Fluorinated lithium-rich manganese-based oxide positive electrode materials for lithium ion circulating batteries and methods of making same

Abstract

A positive electrode of a battery for cycling lithium ions includes a fluorinated lithium rich manganese based oxide (LMR) material. A fluorinated LMR material has the formula: Li1 + xMe (1-x) O2-yFy, wherein: Me is a transition metal selected from the group consisting of Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W; me comprises greater than or equal to 50 at% Mn; x is greater than 0 and less than or equal to 0.33; and y is greater than 0 and less than or equal to 0.1.

Description

Technical Field

[0001] The present disclosure relates to a positive electrode for a battery pack for cycling lithium ions, and more particularly to a positive electrode comprising a fluorinated lithium-rich manganese-based oxide as an electroactive material. Background Art

[0002] The information provided in this section is intended to generally introduce the background of the present disclosure. To the extent that the work currently attributed to the inventors is described in this section, and aspects of the specification that may not otherwise be determined to be prior art at the time of filing, are not expressly or implicitly admitted to be prior art against the present disclosure.

[0003] The present disclosure relates to a positive electrode for a battery pack for cycling lithium ions, and more particularly to a positive electrode comprising a fluorinated lithium-rich manganese-based oxide as an electroactive material.

[0004] A battery pack for cycling lithium ions typically includes a positive electrode, a negative electrode spaced apart from the positive electrode, and an ion-conductive electrolyte that provides a medium for the conduction of lithium ions between the positive and negative electrodes during discharge and charge of the battery pack. Layered lithium-rich and manganese-based oxide (LMR) has become an attractive candidate for a positive electrode electroactive material due to its relatively high capacity (e.g., >250 mAh / g), thermal stability, and relatively low cost. However, LMR has been found to exhibit voltage decay, low Coulombic efficiency, and irreversible capacity loss after repeated charge and discharge cycles. Summary of the Invention

[0005] According to one or more embodiments of the present disclosure, a positive electrode for a battery pack for cycling lithium ions comprises a fluorinated lithium-rich manganese-based oxide (LMR) material. The fluorinated LMR material has the formula: Li 1+x Me 1-x O 2-y F y , where Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W; Me comprises greater than or equal to 50 atomic % Mn; x is greater than 0 and less than or equal to 0.33; and y is greater than 0 and less than or equal to 0.1.

[0006] In various embodiments, y may be greater than or equal to 0.005 and less than or equal to 0.08.

[0007] The fluorinated LMR material may have a layered crystal structure including a transition metal layer, an oxygen layer, and a lithium layer, and wherein fluoride ions in the fluorinated LMR material are present at anion sites within the oxygen layer.

[0008] The fluorinated LMR material may have the following formula: Li a Ni b Mn c O 2-y F y , where: a is greater than or equal to 1.1 and less than or equal to 1.2; b is greater than or equal to 0.25 and less than or equal to 0.4; c is greater than or equal to 0.6 and less than or equal to 0.75; and y is greater than or equal to 0.005 and less than or equal to 0.08.

[0009] According to one or more embodiments of the present disclosure, a battery pack for cycling lithium ions includes a negative electrode, a positive electrode, and an electrolyte that permeates the positive electrode. The negative electrode contains an electroactive negative electrode material. The positive electrode contains a fluorinated lithium-rich manganese-based oxide (LMR) material. The fluorinated LMR material has the following formula: Li 1+x Me 1-x O 2-y F y , where: Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W; Me contains greater than or equal to 50 atomic % of Mn; x is greater than 0 and less than or equal to 0.33; and y is greater than 0 and less than or equal to 0.1. The electrolyte contains an organic solvent and a lithium salt in the organic solvent.

[0010] In various embodiments, y may be greater than or equal to 0.005 and less than or equal to 0.08.

[0011] The fluorinated LMR material may have a layered crystal structure including a transition metal layer, an oxygen layer, and a lithium layer, and wherein fluoride ions in the fluorinated LMR material are present at anion sites within the oxygen layer.

[0012] The fluorinated LMR material may have the following formula: Li a Ni b Mn c O 2-y F y , where: a is greater than or equal to 1.1 and less than or equal to 1.2; b is greater than or equal to 0.25 and less than or equal to 0.4; c is greater than or equal to 0.6 and less than or equal to 0.75; and y is greater than or equal to 0.005 and less than or equal to 0.08.

[0013] The organic solvent may include fluoroethylene carbonate (FEC) and diethyl carbonate (DEC).

[0014] The lithium salt may include lithium hexafluorophosphate (LiPF6).

[0015] The electrolyte may further contain lithium difluorophosphate (LiPO2F2).

[0016] In some embodiments, the electroactive negative electrode material may include a silicon oxide-based material and a carbon-based material.

[0017] In other embodiments, the electroactive negative electrode material may contain greater than 97 wt% lithium.

[0018] According to one or more embodiments of the present disclosure, a method of manufacturing a positive electrode for a battery pack for cycling lithium ions includes (a) mixing a non-fluorinated lithium-rich manganese-based oxide (LMR) material with a fluorine-containing solution containing a fluorine compound in a first solvent to form a precursor mixture, (b) removing the first solvent from the precursor mixture to form a fluorinated lithium-rich manganese-based oxide (LMR) material, (c) mixing the fluorinated LMR material with a polymer binder and a second solvent to form a slurry, (d) depositing the slurry on a substrate, and then (e) removing the second solvent from the slurry to form the positive electrode. The fluorinated LMR material has the formula: Li 1+ x Me 1-x O 2-y F y , where: Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W; Me contains greater than or equal to 50 atomic % Mn; x is greater than 0 and less than or equal to 0.33; and y is greater than 0 and less than or equal to 0.1.

[0019] y may be greater than or equal to 0.005 and less than or equal to 0.08.

[0020] The fluorine compound may include ammonium fluoride (NH4F), titanium fluoride (TiF4), lithium fluoride (LiF), or a combination thereof.

[0021] The first solvent may include acetone.

[0022] The first solvent may be removed from the precursor mixture by heating the precursor mixture at a temperature greater than or equal to 30 °C and less than or equal to 150 °C.

[0023] The method may further include, before step (c), heating the fluorinated LMR material at a temperature greater than or equal to 300 °C and less than or equal to 600 °C for a duration greater than or equal to 1 hour and less than or equal to 12 hours.

