US 5,955,052 AGrant

Method for Making Lithiated Manganese Oxide

Issue Date:1999-09-21

•45 Claims

Abstract

The invention is a process which provides a high purity lithiated manganese oxide (Li.sub.1+x Mn.sub.2-y O.sub.4) from chemically made MnO.sub.2. The lithiated manganese oxide has an especially effective utility for use as a cathodic material in rechargeable batteries. The process of the invention includes blending a lithium compound with a chemically made manganese dioxide to form a manganese dioxide/lithium compound blend. The lithium compound in the blend is at least about one mole of lithium for every mole of manganese dioxide. The manganese dioxide and lithium compound in the blend are reacted to provide an ion replaced product where lithium ions have replaced sodium and potassium ions in the MnO.sub.2 to form an ion replaced product. Thereafter, the ion replaced product is heated or calcined to provide the lithiated manganese oxide.

Metadata

Assignee

Carus Corporation

Inventors

Akshaya Kumar Padhi
G. Chithambarathanu Pillai

Application Information

Application Number:US 0823295

Filing Date:1998-05-21

Priority Date:1998-05-21

Art Unit:174

Classifications

IPC:

C01G 3714C01G 4512C01G 4502H01M 450

Field of Search:

423429599;605224

Patent Drawings

This patent does not have any drawings.

Description

Field of the Invention

This invention relates to a method of making lithiated manganese oxide which is particularly useful in the manufacture of lithium/manganese batteries or other applications involving lithium intercalation or deintercalation. More particularly, this invention is directed to making LiMn.sub.2 O.sub.4 from a manganese dioxide where the LiMn.sub.2 O.sub.4 has an x-ray pattern recognized as particularly useful in the manufacture of batteries.

Background of the Invention

Manganese dioxide is a known material for use as a cathodic material in batteries. It also is known that it is not particularly suitable for rechargeable batteries. Apparently irreversible structural changes occur in manganese dioxide during discharge which do not permit recharging.

Lithiated manganese oxide made from manganese dioxide (MnO.sub.2) has been investigated for use in rechargeable batteries. The method of making the lithiated manganese oxide and the manganese dioxide starting material appears to materially affect the effectiveness of the lithiated manganese oxide used in rechargeable batteries. U.S. Pat. Nos. 4,312,930 and 4,246,253 to Hunter describe a lithiated manganese oxide which Hunter says has a particularly effective utility for rechargeable batteries. Each of these Hunter patents is incorporated herein as if fully rewritten.

Making lithiated manganese compounds is not necessarily new. Monchilov and Manev describe making lithiated manganese compounds (see Journal of Power Sources, 41 (1993) 305-314 and Log Batteries, Battery Mater., Vol. 14 (1995), respectively), but do not describe making such compounds from relatively impure compounds which have a high sodium and/or potassium content and making relatively pure lithiated manganese compounds by removing the sodium and/or potassium and replacing those alkali metals with lithium to make a pure lithiated manganese compound.

Copending application Ser. No. 08/726,323 filed Oct. 3, 1996 and copending application Ser. No. PCT/US97/17081, filed Sep. 30, 1997, which is a continuation-in-part application of Ser. No. 08/726,323 describe making lithiated manganese oxide from manganese dioxide. When compared to the process described herein, the process described in these copending applications are more complex, take more steps and require at least two heating steps which make them more energy intensive.

An object of this invention is to provide a process for making lithiated manganese oxide.

Another object of this invention is to use chemically made manganese dioxide in making the lithiated manganese oxide by the process of the invention.

Yet another object of this invention is to make a pure form of lithiated manganese oxide from the reduction of an alkali metal permanganate or manganate such that the lithiated manganese oxide has a utility that is particularly effective for a cathodic material for rechargeable batteries.

Yet another object of the invention is to make a lithiated manganese oxide by a process which has few steps, has a low manganese and lithium loss and is energy efficient.

Further objects and advantages of the invention will be found by reference to the following specification.

As used herein, LiMn.sub.2 O.sub.4 means a lithiated manganese oxide with the general formula Li.sub.1+x Mn.sub.2-y O.sub.4 where x is greater than about -0.11 and less than about +0.33, and y is equal to about 0 to about 0.33.

