A CATHODE

Abstract

Disclosed are a cathode materials suitable for an aluminium ion battery, wherein the cathode materials comprise a main group element nitride, and an oxide of a main group element or an oxide of a element in Group 1 to 13. The nitride is preferably a 2-dimensional layered material. Preferably, the ratio of the main group element nitride to the oxide is between 5:95 and 95:5 (by weight).

Claims

1. A cathode for an aluminium ion battery, wherein the cathode comprises an oxide of boron, and a boron nitride, having a ratio of the oxide of boron to the boron nitride is between 5:95 and 95:5 (by weight).

2. The cathode of claim 1, having a ratio of the oxide of boron to the boron of nitride of between 10:90 and 90:10 (by weight).

3. The cathode of claim 1, having a ratio of the oxide of boron to the boron nitride of about 1:1 (by weight).

4. The cathode of claim 1, wherein the oxide of boron comprises boric anhydride.

5. The cathode of claim 1, wherein the boron nitride comprises a 2D layered material.

6. The cathode of claim 1, wherein the boron nitride comprises hexagonal boron nitride.

7. The cathode of claim 1, further comprising a conductive material.

8. The cathode of claim 7, where in the conductive material comprises conductive carbon.

9. An aluminium ion battery cell comprising a cathode of claim 1 and an anode, wherein the anode comprises aluminium, an electrolyte in electrical contact with the anode and/or cathode, and optionally an ion permeable separator located between the anode and the cathode.

10-25. (canceled)

26. A cathode for an aluminium ion battery, wherein the cathode comprises a main group element nitride, and an oxide of an element in Group 1-13 having a ratio of the oxide of an element in Group 1-13 to the main group element nitride is between 5:95 and 95:5 (by weight).

27. (canceled)

28. The cathode of claim 26, wherein the oxide of an element in Group 1-13 comprises an oxide of boron, titanium, or manganese.

29. The cathode of claim 26, wherein the main group element nitride comprises a nitride of boron, carbon, aluminium, or silicon.

30. The cathode of claim 26, wherein the main group element nitride comprises a 2D layered material.

31. The cathode of claim 26, wherein the main group element nitride is boron nitride.

32. The cathode of claim 31, wherein the boron nitride comprises hexagonal boron nitride.

33. A cathode for an aluminium ion battery, wherein the cathode comprises a main group element nitride, and an oxide of a main group element having a ratio of the oxide of a main group element to the main group element nitride is between 5:95 and 95:5 (by weight).

34. (canceled)

35. The cathode of claim 33, wherein the main group element nitride is selected from a nitride of boron, carbon, aluminium, and silicon.

36. The cathode of claim 33, wherein the oxide of a main group element is an oxide of boron.

37. An aluminium ion battery cell comprising the cathode of claim 33 and an anode, wherein the anode comprises aluminium, further comprising an electrolyte in electrical contact with the anode and/or cathode, and optionally an ion permeable separator located between the anode and the cathode.

38. (canceled)

39. (canceled)

40. (canceled)

41. (canceled)

42. An aluminium ion battery cell comprising the cathode of claim 26 and an anode, wherein the anode comprises aluminium, further comprising an electrolyte in electrical contact with the anode and/or cathode, and optionally an ion permeable separator located between the anode and the cathode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0121] One or more embodiments of the invention will be described below by way of example only, and without intending to be limiting, with reference to the following drawings, in which:

[0122] FIG. 1 is a representative schematic of an aluminium ion cell, comprising AlCl.sub.3/imidazolium chloride ionic liquid electrolyte, according to an embodiment of the present invention showing flow of electrons during the charging and discharge cycles of the battery.

[0123] FIG. 2 shows a schematic representation of a lab prototype. It shows the arrangement of electrodes inside a cell.

[0124] FIG. 3 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and hexagonal boron nitride at the 1.sup.st (□), 2.sup.nd (Δ), 10th (⋄) and 20th (⋆) cycles, at 50 mA/g.

[0125] FIG. 4 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and hexagonal boron nitride at current densities of 50 mA/g (□), 500 mA/g (O), 900 mA/g (Δ), 1000 mA/g (⋄), 1500 mA/g (⋆) and at 50 mA/g at the 100th cycle ().

[0126] FIG. 5 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 900 mA/g (C) to 1 A/g (D) to 1.5 A/g (E) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and hexagonal boron nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0127] FIG. 6 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and carbon nitride (C.sub.3N.sub.4) at current densities of 50 mA/g (□), 500 mA/g (Δ), 900 mA/g (∇), 1000 mA/g (⋄), 1500 mA/g (⋆), 50 mA/g at the 20th cycle (O) and 50 mA/g at the 100th cycle ().

[0128] FIG. 7 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 900 mA/g (C) to 1 A/g (D) to 1.5 A/g (E) and then back to 50 mA/g (A) for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and carbon nitride (C.sub.3N.sub.4). Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0129] FIG. 8 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and AlN aluminium nitride at current densities of 50 mA/g (□), 500 mA/g (O), 1000 mA/g (Δ), 1500 mA/g (⋄), and at 50 mA/g at the 100th cycle (⋆).

[0130] FIG. 9 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and aluminium nitride (AlN). Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0131] FIG. 10 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and Si.sub.3N.sub.4 silicon nitride at current densities of 50 mA/g (□), 500 mA/g (Δ), 1000 mA/g (⋄), 1500 mA/g (), and at 50 mA/g at the 100th cycle (⋆).

[0132] FIG. 11 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of B.sub.2O.sub.3 and Si3N.sub.4 silicon nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0133] FIG. 12 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of MnO.sub.2 and hexagonal boron nitride at current densities of 50 mA/g (□), 500 mA/g (O), 1000 mA/g (Δ), 1500 mA/g (), and at 50 mA/g at the 100th cycle (⋆).

[0134] FIG. 13 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of MnO.sub.2 and hexagonal boron nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0135] FIG. 14 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of MnO.sub.2 and carbon nitride at current densities of 50 mA/g (□), 500 mA/g (O), 1000 mA/g (⋄), 1500 mA/g (), and at 50 mA/g at the 100th cycle (⋆).

[0136] FIG. 15 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of MnO.sub.2 and carbon nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0137] FIG. 16 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of MnO.sub.2 and silicon nitride at current densities of 50 mA/g (□), 500 mA/g (Δ), 1000 mA/g (⋄), 1500 mA/g (), and at 50 mA/g at the 20th cycle (O) and 50 mA/g at the 100th cycle (⋆).

[0138] FIG. 17 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of MnO.sub.2 and silicon nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0139] FIG. 18 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of TiO.sub.2 and hexagonal boron nitride at current densities of 50 mA/g (□), 500 mA/g (O), 1000 mA/g (Δ), 1500 mA/g (⋄), and at 50 mA/g at the 100th cycle (⋆).

[0140] FIG. 19 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of TiO.sub.2 and hexagonal boron nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0141] FIG. 20 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of TiO.sub.2 and carbon nitride at current densities of 50 mA/g (□), 500 mA/g (Δ), 1000 mA/g (⋄), 1500 mA/g (), and at 50 mA/g at the 20.sup.th cycle (O) and 50 mA/g at the 100.sup.th cycle (⋆).

[0142] FIG. 21 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode with a 1:1 ratio (by weight) of TiO.sub.2 and carbon nitride. Symbol .square-solid. denotes the specific capacity and symbol 0 represents the coulombic efficiency.

[0143] FIG. 22 shows charge/discharge curves for aluminium ion cells comprising cathodes with an active material composition of B.sub.2O.sub.3 and hexagonal boron nitride in B.sub.2O.sub.3: hBN ratios of 75:25 (⋆), 80:20 (), 85:15 (⋄), 90:10 (O), 95:5 () (by weight) and 100% B.sub.2O.sub.3 (□) respectively.

[0144] FIG. 23 (a) shows charge/discharge cycles of aluminium ion cells comprising B.sub.2O.sub.3 as the active material at a current rate of 50 mA/g for the 1st cycle (□), 2nd cycle (O) and 15.sup.th cycle (⋆). b) shows charge/discharge curves for an aluminium ion cell comprising a cathode with active material of B.sub.2O.sub.3/hBN in a 1:1 ratio (by weight) at current rate of 50 mA/g at the 1.sup.st cycle (□), 2.sup.nd cycle (O), 10.sup.th cycle (Δ) and 20.sup.th cycle (⋆).

[0145] FIG. 24 shows charge/discharge curves for an aluminium ion cell comprising a cathode with a boric anhydride:hexagonal boron nitride ratio of 5:95 (by weight) at current densities of 50 mA/g (□) and 1000 mA/g (O), and at 50 mA/g at the 100.sup.th cycle (⋆).

[0146] FIG. 25 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, shifting at approximately 20 cycle intervals from 50 mA/g (A) to 500 mA/g (B) to 1 A/g (C) to 1.5 A/g (D) and then back to 50 mA/g (A), for an aluminium ion cell comprising a cathode containing a boric anhydride:hexagonal boron nitride ratio of 5:95 (by weight).