[0024] The method may further include preparing the non-fluorinated LMR material by mixing a transition metal source and a lithium source to form a mixture and heating the mixture to form the non-fluorinated LMR material. The transition metal source may include a transition metal carbonate (MeCO3), a transition metal hydroxide (Me(OH)2), or a combination thereof, and the lithium source may include lithium carbonate (Li2CO3), lithium hydroxide (LiOH), or a combination thereof.

[0025] The present invention discloses the following solutions:

[0026] Solution 1. A positive electrode for a battery pack for recycling lithium ions, the positive electrode comprising:

[0027] Lithium-rich manganese fluoride-based oxide (LMR) material, the fluorinated LMR material having the following formula (1):

[0028] Li 1+x Me 1-x O 2-y F y , (1)

[0029] Wherein:

[0030] Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W;

[0031] Me contains greater than or equal to 50 atomic% of Mn;

[0032] x is greater than 0 and less than or equal to 0.33; and

[0033] y is greater than 0 and less than or equal to 0.1.

[0034] Solution 2. The positive electrode according to Solution 1, wherein the y is greater than or equal to 0.005 and less than or equal to 0.08.

[0035] Solution 3. The positive electrode according to Solution 1, wherein the fluorinated LMR material has a layered crystal structure including a transition metal layer, an oxygen layer, and a lithium layer, and wherein fluoride ions in the fluorinated LMR material are present at anion sites within the oxygen layer.

[0036] Solution 4. The positive electrode according to Solution 1, wherein the fluorinated LMR material has the following formula (2):

[0037] Li a Ni b Mn c O 2-y F y , (2)

[0038] Wherein:

[0039] a is greater than or equal to 1.1 and less than or equal to 1.2;

[0040] b is greater than or equal to 0.25 and less than or equal to 0.4;

[0041] c is greater than or equal to 0.6 and less than or equal to 0.75; and

[0042] y is greater than or equal to 0.005 and less than or equal to 0.08.

[0043] Solution 5. A battery pack for recycling lithium ions, the battery pack comprising:

[0044] A negative electrode including an electroactive negative electrode material;

[0045] A positive electrode including a fluorinated lithium-rich manganese-based oxide (LMR) material, the fluorinated LMR material having the following formula (1):

[0046] Li 1+x Me 1-x O 2-y F y , (1)

[0047] Wherein:

[0048] Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W;

[0049] Me contains greater than or equal to 50 atomic % of Mn;

[0050] x is greater than 0 and less than or equal to 0.33; and

[0051] y is greater than 0 and less than or equal to 0.1; and

[0052] An electrolyte permeating the positive electrode, the electrolyte comprising an organic solvent and a lithium salt in the organic solvent.

[0053] Solution 6. The battery pack according to Solution 5, wherein the y is greater than or equal to 0.005 and less than or equal to 0.08.

[0054] Solution 7. The battery pack according to Solution 5, wherein the fluorinated LMR material has a layered crystal structure including a transition metal layer, an oxygen layer, and a lithium layer, and wherein fluoride ions in the fluorinated LMR material are present at anion sites within the oxygen layer.

[0055] Solution 8. The battery pack according to Solution 5, wherein the fluorinated LMR material has the following formula (2):

[0056] Li a Ni b Mn c O 2-y F y , (2)

[0057] Wherein:

[0058] a is greater than or equal to 1.1 and less than or equal to 1.2;

[0059] b is greater than or equal to 0.25 and less than or equal to 0.4;

[0060] c is greater than or equal to 0.6 and less than or equal to 0.75; and

[0061] y is greater than or equal to 0.005 and less than or equal to 0.08.

[0062] Aspect 9. The battery pack according to Aspect 5, wherein the organic solvent comprises fluoroethylene carbonate (FEC) and diethyl carbonate (DEC).

[0063] Aspect 10. The battery pack according to Aspect 9, wherein the lithium salt comprises lithium hexafluorophosphate (LiPF6).

[0064] Aspect 11. The battery pack according to Aspect 10, wherein the electrolyte further comprises lithium difluorophosphate (LiPO2F2).

[0065] Aspect 12. The battery pack according to Aspect 5, wherein the electroactive negative electrode material comprises a silicon oxide-based material and a carbon-based material.

[0066] Aspect 13. The battery pack according to Aspect 5, wherein the electroactive negative electrode material contains more than 97 wt% of lithium.

[0067] Aspect 14. A method of manufacturing a positive electrode of a battery pack for cycling lithium ions, the method comprising:

[0068] (a) mixing a non-fluorinated lithium-rich manganese-based oxide (LMR) material with a fluorine-containing solution to form a precursor mixture, the fluorine-containing solution comprising a fluorine compound in a first solvent;

[0069] (b) removing the first solvent from the precursor mixture to form a fluorinated lithium-rich manganese-based oxide (LMR) material, the fluorinated LMR material having the following formula (1):

[0070] Li 1+x Me 1-x O 2-y F y , (1)

[0071] wherein:

[0072] Me is a transition metal selected from Co, Ni, Mn, Fe, Al, and V;

[0073] Me contains greater than or equal to 50 atomic% of Mn;

[0074] x is greater than 0 and less than or equal to 0.33; and

[0075] y is greater than 0 and less than or equal to 0.1;

[0076] (c) Mix the fluorinated LMR material with a polymer binder and a second solvent to form a slurry;

[0077] (d) Deposit the slurry on a substrate; then

[0078] (e) Remove the second solvent from the slurry to form a positive electrode.

[0079] Aspect 15. The method according to aspect 14, wherein y is greater than or equal to 0.005 and less than or equal to 0.08.

[0080] Aspect 16. The method according to aspect 14, wherein the fluorine compound comprises ammonium fluoride (NH4F), titanium fluoride (TiF4), lithium fluoride (LiF), or a combination thereof.

[0081] Aspect 17. The method according to aspect 14, wherein the first solvent comprises acetone.

[0082] Aspect 18. The method according to aspect 14, wherein the first solvent is removed from the precursor mixture by heating the precursor mixture at a temperature greater than or equal to 30 °C and less than or equal to 150 °C.

[0083] Aspect 19. The method according to aspect 14, further comprising:

[0084] Before step (c), heating the fluorinated LMR material at a temperature greater than or equal to 300 °C and less than or equal to 600 °C for a duration greater than or equal to 1 hour and less than or equal to 12 hours.

[0085] Aspect 20. The method according to aspect 14, further comprising:

[0086] Preparing a non-fluorinated LMR material by mixing a transition metal source and a lithium source to form a mixture; and

[0087] Heating the mixture to form a non-fluorinated LMR material,

[0088] wherein the transition metal source comprises a transition metal carbonate (MeCO3), a transition metal hydroxide (Me(OH)2), or a combination thereof, and

[0089] wherein the lithium source comprises lithium carbonate (Li2CO3), lithium hydroxide (LiOH), or a combination thereof.

[0090] From the detailed description, the claims, and the drawings, further applicable fields of the present disclosure will become apparent. The detailed description and specific examples are only intended to illustrate and are not intended to limit the scope of the present disclosure. Description of the Drawings

[0091] The present disclosure will be more fully understood by way of specific embodiments and the drawings, wherein:

[0092] Figure 1 is a schematic perspective view of a motor vehicle powered by a battery pack including a plurality of battery pack modules.

[0093] Figure 2 is Figure 1 a schematic cross-sectional view of a part of one of the battery pack modules, the battery pack module including a plurality of electrochemical cells or battery packs that cycle lithium ions.

[0094] Figure 3 is a schematic cross-sectional view of a battery pack that cycles lithium ions, the battery pack including a positive electrode, a negative electrode, a porous separator, and an electrolyte that permeates the positive electrode, the negative electrode, and the porous separator.

[0095] Figure 4 is a graph of the specific capacity (mAh / g) of a battery including a non-fluorinated LMR positive electrode material and a battery including a fluorinated LMR positive electrode material versus voltage (V versus Li / Li + ).

[0096] Figure 5 is a graph of the voltage (V versus Li / Li + ) of a battery including a non-fluorinated LMR positive electrode material and a battery including a fluorinated LMR positive electrode material versus differential capacitance dQ / dV (mAh / g / V).

[0097] In the drawings, reference numerals may be reused to identify similar and / or identical elements. Specific Embodiments

[0098] The presently disclosed fluorinated lithium-rich manganese-based oxide (LMR) materials can be used as electroactive positive electrode materials in battery packs that cycle lithium ions, thereby improving electrochemical performance, for example, by increasing their specific capacity and Coulombic efficiency as compared to battery packs including non-fluorinated LMR materials as electroactive positive electrode materials.

[0099] The LMR materials have a layered crystal structure that has repeating transition metal (TM) layers, oxygen layers, and lithium (Li) layers. The TM layer contains transition metal (Me) ions (e.g., Mn ions and Ni ions), the O layer contains oxygen anions (O 2- ), and the Li layer contains lithium ions (Li +)。In currently disclosed fluorinated LMR materials, fluorine can be present as F- ions in anionic sites in the oxygen layer of the fluorinated LMR material in the form of anions. Without wishing to be bound by theory, it is believed that the inclusion of F- ions in the anionic sites in the oxygen layer of currently disclosed fluorinated LMR materials can improve the specific capacity and cycling stability of the fluorinated LMR material, for example, by stabilizing the crystal structure of the fluorinated LMR material and preventing the undesired and irreversible release of oxygen therefrom.

[0100] Figure 1 Depicted is a motor vehicle 2 powered by an electric motor 4 that draws electrical power from a battery pack 6 including one or more battery pack modules 8. The battery pack modules 8 can be electrically coupled together in series and / or parallel arrangements to meet the desired capacity and power requirements of the electric motor 4. The vehicle 2 can be a fully electric vehicle and can be powered solely by the electric motor 4, or the vehicle 2 can be a hybrid electric vehicle and can be powered by the electric motor 4 and an internal combustion engine (not shown).

[0101] As Figure 2 shown, each battery pack module 8 includes one or more electrochemical cells or battery packs 10 that cycle lithium ions. In practice, the battery packs 10 in the battery pack module 8 are typically assembled as a stack of layers that includes a negative electrode layer 12, a negative electrode current collector 13, a positive electrode layer 14, a positive electrode current collector 15, and a separator layer 16. Each battery pack 10 is defined by the negative electrode layer 12 and the positive electrode layer 14, and the negative electrode layer 12 and the positive electrode layer 14 are spaced apart from each other by the separator layer 16. In practice, the separator layer 16 can be impregnated with an electrolyte that provides a medium for the conduction of lithium ions between the negative electrode layer 12 and the positive electrode layer 14, or the separator layer 16 itself can act as the electrolyte. The negative electrode layer 12 is disposed on the negative electrode current collector 13 and is in electrical communication with the negative electrode current collector 13, and the positive electrode layer 14 is disposed on the positive electrode current collector 15 and is in electrical communication with the positive electrode current collector 15. As Figure 2 shown, for efficiency, these layers can be stacked such that some of the negative electrode current collectors 13 and some of the positive electrode current collectors 15 are double-sided and include the negative electrode layer 12 or the positive electrode layer 14, respectively, on both sides thereof. In this arrangement, adjacent negative electrode layers 12 and positive electrode layers 14 share a single negative electrode current collector 13 or positive electrode current collector 15, respectively.

[0102] Figure 3 Depicted is an electrochemical cell or battery pack 20 that cycles lithium ions. The battery pack 20 can generate an electric current during discharge that can be used to power a load device (e.g., the electric motor 4) and can be charged by connecting to a power source. Similar to Figure 1 and 2The battery pack 10 shown in [FIGURE REFERENCE] can, in various aspects, be used to power the electric motor 4 of a motor vehicle 2. Additionally or alternatively, the battery pack 20 can be used in other transportation applications (e.g., motorcycles, boats, tractors, buses, scooters, mobile homes, campers, tanks, and airplanes) and can be used to provide power to fixed and / or portable electronic devices, components, and assemblies used in a variety of other industries and applications (as non-limiting examples, including industrial, residential, and commercial buildings, consumer goods, industrial equipment and machinery, agricultural or farming equipment, and heavy machinery).

[0103] The battery pack 20 includes a negative electrode 22, a positive electrode 24, a separator 26, and an electrolyte 28 that provides a medium for the conduction of lithium ions between the negative electrode 22 and the positive electrode 24. The negative electrode 22 is disposed on a major surface of a negative electrode current collector 30, and the positive electrode 24 is disposed on a major surface of a positive electrode current collector 32. In effect, the negative electrode current collector 30 and the positive electrode current collector 32 are electrically coupled to a power source or load 34 (e.g., the electric motor 4) via an external circuit 36. The negative electrode 22 and the positive electrode 24 are formulated such that an electrochemical potential difference is established between the negative electrode 22 and the positive electrode 24 when the battery pack 20 is at least partially charged. During discharge of the battery pack 20, the electrochemical potential established between the negative electrode 22 and the positive electrode 24 drives spontaneous reduction and oxidation (redox) reactions within the battery pack 20 and the release of lithium ions and electrons from the negative electrode 22. The released lithium ions travel from the negative electrode 22 through the separator 26 and the electrolyte 28 to the positive electrode 24, while the electrons travel from the negative electrode 22 to the positive electrode 24 via the external circuit 36, thereby generating an electric current. After the negative electrode 22 has been partially or fully depleted of lithium, the battery pack 20 can be charged by connecting the negative electrode 22 and the positive electrode 24 to a power source 34, which drives non-spontaneous redox reactions within the battery pack 20 and releases lithium ions and electrons from the positive electrode 24. Repeated discharge and charge of the battery pack 20 can be referred to herein as a “cycle,” where one complete discharge event following one complete charge event is considered one full cycle.

[0104] The positive electrode 24 is formulated to store and release lithium ions during discharge and charge of the battery pack 20. The positive electrode 24 can be in the form of a continuous porous layer disposed on a major surface of the positive electrode current collector 32. The positive electrode 24 includes an electrochemically active (electroactive) material (electroactive positive electrode material), a polymeric binder, and optionally a conductive material. In various aspects, the electroactive material of the positive electrode 24 can be particulate material, and the particles of the electroactive material of the positive electrode 24 can be mixed with the polymeric binder and the optionally conductive material.

[0105] The electroactive material of the positive electrode 24 can store and release lithium ions by undergoing a reversible redox reaction with lithium at an electrochemical potential higher than that of the electrochemical active material of the negative electrode 22, such that there is an electrochemical potential difference between the negative electrode 22 and the positive electrode 24. In various embodiments, the electroactive material of the positive electrode 24 can include a high-voltage electroactive material configured to operate at a voltage greater than or equal to 4.4 volts (V), optionally greater than or equal to 4.5 V, or optionally greater than or equal to 4.6 V and less than or equal to 5 V relative to Li + / Li. The electroactive material of the positive electrode 24 can constitute greater than or equal to about 50 wt%, optionally greater than or equal to about 60 wt%, or optionally greater than or equal to about 70 wt% and less than or equal to about 97 wt%, optionally less than or equal to about 90 wt%, or optionally less than or equal to about 80 wt% of the positive electrode 24.

[0106] The electroactive material of the positive electrode 24 includes an insertion host material (i.e., a lithium transition metal oxide) that can undergo reversible insertion or intercalation of lithium ions. More specifically, the electroactive material of the positive electrode 24 includes a fluorinated lithium-rich manganese-based oxide (LMR) material. The fluorinated LMR material has the following formula (1):

[0107] Li 1+x Me 1-x O 2-y F y ,(1)

[0108] where Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti, and W; Me contains greater than or equal to 50 atomic % of Mn; x is greater than 0 and less than or equal to 0.33 (0 < x ≤ 0.33); and y is greater than 0 and less than or equal to 0.1 (0 < y ≤ 0.1). In various embodiments, y can be greater than or equal to 0.005, optionally greater than or equal to 0.01, or optionally greater than or equal to 0.03, and less than or equal to 0.08, or optionally less than or equal to 0.05.

[0109] In various embodiments, lithium (Li) can constitute greater than or equal to 25 atomic %, or optionally greater than or equal to 28 atomic %, and less than or equal to 33 atomic %, or optionally less than or equal to 30 atomic % of the fluorinated LMR material of formula (1). The transition metal (Me) can constitute greater than or equal to 16.75 atomic %, optionally greater than or equal to 20 atomic %, and less than 25 atomic %, or optionally less than or equal to 22 atomic % of the fluorinated LMR material of formula (1). Oxygen (O) can constitute greater than or equal to 47.5 atomic %, or optionally greater than or equal to 48.75 atomic %, and less than or equal to 49.98 atomic %, or optionally less than or equal to 49.75 atomic % of the fluorinated LMR material of formula (1). Fluorine (F) can constitute greater than or equal to 0.025 atomic %, optionally greater than or equal to 0.25 atomic %, or optionally greater than or equal to 1 atomic %, and less than or equal to 2.5 atomic %, optionally less than or equal to 2 atomic %, or optionally less than or equal to 1.5 atomic % of the fluorinated LMR material of formula (1).

[0110] In various embodiments, Me can include Mn and Ni. In this case, manganese (Mn) can constitute greater than or equal to 12.5 atomic %, optionally greater than or equal to 15 atomic %, and less than or equal to 25 atomic %, or optionally less than or equal to 20 atomic % of the fluorinated LMR material of formula (1), and nickel (Ni) can constitute greater than 0 atomic %, optionally greater than or equal to 5 atomic %, or optionally greater than or equal to 8 atomic %, and less than 12.5 atomic %, or optionally less than or equal to 10 atomic % of the fluorinated LMR material of formula (1).

[0111] In embodiments where Me includes Mn and Ni, the fluorinated LMR material can have the following formula (2):

[0112] Li a Ni b Mn c O 2-y F y , (2)

[0113] where a is greater than or equal to 1.1 and less than or equal to 1.2 (1.1 ≤ a ≤ 1.2); b is greater than or equal to 0.25 and less than or equal to 0.4 (0.25 ≤ b ≤ 0.4); c is greater than or equal to 0.6 and less than or equal to 0.75 (0.6 ≤ c ≤ 0.75); and y is greater than or equal to 0.005 and less than or equal to 0.1 (0.005 ≤ y ≤ 0.1). In various embodiments, a can be 1.15, b can be 0.325, c can be 0.675, and y can be greater than or equal to 0.01 and less than or equal to 0.08 (0.01 ≤ y ≤ 0.08).