As used herein, "amorphous manganese dioxide" means a manganese dioxide which does not have a substantially identifiable crystal structure as determined by x-ray diffractometry.

As used herein, "delta manganese dioxide" means a manganese dioxide which does not have a single crystal structure which dominates to provide a manganese dioxide with at least one identifiable crystal structure. Delta manganese dioxide is often described as having the following general formula M.sub.2 O. 4MnO.sub.2 where M is an alkali metal cation.

As used herein, "reducing permanganate" means taking the oxidation state of manganese (VII) to manganese (III or IV).

As used herein, "substantially all Mn IV" means at least about 90 weight percent Mn IV and not more than about 10 weight percent Mn III.

As used herein, "defect spinel" is all material within the general formula Li.sub.1+x Mn.sub.2-y O.sub.4 where x is greater than about -0.11 and less than about +0.33 and y is about 0 to about 33, but not LiMn.sub.2 O.sub.4 (where x & y are O). A specific defect spinel which has utility is where the Li to Mn ion molar ratio is about 0.5.

Another type of defect spinel which has utility is a stoichiometric spinel where the oxidation state of the manganese varies from about 3.5 to 4.0. In the former example of a defect spinel, the Li to Mn ion molar ratio is controlled by how much sodium and potassium ions are in the MnO.sub.2 and pH control of the reaction (through the use of LiOH) to get the spinel. To raise the Li to Mn ratio to about 0.6, the pH should be raised. The nature of stoichiometric spinel may be controlled by reaction temperature. Increase the reaction temperature to get the spinel and decrease the oxidation state of the Mn.

Summary of the Invention

The process of the invention provides a high purity LiMn.sub.2 O.sub.4 from chemically made amorphous MnO.sub.2 that has sodium and potassium impurities therein. The lithiated manganese oxide has an especially effective utility for use as a cathodic material in rechargeable batteries. The invention is particularly useful and nonobvious because (1) it utilizes as a starting material a relatively inexpensive chemically made manganese dioxide with alkali metal impurities in it, (2) removes the unwanted alkali metals such as sodium and potassium with less manganese loss than previously known processes, (3) replaces the sodium and/or potassium with lithium in less steps than previously known processes, (4) lowers or mitigates lithium loss relative to previously known processes, (5) lowers energy consumption relative to previously known processes to make a pure spinel LiMn.sub.2 O.sub.4 material, (6) exhibits higher degrees of control over the physical properties of the material than previously known processes, and (7) provides a method of preparing a series of defect and stoichiometric spinels. It is the spinel material which is especially useful for batteries. Moreover, the invention has the ability to remove sodium and/or potassium to an amount of at least not more than about 0.001 moles of sodium and potassium together per mole of manganese in the lithiated manganese compound (not more than about 0.001 moles of sodium and potassium per mole manganese are left in the lithiated manganese compound).

In an important aspect, the method of the invention includes blending a lithium compound with a manganese dioxide made from the reduction of sodium and/or potassium permanganate and/or manganate to obtain a lithium compound blend. In a very important aspect the starting material for the amorphous manganese dioxide is sodium and/or potassium permanganate. The lithium compound in the blend is in a stoichiometric excess which is effective for replacing sodium ions and/or potassium ions in the manganese dioxide with lithium ions to make an ion replaced product. The amorphous manganese dioxide and lithium compound are reacted in a liquid media to exchange the sodium and potassium ions in the manganese dioxide with lithium ions. The liquid media may be a melt by melting the lithium compound, or may be a solvent for the lithium compound in the manganese oxide/lithium compound blend. In an important aspect, the lithium compound blend is heated from about 5.degree. C. to about 400.degree. C. for a time sufficient that after heating the blend the ion replaced product has at least about 0.45 moles Li per mole Mn. This step may be repeated as often as necessary to reach the desired Li:Mn ratio. In another important aspect, the lithium compound is in stoichiometric excess which is effective for replacing sodium and/or potassium such that the ion replaced product has not more than about 0.001 moles sodium and/or potassium per mole manganese. In general, the stoichiometries of lithium compound in the lithium compound blend is at least about 1 equivalent mole of lithium for every mole of manganese dioxide.

The ion replaced product is heated at a temperature of from about 500.degree. C. to about 900.degree. C. for a time effective to provide a lithiated manganese oxide having the formula Li.sub.1+x Mn.sub.2-y O.sub.4. The heating at the latter temperature range is generally from about 0.5 to about 16 hours. The process of the invention permits a spinel phase purity of at least 99.5 weight percent. Moreover, for a given calcining or heating temperature, the process of the invention produces less of the "rock salt phase" lithiated manganese oxide (Li.sub.2 MnO.sub.3) and less of the Mn.sub.2 O.sub.3 phase which would be produced by merely heating MnO.sub.2 with a lithium compound.

The excess of lithium compound, the time and temperature of the first heating of the blend of lithium compound and manganese dioxide, and the time and temperature of the second heating step which heats the ion replaced product, all effect the purity of the Li.sub.x Mn.sub.2 O.sub.4 spinel and the ability of that spinel to generate an electromotive force. In an important aspect, this electromotive force is from about 3 to about 4 volts when it is used as a cathodic material in a battery containing a Li metal anode which is recyclable at least about fifty times.

In another important aspect, the lithium compound with which the manganese oxide is blended is selected from the group consisting of lithium nitrate, lithium hydroxide, lithium chloride, lithium bromide, lithium iodide, lithium sulfate, and mixtures thereof. Use of lithium nitrate is a particularly important aspect of the invention.

Finally, in yet another important aspect, the chemically reduced manganese dioxide used in the lithium compound/manganese dioxide blend is a reaction product of sodium and/or potassium permanganate with an organic reducing agent. In a particularly important aspect, the organic reducing agent has side chain lower alkyl groups (side chains having one to four carbon atoms, such as methyl, ethyl, propyl and butyl groups). Such compounds include alkyl substituted pyridines and dialkyl substituted pyridines having the general formula ##STR1## where at least one of x and y are methyl, ethyl, propyl and butyl, but one x or y may be H. Other organic compounds which may be used to reduce the permanganate include fumaric acid, propanol, glucose, toluene sulphonamide, picoline. Use of an organic reducing agent permits control of the particle size of the manganese dioxide which in turn permits a precise control the particle size of the Li.sub.x Mn.sub.2 O.sub.4 spinel.

Detailed Description of the Invention

The invention provides a method of making LiMn.sub.2 O.sub.4 from chemically made manganese dioxide. The method of the invention provides LiMn.sub.2 O.sub.4 which is particularly useful as cathodic material for rechargeable batteries. The invention permits the use of a MnO.sub.2 which is a product of an oxidation/reduction reaction. In an important aspect a sodium and/or potassium permanganate or manganate salt, particularly a sodium and/or potassium permanganate, is reduced during an oxidation of an organic compound by the permanganate or manganate salt. The oxidation/reduction reaction using an organic reducing agent is conducted at a pH of at least 7, but in an important aspect is conducted at a pH above about 10. The manganese dioxide that results from the oxidation/reduction reaction may be characterized as amorphous or delta manganese dioxide. The organic compound reduces permanganate or the manganate such that the resulting manganese dioxide is substantially all manganese IV (at least about 90 weight percent manganese IV). Not more than about 10 weight percent of the resulting manganese dioxide is manganese III.

Another aspect of the invention permits control of the particle size of the LiMn.sub.2 O.sub.4 by controlling the particle size of the amorphous MnO.sub.2 used to make the spinel lithiated manganese oxide (LiMn.sub.2 O.sub.4). After making the amorphous MnO.sub.2, the process of the invention is sufficiently gentle so as not to reduce the mean particle size of the product by more than about 20% and in an important aspect not more than 10% from the particle size of the MnO.sub.2 used to make the LiMn.sub.2 O.sub.4. The particle size of the amorphous MnO.sub.2 may be controlled by controlling the rate of mixing the reactants used to make the amorphous MnO.sub.2, controlling the rate of agitation of the reactants and controlling the reaction temperature to make the MnO.sub.2. Increasing the rate of mixing the reactants, increasing the agitation of the reactants during the reaction and the increasing the reaction temperature will reduce the particle size of the MnO.sub.2.

In an important aspect, the invention controls the mean particle size of the lithiated manganese oxide to a range of from about 2 to about 35 microns through using a temperature of from about 10.degree. C. to about 200.degree. C. using an organic compound as a reducing agent and Mn.sup.+7 or Mn.sup.+6 as the oxidizing agent to form the precursor manganese dioxide.

The organic compound which may be used in the oxidation/reduction reaction may be an organic compound having side chain lower alkyl groups (side chains having one to four carbon atoms, such as methyl, ethyl, propyl and butyl groups). Such compounds include alkyl substituted pyridines and dialkyl substituted pyridines having the general formula ##STR2## where at least one of x and y are methyl, ethyl, propyl and butyl, but one x or y may be H. Other organic compounds which may be used to reduce the permanganate or manganate include fumaric acid, propanol, glucose, toluene sulphonamide, picoline and the compounds listed below in Table I. Table I illustrates the pH of the dependency of the oxidation/reduction reaction and illustrates the need for alkaline conditions when an organic reducing agent is used.

In another aspect an inorganic reducing agent may be used. By way of example, when manganese nitrate is used as the reducing agent, acid or alkaline conditions may be used.

To make the lithiated manganese dioxide, the manganese dioxide from the oxidation/reduction reaction is blended with an excess of lithium compound such as lithium nitrate, lithium hydroxide, lithium chloride, lithium bromide, lithium iodide, and lithium sulfate, to provide a lithium compound/manganese dioxide blend. Use of lithium nitrate is a particularly important aspect of the invention. The lithium in the lithium compound is in stoichiometric excess of the manganese in the manganese dioxide, such that there is more than about 1 equivalent mole lithium for every mole of manganese dioxide. The excess of lithium compound should be sufficient to replace potassium and/or sodium in the manganese dioxide which excess also is effective for providing the resulting lithiated manganese oxide with the ability to provide at least about three volts, and in an important aspect about 4 volts, of electromotive force with respect to a Li metal anode when the lithiated manganese oxide spinel is used as a cathode material in a rechargeable battery which is recyclable at least about fifty times. In an important aspect, the cathode material permits recyclable recharging at least 300 times. In another important aspect, the lithium compound blend should comprise sufficient lithium compound for every mole of manganese dioxide such that after heating the lithium compound blend, the ion replaced product has at least about 0.45 moles Li per mole Mn. The ion replaced product also should not have more than about 0.001 mole sodium and/or potassium per mole Mn. More than about 3 mole equivalents of lithium could be used, but to keep the process economic, recycling or some other method of conserving the lithium probably would have to be used.

The excess of the lithium compound creates a concentration gradient which is sufficient to drive the reaction which replaces the sodium and/or potassium ions with lithium ions such that the ion replaced product has at least about 0.45 moles Li per mole Mn or the ion replaced product has not more than about 0.001 mole sodium and/or potassium per mole Mn after the reaction of the lithium compound with the manganese dioxide and then optionally repeating the reaction using an intermediate ion replaced product reactant to obtain a final ion replaced product with the desired lithium ion content and lowered sodium and potassium content.

The reaction between the manganese dioxide and the lithium compound may be done by blending the manganese dioxide and lithium compound, melting the lithium compound into a melt to make a manganese dioxide/melt blend and heating the manganese dioxide/melt blend at least at the melting point of the lithium compound (such as about 264.degree. C. for lithium nitrate). Thereafter, the heated manganese dioxide/melt blend reaction product is washed with a solvent to dissolve and remove excess lithium compound. The solvent with excess lithium is separated from the ion replaced product. The solvent then is evaporated to recover the excess lithium compound. As previously described, the reaction to obtain the ion replaced product may be optionally repeated (a number of "exchanges") using an intermediate ion replaced product or a blend of manganese dioxide and ion replaced product to react with the lithium compound until the desired level of lithium is obtained in the final ion replaced product. washing may be effected with deionized water with the product.

The manganese dioxide and lithium compound alternatively may be dispersed or dissolved in a solvent, such as water and/or acetonitrile, and the solvent/reactant blend may thereafter be heated for a time and temperature to effect the replacement of sodium and/or potassium with lithium as described above. The ratio of lithium compound and manganese dioxide, the lithium compound which is used, the type of solvent (if any) which is used, the time and temperature of the heating of the lithium compound/manganese dioxide blend and the number of exchange reactions are all conditions which affect the amount of potassium and sodium ions which are replaced by lithium ions. A particularly effective solvent system in the invention is the use of an aqueous dispersion with a MnO.sub.2 /lithium compound ratio of 1:2 with about 4 exchanges, or a MnO.sub.2 /lithium compound ratio of about 1:3 with about 3 exchanges at about 25.degree. C. Various reactants and their effectiveness are shown in Table III shown below. Reference to Table below indicates that lithium nitrate (LiNO.sub.3) is very effective for replacing sodium and potassium ions with lithium ions. Multiple ion exchanges are more effective than single step reactions.

The washed final ion exchanged product which is from the reaction of the manganese dioxide and lithium compound then is heated or calcined at from about 300.degree. C. to about 900.degree. C. for about 0.5 to about 16 hours. The temperature of the calcination of the final ion replaced product has an affect on the particle size, surface area and the lattice parameter of the manganese oxide spinel product. In general, however, the process of the invention is gentle and the mean particle size of the LiMn.sub.2 O.sub.4 can be controlled through the control of the particle size of the amorphous MnO.sub.2 being used in the process. This is illustrated in Table IV.

The calcining temperature of the final ion exchanged product to produce the manganese oxide spinel also affects the type of defect spinel produced by the process and the discharge characteristics of the spinel. As noted above, an increase in temperature will decrease the oxidation state of the Mn in the spinel.

The specific capacity and the fade in capacity of the spinel is affected as to how fast the product is cooled after calcining. The specific capacity of the samples slow cooled fades faster than that of the samples rapidly cooled to room temperature. In the invention, better capacity is obtained by cooling the product to almost room temperature in less than 2 hours, and in an important aspect, less than about 1/2 hours. Alternatively, slower cooling can be done in a controlled-free environment wherein there is not sufficient O.sub.2 in the cooling environment to substantially affect capacity.

Claims

What is claimed is:

1. A method for making lithiated manganese oxide, the method comprising: blending a lithium compound and chemically made amorphous MnO.sub.2 which includes alkali metal ions selected from the group consisting of sodium ions, potassium ions and mixtures thereof to obtain a lithium compound blend, the ratio of said alkali metal ions to manganese in the amorphous manganese dioxide being at least about 0.45; ion exchanging said alkali metal ions for lithium ions in the MnO.sub.2 which is in the lithium compound blend at a temperature of from about 5.degree. C. to about 400.degree. C. to obtain an ion replaced product, the lithium compound blend having more lithium ions from the lithium compound than said alkali metal ions such that after the exchange, the ion replaced product has at least about 0.45 moles Li per mole Mn; separating the ion exchanged product from said alkali metal ions which have been removed from the amorphous manganese dioxide; and heating the ion replaced product at a temperature of from about 300.degree. C. to about 900.degree. C. for a time effective to provide a lithiated manganese oxide spinel having the formula Li.sub.1+x Mn.sub.2-y O.sub.4 where x is greater than about -0.11 and less than about +0.33, and y is from about 0 to about 0.33.

2. A method as recited in claim 1 wherein the ion replaced product is heated at about 300.degree. C. to about 900.degree. C. for about 0.5 hours to about 16 hours.

3. A method as recited in claim 1 wherein the lithium compound is selected from the group consisting of lithium hydroxide, lithium nitrate, lithium chloride, lithium bromide lithium iodide, lithium sulfate, and mixtures thereof.

4. A method as recited in claim 1 wherein the lithiated manganese oxide is effective for providing an electromotive force of from about 3 to about 4 volts when it is used as a cathodic material in a battery employing a lithium metal anode which is recyclable at least about fifty times.

5. A method as recited in claim 4 wherein ion exchanging said alkali metal ions in the amorphous MnO.sub.2 in the lithium compound blend provides an intermediate ion replaced product and the method further comprises separating the intermediate ion exchanged product from said alkali metal ions which have been removed from the amorphous manganese dioxide, an blending and exchanging said alkali metal ions in the MnO.sub.2 in the intermediate ion replaced product with lithium ions from the lithium compound to provide a final ion replaced product which does not have more than about 0.001 moles of said alkali metal ions per mole Mn after repeating the blending and exchanging of the intermediate ion replaced product, the final ion replaced product being heated at a temperature of from about 300.degree. C. to about 900.degree. C. to provide the Li.sub.1+x Mn.sub.2-y O.sub.4.

6. A method as recited in claim 4 or 5 wherein the lithium compound is lithium nitrate.

7. A method as recited in claim 1, wherein the ion exchanging is done in a liquid media and the liquid media is a melt of the amorphous manganese dioxide and the lithium compound.

8. A method as recited in claim 1, wherein the ion exchanging is done in a liquid media and the liquid media is comprises water and the ion exchange is done with a slurry which comprises the lithium compound and the amorphous manganese dioxide.

9. A method as recited in claim 1, wherein the ion exchanging is done in a liquid media and the liquid media comprises an organic solvent.

10. A method for making lithiated manganese oxide, the method comprising: blending a lithium compound and amorphous MnO.sub.2 made by chemically reducing an alkali metal manganese compound selected from the group consisting of potassium permanganate, sodium permanganate, potassium manganate, sodium manganate and mixtures thereof to obtain a lithium compound blend, the ratio of alkali metal ions to manganese being at least about 0.45; ion exchanging alkali metal ions selected from the group consisting of sodium ions, potassium ions and mixtures thereof in the amorphous MnO.sub.2 for lithium ions from the lithium compound in the blend at a temperature of from about 5.degree. C. to about 400.degree. C., the blend having more lithium ions from the lithium compound than said alkali metal ions such that after the exchange, a final ion replaced product is obtained which does not have more than about 0.001 mole of said alkali metal ions per mole Mn; separating the ion exchanged product from said alkali metal ions which have been removed from the amorphous manganese dioxide; and heating the final ion replaced product at a temperature of from about 300.degree. C. to about 900.degree. C. for a time effective to provide a lithiated manganese oxide having the formula Li.sub.1+x Mn.sub.2-y O.sub.4 where x is greater than about -0.11 and less than about +0.33, and y from about 0 to about 0.33.

11. A method as recited in claim 10 wherein ion exchanging said alkali metal ions in the amorphous MnO.sub.2 in the lithium compound blend provides an intermediate ion replaced product and the method further comprises separating the intermediate ion exchanged product from said alkali metal ions which have been removed from the amorphous manganese dioxide, and blending and exchanging said alkali metal ions in the MnO.sub.2 in the intermediate ion replaced product with the lithium compound to provide the final ion replaced product which does not have more than about 0.001 moles of said alkali metal ions per mole Mn after repeating the blending and exchanging of the intermediate ion replaced product.

12. A method as recited in claim 4, 10 or 11 wherein the final ion replaced product is heated at about 300.degree. C. to about 900.degree. C. for about 0.5 hours to about 16 hours.

13. A method as recited in claim 12 wherein the final ion replaced product is heated at about 300.degree. C. to about 900.degree. C. for about 0.5 hours to about 16 hours.

14. A method as recited in claim 12 wherein the alkali metal manganese compound is selected from the group consisting of potassium permanganate, sodium permanganate and mixtures thereof.

15. A method as recited in claim 10 or 11 wherein the lithium compound is selected from the group consisting of lithium hydroxide, lithium nitrate, lithium chloride, lithium bromide lithium iodide, lithium sulfate, and mixtures thereof.

16. A method as recited in claim 10 or 11 wherein the lithiated manganese oxide is effective for providing an electromotive force of from about 3 to about 4 volts when it is used as a cathodic material in a battery employing a Li metal anode which is recyclable at least about fifty times.

17. A method as recited in claim 10 or 11 wherein the lithium compound is lithium nitrate.

18. A method as recited in claim 10, wherein the ion exchanging is done in a liquid media and the liquid media is a melt of the amorphous manganese dioxide and the lithium compound.

19. A method as recited in claim 10, wherein the ion exchanging is done in a liquid media and the liquid media is comprises water and the ion exchange is done with a slurry which comprises the lithium compound and the amorphous manganese dioxide.

20. A method as recited in claim 10, wherein the ion exchanging is done in a liquid media and the liquid media comprises an organic solvent.

21. A method for making lithiated manganese oxide, the method comprising: blending a lithium compound and amorphous MnO.sub.2 made by chemically reducing an alkali metal manganese compound selected from the group consisting of potassium permanganate, sodium permanganate, potassium manganate, sodium manganate and mixtures thereof to obtain a lithium compound blend, the ratio of alkali metal ions to manganese in the amorphous manganese dioxide being at least about 0.45, said alkali metal ions being selected from the group consisting of sodium, potassium and mixtures thereof; exchanging said alkali metal ions for lithium ions in the amorphous MnO.sub.2 which is in the lithium compound blend at a temperature of from about 5.degree. C. to about 400.degree. C. to obtain an ion replaced product, the lithium compound blend having more lithium ions from the lithium compound than said alkali metal ions such that after the exchange the ion replaced product has at least about 0.45 moles Li per mole Mn; separating the ion replaced product from said alkali metal ions which have been removed from the amorohous manganese dioxide; and heating the ion replaced product, the heating of the lithium compound blend for a time and temperature, the lithium compound being in excess of the chemically reduced alkali metal manganese compound and the heating of the ion replaced product for a time and temperature which are effective for providing a lithiated manganese oxide having the formula Li.sub.1+x Mn.sub.2-y O.sub.4 where x is greater than about -0.11 and less than about +0.33, and y is from about 0 to about 0.33 and wherein the lithiated manganese oxide product is effective for providing an electromotive force of from about 3 to about 4 volts when it is used as a cathodic material in a battery employing a Li metal anode which is recyclable at least about fifty times.

22. A method as recited in claim 21 wherein the ion replaced product is heated at about 300.degree. C. to about 900.degree. C. for about 0.5 hours to about 16 hours.

23. A method as recited in claim 21 wherein alkali metal manganese compound is selected from the group consisting of potassium permanganate, sodium permanganate and mixtures thereof.

24. A method as recited in claim 21, 22 or 23 wherein ion exchanging said alkali metal ions in the amorphous manganese dioxide in the lithium compound blend provides an intermediate ion replaced product and the method further comprises separating the intermediate ion exchanged product from said alkali metal ions which have been removed from the amorphous manganese dioxide; and blending and exchanging said alkali metal ions in the amorphous manganese dioxide in the intermediate ion replaced product with lithium ions from the lithium compound to provide a final ion replaced product, the final ion replaced product, not having more than about 0.001 moles of said alkali metal ions per mole Mn after repeating the blending and exchanging of the intermediate ion replaced product, the final ion replaced product being heated at a temperature of from about 300.degree. C. to about 900.degree. C. to provide the Li.sub.1+x Mn.sub.2-y O.sub.4.

25. A method as recited in claim 24 wherein the lithium compound is lithium nitrate.

26. A method as recited in claim 21 or 23 wherein the lithium compound is selected from the group consisting of lithium hydroxide, lithium nitrate, lithium chloride, lithium bromide, lithium iodide, lithium sulfate, and mixtures thereof.

27. A method as recited in claim 21, wherein the ion exchanging is done in a liquid media and the liquid media is a melt of the amorphous manganese dioxide and the lithium compound.

28. A method as recited in claim 21, wherein the ion exchanging is done in a liquid media and the liquid media is comprises water and the ion exchange is done with a slurry which comprises the lithium compound and the amorphous manganese dioxide.

29. A method as recited in claim 21, wherein the ion exchanging is done in a liquid media and the liquid media comprises an organic solvent.

30. A method for making lithiated manganese oxide, the method comprising: blending a lithium compound and chemically made amorhpous MnO.sub.2 which includes alkali metal ions selected from the group consisting of sodium ions, potassium ions and mixtures thereof to provide a lithium compound blend, the ratio of said alkali metal ions to manganese in the amorphous MnO.sub.2 being at least about 0.45, to obtain a lithium compound blend, the amorphous manganese dioxide made by chemically reducing an alkali metal manganese compound with an organic reducing compound which includes side chains having from about one to about four carbon atoms, the lithium compound blend having more lithium ions from the lithium compound than said alkali metal ions such that after an exchange of the alkali metal ions for lithium ions in the MnO.sub.2, the ion replaced product has at least about 0.45 mole Li ions per mole Mn; ion exchanging the alkali metal ions in the amorphous MnO.sub.2 for lithium ions in the lithium compound blend in a liquid media to obtain an ion replaced product; separating the ion replaced product from said alkali metal ions which have been removed from the amorphous manganese dioxide; and heating the ion replaced product at a temperature of from about 300.degree. C. to about 900.degree. C. for a time effective to provide a lithiated manganese oxide having the formula Li.sub.1+x Mn.sub.2-y O.sub.4, where x is greater than about -0.11 and less than about +0.33, and y is from about 0 to about 0.33, the time and temperature of the heating being effective so as to produce a mean particle size of the lithiated manganese oxide of from about 2 to about 35 microns and not less than about 80 percent of the particle size of the amorphous MnO.sub.2.

31. A method as recited in claim 30 wherein ion exchanging said alkali metal ions in the amorphous manganese dioxide in the lithium compound blend provides an intermediate ion replaced product and the method further comprises separating the intermediate ion replaced product from said alkali metal ions which have been removed from the amorphous manganese dioxide and blending and exchanging said alkali metal ions in the manganese dioxide in the intermediate ion replaced product with the lithium compound to provide a final ion replaced product which does not have more than about 0.001 moles of said alkali metal ions per mole Mn after repeating the blending and exchanging of the intermediate ion replaced product.

32. A method as recited in claim 30 or 31 wherein the liquid media is a melt.

33. A method as recited in claim 30 or 31 wherein the liquid media comprises water and the lithium compound blend is heated as a slurry.

34. A method as recited in claim 30 wherein a solvent is blended with the manganese dioxide and lithium compound to provide the liquid media in which said alkali metal ions selected from the group consisting of sodium and potassium ions in the manganese dioxide are exchanged for lithium ions.

35. A method as recited in claim 34 wherein the solvent is water.

36. A method as recited in claim 34 wherein ion exchanging said alkali metal ions in the amorphous manganese dioxide in the lithium compound blend provides an intermediate ion replaced product and the method further comprises separating the intermediate ion exchange product from said alkali metal ions which have been removed from the amorphous manganese dioxide, and blending and exchanging said alkali metal ions in the MnO.sub.2 in the intermediate ion replaced product with the lithium compound to provide a final ion replaced product which does not have more than about 0.001 moles of said alkali metal ions per mole Mn after repeating the blending and exchanging of the intermediate ion replaced product.

37. A method as recited in claim 30 or 31 wherein the lithiated manganese oxide has a phase purity of the spinel is at least about 99.5 weight percent.

38. A method as recited in claim 37 wherein the alkali metal manganese compound is selected from the group consisting of sodium permanganate, potassium permanganate and mixtures thereof.

39. A method as recited in claim 30 or 31 wherein the lithium compound is selected from the group consisting of lithium hydroxide, lithium nitrate, lithium chloride, lithium bromide, lithium iodide, lithium sulfate and mixtures thereof.

40. A method as recited in claim 38 wherein the lithiated manganese oxide is effective for providing an electromotive force of from about 3 to about 4 volts when it is used as a cathodic material in a battery employing a Li metal anode which is recyclable at least about fifty times.

41. A method as recited in claim 38 wherein the lithiated manganese oxide is cooled to about room temperature in less than about 2 hours.

42. A method as recited in claim 30 or 31 wherein the lithiated manganese oxide is effective for providing an electromotive force of from about 3 to about 4 volts when it is used as a cathodic material in a battery employing a Li metal anode which is recyclable at least about fifty times.

43. A method as recited in claim 42 wherein the alkali metal manganese compound is selected from the group consisting of sodium permanganate, potassium permanganate and mixtures thereof.

44. A method as recited in claim 43 wherein the lithium compound is lithium nitrate.

45. A method as recited in claim 42 wherein the lithium compound is lithium nitrate.

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Abstract

Description