[0147] FIG. 26 shows charge/discharge curves for an aluminium ion cell comprising a cathode containing hexagonal boron nitride (100% of the active material) at current densities of 50 mA/g for the first few cycles (⋆□Δ⋄) and 500 mA/g (O).

[0148] FIG. 27 shows a plot of the specific capacity and coulombic efficiency over repeated charge/discharge cycles, in which approximately the first 25 cycles were at 50 mA/g (A), shifting to 500 mA/g for a further approximately 25 cycles (B), for an aluminium ion cell comprising a cathode containing hexagonal boron nitride (100% of the active material). Symbol .square-solid. denotes the specific capacity and symbol O represents the coulombic efficiency.

DEFINITIONS

[0149] “Main group elements” means the elements of groups 1 and 2 (s-block), and groups 13 to 17 (p-block, excluding the noble gases) of the periodic table.

[0150] “Group 13 elements” means boron, aluminium, gallium, indium and tellurium.

[0151] “Chalcogenides” means oxides, sulfides, selenides and tellurides.

[0152] “Active material” with respect to cathode materials in a cell, means the materials in the cathode that react during discharging of the cell to, in part, generate an electromotive force.

DETAILED DESCRIPTION

[0153] Aluminium ion batteries are promising alternatives to other ion batteries such as lithium ion batteries. The present invention relates to cathodes for use in aluminium ion batteries. Ion batteries work using a reversible electrochemical deposition and dissolution process. During discharge of an ion battery, ions may be inserted into the interstitial gaps between the layers of material forming the cathode and electrons flow from the anode to the cathode to provide an EMF (electromotive force) to drive a load. This process is reversed during charging of the battery i.e. ions are removed from the interstitial gaps between the layers of material forming the cathode and electrons flow from the cathode to the anode.

[0154] The present inventors have surprisingly found that nitride compounds of the main group elements show surprisingly good activity as cathode active materials for use, and when used in aluminium ion batteries.

[0155] The present inventors have surprisingly found that boron oxide compounds, particularly boric anhydride, show surprisingly good activity as cathode active materials for use, and when used in aluminium ion batteries.

[0156] The present inventors have further surprisingly found that the combination of nitride compounds of the main group elements, and Group 1-13 oxides, show surprisingly good activity as cathode active materials for use, and when used in aluminium ion batteries.

[0157] In particular, the present inventors have surprisingly found that the combination of boron nitride and oxides of boron show surprisingly good activity as cathode active materials for use, and when used in aluminium ion batteries. Further, the present inventors have surprisingly found that the combination of hexagonal boron nitride and boric anhydride show surprisingly good activity as cathodes for use, and when used in aluminium ion batteries.

[0158] Referring to FIGS. 1 and 2 which are a representative schematic of a battery (100) according to an embodiment of the present invention. The battery (100) is an aluminium ion battery having a cathode (102) and anode (104) which are provided within a housing (106). The housing (106) may be any housing suitable for use in battery and will be readily understood by those of skill in the art. For example, suitable housings may comprise, but are not limited only to: coin cells, pouch cells, cylindrical cells, prismatic cells. An electrolyte (108) in the form of an ionic liquid is provided in the housing (106) and provides an electrical connection between the cathode (102) and the anode (104) when the battery (100) is being charged or discharged.

[0159] The battery (100) also includes a separator (110) which in structured and/or arranged to prevent the anode and cathode directly contacting each other. The separator (110) is preferably glass microfibers which are mounted in the housing (106). However, those of skill in the art will realise that any material or structure that is electrically insulating and can prevent the cathode and anode touching.

[0160] The cathode (102) and the anode (104) each have a terminal, which are indicated as (120) and (120′) respectively. The terminals (120 and 120′) (FIG. 2) such as molybdenum rods, facilitate attaching the battery to an external load or charging device.

[0161] Further embodiments of the battery (100) will become clearer from the following description of specific components thereof.

[0162] Referring to FIGS. 3 to 5, and FIG. 23(b), an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of boric anhydride and hexagonal boron nitride (Cell 4 in Table 1). Cycling the cell at 50 mA/g shows a specific capacity around 220 mAh/g at a current density of 50 mA/g, and stabilising between about 10-25 mAh/g for current densities of 500-1500 mA/g.