[0114] The fluorinated LMR material can have a layered crystal structure having repeating transition metal (TM) layers, oxygen (O) layers, and lithium (Li) layers. The TM layers contain transition metal (Me) ions (e.g., Mn ions and Ni ions) and the O layers contain oxygen anions (O 2- ). In various aspects, the TM layers can also contain Li + ions. Fluorine in the fluorinated LMR material can be present as fluoride ions (F−) in anionic sites within the O layers of the fluorinated LMR material in anionic form. In other words, the fluorinated LMR material can be doped with F - ions, where the F - ions replace O 2- ions in the O layers. Without wishing to be bound by theory, it is believed that including F - ions at anionic sites in the oxygen layers of the presently disclosed fluorinated LMR material can reduce the average anionic valence in the O layers in the discharged state and, in turn, reduce the counter cation valence in the TM layers, thereby increasing the redox activity of the Me ions in the TM layers. By reducing the average anionic valence in the O layers, the proportion of relatively low-valence redox-active transition metal ions in the TM layers can be increased while maintaining a fixed excess stoichiometric amount of Li.

[0115] In various embodiments, in addition to the fluorinated LMR material, the electroactive material of the positive electrode 24 can further comprise a non-fluorinated layered lithium transition metal oxide represented by the formula LiMeO2 and / or Li2MeO3, a layered lithium-rich transition metal oxide represented by the formula Li 1+x Me 1-x O2 (where 0 < x ≤ 0.33), an olivine-type lithium transition metal oxide represented by the formula LiMePO4, a monoclinic lithium transition metal oxide represented by the formula Li3Me2(PO4)3, a spinel-type lithium transition metal oxide represented by the formula LiMe2O4, a tavorite represented by one or both of the following formulas LiMeSO4F or LiMePO4F, or a combination thereof, where Me is a transition metal (e.g., Co, Ni, Mn, Fe, Al, V, or a combination thereof). Specifically, in various embodiments, in addition to the fluorinated LMR material, the electroactive material of the positive electrode 24 can further include spinel-phase lithium manganese oxide (LiMn2O4, LMO), high-voltage spinel-phase lithium nickel manganese oxide (LiNi 0.5 Mn 1.5 O4, LNMO), lithium nickel cobalt manganese aluminum oxide (NCMA), lithium nickel manganese cobalt oxide (NMC), lithium nickel manganese oxide (LNMO), such as LiNi 0.5 Mn 1.5 O4 and / or Li 1.2 Ni 0.2 Mn 0.6O2, lithium manganese iron phosphate (LMFP), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA), or combinations thereof.

[0116] The polymeric binder is electrochemically inert and can be included in the positive electrode 24 to provide structural integrity to the positive electrode 24 and / or assist the positive electrode 24 in adhering to the main surface of the positive electrode current collector 32. Examples of polymeric binders include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), styrene-ethylene-butylene-styrene copolymer (SEBS), polyacrylate, alginate, polyacrylic acid, and combinations thereof. The polymeric binder can constitute greater than or equal to about 1 wt%, or optionally greater than or equal to about 5 wt%, and less than or equal to about 10 wt% of the positive electrode 24.

[0117] The optional conductive material is electrochemically inert and can be included in the positive electrode 24 to provide sufficient conductivity to the positive electrode 24 to support electron infiltration therethrough. Examples of conductive materials include carbon-based materials, metals (such as nickel), and / or conductive polymers. Examples of conductive carbon-based materials include carbon black (CB) (e.g., acetylene black), graphite, graphene (e.g., graphene nanosheets, GNP), graphene oxide, carbon nanotubes (CNT), and / or carbon fibers (e.g., carbon nanofibers). Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, and / or polypyrrole. When included in the positive electrode 24, the optional conductive material can constitute greater than 0 wt%, optionally greater than or equal to about 1 wt%, or optionally greater than or equal to about 5 wt% and less than or equal to about 10 wt% of the positive electrode 24.

[0118] The negative electrode 22 is configured to store and release lithium ions to facilitate charging and discharging of the battery pack 20, respectively. The negative electrode 22 may be in the form of a continuous material layer disposed on the major surface of the negative electrode current collector 30. The negative electrode 22 includes an electroactive material (electroactive negative electrode material) capable of storing and releasing lithium ions through reversible redox reactions with lithium during charging and discharging of the battery pack 20. Examples of electroactive negative electrode materials include lithium, lithium-based materials (e.g., alloys of lithium with silicon, aluminum, indium, and / or tin), carbon-based materials (e.g., graphite, activated carbon, carbon black, hard carbon, soft carbon, and / or graphene), silicon, silicon-based materials (e.g., alloys of silicon with lithium, tin, iron, aluminum, and / or cobalt), silicon oxides, silicon-oxide-based materials (e.g., lithium silicon oxide), tin oxides, aluminum, indium, zinc, germanium, titanium oxides, lithium titanate, and combinations thereof. The electroactive material of the negative electrode 22 may constitute greater than or equal to about 50 wt%, optionally greater than or equal to about 60 wt%, or optionally greater than or equal to about 70 wt% and less than or equal to about 97 wt%, optionally less than or equal to about 90 wt%, or optionally less than or equal to about 80 wt% of the negative electrode 22.

[0119] In various embodiments, the electroactive material of the negative electrode 22 may include silicon-oxide-based materials (e.g., Si, SiO x and / or Li y SiO x ) and carbon-based materials (e.g., graphite). In such a case, the silicon-oxide-based materials may constitute greater than or equal to 1 wt%, or optionally greater than or equal to 5 wt%, and less than or equal to 70 wt%, optionally less than or equal to 30 wt%, or optionally less than or equal to 10 wt% of the electroactive material of the negative electrode 22, and the carbon-based materials (e.g., graphite) may constitute greater than or equal to 30 wt%, optionally greater than or equal to 70 wt%, or optionally greater than or equal to 90 wt%, and less than or equal to 99 wt%, or optionally less than or equal to 95 wt% of the electroactive material of the negative electrode 22.

[0120] In various embodiments, the negative electrode 22 can be porous and the electroactive material of the negative electrode 22 can be particulate material. In embodiments where the electroactive material of the negative electrode 22 is particulate material, the particles of the electroactive material of the negative electrode 22 can be mixed with a polymeric binder and an optional conductive material. The same polymeric binder and / or conductive material disclosed above for the positive electrode 24 can be used in the negative electrode 22 in substantially the same amounts. In other embodiments, the electroactive material of the negative electrode 22 can consist of lithium, and the negative electrode 22 can be in the form of a non-porous metal film or foil, such as a lithium metal film or lithium metal foil. In such a case, the negative electrode 22 can contain greater than 97 wt% lithium, or optionally greater than 99 wt% lithium. In embodiments where the electroactive material of the negative electrode 22 consists of lithium, the negative electrode 22 can be substantially free of elements or compounds that undergo a reversible redox reaction with lithium during operation of the battery pack 20. Additionally, in such embodiments, the negative electrode 22 can be substantially free of polymeric binder.

[0121] The separator 26 physically and electrically separates the negative electrode 22 and the positive electrode 24 from each other while allowing lithium ions to pass therethrough. The separator 26 has an open microporous structure and can comprise organic and / or inorganic materials. For example, the separator 26 can comprise a polymer. Examples of polymers for the separator 26 include polyolefins (e.g., polyethylene PE and / or polypropylene PP), polyamides (PA), poly(tetrafluoroethylene) (PTFE), poly(vinylidene fluoride) (PVDF), poly(vinyl chloride) (PVC), and combinations thereof. In one form, the separator 26 can comprise a polymer laminate, such as a laminate of PE and PP. In various aspects, the separator 26 can comprise a ceramic coating (not shown) disposed on one or both of its sides. In such a case, the ceramic coating can comprise particles of alumina (Al2O3) and / or silica (SiO2).

[0122] The electrolyte 28 is ion-conductive and provides a medium for the conduction of lithium ions between the negative electrode 22 and the positive electrode 24. The electrolyte 28 comprises an organic solvent, a lithium salt in the organic solvent, and an optional additive in the organic solvent.

[0123] The organic solvent may include a non-aqueous aprotic organic solvent. Non-limiting examples of non-aqueous aprotic organic solvents include cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), fluoroethylene carbonate (FEC), and vinylene carbonate (VC)); linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC)); aliphatic carboxylates (e.g., methyl formate, methyl acetate, methyl propionate); lactones (e.g., γ-butyrolactone, γ-valerolactone, and / or δ-valerolactone); nitriles (e.g., succinonitrile, glutaronitrile, and / or adiponitrile); sulfones (e.g., tetramethylene sulfone, ethyl methyl sulfone, vinyl sulfone, phenyl sulfone, 4-fluorophenyl sulfone, benzyl sulfone, and / or sulfolane); aliphatic ethers (e.g., triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dimethoxypropane, 1,2-dimethoxyethane, 1,2-diethoxyethane, and / or ethoxymethoxyethane); cyclic ethers (e.g., 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane); phosphate esters (e.g., triethyl phosphate and / or trimethyl phosphate); and combinations thereof. In various aspects, the organic solvent may comprise a mixture of a cyclic carbonate (e.g., FEC) and a linear carbonate (e.g., DMC). The organic solvent may constitute greater than or equal to about 80 wt% of the electrolyte 28, or optionally greater than or equal to about 85 wt%, and less than or equal to about 95 wt%, or optionally less than or equal to about 90 wt%.

[0124] The lithium salt is soluble in the organic solvent and provides a channel for lithium ions to pass through the electrolyte 28. The lithium salt may include an inorganic lithium salt, an organic lithium salt, or a combination thereof. Examples of lithium salts include lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethyl)sulfonylimide (LiN(CF3SO2)2), lithium bis(fluorosulfonyl)imide (LiN(FSO2)2) (LiFSI), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalato)borate (LiB(C2O4)2) (LiBOB), lithium difluoro(oxalato)borate (LiBF2(C2O4)) (LiDFOB), and combinations thereof. In various aspects, the lithium salt may comprise LiPF6. The lithium salt may be dissolved in the organic solvent at a concentration greater than or equal to about 0.5 mole and less than or equal to about 2 moles. In various aspects, the lithium salt may be dissolved in the organic solvent at a concentration of about 1.2 moles. The lithium salt may constitute greater than or equal to about 5 wt% of the electrolyte 28, optionally greater than or equal to about 10 wt%, and less than or equal to about 20 wt%, or optionally less than or equal to about 15 wt%.

[0125] The optional additive is formulated to improve the ionic conductivity of the electrolyte 28 and can help promote the formation of an electrically insulating and ionically conductive solid electrolyte interface on the surface of the electroactive material of the positive electrode 24, which can help improve the cycle stability and capacity retention of the battery pack 20. The optional additive can include lithium difluorophosphate (LiPO2F2). When included in the electrolyte 28, the optional additive can constitute greater than or equal to 0.1 wt%, or optionally greater than or equal to 0.5 wt%, and less than or equal to 2 wt%, or optionally less than or equal to 1.5 wt% of the electrolyte 28. In various embodiments, when included in the electrolyte 28, the optional additive can constitute about 1 wt% of the electrolyte 28.

[0126] The negative electrode current collector 30 and the positive electrode current collector 32 are conductive and provide electrical connections between the external circuit 36 and the negative electrode 22 and the positive electrode 24, respectively. In various aspects, the negative electrode current collector 30 and the positive electrode current collector 32 can be made of metal and can be in the form of a non-porous metal foil, a perforated metal foil, a porous metal mesh, or a combination thereof. The negative electrode current collector 30 can be made of copper, nickel, or an alloy thereof, stainless steel, or other suitable conductive material. The positive electrode current collector 32 can be made of aluminum (Al) or other suitable conductive material.

[0127] Method

[0128] The positive electrode 24 can be manufactured by: preparing a fluorinated LMR material, mixing the particles of the fluorinated LMR material with a polymer binder, an optional conductive material, and a solvent to form a slurry, depositing the slurry on a substrate, and then removing the solvent therefrom to form the positive electrode 24. The fluorinated LMR material can be manufactured by preparing a non-fluorinated lithium-rich manganese-based oxide (LMR) material and then doping the non-fluorinated LMR material with fluorine or a fluorine-containing compound.

