Title of Invention	A PROCESS FOR THE SYNTHESIS OF LITHIUM COBALT MANGANATE USEFUL AS BATTERY CATHODE MATERIAL FOR LITHIUM ION CELLS
Abstract	A process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells by heating a paste prepared by mixing lithium cobalt and managanese sources such as herein described in the ratio of 1:1:1 respectively in glycerol at a temperature upto 800°C for a maximum period upto 12 hrs., cooling the product obtained above to get lithium cobalt manganate (LiCoMnO4).

Title of Invention

A PROCESS FOR THE SYNTHESIS OF LITHIUM COBALT MANGANATE USEFUL AS BATTERY CATHODE MATERIAL FOR LITHIUM ION CELLS

Abstract

A process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells by heating a paste prepared by mixing lithium cobalt and managanese sources such as herein described in the ratio of 1:1:1 respectively in glycerol at a temperature upto 800°C for a maximum period upto 12 hrs., cooling the product obtained above to get lithium cobalt manganate (LiCoMnO4).

Full Text	The present invention relates to a process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells, This invention particularly relates to a process of preparation of LiCoMnO4 as composite for rocking chair lithium ion cells based on solid polymer electrolytes, non aqueous systems and solid state materials. This invention more particularly relates to the preparation of lithium cobalt manganate (LiCoMnO4) a composite, which is very useful for high voltage lithium cells and can be prepared by chemical combustion method. Preparation of spinel LiCoMnO4 compound is known from the recent literature cited in 1998 as a battery cathode for high voltage lithium cells. This compound can be prepared by mixing LiCO3, CoO and MnCO3 together and fired in air initially at 650°C for 24 hours and then at 800°C for 3 days with intermittent regrinding and finally at 600°C for 3 days before quenching to room temperature [H.Kawai, M.Nagata, and A.R. West, Electrochem, Solid state Letters, 1(1998)212]. As available in literasture LiCoxMn2x04 can be alternatively prepared from MnCo3, CoC2O4 and Li2CO3. The powders were ground heated in air to 750°C in three 24 hrs cycles, followed by cooling at 2°C per minutes to room temperature. [P.Aitchison, D.J.Jones, G.Burns and J.Roziere, J.Mater.Chem., 9(1999)3125]. In the above mentioned methods any one of the following disadvantages are observed. 1. Phase purity 2. Intermitent heating 3. Long time heating etc. The main novel object of the present invention is to provide a novel process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells which obviates the drawbacks of the known methods. Further object of the invention, the cyclability of the system is retained by keeping Co in the compound. Still another object is to use glycerol as binding agent to make a uniform homogeneous mixing which inhibit the decomposition of the product in situ. Yet still another object of the invention is to prepare LiCoMnO4 using hydroxides and oxides. Accordingly, the present invention relates to a process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells which comprises heating a paste prepared by mixing lithium cobalt and managanese sources such as herein described in the ratio of 1:1:1 respectively in glycerol at a temperature upto 800°C for a maximum period upto 12 hrs., cooling the product obtained above to get lithium cobalt manganate (LiCoMnO4). In an embodiment of the invention the source of lithium may be selected from LiNO3, LiOH. In another embodiment the source of Co may be selected from Co(NC3)2 and Co3OH. The source of manganese may be selected from Mn(NO3)2 or MnO3 In yet another embodiment of the invention the molar ratio of LiNO3, Co(NO3)i and Mn(NC3)2 may be 1:1:1 respectively. In still another embodiment of the invention the molar ratio of LiOH Co3O4 and Mn2O3 may be 1:1:1, respectively. The paste of Li, Co & Mn source may be prepared by adding glycerol optionally in presence of citric acid urea, ammonium nitrite, formamide, succinic acid, ammonium formate, sugar or glucose as binding agent. In a feature of the invention heating may be carried at a temperature in the range of 200 to 600°C when nitrates are used for preparing the paste. In another feature of the invention heating may be carried out a temperature in the range of 200-800°C when LiOH, CoaO4, Mn2O3 are used to prepare the paste. The present invention, describes the method of synthesis of the cathode material for a secondary battery, by heating a paste prepared by mixing fine particles of LiOH, CO304 and Mn203 made in