Title of Invention	A THERMAL PROCESS FOR THE PREPARATION OF LITHIUM COBALT NICKELETE (LI CO 0.5 NI0.5O2) USEFUL AS CATHODE MATERIAL FOR LITHIUM CELLS
Abstract	The present invention relates to a thermal process for the preparation of LiCoo.5Ni0.5O2 useful as cathode material for reversible lithium ion cells. The lithium cobalt nickelete is a composite which is very useful for high voltage lithium reversible cells and can be prepared by mixing oxides of cobalt, nickel with lithium hydroxide by heating together all in solid state condition. LiCoo.5Ni0.5O2 is a reversible cathode material useful for high voltage cells of lithium in non-aqueous solid state and polymer based cells. A novel method of preparing this compound viz, LiCoo.5Ni0.5O2 was carried out by uniform mixing of oxides of Co and Ni with LiOH and this mixture was made into a paste by adding necessary quantity of glycerol and the paste was calcined at 750°C continuously for 12 hours in a furnace.

Title of Invention

A THERMAL PROCESS FOR THE PREPARATION OF LITHIUM COBALT NICKELETE (LI CO 0.5 NI0.5O2) USEFUL AS CATHODE MATERIAL FOR LITHIUM CELLS

Abstract

The present invention relates to a thermal process for the preparation of LiCoo.5Ni0.5O2 useful as cathode material for reversible lithium ion cells. The lithium cobalt nickelete is a composite which is very useful for high voltage lithium reversible cells and can be prepared by mixing oxides of cobalt, nickel with lithium hydroxide by heating together all in solid state condition. LiCoo.5Ni0.5O2 is a reversible cathode material useful for high voltage cells of lithium in non-aqueous solid state and polymer based cells. A novel method of preparing this compound viz, LiCoo.5Ni0.5O2 was carried out by uniform mixing of oxides of Co and Ni with LiOH and this mixture was made into a paste by adding necessary quantity of glycerol and the paste was calcined at 750°C continuously for 12 hours in a furnace.

Full Text	The present invention relates to the novel process for the preparation of lithium cobalt nickelate usgal as a battery cathode material for lithium cells. The present invention relates to the preparation of lithium cobalt nickelate (LiCoo.5 Ni0.5O2) a composite, which is very useful for high voltage lithium revesible cells and can be prepared by mixing oxides of cobalt, nickel with lithium hydroxide by heating together all in solid state condition. LiCoo.5 Ni0.5O2 is a reversible cathode material useful for high voltage cells of lithium in non-aqueous ,solid state and polymer basedcells. LiCoo.5 Ni0.5O2 compound is hexagonal material is well known from 1992 as a good battery cathode for reversibility in non-aqueous solutions. This compound can be prepared by heating the oxides, hydroide of Ni, Co & carbonate of lithium for long duration (>24 hrs) and high temperature calcination (>800°C) [C. Delmes and I.Saadoune, Solid State Ionics, 66 (1993) 143]. This compound can be alternatively obtained by a sol-gel method in which stoichiometric quantities of Li, Ni & Co nitrate salts were dissolved in aqueous solutions. This solutions was mixded with already prepared aqueous solution of PPA of known proportions. The resulting mixture was heated to dryness and calcinated to 800°C for an hour to obtain the product. [Yang -Kook Sun, In - Hwan oh and kwang Yul kirn, J. Mater, Chem., 7(1997) 1481]. In the recent years a precipitation method was developed for the preparation of LiCoo.5 Ni0.5O2 compound from Ni(N03)2 & Co(No3)2 solution . The above solution was treated with NaOH to precipitate hydroxides of Co & nickel and then the hydroxides were filtered .washed and dried and then mixed with Li2C03 and calcined to 800°C for 48 hours to get the battery cathode product. [Izumi Nakai and Tatsuji Nakagome, Electochemical and solid state batters 1(1998)259]. Two simple methods were developed by Jaephil Cho et al recently, to prepare Lithium nickel cobaltate from the hydroxides of Li, Co & Ni by combustion procedures. [Jaephil Cho, G. Kim and H.S. Lim, J. ElectroChem. Soc., 146(1999)3571]. In all the above procedures available in the literature some disadvantages were observed. They are as follows : 1. Phase impurity 2. Longer duration of thermal preparation 3. High temperature of operation 4. pH control 5. Several steps of preparation A novel method of preparing this compound viz, LiCoo.5 Ni0.5O2 was carried out by uniform mixing of oxides of Co and Ni with LiOH and this mixture was made into a paste by adding necessary quantity of glycerol and the paste was calcined at 750°C continuously for 12 hours in a furnace. The prepared product was subjected to x-ray analysis. The product was found to be in single phase. The present invention, describes the method of synthesis of cathode material for a secondary battery, by heating a paste prepared by mixing fine particles of LiOH, Co304 and NiO in glycerol. This paste was initially heated slowly in a furnace to evaporate off glycerol in order to get a dried mass at 250°C. This compound 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 colour and was homogenous. X-rays analysis confirmed the formation of LiCoo.5 Ni0.5O2 according to Fig 1. The main object of the present invention is to formulate a new procedure for the syntheis of LiCoo.5 Ni0.5O2 cathode material for reversible lithium ion cells which obviates the draw backs of the known methods. Another object of this invention is to synthesis LiCoo.5 Ni0.5O2 under suitable solid state reaction method which obviates the defects and draw backs hither to known in other methods of preparation of this compound from already known procedures in literatures. Further, the object of this invention is to increase tthe cyclability of this material when used as cathode in which Co is used as one of the components in the compound whose presence has important bearing in the reversibililty of the electrode. Still another objective is to use glycerol as a binding agent to make a uniform homogeneous mixture which permits uniform reaction to occur without any side reaction. Yet another object of this invention is to prepare LiCoo.5 Ni0.5O2 with Li OH and oxides of Ni & Co. Accordingly the present invention relates to a thermal process for the preparation of lithium cobalt nickelete (LiCoo.5 Ni0.5O2) useful as cathode material for lithium cells which comprises: preparing a paste by mixing lithium hydroxide, nickel oxide and cobalt oxide in molar ratio of 1:1/2:1/2 respectively in glycerol, heating the above said paste upto 800°C for a maximum period of 12hr, cooling the product to get lithium cobalt nickelete. In a feature of this invention glycerol used as a binder with LiOH and oxides to assist the reaction to proceed verify without undergoing side reaction. In another embodiment of this invention the temperature of the preparation ranges from 600°C to 800°C. The thermal procedure for the synthesis of LiCoo.5 Ni0.5O2 cathode material for reversible lithium ion cells which comprises a mixture taken in the molar ratio as follows. The mixture containing to this nickel and cobalt is in the molar ratio 1/2, 1/2, initially the mixture was ground well so as to obtain fine particles. This mixture was mixed well with glycerol so as to get a fine paste. This paste was taken in a crucible was heated initially to 200°C and was then heated strongly to 800°C to get the reactant material. This product was confirmed to its purity and identity by x-ray analysis. The following examples are given by way of illustration and should not be construed the scope of this invention. Example-1 Components and parameters LiOH 0.839 gm NiO 0.747 gm Co304 0.802 gm Binder (Glycerol) 2 ml Temperature 200°C-800°C Duration of heating 12 hrs. Colour of the product Black Efficiency of the product 90% Phase . Single Single electrode potential of hiC00.5Nio.502 w.r.t. LiinlMLiCI04 3.01V in propylene carbonate. Oxides of Ni & Co were mixed with hydroxides of lithium in molar proportions and were groundeed well in a crucible with a pestle and motar arrangement. The ground powder was mixed with glycerol till a paste was formed during mixing. The paste was transferred into a crucible and was heated in muffle furnace initially at 200°C and finally the temperature was raised to 800°C. The product was heated to the same temperature for 12 hours. The product was cooled well and ground to fine powder. The powder was examined by x-ray for its identify.Standard procedure is followed to measure the single electrode potential of the cathode. Example-2 Components and parameters LiOH 0.839 gm NiO 0.747 gm Co304 0.802 gm Flux (urea) 2.402 gm Binder (Glycerol) 3 ml Temperature 250°C-800°C Duration of heating 12 hrs. Colour of the product Black Efficiency of the product 90% Phase Single Single electrode potential of hiCo.5Ni0.5O2 .w.r.t. LiinlMLiCI04 3.01V in propylene carbonate. Method used for preparation of lithium cobalt nicklete is same as given in example 1. Standard procedure is followed to measure the single electrode potential of the cathode. This process gives pure product and leaves behind no unracted components as evidenced by X- ray analysis . This is due to the binder glycerole which controls the reaction uniformly. This process dose not involve any obnoxious gas formation unlike other methods. We claim: 1. A thermal process for the preparation of lithium cobalt nickelete (LiCoo.5 Nio.5O2) useful as cathode material for lithium cells which comprises: preparing a paste by mixing lithium hydroxide, nickel oxide and cobalt oxide in molar ratio of 1:1/2:1/2 respectively in glycerol, heating the above said paste upto 800°C for a maximum period of 12hr, cooling the product to get lithium cobalt nickelete. 2. A process as claimed in claim 1 wherein the fine particles of the reactants LiOH, Co3O4 and NiO were bound by glycerol and made the mixture into a paste for uniform reaction during heating. 3. A process as claimed in claims 1-2, wherein all the reactants react uniformly leaving no un-reacted initial reactant components. 4. A process as claimed in claims 1-3, wherein all the reactants are heated slowly at 200°C to get dried mass and finally heated at a temperature 600 to 800°C for a period of 10 to 12hr. 5. A thermal process for the preparation of(LiCoo.5 O2) useful as cathode material for reversible lithium ion cells substantially as herein described with reference to the examples and drawing accompany the specification.

Full Text

The present invention relates to the novel process for the preparation of
lithium cobalt nickelate usgal as a battery cathode material for lithium cells.
The present invention relates to the preparation of lithium cobalt nickelate (LiCoo.5 Ni0.5O2) a composite, which is very useful for high voltage lithium revesible cells and can be prepared by mixing oxides of cobalt, nickel with lithium hydroxide by heating together all in solid state condition. LiCoo.5 Ni0.5O2 is a reversible cathode material useful for high voltage cells of lithium in non-aqueous ,solid state and polymer basedcells.
LiCoo.5 Ni0.5O2 compound is hexagonal material is well known from 1992 as a good battery cathode for reversibility in non-aqueous solutions. This compound can be prepared by heating the oxides, hydroide of Ni, Co & carbonate of lithium for long duration (>24 hrs) and high temperature calcination (>800°C) [C. Delmes and I.Saadoune, Solid State Ionics, 66 (1993) 143].
This compound can be alternatively obtained by a sol-gel method in which stoichiometric quantities of Li, Ni & Co nitrate salts were dissolved in aqueous solutions. This solutions was mixded with already prepared aqueous solution of PPA of known proportions. The resulting mixture was heated to dryness and calcinated to 800°C for an hour to obtain the product. [Yang -Kook Sun, In - Hwan oh and kwang Yul kirn, J. Mater, Chem., 7(1997) 1481].
In the recent years a precipitation method was developed for the preparation of LiCoo.5 Ni0.5O2 compound from Ni(N03)2 & Co(No3)2 solution . The above solution was treated with NaOH to precipitate hydroxides of Co & nickel and then the hydroxides were filtered .washed and dried and then mixed with

Li2C03 and calcined to 800°C for 48 hours to get the battery cathode product. [Izumi Nakai and Tatsuji Nakagome, Electochemical and solid state batters 1(1998)259].
Two simple methods were developed by Jaephil Cho et al recently, to prepare Lithium nickel cobaltate from the hydroxides of Li, Co & Ni by combustion procedures. [Jaephil Cho, G. Kim and H.S. Lim, J. ElectroChem. Soc., 146(1999)3571].
In all the above procedures available in the literature some disadvantages were observed. They are as follows :
1. Phase impurity
2. Longer duration of thermal preparation
3. High temperature of operation
4. pH control
5. Several steps of preparation
A novel method of preparing this compound viz, LiCoo.5 Ni0.5O2 was carried out by uniform mixing of oxides of Co and Ni with LiOH and this mixture was made into a paste by adding necessary quantity of glycerol and the paste was calcined at 750°C continuously for 12 hours in a furnace. The prepared product was subjected to x-ray analysis. The product was found to be in single phase.
The present invention, describes the method of synthesis of cathode material for a secondary battery, by heating a paste prepared by mixing fine

particles of LiOH, Co304 and NiO in glycerol. This paste was initially heated slowly in a furnace to evaporate off glycerol in order to get a dried mass at 250°C. This compound 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 colour and was homogenous. X-rays analysis confirmed the formation of LiCoo.5 Ni0.5O2 according to Fig 1.
The main object of the present invention is to formulate a new procedure for the syntheis of LiCoo.5 Ni0.5O2 cathode material for reversible lithium ion cells which obviates the draw backs of the known methods.
Another object of this invention is to synthesis LiCoo.5 Ni0.5O2 under suitable solid state reaction method which obviates the defects and draw backs hither to known in other methods of preparation of this compound from already known procedures in literatures.
Further, the object of this invention is to increase tthe cyclability of this material when used as cathode in which Co is used as one of the components in the compound whose presence has important bearing in the reversibililty of the electrode.
Still another objective is to use glycerol as a binding agent to make a uniform homogeneous mixture which permits uniform reaction to occur without any side reaction.
Yet another object of this invention is to prepare LiCoo.5 Ni0.5O2 with Li OH and oxides of Ni & Co.