[0129] The non-fluorinated LMR material can be prepared, for example, using a co-precipitation reaction method, in which a transition metal source is mixed with a lithium source to form a mixture, and then the mixture is heated to form a lithium transition metal oxide. The transition metal source can include transition metal carbonates (MeCO3), transition metal hydroxides (Me(OH)2), or a combination thereof. The lithium source can include lithium carbonate (Li2CO3), lithium hydroxide (LiOH), or a combination thereof.

[0130] The amounts of the transition metal source and the lithium source in the mixture can be selected to achieve the desired ratio of (one or more) transition metals and lithium in the fluorinated LMR material. For example, the amount of the lithium source included in the mixture can be selected such that the ratio of lithium to (one or more) transition metals (Li:Me) is greater than 1:1. The mixture can be heated at a temperature greater than or equal to 250 degrees Celsius (°C) and less than or equal to 600 °C for a duration greater than or equal to 1 hour and less than or equal to 8 hours, and then heated to a temperature greater than or equal to 700 °C and less than or equal to 1200 °C for a duration greater than or equal to 12 hours and less than or equal to 24 hours to form a non-fluorinated LMR material. In various embodiments, the mixture can be heated at a temperature of 500 °C for a duration of 5 hours, and then heated to a temperature of 900 °C for a duration of 15 hours to form a non-fluorinated LMR material.

[0131] The non-fluorinated LMR material can be doped with fluorine or a fluorine-containing compound using a wet chemical method, wherein a fluorine-containing solution containing a fluorine-containing compound dissolved in a solvent is prepared, the fluorine-containing solution is mixed with the non-fluorinated LMR material to form a precursor mixture, and then the solvent is removed from the precursor mixture to form a fluorinated LMR material. The fluorine-containing solution can include ammonium fluoride (NH4F), titanium fluoride (TiF4), lithium fluoride (LiF), or a combination thereof. The solvent can include a polar aprotic organic solvent (such as acetone). The fluorine-containing compound can be dissolved in the solvent using a stirrer at 400 rpm on a hot plate at 80 °C to form a fluorine-containing solution. Then, the non-fluorinated LMR material can be added to the fluorine-containing solution to form a precursor mixture. In the precursor mixture, the fluorine in the fluorine-containing solution can react with the non-fluorinated LMR material by replacing some oxygen atoms in the lattice of the non-fluorinated LMR material.

[0132] The solvent can be removed from the precursor mixture to form a fluorinated LMR material by heating the precursor mixture at a temperature greater than or equal to 30 °C and less than or equal to 150 °C. In various embodiments, the solvent can be removed from the precursor mixture by heating the precursor mixture in an oven at a temperature of 80 °C to form a fluorinated LMR material. Then, the fluorinated LMR material can be heated at a temperature greater than or equal to 300 °C and less than or equal to 600 °C for a duration greater than or equal to 1 hour and less than or equal to 12 hours to remove chemical reaction by-products and residual solvent therefrom. For example, in various embodiments, the fluorinated LMR material can be heated at a temperature of 450 °C for a duration of 5 hours. In an embodiment where the fluorine-containing solution includes NH4F, the fluorinated LMR material can be heated to remove ammonium ions (NH4 + )

[0133] Experimental

[0134] Full button cells including different positive electrode formulations were assembled and evaluated using a constant current charge and discharge method. All cells included a negative electrode consisting of an electroactive material composed of a mixture of 5.5 wt% silicon oxide, graphite, conductive particles, and a polymer binder. All cells included an electrolyte consisting of 1.2 mol LiPF6 in a mixture of FEC and DMC (FEC:DMC = 1:4 volume / volume) and 1 wt% LiPO2F2. All cells included a positive electrode consisting of a mixture of electroactive material particles (94 wt%), conductive particles (3 wt%), and a polymer binder (3 wt%). The electroactive material particles in the positive electrode consisted of non-fluorinated LMR material (non-F LMR) having the formula Li 1.15 Ni 0.325 Mn 0.675 O2, fluorinated LMR material (0.25 atomic % F-LMR) having the formula Li 1.15 Ni 0.325 Mn 0.675 O 1.99 F 0.01 , or fluorinated LMR material (1.25 atomic % F-LMR) having the formula Li 1.15 Ni 0.325 Mn 0.675 O 1.95 F 0.05 .

[0135] Cells including non-F LMR positive electrodes, 0.25 atomic % F-LMR positive electrodes, and 1.25 atomic % F-LMR positive electrodes were charged and discharged at a constant current at 25 °C. During formation, the cells were charged to 4.6 V at a C / 20 rate. Then, using a constant current and constant voltage (CCCV) method, the cells were charged at a constant current using a C / 3 charge rate to a potential of about 4.6 V and then charged at a constant voltage of 4.6 V until the current reached C / 20. Subsequently, the cells were discharged at a constant current using a C / 3 discharge rate to 2.0 V.

[0136] Figure 4 is a graph of the specific capacity (mAh / g)100 of cells including a cell (110) with a non-F LMR positive electrode, a cell (120) with a 0.25 atomic % F-LMR positive electrode, and a cell (130) with a 1.25 atomic % F-LMR positive electrode versus voltage (V versus Li / Li + ). As Figure 4As shown, the battery including the F-LMR positive electrode has a higher initial discharge capacity and first-cycle Coulombic efficiency than the battery including the non-FLMR positive electrode (the initial discharge capacity increases from 258 mAh / g to 281 mAh / g, and the first-cycle Coulombic efficiency increases from 83% to 90%).

[0137] Figure 5 are the voltage (V vs. Li / Li + ) of the battery (110) including the non-F LMR positive electrode, the battery (120) including 0.25 atomic % F-LMR positive electrode, and the battery (130) including 1.25 atomic % F-LMR positive electrode plotted against the differential capacitance dQ / dV (mAh / g / V). As Figure 5 shown, the initial charge capacities of the batteries including the non-F LMR positive electrode and the F-LMR positive electrode are the same, but during discharge, the Mn 4+ / Mn 3+ and Ni 4+ / Ni 3+ / Ni 2+ redox of the battery including the F-LMR positive electrode is higher. For example, for the battery including the F-LMR positive electrode, the reduction of Mn 4+ to Mn 3+ is higher. Without wishing to be bound by theory, it is believed that the NH4F solution of the fluorinated LMR material used to prepare the F-LMR positive electrode greatly reduces the surface-unstable lattice oxygen, which results in enhanced surface stability, for example, by binding surface oxygen vacancies, F-doping, and the formation of a spinel phase having a coherent structure with the layered phase. As Figure 5 confirmed by the circle 140 in, the higher amount of F in the 1.25 atomic % F-LMR positive electrode induces the formation of a spinel phase on the surface of the 1.25 atomic % F-LMR positive electrode, for example, by surface reconstruction. Without wishing to be bound by theory, it is believed that the high F content in the 1.25 atomic % F-LMR positive electrode induces the formation of the spinel phase because of Li deficiency on the surface due to the formation of more LiF together with Me-F.

[0138] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Thus, while the disclosure includes specific examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the appended claims. It should be understood that one or more steps within a method may be implemented in a different order (or concurrently) without altering the principles of the disclosure. Further, although the embodiments are described above as having certain features, any one or more of the features described with respect to any one embodiment of the disclosure may be implemented in and / or combined with the features of any other embodiment, even if not explicitly described in that combination. In other words, the described embodiments are not mutually exclusive, and the interchanging of one or more embodiments is still within the scope of the disclosure.

[0139] The terms used herein are for the purpose of describing particular exemplary embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, as used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms. The terms “comprising,” “including,” “covering,” and “having” are inclusive and thus specify the presence of the stated features, elements, compositions, steps, integers, operations, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Although the open-ended term “comprising” is to be understood as a non-limiting term used to describe and claim the various embodiments herein, in some instances, this term may alternatively be understood to be more limiting and restrictive terms such as “consisting of” or “consisting essentially of.” Thus, for any given embodiment reciting compositions, materials, components, elements, features, integers, operations, and / or method steps, the disclosure specifically includes embodiments consisting of, or consisting essentially of, such recited compositions, materials, components, elements, features, integers, operations, and / or method steps. In the case of “consisting of,” alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operations, and / or method steps, while in the case of “consisting essentially of,” any additional compositions, materials, components, elements, features, integers, operations, and / or method steps that materially affect the basic and novel characteristics are excluded from such embodiments, but any compositions, materials, components, elements, features, integers, operations, and / or method steps that do not materially affect the basic and novel characteristics may be included in the embodiments.

[0140] The phrase “at least one of A, B, and C” used herein should be construed to mean a logical (A OR B OR C) using a non-exclusive logical OR and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0141] As used herein, the terms "composition" and "material" are used interchangeably and generally refer to a substance that comprises at least a preferred chemical component, element, or compound, but may also contain additional elements, compounds, or substances, including trace impurities, unless otherwise specified. An "X-based" composition or material generally refers to a composition or material in which "X" is the single largest component by weight percentage (%) in the composition or material. This can include compositions or materials having greater than 50% by weight of X, as well as compositions or materials having less than 50% by weight of X, provided that X is the single largest component based on the overall weight of the composition or material.

Claims

1. A battery pack for circulating lithium ions, the battery pack comprising: a negative electrode comprising an electroactive negative electrode material; A positive electrode comprising a fluorinated lithium-rich manganese-based oxide (LMR) material having the following formula (1): Li 1+x Along with 1-x O 2-y F y ,(1) in: Me is a transition metal selected from Co, Ni, Mn, Fe, Al, V, Mo, Nb, Zr, Zn, Mg, Cu, Ti and W; Me contains greater than or equal to 50 atomic % of Mn; x is greater than 0 and less than or equal to 0.33; and y is greater than 0 and less than or equal to 0.1; and The positive electrode is impregnated with an electrolyte, the electrolyte comprising an organic solvent and a lithium salt in the organic solvent. 2 . The battery pack according to claim 1 , wherein the y is greater than or equal to 0.005 and less than or equal to 0.

08.

3. The battery according to claim 1, wherein the fluorinated LMR material has a layered crystal structure including a transition metal layer, an oxygen layer, and a lithium layer, and wherein fluoride ions in the fluorinated LMR material are present at anion sites within the oxygen layer.

4. The battery pack according to claim 1, wherein the fluorinated LMR material has the following formula (2): Li a Ni b Mr c O 2-y F y (2) in: a is greater than or equal to 1.1 and less than or equal to 1.2; b is greater than or equal to 0.25 and less than or equal to 0.4; c is greater than or equal to 0.6 and less than or equal to 0.75; and y is greater than or equal to 0.005 and less than or equal to 0.

08. 5 . The battery pack according to claim 1 , wherein the organic solvent comprises fluoroethylene carbonate (FEC) and diethyl carbonate (DEC).

6. The battery of claim 5, wherein the lithium salt comprises lithium hexafluorophosphate (LiPF6).

7. The battery of claim 6, wherein the electrolyte further comprises lithium difluorophosphate (LiPO2F2).

8. The battery of claim 1, wherein the electroactive negative electrode material comprises a silicon oxide based material and a carbon based material.

9. The battery of claim 1 wherein the electroactive negative electrode material comprises greater than 97% by weight lithium.

10. A method of making a positive electrode for a battery for cycling lithium ions, the method comprising: (a) mixing a non-fluorinated lithium-rich manganese-based oxide (LMR) material with a fluorine-containing solution to form a precursor mixture, wherein the fluorine-containing solution comprises a fluorine compound in a first solvent, wherein the fluorine compound comprises ammonium fluoride (NH4F), titanium fluoride (TiF4), lithium fluoride (LiF), or a combination thereof, wherein the first solvent comprises a polar aprotic organic solvent; (b) removing the first solvent from the precursor mixture to form a fluorinated lithium-rich manganese-based oxide (LMR) material, wherein the fluorinated LMR material has the following formula (1): Li 1+x Along with 1-x O 2-y F y ,(1) in: Me is a transition metal selected from Co, Ni, Mn, Fe, Al and V; Me contains greater than or equal to 50 atomic % of Mn; x is greater than 0 and less than or equal to 0.33; and y is greater than 0 and less than or equal to 0.1; (c) heating the fluorinated LMR material at a temperature greater than or equal to 300° C. and less than or equal to 600° C. for a duration greater than or equal to 1 hour and less than or equal to 12 hours; (d) mixing the fluorinated LMR material with a polymer binder and a second solvent to form a slurry; (e) depositing the slurry on a substrate; and then (e) removing the second solvent from the slurry to form a positive electrode.

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