[0163] Referring to FIGS. 6 and 7, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of boric anhydride and carbon nitride, C.sub.3N.sub.4 (Cell 10 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 90-120 mAh/g at a current density of 50 mA/g, and stabilising between about 10-30 mAh/g for current densities of 500-1500 mA/g.

[0164] Referring to FIGS. 8 and 9, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of boric anhydride and aluminium nitride, AlN (Cell 11 in Table 1). Cycling the cell at 50 mA/g shows specific capacity around 32-34 mAh/g at a current density of 50 mA/g, and stabilising at about 15-20 mAh/g for current densities of 500-1500 mA/g.

[0165] Referring to FIGS. 10 and 11, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of boric anhydride and silicon nitride, Si.sub.3N.sub.4 (Cell 12 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 25-28 mAh/g at a current density of 50 mA/g, and stabilising at about 10-20 mAh/g for current densities of 500-1500 mA/g.

[0166] Referring to FIGS. 12 and 13, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of manganese oxide (MnO.sub.2) and hexagonal boron nitride (Cell 13 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 27-29 mAh/g at a current density of 50 mA/g, and stabilising at about 10-20 mAh/g for current densities of 500-1500 mA/g.

[0167] Referring to FIGS. 14 and 15, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of manganese oxide (MnO.sub.2) and carbon nitride, C.sub.3N.sub.4 (Cell 14 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 30 mAh/g at a current density of 50 mA/g, and stabilising at about 10-20 mAh/g for current densities of 500-1500 mA/g.

[0168] Referring to FIGS. 16 and 17, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of manganese oxide (MnO.sub.2) and silicon nitride, Si.sub.3N.sub.4 (Cell 15 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 40-55 mAh/g at a current density of 50 mA/g, and stabilising at about 10-20 mAh/g for current densities of 500-1500 mA/g.

[0169] Referring to FIGS. 18 and 19, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of titanium oxide (TiO.sub.2) and hexagonal boron nitride (Cell 16 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 60 mAh/g at a current density of 50 mA/g, and stabilising at about 20-30 mAh/g for current densities of 500-1500 mA/g.

[0170] Referring to FIGS. 20 and 21, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 1:1 ratio of titanium oxide (TiO.sub.2) and carbon nitride, C.sub.3N.sub.4(Cell 17 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 100%, and specific capacity around 40-55 mAh/g at a current density of 50 mA/g, reducing over cycles to about 10-15 mAh/g.

[0171] Referring to FIG. 22, aluminium ion battery cells were prepared in accordance with the method described in the Examples, comprising a cathode with boric anhydride and hexagonal boron nitride active materials. The ratio of boric anhydride varied between 75% and 100% of the active materials in the cathode (Cells 5-9 in Table 1). Referring to Table 1, Cells 5 to 9 showed cell potentials of about 0.6-0.7 V, and specific capacities (measured at 50 mA/g) tending to stabilise between 40 and 60 mAh/g.

[0172] Referring to FIG. 23(a), an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of 100% boric anhydride (Cell 1 in Table 1). Cycling the cell at 50 mA/g shows coulombic efficiency stabilising at approximately 90-100%, and specific capacity stabilising around 100-150 mAh/g at a current density of 50 mA/g, and coulombic efficiency between 80 and 85%.

[0173] Referring to FIGS. 24 and 25, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of a 5:95 ratio (by weight) of boric anhydride and hexagonal boron nitride (Cell 3 in Table 1). Cycling the cell at a current density of 50 mA/g shows the specific capacity stabilising around 30 mAh/g, and stabilising between 5-10 mAh/g for current densities of 500-1500 mA/g.

[0174] Referring to FIGS. 26 and 27, an aluminium ion battery cell was prepared in accordance with the method described in the Examples, comprising a cathode with active materials consisting of 100% hexagonal boron nitride (Cell 2 in Table 1). Cycling the cell at 50 mA/g and 500 mA/g shows coulombic efficiency stabilising at approximately 90-100%, and specific capacity stabilising around 20 mAh/g at a current density of 50 mA/g, and about 5-10 mAh/g at a current density of 500 mA/g.

Example 1—Cathode Manufacture

[0175] Generally, a slurry comprising 85% w/w of active material is prepared by combining and mixing with 6% of binder and 9% of conductive material in a solvent at room temperature. The slurry is sonicated and stirred continuously to form a homogenous mixture and is doctor bladed onto a current collector. The slurry is dried at room temperature, and then dried under vacuum at 120° C. for 12 hours to evaporate any residual solvent. Discs are cut out of the dried sheets and used as cathodes in laboratory battery test cells.

Example 2— Manufacture of Hexagonal Boron Nitride/Boron Oxide Cathode Material

[0176] A 1:1 hexagonal boron nitride (hBN)/boric anhydride cathode was prepared as follows: A slurry was prepared comprising a 1:1 mixture (by weight) of boric anhydride and boron nitride (85% by wt.), polyvinyl diethylene fluoride (PVDF) binder (9% by wt.) and a conductive carbon (6% by wt.) in N-methyl pyrrolidone. The slurry was doctor-bladed on molybdenum foil (thickness 0.1 mm, MTI Corporation) and dried in a vacuum oven at 120° C. for 12 hours to adhere the slurry on the conductive substrate and evaporate the solvent. The specific loading of the hBN and boric anhydride active materials was about 12 mg cm.sup.−2.

[0177] The above procedure was followed to prepare hBN/boric anhydride cathodes having 5%, 75%, 80%, 85%, 90%, 95% and 100% boric anhydride.

Example 3— Manufacture of Cathode Materials Comprising Other Oxide/Nitride Combinations

[0178] The methods described in Examples 1 and 2 were followed to prepare cathode materials comprising the combinations of oxides and nitrides listed in Table 1.

Example 4— Electrolyte

[0179] An electrolyte was prepared as follows: under inert conditions, anhydrous aluminium trichloride, AlCl.sub.3 (Sigma-Aldrich) and 1-ethyl-3-methyl imidazolium chloride, EMImCl (97%, Sigma-Aldrich) were mixed in a molar ratio of 1.3:1, at room temperature.

Example 5— Cells

[0180] Polyether ether ketone (PEEK) pouch cells were prepared as follows: under inert conditions, the cathode was positioned at the bottom of the PEEK cell. A glass microfiber (Grade GF/F, Whatman) separator was positioned in the cell. 80 μl of the electrolyte of Example 4 was added to wet the separator. Aluminium foil (thickness 0.1 mm, 99%, Good Fellow) used as an anode and placed on top of the separator. The cell was then sealed to avoid incursion of air or moisture into the cell.

[0181] Cells were prepared with cathodes having the active materials (oxide component, nitride component) defined in Table 1, where each cathode was prepared following the general procedure described in Example 2. Testing was performed with a Neware® battery analysyer, BTS 3000. Testing parameters included a current densities of 50, 500, 1000, or 1500 mA/g between voltages of 0.02 and 2.35 V. Each cell was cycled 50 times for each current density.

TABLE-US-00001 TABLE 1 Ratio of Cell Specific Coulombic Cell Oxide Nitride oxide/nitride Potential capacity efficiency no. component component (by weight) (V) (mAh/g) (%) 1 B.sub.2O.sub.3 — 100/0  0.5 ~100-150  ~80-85 2 — hBN  0/100 0.6 20-60 ~70-90 3 B.sub.2O.sub.3 hBN  5/95 1.6 30  ~95-100 (bend) 4 B.sub.2O.sub.3 hBN 50/50  0.75 220  ~80-85 5 B.sub.2O.sub.3 hBN 75/25 0.7 45 6 B.sub.2O.sub.3 hBN 80/20 0.7 60 >100 7 B.sub.2O.sub.3 hBN 85/15  0.65 50 >70, <100 8 B.sub.2O.sub.3 hBN 90/10  0.65 50-60 ~60-80 9 B.sub.2O.sub.3 hBN 95/5  0.6  60-320 ~70-80 10 B.sub.2O.sub.3 C.sub.3N.sub.4 50/50 ~1.7  90-120 ~80 (bend) 11 B.sub.2O.sub.3 AlN 50/50 1.6-1.8 32-34 ~85-90 (bend) 12 B.sub.2O.sub.3 Si.sub.3N.sub.4 50/50 1.5-1.6 25-28 ~95 (bend) 13 MnO.sub.2 hBN 50/50 1.9 27-29 >95 14 MnO.sub.2 C.sub.3N.sub.4 50/50 1.6-1.7 30 >90 (bend) 15 MnO.sub.2 Si.sub.3N.sub.4 50/50 ~1.5 40-55 >80 (bend) 16 TiO.sub.2 hBN 50/50 1.5 ~60  ~90 (bend), 1.0 (plateau) 17 TiO.sub.2 C.sub.3N.sub.4 50/50 1.1 40-55 ~100 (plateau)

[0182] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense in the sense of “including, but not limited to”.

[0183] It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

[0184] The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

[0185] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

[0186] The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0187] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[0188] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included in the present invention.

REFERENCES

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