Accordingly the present invention relates to a thermal process for the preparation of lithium cobalt nickelete (LiCoo.5 Ni0.5O2) useful as cathode material for lithium cells which comprises: preparing a paste by mixing lithium hydroxide, nickel oxide and cobalt oxide in molar ratio of 1:1/2:1/2 respectively in glycerol, heating the above said paste upto 800°C for a maximum period of 12hr, cooling the product to get lithium cobalt nickelete.
In a feature of this invention glycerol used as a binder with LiOH and oxides to assist the reaction to proceed verify without undergoing side reaction.
In another embodiment of this invention the temperature of the preparation ranges from 600°C to 800°C.
The thermal procedure for the synthesis of LiCoo.5 Ni0.5O2 cathode material for reversible lithium ion cells which comprises a mixture taken in the molar ratio as follows. The mixture containing to this nickel and cobalt is in the molar ratio 1/2, 1/2, initially the mixture was ground well so as to obtain fine particles. This mixture was mixed well with glycerol so as to get a fine paste. This paste was taken in a crucible was heated initially to 200°C and was then heated strongly to 800°C to get the reactant material. This product was confirmed to its purity and identity by x-ray analysis.
The following examples are given by way of illustration and should not be construed the scope of this invention.
Example-1
Components and parameters
LiOH 0.839 gm
NiO 0.747 gm
Co304 0.802 gm
Binder (Glycerol) 2 ml
Temperature 200°C-800°C
Duration of heating 12 hrs.
Colour of the product Black
Efficiency of the product 90%
Phase . Single
Single electrode potential of hiC00.5Nio.502
w.r.t. LiinlMLiCI04 3.01V
in propylene carbonate.
Oxides of Ni & Co were mixed with hydroxides of lithium in molar proportions and were groundeed well in a crucible with a pestle and motar arrangement. The ground powder was mixed with glycerol till a paste was formed during mixing. The paste was transferred into a crucible and was heated in muffle furnace initially at 200°C and finally the temperature was raised to 800°C. The product was heated to the same temperature for 12 hours. The product was cooled well and ground to fine powder. The powder was examined by x-ray for its identify.Standard procedure is followed to measure the single electrode potential of the cathode.
Example-2
Components and parameters
LiOH 0.839 gm
NiO 0.747 gm
Co304 0.802 gm
Flux (urea) 2.402 gm
Binder (Glycerol) 3 ml
Temperature 250°C-800°C
Duration of heating 12 hrs.
Colour of the product Black
Efficiency of the product 90%
Phase Single
Single electrode potential of hiCo.5Ni0.5O2
.w.r.t. LiinlMLiCI04 3.01V
in propylene carbonate.
Method used for preparation of lithium cobalt nicklete is same as given in example 1. Standard procedure is followed to measure the single electrode potential of the cathode.
This process gives pure product and leaves behind no unracted components as evidenced by X- ray analysis . This is due to the binder glycerole which controls the reaction uniformly. This process dose not involve any obnoxious gas formation unlike other methods.

We claim:
1. A thermal process for the preparation of lithium cobalt nickelete (LiCoo.5 Nio.5O2)
useful as cathode material for lithium cells which comprises: preparing a paste by
mixing lithium hydroxide, nickel oxide and cobalt oxide in molar ratio of
1:1/2:1/2 respectively in glycerol, heating the above said paste upto 800°C for a
maximum period of 12hr, cooling the product to get lithium cobalt nickelete.
2. A process as claimed in claim 1 wherein the fine particles of the reactants LiOH,
Co3O4 and NiO were bound by glycerol and made the mixture into a paste for
uniform reaction during heating.
3. A process as claimed in claims 1-2, wherein all the reactants react uniformly
leaving no un-reacted initial reactant components.
4. A process as claimed in claims 1-3, wherein all the reactants are heated slowly at
200°C to get dried mass and finally heated at a temperature 600 to 800°C for a
period of 10 to 12hr.
5. A thermal process for the preparation of(LiCoo.5 O2) useful as cathode material for
reversible lithium ion cells substantially as herein described with reference to the
examples and drawing accompany the specification.

Documents:

526-del-2001-abstract.pdf

526-del-2001-claims.pdf

526-del-2001-correspondence-others.pdf

526-del-2001-correspondence-po.pdf

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

526-del-2001-drawings.pdf

526-del-2001-form-1.pdf

526-del-2001-form-18.pdf

526-del-2001-form-2.pdf

526-del-2001-form-3.pdf

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Patent Number

231696

Indian Patent Application Number

526/DEL/2001

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

08-Mar-2009

Date of Filing

26-Apr-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 630003. TAMILNADU, INDIA.
2	ARIYANAN MANI	CENTRAL ELECTRO-CHEMICAL RESEARCH INSTITUTE, KARAIKUDI 630006, TAMILNADU, INDIA.
3	THIAGARAJAN VASUDEVAN	INDUSTRIAL CHEMISTRY, ALAGAPPA UNIVERSITY, KARAKUDI 630003, TAMILNADU, INDIA.
4	RAMAIYER GANGDHARAN,	INDUSTRIAL CHEMISTRY, ALAGAPPA UNIVERSITY, KARAKUDI 630003, TAMILNADU, INDIA.

PCT International Classification Number

H01M 4/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA