 50 atomic percent, optionally greater than or equal to 80 atomic percent, (with at% relative to all elements in M and totaling 100 at%) and optionally one or more of Mn, Mg, or Co. In some aspects, M includes Ni, Co, and Mn. Optionally, a cathode electrochemically active material includes Ni at about 30 at% to about 70 at%, optionally about 30 at% to about 50 at%, optionally about 30 at% to about 45 at%, optionally about 39 at% to about 41 at% of M, Co at about 2 at% to about 6 at% of M, optionally about 5 to about 6 atomic percent of M, and Mn at about 20 at% to 65 at% of M, optionally 45 at% to 65 at% of M, optionally about 53 at% to about 55 at% of M, optionally 50 at% to 65 at% of M. Optionally, M further comprises one or more elements selected from the group consisting of Na, K, Al, Mg, Co, Mn, Ca, Sr, Ba, Zn, Ti, Zr, Y, Cr, Mo, Fe, V, Si, Ga and B, said one or more elements residing in a Li layer, a M layer, or both. Optionally, M comprises an atomic percent of nickel greater than or equal to 30 percent.

[0099] As such, it is appreciated that in some aspects, a cathode electrochemically active material may be defined by a composition of Lii+xMO2+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni componentof M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In someillustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some aspects if any of the foregoing, an anode for the above cathodes includes carbon, optionally graphite. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V.

[0100] The cycle life enhancement of Li-ion cells cycled to a charge cutoff voltage greater than 4.3 V, for example 4.65 V, containing NMC cathode and graphitic carbon anode can be significantly enhanced by an electrolyte as provided herein and as illustrated in Fig. 25.

[0101] It was surprising that specific components of the electrolytes as provided herein along with the absence of EC can significantly enhance the cycle life of lithium ion cells specifically Ni / Mn / Co (NMC) containing cathodes when charged to greater than 4.3 V, and more surprisingly wherein the Mn content is greater than 45 at%. For example, the electrolytes in Examples 1, 5 and 6 demonstrated significantly improved cycle life versus EDEVI when used in lithium ion cells charged to 4.65V comprising NMC (40:56:4 at% Ni:Mn:Co respectively) as the cathode active material (e.g. FIG. 25). However, the same electrolytes used in Examples 1, 5 and 6 demonstrated no cycle life improvement versus EDEVI when used in lithium ion cells charged to 4.65V comprising a NCA cathode (Ni:Co:Al at 91 :6:3 at% respectively) as seen in FIG. 26. Also, the same electrolytes as used in Example 1, 5 and 6 demonstrated no cycle life improvement versus EDEVI when used in lithium ion cells charged to 4.65V including NMCA cathodes (90:2:6:2 mole% Ni:Mn:Co:Al respectively) as is illustrated in FIG. 27.

[0102] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include lithium hexafluorophosphate (LiPFe), dimethylcarbonate(DMC), fluoroethylene carbonate (FEC), alone or in combination with one or more additives as provided herein, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The Mcomponent may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of theforegoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are full cells, optionally with an NMC cathode / carbon (e.g. graphite) anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0103] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include lithium hexafluorophosphate (LiPFe), dimethylcarbonate (DMC), fluoroethylene carbonate (FEC), and difluoroethylene carbonate (F2EC), wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material,Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In someaspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are full cells, optionally with an NMC cathode and a carbon anode (e.g. graphite) cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0104] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, and lithium difluoro(oxalato)borate (LiDFOB), wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known inthe art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional elementconsists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable ofbeing cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0105] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, tris(trimethylsilyl)malonate (TMSM), and LiBOB, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Nicomponent of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% toabout 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0106] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, TMSPO4, and LiBOB, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19,-0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%,optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0107] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, LiBOB, and tris(trimethylsilyl)phosphite (TMSPi), wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically activematerial on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. Inparticular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of beingcycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0108] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, TMSPO4, and TMSM, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than orequal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at%of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0109] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, TMSPi, TMSM, and LiBOB, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29,or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present atabout 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0110] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode.An electrolyte may include LiPFe, DMC, FEC, F2EC, TMSPi, and TMSM, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one ormore additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cellincluding the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. [OHl] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, TMSPi, TMSM, and LiBOB, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Nicomponent of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%,optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0112] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, and LiDFOB, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02,-0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionallyabout 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0113] Also, provided herein are electrochemical cells that include a cathode including acathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, LiDFOB, TFETFPE, and TMSPO4, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell includingthe anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0114] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, TFETFPE and TMSPO4, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at of 10 atomic percent to 100 atomic percent (at%) of the Melement. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%,optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0115] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC, F2EC, and LiBOB, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In someaspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about 39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacityretention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0116] Also, provided herein are electrochemical cells that include a cathode including a cathode electrochemically active material, an anode including an anode electrochemically active material and an electrolyte contacting the cathode and the anode. An electrolyte may include LiPFe, DMC, FEC and F2EC, wherein the electrolyte excludes ethylene carbonate (EC). The anode may include a coating of an anode electrochemically active material on a current collector. The coating may include a suitable carbon, such as graphite, coke, a hard carbon, or a mesocarbon such as a mesocarbon microbead, for example. The current collector may be aluminum foil or copper foil, for example, but other current collector materials known in the art may be used. The cathode may include a cathode electrochemically active material defined by a composition of Lii+xMCh+y (Formula I) where -0.1<x<0.3 and -0.3<y<0.3. In some aspects x is -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally x is greater than or equal to -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30. In some aspects, y is -0.3, optionally -0.2, optionally -0.1, optionally 0, optionally 0.1, optionally 0.2, or optionally 0.3. Optionally, y is greater than or equal to -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. In a cathode electrochemically active material, Ni is optionally present at 10 atomic percent to 100 atomic percent (at%) of the M element. Optionally, the Ni component of M is greater than or equal to 10 at%. Optionally, the Ni component of M is greater than or equal to 20 at%. Optionally, the Ni component of M is greater than or equal to 30 at%. Optionally, the Ni component of M is greater than or equal to 40 at%. Optionally, the Ni component of M is greater than or equal to 50 at%. Optionally, the Ni component of M is greater than or equal to 60 at%. Optionally, the Ni component of M is greater than or equal to 70 at%. Optionally, the Ni component of M is greater than or equal to 75 at%. Optionally, the Ni component of M is greater than or equal to 80 at%. Optionally, the Ni component of M is greater than or equal to 85 at%. Optionally, the Ni component of M is greater than or equal to 90 at%. Optionally, the Ni component of M is greater than or equal to 95 at%. Optionally, the Nicomponent of M is greater than or equal to 95 at%. Optionally, the Ni component of M is about 30 at%, 31 at%, 32 at%, 33 at%, 34 at%, 35 at%, 35 at%, 36 at%, 37 at%, 38 at%, 39 at%, 40 at%, 41 at%, 42 at%, 43 at%, 44 at%, 45 at%, 46 at%, 47 at%, 48 at%, 49 at%, 50 at%, 55 at%, 60 at%, 65 at%, 70 at%. The M component may include one or more additional elements. The additional elements are optionally metals. Optionally, an additional element may include or be one or more of Al, Mg, Co, Mn, Ca, Sr, Zn, Ti, Y, Cr, Mo, Fe, V, Si, Ga, or B. In particular aspects, the additional element may include Mn, Co, or a combination thereof. In particular aspects, the additional element may include Mg, Co, Al, or a combination thereof. Optionally, the additional element may be Mg, Al, V, Ti, B, or Mn, or a combination thereof. Optionally, the additional element consists of Mg, Al, V, Ti, B, or Mn. In some aspects, the additional element is Mn or Al, or Mn and Co. The additional element of M may be present in an amount of about 0.01 at% to about 70 at%, specifically about 0.05 at% to about 65 at% of total M. In some examples, M includes Ni, Co and Mn wherein Ni is present at any amount as provided herein, Mn is present at about 20 at% to about 65 at% optionally about 45 at% to about 65 at% and Co is present at about 2 at% to 6 at% of total M. Optionally, Mn is present at about 20 at%, optionally about 25 at%, optionally about 30 at%, optionally about 35 at%, optionally about 40 at%, optionally about 45 at%, optionally about 46 at%, optionally about 47 at%, optionally about 48 at%, optionally about 49 at%, optionally about 50 at%, optionally about 51 at%, optionally about 52 at%, optionally about 53 at%, optionally about 54 at%, optionally about 55 at%, optionally about 56 at%, optionally about 57 at%, optionally about 58 at%, optionally about 59 at%, optionally about 60 at%, optionally about 61 at%, optionally about 62 at%, optionally about 63 at%, optionally about 64 at%, optionally about 65 at% of total M. In some aspects, Co is present at about 2 at%, optionally about 2.5 at%, optionally about 3 at%, optionally about 3.5 at%, optionally about 4 at%, optionally about 4.5 at%, optionally about 5 at%, optionally about 5.1 at%, optionally about 5.2 at%, optionally about 5.3 at%, optionally about 5.4 at%, optionally about 5.5 at%, optionally about 5.6 at%, optionally about 5.7 at%, optionally about 5.8 at%, optionally about 5.9 at%, optionally about 6 at% of total M. In some illustrative examples, M is about 30-50 at% Ni, about 20-65 at% Mn optionally 45-65 at% Mn, and about 2-6 at% Co, alone or further in combination with about 0-10 at% additional elements. In some illustrative examples, M is about 30 at% to about 45 at% of Ni, 50 at% to 65 at% Mn, and about 2 at% to about 6 at % of Co, alone or further in combination with about 0-10 at% additional elements. In some other illustrative examples, M is about39-41 at% Ni, about 53-55 at% Mn, and about 5-6 at% Co, alone or further in combination with about 0-10 at% additional elements. Optionally the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a formation voltage (FV) of greater than about 4.3 V. In some aspects of any of the foregoing the electrochemical cell including the anode, cathode, and electrolyte as provided herein has a charge voltage (CV) of greater than about 4.3 V. Optionally, the electrochemical cells are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.5 V, optionally <4.65V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity. Optionally, the electrochemical cells with an NMC cathode / Li anode are cycled or are capable of being cycled with a charge cutoff of greater than 4.3 V, optionally <4.4 V, optionally <4.50 V, optionally <4.65 V, optionally <4.8 V during cell operation with a capacity retention at 100 cycles of greater than or equal to about 60% relative to a first capacity.

[0117] The electrochemical cell may have any suitable configuration or shape, and may be a pouch cell, cylindrical, or prismatic.

[0118] Various aspects of the present disclosure are illustrated by the following nonlimiting examples. The examples are for illustrative purposes and are not a limitation on any practice of the present invention. It will be understood that variations and modifications can be made without departing from the spirit and scope of the invention.EXPERIMENTAL

[0119] Electrochemical tests were performed using cells that included an NMC cathode, NCA cathode, or NMCA cathode individually paired with a mesocarbon microbead (MCMB) (10-28) graphitic anode in CR2025 coin cells. The NMC cathode included 40 / 56 / 4 at% Ni / Mn / Co respectively. The NCA cathode included 91 / 6 / 3 at% Ni / Co / Al. The NMCA cathode included 90 / 2 / 6 / 2 at% Ni / Mn / Co / Al.

[0120] The as-received coin cell parts were modified in house with about 3 pm thick of an anti-corrosion layer deposited on the cathode side of the coin cell base. The cathode electrodes were prepared by casting onto aluminum foil substrate at a formulation of 94:3:3 cathode active material conductive carbon:PVDF binder and a loading of about 8 mg / cm2. The cathode was calendared at 100 pounds per square inch (psi) resulting in a density of 2.8-3.0 g / cm3. MCMB anodes were similarly prepared at 92:3:5 formulation (anode active material conductive carbon:PVDF binder) and cast onto copper foil at aloading range of 5-6 mg / cm2. These electrode loadings provide an anode to cathode (A / C) capacity ratio with a range of 1.16 to 1.32. A high A / C capacity ratio was used to accommodate a larger diameter anode (anode at 21 / 32” versus cathode at 5 / 8”) to minimize electrode alignment issues during cell assembly. The cell separator was a Celgard 2325 microporous polyolefin film.

[0121] Cells prepared in this way were used to evaluate various electrolyte formulations. The as built cells contained 65 microliters (pl) of the test electrolyte and were cycled at room temperature between a voltage range of 4.65 V and 2.5 V, or as otherwise provided herein. The cells were subjected to three initial formation cycles consisting of CC-CV (constant current-constant voltage) charge of C / 20, C / 20 discharge, and two CC-CV C / 5 charge-C / 5 discharge cycles. The cells were then cycled at room temperature between a voltage range of 4.65 V and 2.5 V (or as otherwise provided herein) at a rate of 1C charge and 1C discharge with two discharge rate checks of C / 5 and 2C every 20 1C-1C cycles for a total of 400 cycles or until the cell capacity decayed below 50% of initial capacity.

[0122] Table 1 provides a summary of electrochemical testing of various electrolytes. The capacities are reported after 100, 200 and 300 charge-discharge cycles at room temperature. The “high voltage shuttling” column refers to the presence of greater than 4.65 V anomalous, unstable, and undesirable charging voltage in the examples and can be observed in the charge voltage graph in FIGs. 16-24.Table 1Example 1

[0123] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2 wt% F2EC, 1 wt% TMSPO4, 1 wt% TMSM and 0.5 wt% LiBOB. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 1, the 100, 200 and 300 cycle capacities are 139, 114 and 70 mAh / g respectively. There was no shuttling reaction. The electrolyte was color-free after 1 week and showed some level of discoloration at 1 month.Example 2

[0124] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2 wt% F2EC, 1 wt% TMSPi, and 1 wt% TMSM. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 2, the 100, 200 and 300 cycle capacities are 143, 119 and 84 mAh / g respectively. There was no shuttling reaction. The electrolyte discolored after 1 week.Example 3

[0125] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2 wt% F2EC, 1 wt% TMSPi, 1 wt% TMSM and 1 wt% LiBOB. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 3, the 100, 200 and 300 cycle capacities are 149, 119, 82 mAh / g respectively. There was no shuttling reaction. The electrolyte discolored after 1 week.Example 4

[0126] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2.3 wt% TMSPi, 2 wt% TMSM and 1 wt% LiBOB. The cells were cycled from 4.65V to 2.5Vat room temperature. As illustrated in FIG. 4, the 100, 200 and 300 cycle capacities are 142, 113, 83 mAh / g respectively. There was no shuttling reaction. The electrolyte discolored after 1 week.Example 5

[0127] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 2.0 M LiPFe in DMC, plus 4 wt% FEC, and 2 wt% LiDFOB. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 5, the 100, 200 and 300 cycle capacities are 140, 102 and 62 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color free after 1 month.Example 6

[0128] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2 wt% F2EC, 1 wt% TMSPO4 and 1 wt% TMSM. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 6, the 100, 200 and 300 cycle capacities are 137, 110 and 60 mAh / g, respectively. There was no shuttling reaction. The electrolyte remained color free after 1 week and showed some level of discoloration after 1 month.Example 7

[0129] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 1 wt% F2EC, 1 wt% LiBOB, and 1 wt% TMSM. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 7, the 100, 200 and 300 cycle capacities are 140, 104 and 64 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color free after 1 week and showed some level of discoloration after 1 month.Example 8

[0130] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 1 wt% F2EC, 1 wt% LiBOB, and 1 wt% TMSPi. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated at FIG. 8, the 100, 200 and 300 cycle capacities are 151, 111 and 90 mAh / g respectively. There was no shuttling reaction. The electrolytediscolored after 1 week.Example 9

[0131] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC and 2 wt% F2EC. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 9, the 100, 200 and 300 cycle capacities are 130, 84 and 32 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color-free after 1 month.Example 10

[0132] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2 wt% F2EC, 1 wt% TMSPO4, 1 wt% TMSM and 0.5 wt% LiBOB. Cells underwent an initial formation cycle at 4.65V at 25 °C (RT) and were subsequently 1C rate cycled at 4.3, 4.4, 4.5 and 4.6V at 45 °C. The 8thcycle capacities are 161, 172, 184 and 192 mAh / g for 4.3, 4,4, 4,5 and 4.6V charge cutoff cycling respectively. The 196thcapacities are 138, 149, 157 and 150 mAh / g for 4.3, 4,4, 4,5 and 4.6V charge cutoff cycling respectively. Results are illustrated in FIG. 10.Example 11

[0133] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPFe in DMC, plus 4 wt% FEC, 2 wt% F2EC, 1 wt% TMSPO4, 1 wt% TMSM and 0.5 wt% LiBOB. Cells underwent an initial formation cycle at 4.3 V at RT and were subsequently 1C rate cycled at 4.3 V, 4.4 V, 4.5 V and 4.6 V at 45 °C. The 8thcycle capacities are 110, 149, 184 and 192 mAh / g for 4.3 V, 4.4 V, 4.5 V and 4.6 V charge cutoff cycling respectively. The 196thcapacities are 117, 154, 165 and 155 for 4.3, 4.4, 4.5 and 4.6V charge cutoff cycling respectively. Results are illustrated in FIG. 11.Example 12

[0134] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 2.0 M LiPF6 in DMC, plus 4 wt% FEC, 2 wt% LiDFOB and 2 wt% F2EC. The cells were cycled from 4.65V to 2.5V at roomtemperature. The 100, 200 and 300 cycle capacities are 134, 97 and 28 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color free after 1 month. Results are illustrated in FIG. 28.Example 13

[0135] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 2.0 M LiPF6 in DMC, plus 4 wt% FEC, 2 wt% LiDFOB, 2 wt.% F2EC, 11 wt.% TFETFPE and 2 wt.% TMSPO4. The cells were cycled from 4.65V to 2.5V at room temperature. The 100, 200 and 300 cycle capacities are 145, 119 and 86 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color free after 1 month. Results are illustrated in FIG. 12.Example 14

[0136] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 2.0 M LiPF6 in DMC, plus 4 wt% FEC, 2 wt% F2EC, 11 wt% TFETFPE and 2 wt% TMSPO4. The cells were cycled from 4.65V to 2.5V at room temperature. The 100, 200 and 300 cycle capacities are 143, 128 and 111 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color free after 1 month. Results are illustrated in FIG. 13.Example 15

[0137] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 2.0 M LiPF6 in DMC, plus 4 wt% FEC, 2 wt% LiDFOB, 2 wt% F2EC, and 2 wt% TMSPO4. The cells were cycled from 4.65V to 2.5V at room temperature. The 100, 200 and 300 cycle capacities are 144, 121 and 90 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color free after 1 month. Results are illustrated in FIG. 14.Example 16

[0138] Electrochemical coin cells as described above were constructed using a Celgard 2325 separator and filled with 65 pl of 1.3 M LiPF6 in DMC, plus 4 wt% FEC, 2 wt% F2EC and 0.5 wt% LiBOB. The cells were cycled from 4.65V to 2.5V at room temperature. The 100, 200 and 300 cycle capacities are 151, 126 and 99 mAh / g respectively. There was no shuttling reaction. The electrolyte remained color-free after1 month. Results are illustrated in FIG. 15.Comparative Example 1

[0139] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of EDEVI. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 16, the 100, 200 and 300 cycle capacities are 67, 17 and 11 mAh / g respectively. There was a shuttling reaction. The electrolyte remained color-free after 1 week.Comparative Example 2

[0140] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in EC:DMC 3:7. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 17, the 100, 200 and 300 cycle capacities are 18, 5 and 3 mAh / g respectively. There was a shuttling reaction. The electrolyte remained color-free after 1 week.Comparative Example 3

[0141] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.15 M LiPFe in EC:DEC:DMC 3:3:4. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in Fig. 18, the 100, 200 and 300 cycle capacities are 18, 5 and 3 mAh / g respectively. There was a shuttling reaction. The electrolyte remained color-free after 1 week.Comparative Example 4

[0142] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in DMC. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 19, the 100, 200 and 300 cycle capacities are 82, 79 and 43 mAh / g respectively. There was a shuttling reaction. The electrolyte remained color-free after 1 week.Comparative Example 5

[0143] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in DMC plus 2 wt% TMSM. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG.20, the 100, 200 and 300 cycle capacities are 132, 99 and 48 mAh / g respectively. There was a shuttling reaction. The electrolyte discolored after 1 week.Comparative Example 6

[0144] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in DMC plus 2 wt% TMSPi. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 21, the 100, 200 and 300 cycle capacities are 116, 81 and 26 mAh / g respectively. There was a shuttling reaction. The electrolyte discolored after 1 week.Comparative Example 7

[0145] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in DMC plus 4 wt% FEC. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 22, the 100, 200 and 300 cycle capacities are 136, 93 and 49 mAh / g respectively. There was a shuttling reaction. The electrolyte remained color-free after 1 week.Comparative Example 8

[0146] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in DMC plus 4 wt% FEC and 2 wt% TMSM. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 23, the 100, 200 and 300 cycle capacities are 139, 92 and 28 mAh / g respectively. There was a shuttling reaction. The electrolyte discolored after 1 week.Comparative Example 9

[0147] Electrochemical coin cells as described above were constructed using Celgard 2325 separator and filled and with 65 pl of 1.3 M LiPFe in DMC plus 4 wt% FEC and 2 wt% TMSPi. The cells were cycled from 4.65V to 2.5V at room temperature. As illustrated in FIG. 24, the 100, 200 and 300 cycle capacities are 146, 86 and 33 mAh / g respectively. There was a shuttling reaction after 200 cycles. The electrolyte discolored after 1 week.Additional illustrative listing of itemsItem 1. A Li-ion electrochemical cell electrolyte including lithiumhexafluorophosphate (LiPFe), dimethylcarbonate (DMC), fluoroethylene carbonate (FEC), and difluoroethylene carbonate (F2EC), wherein the electrolyte excludes ethylene carbonate (EC).Item 2. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, and lithium difluoro(oxalato)b orate (LiDFOB), wherein the electrolyte excludes EC.Item 3. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, tris(trimethylsilyl)malonate (TMSM), and LiBOB, wherein the electrolyte excludes EC.Item 4. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, TMSPO4, and LiBOB, wherein the electrolyte excludes EC.Item 5. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, LiBOB, and tris(trimethylsilyl)phosphite (TMSPi), wherein the electrolyte excludes EC.Item 6. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, TMSPO4, and TMSM, wherein the electrolyte excludes EC.Item 7. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, TMSPi, TMSM, and LiBOB, wherein the electrolyte excludes EC.Item 8. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, TMSPi, and TMSM, wherein the electrolyte excludes EC.Item 9. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, TMSPi, TMSM, and LiBOB, wherein the electrolyte excludes EC.Item 10. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, and LiDFOB, wherein the electrolyte excludes EC.Item 11. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, LiDFOB, TFETFPE, and TMSPO4, wherein the electrolyte excludes EC.Item 12. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, TFETFPE and TMSPO4, wherein the electrolyte excludes EC.Item 13. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC, F2EC, and LiBOB, wherein the electrolyte excludes EC.Item 14. A Li-ion electrochemical cell electrolyte including LiPFe, DMC, FEC and F2EC, wherein the electrolyte excludes EC.Item 15. The electrolyte of any one of items 1-14, wherein a concentration of LiPFe is more than 1.0 molar (M), optionally more than 1.2 M.Item 16. The electrolyte of any one of items 1-15, wherein a concentration of FEC is more than 1 wt%, optionally more than 3 wt%.Item 17. The electrolyte of any one of items 1, 3-8, or 10-14, wherein a concentration of F2EC is more than 0.5 wt%, optionally more than 1 wt%.Item 18. The electrolyte of any one of items 4, 6, or 11-12 wherein a concentration of TMSPO4 is less than 5 wt%, optionally less than 3 wt%.Item 19. The electrolyte of any one of item 3, 6, 7, 8, or 9, wherein a concentration of TMSM is less than 5 wt%, optionally less than 3 wt%.Item 20. The electrolyte of any one of items 5, 7, 8, or 9, wherein a concentration of TMSPi is less than 5 wt%, optionally less than 3 wt%.Item 21. The electrolyte of item 2, 10, 11, or 12, wherein a concentration of LiPFe is more than 1.5 M, optionally more than 1.9 M.Item 22. The electrolyte of item 11 or 12, wherein the concentration of TFETFPE is less than 20 wt%, optionally less than 11 wt%.Item 23. An electrochemical cell including the electrolyte of any one of items 1-22.Item 24. An electrochemical cell including the electrolyte of any one of items 1-22 and further including an anode including or consisting of graphite, and a cathode including Ni, Mn, Mg, Co, or combinations thereof, optionally a combination of Ni, Mn and Co.Item 25. The electrochemical cell of items 23 or 24, wherein the cell is a lithium ion cell.Item 26. The electrochemical cell of item 23 further including an anode electrochemically active material, the anode electrochemically active material including or consisting of graphite.Item 27. The electrochemical cell of items 23 to 26, wherein a cathode includs a cathode electrochemically active material defined by Lii+xMCh+y (Formula I) wherein -0.1<x<0.3, -0.3<y<0.3, optionally wherein M comprises Ni, Mn, Mg, Co, or combinations thereof.Item 28. The electrochemical cell of item 27, wherein the cathode electrochemically active material comprises Ni, Mn and Co.Item 29. The electrochemical cell of any one of items 27-28, wherein the Ni is present at about 30 at% to about 50 at% of M, Mn at about 20 at% to 65 at% optionally 45 at% to 65 at% of M, and Co at about 2 at% to about 6 at % of M.Item 30. The electrochemical cell of any of items 23-29, wherein the cells are formed with a charge cutoff voltage of greater than about 4.3 V.Item 31. The electrochemical cell of any of items 23-30, wherein the cells are cycled with a charge cutoff of greater than 4.3 V, optionally <4.6 V, optionally <4.65 V,optionally <4.8 V during cell operation.Item 32. The electrochemical cell of any of items 23-31, excluding a toxic additive.Item 33. The electrochemical cell of item 32, wherein the additive is or includes one or more organic sulfates and / or organic sultones.CHEMICAL ABBREVIATIONSLiPFe - Lithium HexafluorophosphateEC - Ethylene CarbonateEMC - Ethyl Methyl CarbonateDEC - Diethylene CarbonateVC - Vinylene CarbonateDMC - Dimethyl CarbonateEDEVI - IM LiPFe in 1 :1 : 1 EC:DMC:EMC plus 1% VCFEC - Fluoroethylene CarbonateF2EC - Difluoroethylene CarbonateLiDFOB - Lithium Difluoro(oxalato)borateLiBOB - Lithium Bis(oxalato)b orateTMSM - Tris (trimethylsilyl)malonateTMSPi - Tris (trimethyl silyl) phosphiteTMSP04 - Tris (trimethyl silyl) phosphateTFETFPE - 1,1,2,2-Tetrafluoroethyl 2,2,3,3-Tetrafluoropropyl Ether

[0148] Various modifications, in addition to those shown and described herein, will be apparent to those skilled in the art of the above description. Such modifications are also intended to fall within the scope of the disclosure.

[0149] It is appreciated that all reagents are obtainable by sources known in the art unless otherwise specified.

[0150] Patents, publications, and applications mentioned in the specification are indicative of the levels of those skilled in the art to which the disclosure pertains. These patents, publications, and applications are incorporated herein by reference to the same extent as if each individual patent, publication, or application was specifically andindividually incorporated herein by reference.

[0151] The foregoing description is illustrative of particular aspects of the invention, but is not meant to be a limitation upon the practice thereof.

[0152] We claim:

Claims

CLAIMS1. A Li-ion electrochemical cell electrolyte comprising lithium hexafluorophosphate (LiPFe), dimethylcarbonate (DMC), fluoroethylene carbonate (FEC), and optionally further comprising difluoroethylene carbonate (F2EC), wherein said electrolyte excludes ethylene carbonate (EC).

2. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, and lithium bis(oxalato)borate (LiDFOB), wherein said electrolyte excludes EC.

3. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, tris(trimethylsilyl)malonate (TMSM), and LiBOB, wherein said electrolyte excludes EC.

4. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, TMSPO4, and LiBOB, wherein said electrolyte excludes EC.

5. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, LiBOB, and tris(trimethylsilyl)phosphite (TMSPi), wherein said electrolyte excludes EC.

6. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, TMSPO4, and TMSM, wherein said electrolyte excludes EC.

7. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, TMSPi, TMSM, and LiBOB, wherein said electrolyte excludes EC.

8. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, TMSPi, and TMSM, wherein said electrolyte excludes EC.

9. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, TMSPi, TMSM, and LiBOB, wherein said electrolyte excludes EC.

10. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC,F2EC, and LiDFOB, wherein said electrolyte excludes EC.

11. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, LiDFOB, TFETFPE, and TMSPO4, wherein said electrolyte excludes EC.

12. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, TFETFPE and TMSPO4, wherein said electrolyte excludes EC.

13. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC, F2EC, and LiBOB, wherein said electrolyte excludes EC.

14. A Li-ion electrochemical cell electrolyte comprising LiPFe, DMC, FEC and F2EC, wherein said electrolyte excludes EC.

15. The electrolyte of any one of claims 1-14, wherein a concentration of LiPFe is more than 1.0 molar (M), optionally more than 1.2 M.

16. The electrolyte of any one of claims 1-14, wherein a concentration of FEC is more than 1 wt%, optionally more than 3 wt%.

17. The electrolyte of any one of claims 1, 3-8, or 10-14, wherein a concentration of F2EC is more than 0.5 wt%, optionally more than 1 wt%.

18. The electrolyte of any one of claims 4, 6, or 11-12 wherein a concentration of TMSPO4 is less than 5 wt%, optionally less than 3 wt%.

19. The electrolyte of any one of claims 3, 6, 7, 8, or 9, wherein a concentration of TMSM is less than 5 wt%, optionally less than 3 wt%.

20. The electrolyte of any one of claims 5, 7, 8, or 9, wherein a concentration of TMSPi is less than 5 wt%, optionally less than 3 wt%.

21. The electrolyte of claim 2, 10, 11, or 12, wherein a concentration of LiPFe is more than 1.5 M, optionally more than 1.9 M.

22. The electrolyte of claim 11 or 12, wherein the concentration of TFETFPE is less than 20 wt%, optionally less than 11 wt%.

23. An electrochemical cell comprising the electrolyte of any one of claims 1-14.

24. The electrochemical cell of claim 23 further comprising an anode electrochemically active material, said anode electrochemically active material comprising or consisting of graphite.

25. An electrochemical cell comprising the electrolyte of any one of claims 1-14 and further comprising an anode comprising or consisting of graphite, and a cathode comprising Ni, Mn, Mg, Co, or combinations thereof, optionally a combination of Ni, Mn and Co.

26. The electrochemical cell claim 25, wherein said cell is a lithium ion cell.

27. The electrochemical cell of claim 24, further comprising a cathode comprising a cathode electrochemically active material defined by Lii+xMCh+y (Formula I) wherein -0. l<x<0.3, -0.3<y<0.3, optionally wherein M comprises Ni, Mn, Mg, Co, or combinations thereof.

28. The electrochemical cell of claim 27, wherein said cathode electrochemically active material comprises Ni, Mn and Co.

29. The electrochemical cell of claim 27, wherein said Ni is present at about 30 at% to about 70 at% of M, Mn at about 20 at% to 65 at% of M, and Co at about 2 at% to about 6 at % of M.

30. The electrochemical cell of claim 27, wherein said Ni is present at about30 at% to about 45 at% of M, Mn at about 50 at% to 65 at% of M, and Co at about 2 at% to about 6 at % of M.

31. The electrochemical cell of claim 23, wherein the cells are formed with a charge cutoff voltage of greater than about 4.3 V.

32. The electrochemical cell of claim 23, wherein the cells are cycled with a charge cutoff of <4.65 V during cell operation, optionally with a charge cutoff greater than about 4.3 V.

33. The electrochemical cell of any of claim 23, excluding organic sulfates and / or organic sultones.