LITHIUM METAL OXIDE AND A PRECURSOR FOR THE SYNTHESIS THEREOF

Abstract

The present invention relates to a compound of Formula I, Li(ox)]2[MlmM2nM3k(OH)pFq; wherein M1, M2 and M3 are metals; and X is a halogen chosen from F, Cl and Br; and m, n and k are, independently, a number between 0 and 5, the sum of m, n and k is 5; p and q are, independently, a number between 0 and 8, and the sum of p and q is 8; and to uses thereof and methods of synthesis thereof.

Claims

1. A compound of Formula I, [Li(ox)].sub.2[M.sup.1.sub.mM.sup.2.sub.nM.sup.3.sub.k(OH).sub.pF.sub.q]; wherein M.sup.1, M.sup.2 and M.sup.3 are metals; and m, n and k are, independently, a number between 0 and 5, and the sum of m, n and k is 5; p and q are, independently, a number between 0 and 8, and the sum of p and q is 8.

2. The compound of claim 1 wherein M.sup.1, M.sup.2 and M.sup.3 are the same or different and are independently selected from cobalt, nickel and manganese.

3. The compound of claim 1 wherein M.sup.1 is nickel, M.sup.2 is manganese and M.sup.3 is cobalt; or wherein m and n are 0; k is 5; and M.sup.3 is cobalt.

4. The compound of Formula I of claim 1 wherein Formula I is [Li(ox)].sub.2[Co.sub.5(OH).sub.8]; or Formula I is [Li(ox)].sub.2[Ni.sub.5/3Mn.sub.5/3Co.sub.5/3(OH).sub.8], wherein 5/3 represents five thirds.

5. A method for synthesizing the compound of claim 1, the method comprising: a first step comprising heating a first reaction mixture comprising a source of the metal or metals, M.sup.1, M.sup.2 and M.sup.3, a source of oxalate anions, lithium ions, and a base at a first reaction temperature for a first reaction time.

6. The method of claim 5, wherein the first heating step is carried out in a sealed reactor or an acid digestion vessel.

7. The method of claim 5, wherein one or more of M.sup.1, M.sup.2 and M.sup.3 is provided as a salt, optionally wherein the, or each, M.sup.1, M.sup.2 and M.sup.3 salt is selected from a cobalt (II) or (III) salt, a manganese (II) or (III) salt or a nickel (II) or (III) salt, or a mixture thereof, or optionally wherein the, or each, M.sup.1, M.sup.2 and M.sup.3 salt is soluble in water under self-generated pressure, at a temperature of 90 C. up to 300 C. and a concentration of 0.5M up to 10M; or optionally wherein the salt is a halide a carboxylate, an oxoanion or a mixture thereof.

8. The method of claim 5, wherein the source of metal or metals is selected from cobalt chloride or cobalt oxalate.

9. The method of claim 5, wherein the source of metal or metals and the source of oxalate anions are collectively selected from cobalt oxalate, manganese oxalate, nickel oxalate, cobalt oxalate or a mixture of two or more thereof, wherein the source of metal or metals and the source of oxalate anions is anhydrous or a hydrate.

10. The method of claim 5 wherein the source of oxalate anions is oxalic acid or an oxalate salt, optionally wherein the oxalate salt is a dihydrate.

11. The method of claim 5, wherein the lithium ion is selected from a lithium salt or a lithium base or a mixture thereof, optionally, wherein the lithium base is lithium hydroxide, optionally in anhydrous or monohydrate form, or optionally wherein the anion of the lithium cation is a halide, a carboxylate, a halite, fluorosilicate, formate, molybdate, nitrate, nitrite, perchlorate, permanganate, selenide, selenite, sulfate, or thiocyanate, optionally wherein the source of fluorine is lithium fluoride.

12. The method of claim 5, further comprising the step of recovering the lithium ions from batteries or further comprising the step of recovering the source of the metal or metals from batteries, optionally wherein the source of metal or metals is recovered by mixing the contents of a battery with an acid for at least 1 to 8 hours.

13. (canceled)

14. The method of claim 5, wherein the first reaction time is between 1 hour and 100 hours; and wherein the first reaction temperature is in the range from 90 C. to 400 C.

15. (canceled)

16. (canceled)

17. The method of claim 5, wherein halogen anions are not intentionally added to the source of the metal or metals, the source of oxalate anions, the lithium ions, and the base.

18. (canceled)

19. The method of claim 5, wherein the first heating step is carried out in a protic solvent, optionally water.

20. The method of claim 5 wherein, in the first heating step, the concentration of the metal or metals combined is at least 10 mmol/L, or optionally, wherein the molar ratio of metal ions to lithium ions in the first reaction mixture before the first heating step is in the range of 1:10 to 5:1.

21. A method for synthesizing a lithium metal oxide, the method comprising: forming a compound of Formula I by the method of claim 5, and further comprising a second heating step comprising heating the compound of Formula I at a second reaction temperature for a second reaction time to form the lithium metal oxide, wherein the compound of Formula I comprises:
[Li(ox)].sub.2[M.sup.1.sub.mM.sup.2.sub.nM.sup.3.sub.k(OH).sub.pF.sub.q]; wherein M.sup.1, M.sup.2 and M.sup.3 are metals; and m, n and k are, independently, a number between 0 and 5, and the sum of m, n and k is 5; p and q are, independently, a number between 0 and 8, and the sum of p and q is 8.

22. The method of claim 21, wherein the second reaction time is between 1 hour and 100 hours; and wherein the second reaction temperature is in the range from 200 C. to 900 C.

23. (canceled)

24. The method of claim 21 further comprising determining the second reaction temperature, optionally via thermogravimetric analysis of the compound of Formula I, or by heating the compound of Formula I and observing or detecting the temperature at which the reaction occurs.

25. The method of claim 21, wherein the second heating step is carried out in an open vessel or a laboratory flask.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0075] FIG. 1a shows a single crystal of [Li(ox)].sub.2[Co.sub.5(OH).sub.8] synthesized via Method 1. FIG. 1b depicts the stacking of layers in [Li(ox)].sub.2[Co.sub.5(OH).sub.8].

[0076] FIG. 2 shows the powder X-ray diffraction pattern was measured for the same [Li(ox)].sub.2[Co.sub.5(OH).sub.8] as for FIG. 1a. The top line is processed for reading, and the middle one still has to be corrected so that all the signals are positive.

[0077] FIG. 3 shows the thermogravimetric analysis of [Li(ox)].sub.2[Co.sub.5(OH).sub.8] leading to formation of LiCoO.sub.2 and Co.sub.3O.sub.4.

[0078] FIG. 4A shows the Scanning Electron Microscopy image of [Li(ox)].sub.2[Co.sub.5(OH).sub.8] prior to decomposition; FIG. 4B shows the resulting compound after decomposition of [Li(ox)].sub.2[Co.sub.5(OH).sub.8].

[0079] FIG. 5 shows the asymmetric unit and selected symmetry equivalents of [Li(C.sub.2O.sub.4)].sub.2[M.sub.5(OH).sub.8](where M=1:1:1 Ni:Mn:Co) from single crystal data collection. Occupancy of each metal site fixed by electronic preference of metal(II) ions within the statistical mixture. Symmetry operators as for FIG. 1.

[0080] FIG. 6 shows powder X-ray diffraction plot of [Li(C.sub.2O.sub.4)].sub.2[M.sub.5(OH).sub.8] where M=1:1:1 Ni:Mn:Co with le Bail profile fit to confirm phase identity.

[0081] FIG. 7 shows the stacked PXRD plots of different NMC ratios. Additional peaks are from lithium hydrogenoxalate monohydrate.

[0082] FIG. 8 shows the thermogravimetric analysis (TGA, black trace) plot of [Li(C.sub.2O.sub.4)].sub.2[M.sub.5(OH).sub.8](where M=1:1:1 Ni:Mn:Co) in air.

DESCRIPTION OF EMBODIMENTS

Abbreviations

[0083] FT-IRFourier-transform infrared spectroscopy [0084] LCOLithium cobalt oxide [0085] LIBsLithium-ion batteries [0086] NMCLithium nickel manganese cobalt oxide [0087] PM-1Precursor material for LCO regeneration, [Li(ox)].sub.2[Co.sub.5(OH).sub.8] [0088] PM-2Precursor material for NMC regeneration, [Li(ox)].sub.2[M.sub.5(OH).sub.8], wherein M= [0089] Ni:Mn:Co in varying ratios [0090] PXRDPowder X-ray diffraction

Synthesis of PM-1, [Li(ox)].SUB.2.[Co.SUB.5.(OH).SUB.8.]

Method 1 for Synthesis of PM-1

[0091] PM-1 was attained by adding COCl.sub.2.Math.6H.sub.2O (1 mmol) 237 mg, LiOH.Math.H.sub.2O (3.408 mmol) 143.7 mg, LiBr (3 mmol) 261 mg and C.sub.2H.sub.2O.sup.4.Math.H.sub.2O (1 mmol) 126 mg to a 23 mL Teflon lined bomb reactor with 10 mL of deionised water. This vessel was heated at 230 C. for 4 hours. The bomb was left to cool, and the contents filtered.

[0092] The yield of [Li(ox)].sub.2[Co.sub.5(OH).sub.8] was over 95%.

[0093] Single crystal X-ray diffraction and powder X-Ray diffraction analysis were carried out to confirm the structure. Thermogravimetric analysis was carried out to monitor conversion to lithium cobalt oxide LiCoO.sub.2, see FIGS. 1-4.

Conversion of LCO to PM-1

Method 2

Step A: Conversion of LCO to Cobalt Oxalate

[0094] LCO (294.1 mg, 3 mmol), oxalic acid dihydrate (1.1345 g, 9 mmol) and water (30 mL) were added to a round bottom flask (50 mL) and refluxed in a glycerol bath at 100 C. for 4 hours until the reaction mixture was entirely pink. The product was filtered and the colourless filtrate was collected. The product was washed with water and acetone. Yield>95%.

Step B: Conversion of Cobalt Oxalate to PM-1

[0095] Cobalt oxalate dihydrate from part A (182.5 mg, 1 mmol) and lithium hydroxide solution (1 M) (2.0 mL, 2 mmol) were placed in a sealed vessel with water (8 mL). The vessel was placed in an oven at 200 C. for 14 hours. A green powder was formed in a colourless liquid.

[0096] The yield of PM-1, [Li(ox)].sub.2[Co.sub.5(OH).sub.8] was >95%.

Extraction of Cobalt Oxalate from LCO with Impurities Found in Spent Batteries
Extraction of Cobalt Oxalate from LCO with Al Foil Present

[0097] LCO (195.6 mg, 2 mmol), oxalic acid dihydrate (0.7452 g, 6 mmol), aluminium foil (97.4 mg, 3.6 mmol) and water (20 mL) were added to a round bottom flask (50 mL) and refluxed in a glycerol bath at 100 C. for 4 hours until the reaction mixture was beige. The product was filtered and the colourless filtrate was collected. The product was washed with water.

Extraction of Cobalt Oxalate from LCO with Cu Turnings Present

[0098] LCO (195.4 mg, 2 mmol), oxalic acid dihydrate (0.7442 g, 6 mmol), copper turnings (122.0 mg, 1.9 mmol) and water (20 mL) were added to a round bottom flask (50 mL) and refluxed in a glycerol bath at 100 C. for 4 hours until the reaction mixture was pink. Copper turnings were still present in the flask and the solution was blue in colour. The product was filtered and the filtrate was collected. The product was washed with water.

Extraction of Nickel Manganese Cobalt Oxalate from NMC

[0099] NMC (192.5 mg, 2 mmol), oxalic acid dihydrate (0.7448 g, 6 mmol) and water (20 mL) were added to a round bottom flask (50 mL) and refluxed in a glycerol bath at 100 C. for 4 hours until the reaction mixture was brown. The product was filtered and the colourless filtrate was collected. The product was washed with water and acetone.

Synthesis of PM-1 with Impurities Found in Spent Batteries

Synthesis of PM-1 with Cu Turnings Present

[0100] Cobalt oxalate dihydrate (183.8 mg, 1 mmol), lithium hydroxide solution (1 M) (2.0 mL, 2 mmol) and copper turnings (61.9 mg, 1 mmol) were placed in a sealed vessel with water (8 mL). The vessel was placed in an oven at 200 C. for 14 hours. A green powder with copper turnings still present was filtered from a colourless solution.

Synthesis of PM-1 with Copper Oxalate Dihydrate Present

[0101] Cobalt oxalate dihydrate (92.4 mg, 0.5 mmol), copper oxalate dihydrate (76.4 mg, 0.5 mmol) and lithium hydroxide solution (1 M) (2.0 mL, 2 mmol) and were placed in a sealed vessel with water (8 mL). The vessel was placed in an oven at 200 C. for 14 hours. A shiny black powder with a few green crystals was filtered from a blue solution.

Synthesis of Metal Oxalates

[0102] Cobalt oxalate dihydrate, nickel oxalate dihydrate and zinc oxalate dihydrate were already available for use as reagents but iron oxalate dihydrate, manganese oxalate dihydrate and cobalt nickel manganese oxalate had to be synthesised prior to use.

Synthesis of Iron Oxalate Dihydrate

[0103] Oxalic acid dihydrate (2.5064 g, 19.88 mmol) and concentrated sulfuric acid (0.3 mL) were added to water (50 mL) and heated to 55 C. while being stirred till the oxalic acid dissolved. Iron (II) ammonium sulfate (5.0011 g, 12.75 mmol) was added and a yellow precipitate formed instantaneously. The precipitate was filtered for use in further reactions.

Synthesis of Manganese Oxalate Dihydrate

[0104] Oxalic acid dihydrate (2.5133 g, 19.94 mmol) and concentrated sulfuric acid (0.3 mL) were added to water (25 mL) and heated to 55 C. while being stirred till the oxalic acid dissolved. Manganese (II) acetate tetrahydrate (3.1261 g, 12.75 mmol) was added and a white precipitate formed instantaneously. The precipitate was filtered for use in further reactions.

Synthesis of Cobalt Nickel Manganese Oxalate

[0105] Oxalic acid dihydrate (14.4928 g, 0.115 mol) and concentrated sulfuric acid (1 mL) were added to water (75 mL) and heated to 55 C. while being stirred till the oxalic acid dissolved. Manganese (II) acetate tetrahydrate (9.0693 g, 0.037 mol), nickel (II) acetate tetrahydrate (9.2052 g, 0.037 mol) and cobalt (II) chloride hexahydrate (8.8029 g, 0.037 mol) was added and a fine purple precipitate formed instantaneously. The precipitate was filtered for use in further reactions.

Synthesis of PM-2, [Li(ox)].SUB.2.[M.SUB.5.(OH).SUB.8.] Wherein M=Ni:Mn:Co in Varying Ratios

[0106] The syntheses were carried out in the same way as above example wherein M=1:1:1: Ni:Mn:Co, with only the relative amounts of metal ion sources changed. For example, instead of using only CoCl.sub.2.Math.6H.sub.2O, as per Method 1 for synthesis of PM-1 above, a mixture of cobalt chloride, nickel chloride and manganese chloride may be used. Alternatively, instead of using cobalt oxalate, as per Method 2 for synthesis of PM-1 above, cobalt nickel manganese oxalate may be used, for example. Again, other sources of metal ions, oxalate ions and lithium ions are tolerated by the method. Impurities, for example iron ions and iron oxide, are also tolerated.

[0107] Single crystal X-ray diffraction and powder X-Ray diffraction analysis were carried out to confirm the structure. Thermogravimetric analysis was carried out to monitor conversion to lithium metal oxide, LiMO.sub.2, see FIGS. 5-8.

Synthesis of Nickel and Cobalt Based Precursor Material

[0108] Nickel oxalate dihydrate (91.3 mg, 0.5 mmol), cobalt oxalate dihydrate (90.6 mg, 0.5 mmol) and lithium hydroxide monohydrate (83.3 mg, 2 mmol) were placed in a sealed vessel with water (10 mL). The vessel was placed in an oven at 200 C. for 14 hours. A green powder was filtered.

Synthesis of Manganese, Nickel and Cobalt Based Precursor Material

[0109] CoCl.sub.2.Math.6H.sub.2O (2 molar solution in water, 166 l, 0.33 mmol), NiCl.sub.2.Math.6H.sub.2O (1 molar solution in water, 333 l, 0.33 mmol), MnCl.sub.2.Math.4H.sub.2O (1 molar solution in water, 333 l, 0.33 mmol), LiOH.Math.H.sub.2O (3 molar solution in water, 2.0 ml, 6 mmol), LiCl (5 molar solution in water, 2.4 ml, 12 mmol) C.sub.2H.sub.2O.sub.4.Math.2H.sub.2O (1 molar solution in water, 2.5 ml, 2.5 mmol) were added to a 23 mL Teflon lined bomb reactor and made up to 10 mL with deionised water. This vessel was heated at 230 C. for 12 hours. The bomb was left to cool, and the contents filtered. The yield of [Li(ox)].sub.2[Mn/Ni/Co.sub.5(OH).sub.8] was over 95%.

Characterisation of the Formed Precursor Materials

[0110] Single crystal X-ray diffraction data were collected in house on a Rigaku Oxford Diffraction SuperNova A diffractometer fitted with an Atlas detector with Cu-K (1.54184 ) and Mo-K (0.71073 ).

[0111] Referring again to FIG. 1a which shows the results of single crystal X-Ray diffraction of [Li(ox)].sub.2[Co.sub.5(OH).sub.8](synthesized by Method 1), it can be seen that the compound crystallises in the triclinic space group P-1 (space group no. 2). The asymmetric unit is comprised of 3 cobalt metal centres, 4 hydroxides, 1 lithium metal centre and 1 oxalate. Two of the cobalt hydroxide centres (Co2; Co3) have near octahedral geometry and are bridged to one another through hydroxides O13 and O14i. The third cobalt centre (Co.sub.1) has near tetrahedral geometry and is coordinated to Co.sub.2 and Co.sub.3 through hydroxyl oxygens 011 and 012 respectively. The lithium metal centre (Li4) is coordinated by 5 oxygen atoms, from the oxalate ligand (O22 and O24) and 3 symmetry generated oxygen atoms from neighbouring oxalate moieties (O21vi, O23vi and O24vii). Li4 is bridged to Co.sub.1 through O22. Symmetry equivalents: i) 1-x, 1-y, 1-z; ii) 1+x, y, z; iii) 2-x, 1-y, 1-z; iv) 2-x, 2-y, 1-z; v) x, 1-y, z; vi) 1+x, y, z.

[0112] FIG. 1b depicts the stacking of the layers of [Li(ox)].sub.2[Co.sub.5(OH).sub.8] with the [Li(ox)].sup.1 layer shown in the top and bottom layers and [Co.sub.5(OH).sub.8].sup.2+ represented by the middle layer. The cobalt can be octahedrally coordinated or tetrahedrally coordinated where systematic depletions occur. One of the reasons this recycling method is successful is due to [Li(ox)].sub.2[Co.sub.5(OH).sub.8] having a layered structure. LCO also contains a layered structure, which allows calcination to be carried out at comparatively low temperatures. This makes the process energy efficient and simple.

[0113] The bond lengths and angles of the above crystal structure are given in the below Table 1.

TABLE-US-00001 TABLE 1 ML d/ LML </ LML </ Co1O14v 1.935 (15) O14vCo1O12 114.5 (6) O12Co3O14i 90.8 (5) Co1O12 1.953 (14) O14vCo1O11 112.7 (6) O12Co3O14 89.2 (5) Co1O11 1.957 (14) O14vCo1O22 108.3 (7) O12iCo3O14 90.8 (5) Co1O22 2.116 (19) O12Co1O11 115.0 (6) O12iCo3O12 180 Co2O14i 2.130 (13) O12Co1O22 99.9 (7) O13Co3O14i 84.5 (5) Co2O12ii 2.123 (13) O11Co1O22 104.9 (6) O13iCo3O14i 95.5 (5) Co2O13 2.057 (14) O12iiCo2O14i 176.8 (5) O13iCo3O14 84.5 (5) Co2O13iii 2.093 (13) O13Co2O14i 84.7 (5) O13Co3O14 95.5 (5) Co2O11iv 2.081 (14) O13iiiCo2O14i 93.8 (5) O13iCo3O12 85.0 (5) Co2O11 2.122 (13) O13iiiCo2O12ii 84.5 (5) O13iCo3O12i 95.0 (5) Co3O14 2.147 (14) O13Co2O12ii 92.3 (5) O13Co3O12 95.0 (5) Co3O14i 2.147 (14) O13Co2O13iii 82.2 (6) O13Co3O12i 85.0 (5) Co3O12 2.147 (14) O13Co2O11iv 175.3 (5) O13Co3O13i 180 Co3O12i 2.147 (14) O13Co2O11 97.4 (5) O23viLi4O24vii 91. (2) Co3O13i 2.048 (13) O13iiiCo2O11 174.8 (5) O22Li4O23vi 167. (3) Co3O13 2.048 (13) O11Co2O14i 91.3 (5) O22Li4O24vii 102. (2) Li4O21vi 2.04 (6) O11ivCo2O14i 90.7 (5) O22Li4O24 83. (2) Li4O22 1.96 (6) O11ivCo2O12ii 92.3 (5) O22Li4O21vi 98. (3) Li4O23vi 2.12 (6) O11Co2O12ii 90.4 (5) O24Li4O23vi 95. (2) Li4O24 2.01 (6) O11ivCo2O13iii 98.1 (5) O24Li4O24vii 91. (2) Li4O24vii 2.34 (6) O11ivCo2O11 82.7 (5) O24Li4O21vi 170. (3) O14Co3O14i 180 O21viLi4O23vi 83. (2) O12iCo3O14i 89.2 (5) O21viLi4O24vii 98. (2)

[0114] Referring again to FIG. 2, the powder X-ray diffraction pattern was measured for [Li(ox)].sub.2[Co.sub.5(OH).sub.8] and Le Bail profile fitted using the cell parameters obtained from the single crystal X-ray data collection. Powder X-ray diffraction (Cu-K, =1.5406) plot with Le Bail profile fit for [Li(ox)].sub.2[Co.sub.5(OH).sub.8]. Pbcn, a=5.3525 (5) , b=6.3448 (5) , c=10.1774 (16) , =98.920, =100.084 (7) , =90.373 (8) , V=335.9 (7) (1.4), R.sub.p=8.85, R.sub.wp=12.00, R.sub.exp=5.48. Powder X-Ray data were collected on a Siemens D500 diffractometer with a Cu-K source. Le Bail profile fits on powder X-ray data were performed in Rietica to ensure phase identity and sample purity.

[0115] Elemental analysis was performed on an Exeter Analytical CE 440 elemental analyser. Expected for PM-1 (%): C:7.74, H:1.30; Found: C7.44, H:1.08.

[0116] Referring again to FIG. 3, there is shown the thermogravimetric analysis of the [Li(ox)].sub.2[Co.sub.5(OH).sub.8]. TGA/MS was measured with TGA Q500 thermogravimetric balance with Evolved Gas Analysis (EGA) furnace. Mass Spectrometer Edwards HPR20. Initial isotherm for 30 minutes at room temperature, followed by heating under in air flow to 900 C., at a ramp rate of 5 C./min, then a final 30-minute isotherm at final temperature. Sample size was 2.143 mg of dry solid.

[0117] Shown is a mass loss starting at 210 C., leading to LiCoO.sub.2 and Co.sub.3O.sub.4 with further mass loss at 860 C. as Co.sub.3O.sub.4 decomposes to 3 CoO. The mass loss is depicted by the upper line labelled TGA in FIG. 3.

[0118] It can be concluded from the TGA data that [Li(ox)].sub.2[Co.sub.5(OH).sub.8] decomposes on heating in air starting at 210 C., losing 31% mass in a single step. This can be explained by the decomposition of the material to LiCoO.sub.2 and Co.sub.3O.sub.4 with a predicted mass loss of 29%:

[Li(ox)].sub.2[Co.sub.5(OH).sub.8].fwdarw.2 LiCoO.sub.2+Co.sub.3O.sub.4+4H.sub.2O+4 CO.sub.2

[0119] Further heating leads to formation of CoO from Co.sub.3O.sub.4.

[0120] FIG. 4A and FIG. 4B show the SEM images of [Li(ox)].sub.2[Co.sub.5(OH).sub.8] prior to and after decomposition. FIG. 4A indicates a side on view of plate like formation; FIG. 4B shows resultant of decomposition and delamination of the layered compound upon heating. This deflagration of the crystals into thin layers with grooves results from production of carbon dioxide and water vapour within the crystals upon decomposition to lithium metal oxide. Scanning electron microscopy (SEM) was carried out with Field Emission Zeiss Ultra Plus-SEM with GEMINIFESEM column.

[0121] Referring now to FIG. 5 which shows the results of single crystal X-Ray diffraction of [Li(ox)].sub.2[M.sub.5(OH).sub.8] where M=1:1:1: Ni:Mn:Co. Occupancy of each metal site fixed by electronic preference of metal(II) ions within the statistical mixture. Symmetry operators are the same as for FIG. 1.

[0122] Since the crystal structure of [Li(ox)].sub.2[M.sub.5(OH).sub.8] where M=1:1:1: Ni:Mn:Co shows the same layered configuration as the example where M=Co, it is primed to undergo the same decomposition upon heating, the results of which can be seen in FIG. 8.

[0123] FIG. 6 shows the powder X-ray diffraction plot of [Li(ox)].sub.2[M.sub.5(OH).sub.8] where M=1:1:1: Ni:Mn:Co.

[0124] FIG. 7 shows the powder X-ray diffraction plot of [Li(ox)].sub.2[M.sub.5(OH).sub.8] illustrating the wide range of ratios of Ni:Mn:Co that the compound of Formula I can comprise. The [Li(ox)].sub.2[M.sub.5(OH).sub.8] was formed with the following ratios of Ni:Mn:Co0:0:1, 1:1:1, 0.25:0.25:0.5, 0.125:0.125:0.75, 0.1:0.1:0.8, 0.55:0:0.45, 0.25:0:0.75, 0.375:0.375, 0.25. In some embodiments, the majority of metal present is nickel. In some embodiments, the majority of the metal is cobalt. In some embodiments no nickel is present. In some embodiments no manganese is present. In some embodiments, cobalt comprises the smallest fraction of all of the metals present in the compound of Formula I. The PXRD confirms that the phase is the same as for PM-1.

[0125] The above ratios which are only exemplary; the precursor forms over a wider range of ratios.

[0126] FIG. 8 shows that the decomposition of [Li(ox)].sub.2[M.sub.5(OH).sub.8] where M=1:1:1: Ni:Mn:Co starts at 320 C. This is a higher temperature than that required for the decomposition wherein M=Co only. Range Istable [Li(C.sub.2O.sub.4)].sub.2[M.sub.5(OH).sub.8]; Range II: decomposition; Range IIILiMO.sub.2+metal oxides where M=1:1:1 Ni:Mn:Co.

[0127] The invention is defined by the appended claims.