glycerol. This paste was initially heated slowly in a furnace to evaporate off glycerol in order to get a dried mass at 150-250°C. This dried mass was then continuously heated to 800°C for 12 hours. The product formed was slowly cooled to room temperature and was ground well and then examined for its particles size, colour and XRD exposure. It was found that the prepared sample was black in coloured and was homogeneous. X-ray analysis confirmed the formation of LiCoMnO4 according to Fig.l. The novelty of this invention is that the binding agent glycerol does not permit side reactions or partial reactions. The binding agent does not influence the quality of particle size or color of the product. The following examples are given by way of illustration and should not construed the scope of the invention. The following examples illustration the synthesis of LiCoMnO4 cathode material by solid state reaction. Example-1 Components LioH 0.84 gm Co3O4 1.60gm Mn2O3 1.58gm Glycerol 5 ml Temperature 800°C Duration of heating 12 hrs Colour of the product black Efficiency of the product 94.5% Phase Single Single electrode potential of LiCoMnO4 w.r.t. Li in 1M LiCIO4 in 3.01 v Propylene carbonate. A standard procedure to measure the single electrode potential of the cathode. Li(NO3)2, Co(NOs)2 and Mn (NOs^ salts taken in the molar ratio of 1:1:1 and were mixed together. Some of the salts are hydroscopic and hence a solution of formed. In this solution added 5 ml. Of glycerol. The new solution was slowly evaporated to dryness (200°C) and finally the dried mass was heated in a muffle furnace to get the product. The product was cooled and then ground well. The powder was examined by x-ray irradiation. Example - 2 Components LiOH 0.84 gm Co3O4 1.60gm Mn2O3 1.58gm Glycerol 5 ml Temperature 800°C Duration of heating 12 hrs Colour of the product black Efficiency of the product 94.5% Phase Single Single electrode potential of LiCoMnO4 w.r.t Li in 1M LiCIO4 3.01v In propylene carbonate. A standard procedure to measure the single electrode potential of the cathode. The following examples give the way of synthesizing LiCoMnO4 Example - 3 Components LiNO3 2.46gm Co(NO3)2 2.91 gm Mn(NO3)2 2.51 gm Citric acid & Glycerol mixture 8 ml Mixture 1:4 molar ratio Temperature 600°C Duration of heating lOhrs Colour of the product black Efficiency of the product 94% Phase Single Single electrode potential of LiCoMn04 w.r.t. in 1M LiCIO4 3.01v In propylene carbonate. Example - 4 Components LiNOa 2.46 gm Co(N03)2 2.91 gm Mn(N03)2 2.51 gm Citric acid & Glycerol Mixture 1:4 molar ratio 3 ml Temperature 200°C - 600°C Duration of heating lOhrs Colour of the product black Efficiency of the product 94% Phase Single Single electrode potential of LiCoMnO4 w.r.t. Li in 1M LiCIO4 3.0Iv In propylene carbonate. Similar procedure was followed by example 2 to 4 as described for example 1. Advantages 1. An uniform homogeneous mixture of the reacting components viz., oxides of cobalt, manganese with lithium hydroxide were made into a paste to get a product of high purity. 2. glycerol was used as a solvent for binding the oxides viz., oxides of cobalt, manganese with lithium hydroxide for making a paste of required consistency. The addition of glycerol enhanced the product of fine particles. 3. The excess addition of glycerol (solvent) as a binding material for the oxides does not change the color or quality of the end product. 4. Since pure oxides are used un fine form and homogenously prepared paste was obtained and the calcinations of the compound leaves all the reactants to react uniformly to get fine resultant product without leaving any unreacted initial components. We claim : 1. A process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells which comprises heating a paste prepared by mixing lithium cobalt and managanese sources such as herein described in the ratio of 1:1:1 respectively in glycerol at a temperature upto 800°C for a maximum period upto 12 hrs., cooling the product obtained above to get lithium cobalt manganate (LiCoMnO4). 2. A process as claimed in claim 1 wherein the source of Li used is selected from Li NO3 or LiOH. 3. A process as claimed in claims 1-2 wherein the source of Co is selected from Co(NO3)2 or Co3O4. 4. A process as claimed in claims 1-3 wherein the heating is carried out at a temperature in the range of 200 to 600°C preferably. 5. A process for the synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion cells substantially as herein described with reference to the examples and drawing accompanying the specification.

Full Text

The present invention relates to a process for the synthesis of lithium cobalt manganate
useful as battery cathode material for lithium ion cells, This invention particularly relates
to a process of preparation of LiCoMnO4 as composite for rocking chair lithium ion cells
based on solid polymer electrolytes, non aqueous systems and solid state materials.
This invention more particularly relates to the preparation of lithium cobalt manganate
(LiCoMnO4) a composite, which is very useful for high voltage lithium cells and can be
prepared by chemical combustion method.
Preparation of spinel LiCoMnO4 compound is known from the recent literature cited in
1998 as a battery cathode for high voltage lithium cells. This compound can be prepared
by mixing LiCO3, CoO and MnCO3 together and fired in air initially at 650°C for 24
hours and then at 800°C for 3 days with intermittent regrinding and finally at 600°C for 3
days before quenching to room temperature [H.Kawai, M.Nagata, and A.R. West,
Electrochem, Solid state Letters, 1(1998)212].
As available in literasture LiCoxMn2x04 can be alternatively prepared from MnCo3,
CoC2O4 and Li2CO3. The powders were ground heated in air to 750°C in three 24 hrs
cycles, followed by cooling at 2°C per minutes to room temperature. [P.Aitchison,
D.J.Jones, G.Burns and J.Roziere, J.Mater.Chem., 9(1999)3125].
In the above mentioned methods any one of the following disadvantages are observed.
1. Phase purity
2. Intermitent heating
3. Long time heating etc.
The main novel object of the present invention is to provide a novel process for the
synthesis of lithium cobalt manganate useful as battery cathode material for lithium ion
cells which obviates the drawbacks of the known methods.
Further object of the invention, the cyclability of the system is retained by keeping Co in
the compound.
Still another object is to use glycerol as binding agent to make a uniform homogeneous
mixing which inhibit the decomposition of the product in situ.
Yet still another object of the invention is to prepare LiCoMnO4 using hydroxides and
oxides.
Accordingly, the present invention relates to a process for the synthesis of lithium cobalt
manganate useful as battery cathode material for lithium ion cells which comprises
heating a paste prepared by mixing lithium cobalt and managanese sources such as herein
described in the ratio of 1:1:1 respectively in glycerol at a temperature upto 800°C for a
maximum period upto 12 hrs., cooling the product obtained above to get lithium cobalt
manganate (LiCoMnO4).
In an embodiment of the invention the source of lithium may be selected from LiNO3,
LiOH.
In another embodiment the source of Co may be selected from Co(NC3)2 and Co3OH.
The source of manganese may be selected from Mn(NO3)2 or MnO3
In yet another embodiment of the invention the molar ratio of LiNO3, Co(NO3)i and
Mn(NC3)2 may be 1:1:1 respectively.
In still another embodiment of the invention the molar ratio of LiOH Co3O4 and Mn2O3
may be 1:1:1, respectively.
The paste of Li, Co & Mn source may be prepared by adding glycerol optionally in
presence of citric acid urea, ammonium nitrite, formamide, succinic acid, ammonium
formate, sugar or glucose as binding agent.
In a feature of the invention heating may be carried at a temperature in the range of 200
to 600°C when nitrates are used for preparing the paste.
In another feature of the invention heating may be carried out a temperature in the range
of 200-800°C when LiOH, CoaO4, Mn2O3 are used to prepare the paste.
The present invention, describes the method of synthesis of the cathode material for a
secondary battery, by heating a paste prepared by mixing fine particles of LiOH, CO304
and Mn203 made in glycerol. This paste was initially heated slowly in a furnace to
evaporate off glycerol in order to get a dried mass at 150-250°C. This dried mass was
then continuously heated to 800°C for 12 hours. The product formed was slowly cooled
to room temperature and was ground well and then examined for its particles size, colour
and XRD exposure. It was found that the prepared sample was black in coloured and was
homogeneous. X-ray analysis confirmed the formation of LiCoMnO4 according to Fig.l.
The novelty of this invention is that the binding agent glycerol does not permit side
reactions or partial reactions.
The binding agent does not influence the quality of particle size or color of the product.
The following examples are given by way of illustration and should not construed the
scope of the invention.
The following examples illustration the synthesis of LiCoMnO4 cathode material by solid
state reaction.
Example-1
Components
LioH 0.84 gm
Co3O4 1.60gm
Mn2O3 1.58gm
Glycerol 5 ml
Temperature 800°C
Duration of heating 12 hrs
Colour of the product black
Efficiency of the product 94.5%
Phase Single
Single electrode potential of
LiCoMnO4 w.r.t. Li in 1M LiCIO4 in 3.01 v
Propylene carbonate.
A standard procedure to measure the single electrode potential of the cathode.
Li(NO3)2, Co(NOs)2 and Mn (NOs^ salts taken in the molar ratio of 1:1:1 and were
mixed together. Some of the salts are hydroscopic and hence a solution
of formed. In this solution added 5 ml. Of glycerol. The new solution was slowly
evaporated to dryness (200°C) and finally the dried mass was heated in a muffle
furnace to get the product. The product was cooled and then ground well. The
powder was examined by x-ray irradiation.
Example - 2
Components
LiOH 0.84 gm
Co3O4 1.60gm
Mn2O3 1.58gm
Glycerol 5 ml
Temperature 800°C
Duration of heating 12 hrs
Colour of the product black
Efficiency of the product 94.5%
Phase Single
Single electrode potential of
LiCoMnO4 w.r.t Li in 1M LiCIO4 3.01v
In propylene carbonate.
A standard procedure to measure the single electrode potential of the cathode.
The following examples give the way of synthesizing LiCoMnO4 Example - 3 Components
LiNO3 2.46gm
Co(NO3)2 2.91 gm
Mn(NO3)2 2.51 gm
Citric acid & Glycerol mixture 8 ml
Mixture 1:4 molar ratio
Temperature 600°C
Duration of heating lOhrs
Colour of the product black
Efficiency of the product 94%
Phase Single
Single electrode potential of
LiCoMn04 w.r.t. in 1M LiCIO4 3.01v
In propylene carbonate.
Example - 4 Components
LiNOa 2.46 gm
Co(N03)2 2.91 gm
Mn(N03)2 2.51 gm
Citric acid & Glycerol
Mixture 1:4 molar ratio 3 ml

Temperature 200°C - 600°C
Duration of heating lOhrs
Colour of the product black
Efficiency of the product 94%
Phase Single
Single electrode potential of
LiCoMnO4 w.r.t. Li in 1M LiCIO4 3.0Iv
In propylene carbonate.
Similar procedure was followed by example 2 to 4 as described for example 1.
Advantages
1. An uniform homogeneous mixture of the reacting components viz., oxides of
cobalt, manganese with lithium hydroxide were made into a paste to get a
product of high purity.
2. glycerol was used as a solvent for binding the oxides viz., oxides of cobalt,
manganese with lithium hydroxide for making a paste of required consistency.
The addition of glycerol enhanced the product of fine particles.
3. The excess addition of glycerol (solvent) as a binding material for the oxides
does not change the color or quality of the end product.
4. Since pure oxides are used un fine form and homogenously prepared paste
was obtained and the calcinations of the compound leaves all the reactants to
react uniformly to get fine resultant product without leaving any unreacted
initial components.

We claim :
1. A process for the synthesis of lithium cobalt manganate useful as battery
cathode material for lithium ion cells which comprises heating a paste
prepared by mixing lithium cobalt and managanese sources such as herein
described in the ratio of 1:1:1 respectively in glycerol at a temperature upto
800°C for a maximum period upto 12 hrs., cooling the product obtained above
to get lithium cobalt manganate (LiCoMnO4).
2. A process as claimed in claim 1 wherein the source of Li used is selected from
Li NO3 or LiOH.
3. A process as claimed in claims 1-2 wherein the source of Co is selected from
Co(NO3)2 or Co3O4.
4. A process as claimed in claims 1-3 wherein the heating is carried out at a
temperature in the range of 200 to 600°C preferably.
5. A process for the synthesis of lithium cobalt manganate useful as battery
cathode material for lithium ion cells substantially as herein described with
reference to the examples and drawing accompanying the specification.

Documents:

395-del-2001-abstract.pdf

395-del-2001-claims.pdf

395-del-2001-correspondence-others.tif.pdf

395-del-2001-correspondence-po.tif.pdf

395-del-2001-description (complete).pdf

395-del-2001-form-1.tif.pdf

395-del-2001-form-18.tif.pdf

395-del-2001-form-2.tif.pdf

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Patent Number

231694

Indian Patent Application Number

395/DEL/2001

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

08-Mar-2009

Date of Filing

29-Mar-2001

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	ANGAIAH SUBRAMANIAN	INDUSTRIAL CHEMISTRY, ALAGAPPA UNIVERSITY, KARAIKUDI-630 003, TAMILNADU, INDIA.
2	ARIYANAN MANI	CENTRAL ELECTRO-CHEMICAL RESEARCH INSTITUTE, KARAIKUDI-630 003, TAMILNADU, INDIA.
3	THIAGARAJAN VASUDEVAN	INDUSTRIAL CHEMISTRY, ALAGAPPA, UNIVERSITY, KARAIKUDI-630 003, TAMILANDU, INDIA.
4	RAMAIYER GANGADHARAN	INDUSTRIAL CHEMISTRY, ALAGAPPA, UNIVERSITY, KARAIKUDI-630 003, TAMILANDU, INDIA.

PCT International Classification Number

H01M 4/50

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA