Indian Patents. 259532:"AN IMPROVED PROCESS FOR THE SYNTHESIS OF LITHIUM COBALT BORATE USEFUL AS CATHODE MATERIAL FOR REVERSIBLE LITHIUM ION CELLS"

Title of Invention	"AN IMPROVED PROCESS FOR THE SYNTHESIS OF LITHIUM COBALT BORATE USEFUL AS CATHODE MATERIAL FOR REVERSIBLE LITHIUM ION CELLS"
Abstract	A process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells by preparing a paste by mixing lithium source with oxides of boron & cobalt in a ratio 1:0.5:0.5 respectively, heating the paste prepared above at a temperature upto 800°C for a period upto 12 hours, followed by cooling to give lithium cobalt borate (LiCo0.5B0.5O2).

Full Text	This invention relates to an improved process for preparation of lithium cobalt borate by thermal method which is a useful cathode material for secondary nonaqueous solid-state & polymer electrolyte cells This invention particularly relates to the preparation of lithium cobalt borate (L1CO0. 5 Bo0 5 O2) a composite, which is very useful for high voltage lithium reversible cells and can be prepared by mixing oxides of cobalt, boron with lithium carbonate / LiOH by heating together all in solid state condition, (L1CO0. 5 N1o0 5 O2) is a reversible cathode material useful for high voltage cells of lithium in non-aqueous media L1C01 y ByO2 compound is hexagonal material is well known from 2000 as a good battery cathode for reversibility in non-aqueous solutions This compound can be prepared by heating LiOH with CoO / C03O4 & B for long duration (>24 hrs) and high temperature calcinations (>750°C) under flow of oxygen [Solid State Ionics Devices, Edited by S Selladurai et al p 159-168,2000] This product can be used as a cathode material for secondary nonaqueous, solid state & polymer electrolyte cells In the above procedure available in the literature some disadvantages were observed They are as follows - 1 Phase purity and particle size 2 Longer duration of thermal preparation 3 High temperature of operation The main object of this invention is to synthesize (L1CO0. 5 Bo0 5 O2) 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 Another object of this present invention is to formulate a new procedure for the synthesis of an improved process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells which obviates the draw backs of the known methods Further object of this invention is the cyclabihty of the system by retaining cobalt with the cathode material and replacing partially by boron Still another object is to use glycerol as a binding agent to make as uniform homogeneous mixture which permits uniform reaction to occur without any side reaction Yet another object of this invention is to prepare L1C01/2 B1/2 B1/2 02 with oxides and carbonate of the components present in the product Accordingly, the present invention provides a process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells which comprises preparing a paste by mixing lithium source with oxides of boron & cobalt in a ratio 10 5 0 5 respectively, heating the paste prepared above at a temperature upto 800°C for a period upto 12 hours, followed by cooling to give lithium cobalt borate (LiCo0 5B0 5O2) In the embodiment of the invention glycerol is used as a binding agent for making paste In another embodiment of the invention heating may be affected at a temperature in the range of 200-750°C Lithium source may be selected from LiOHLiCO3 A novel method of preparing this compound viz , L1C00.5 Bo 5 O4 was carried out by uniform mixing of oxides of Co and B 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 hrs 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, but heating a paste prepared by mixing fine particles of LiOH / L12CO3, C03O4 and B2O3 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 dried mass was then continuously heated to 750°C for 12 hrs The 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-ray analysis confirmed for formation of L1C00 5 Bo 5 O2 according to Fig 1 1 L1B02 is being synthesized by a solid state reaction which as a new technique 2 The product obtained is pure which is evidenced from the x-ray details 3 The product does not undergo any side reactions or partial reaction is again evidenced from x-ray analysis 4 This is a simple step process which does not need any purification as pure components of the reactants ensure product of high purity The following examples are given by the way of illustration and should not be construed the scope of this invention Example - 1 Oxides of boron, cobalt and carbonate of lithium were ground well in to a paste form with pestle & mortar arrangement in glycerol The paste was carefully removed to a ceramic / silica crucible & was slowly heated initially to 300°C till the paste becomes dry & was findally heated to 800°C for 12 hours The reactant was slowly cooled to ambient temperature and was examined for confirmation of the product by x-ray analysis Components LiOH 0 84 gm B203 0 355 gm C03O4 0 80 gm Binder (Glycerol) 2 ml Temperature 200°C - 800°C Duration of heating 12 hrs Colour of the product Deep yellow Efficiency of the product > 95 % Phase Single Single electrode potential of L1C00 5B0 502 w r t in 1M L1CIO4 3 00 v In propylene carbonate Example - 2 Components LiOH 0 84 gm B203 0 355 gm C03O4 0 80 gm Binder (Glycerol) 4 ml Temperature 300°C - 800°C Duration of heating 12 hrs Colour of the product Deep yellow Efficiency of the product > 95 % Phase Single Single electrode potential of L1C00 5B0 5O2 w r t in 1M L1CIO4 3 00 v In propylene carbonate The following advantages are claimed in this invention for the preparation of lithium cobalt borate 1 An uniform homogenous mixture of the regarding compounds viz , oxides of cobalt and boron with L12C03 / LiOH were made into a paste to get a product of high purity 2 Glycerol was used as a solvent for biding the oxides viz , cobalt and boron with L12C03 / LiOH for making a paste of required consistency The addition of glycerol enhanced the product of fine particles 3 The addition of glycerol (solvent) as a binding material for oxides does not affect the quality of the end product We claim : 1. A process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells which comprises preparing a paste by mixing lithium source with oxides of boron & cobalt in a ratio 1:0.5:0.5 respectively, heating the paste prepared above at a temperature upto 800°C for a period upto 12 hours, followed by cooling to give lithium cobalt borate (LiCo0.5B0.5O2). 2. A process as claimed in claim 1 where the oxides of boron & cobalt are mixed with lithium source selected from carbonate of lithium and LiOH. 3. A process as claimed in claims 1-2 wherein a cathode in the product used as secondary lithium cells (in solid state, nonaqueous & polymer electrolyte cells). 4. A process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells substantially as herein desribed with reference to the examples and drawing accompanying the specification.

Full Text

This invention relates to an improved process for preparation of lithium cobalt borate by thermal method which is a useful cathode material for secondary nonaqueous solid-state & polymer electrolyte cells
This invention particularly relates to the preparation of lithium cobalt borate (L1CO0. 5 Bo0 5 O2) a composite, which is very useful for high voltage lithium reversible cells and can be prepared by mixing oxides of cobalt, boron with lithium carbonate / LiOH by heating together all in solid state condition, (L1CO0. 5 N1o0 5 O2) is a reversible cathode material useful for high voltage cells of lithium in non-aqueous media
L1C01 y ByO2 compound is hexagonal material is well known from 2000 as a good battery cathode for reversibility in non-aqueous solutions This compound can be prepared by heating LiOH with CoO / C03O4 & B for long duration (>24 hrs) and high temperature calcinations (>750°C) under flow of oxygen [Solid State Ionics Devices, Edited by S Selladurai et al p 159-168,2000] This product can be used as a cathode material for secondary nonaqueous, solid state & polymer electrolyte cells
In the above procedure available in the literature some disadvantages were observed They are as follows -
1 Phase purity and particle size
2 Longer duration of thermal preparation
3 High temperature of operation
The main object of this invention is to synthesize (L1CO0. 5 Bo0 5 O2) 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
Another object of this present invention is to formulate a new procedure for the
synthesis of an improved process for the synthesis of lithium cobalt borate useful as
cathode material for reversible lithium ion cells which obviates the draw backs of the
known methods
Further object of this invention is the cyclabihty of the system by retaining cobalt
with the cathode material and replacing partially by boron
Still another object is to use glycerol as a binding agent to make as uniform
homogeneous mixture which permits uniform reaction to occur without any side
reaction
Yet another object of this invention is to prepare L1C01/2 B1/2 B1/2 02 with oxides and
carbonate of the components present in the product
Accordingly, the present invention provides a process for the synthesis of lithium
cobalt borate useful as cathode material for reversible lithium ion cells which
comprises preparing a paste by mixing lithium source with oxides of boron & cobalt
in a ratio 10 5 0 5 respectively, heating the paste prepared above at a temperature
upto 800°C for a period upto 12 hours, followed by cooling to give lithium cobalt
borate (LiCo0 5B0 5O2)
In the embodiment of the invention glycerol is used as a binding agent for making
paste
In another embodiment of the invention heating may be affected at a temperature in the range of 200-750°C
Lithium source may be selected from LiOHLiCO3
A novel method of preparing this compound viz , L1C00.5 Bo 5 O4 was carried out by uniform mixing of oxides of Co and B 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 hrs 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, but heating a paste prepared by mixing fine particles of LiOH / L12CO3, C03O4 and B2O3 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 dried mass was then continuously heated to 750°C for 12 hrs The 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-ray analysis confirmed for formation of L1C00 5 Bo 5 O2 according to Fig 1
1 L1B02 is being synthesized by a solid state reaction which as a new technique
2 The product obtained is pure which is evidenced from the x-ray details
3 The product does not undergo any side reactions or partial reaction is again evidenced from x-ray analysis
4 This is a simple step process which does not need any purification as pure components of the reactants ensure product of high purity
The following examples are given by the way of illustration and should not be construed the scope of this invention
Example - 1
Oxides of boron, cobalt and carbonate of lithium were ground well in to a paste form with pestle & mortar arrangement in glycerol The paste was carefully removed to a ceramic / silica crucible & was slowly heated initially to 300°C till the paste becomes dry & was findally heated to 800°C for 12 hours The reactant was slowly cooled to ambient temperature and was examined for confirmation of the product by x-ray analysis
Components
LiOH 0 84 gm
B203 0 355 gm
C03O4 0 80 gm
Binder (Glycerol) 2 ml
Temperature 200°C - 800°C
Duration of heating 12 hrs
Colour of the product Deep yellow
Efficiency of the product > 95 %
Phase Single
Single electrode potential of
L1C00 5B0 502 w r t in 1M L1CIO4 3 00 v
In propylene carbonate
Example - 2
Components
LiOH 0 84 gm
B203 0 355 gm
C03O4 0 80 gm
Binder (Glycerol) 4 ml
Temperature 300°C - 800°C
Duration of heating 12 hrs
Colour of the product Deep yellow
Efficiency of the product > 95 %
Phase Single
Single electrode potential of
L1C00 5B0 5O2 w r t in 1M L1CIO4 3 00 v
In propylene carbonate
The following advantages are claimed in this invention for the preparation of lithium cobalt borate
1 An uniform homogenous mixture of the regarding compounds viz , oxides of cobalt and boron with L12C03 / LiOH were made into a paste to get a product of high purity
2 Glycerol was used as a solvent for biding the oxides viz , cobalt and boron with L12C03 / LiOH for making a paste of required consistency The addition of glycerol enhanced the product of fine particles
3 The addition of glycerol (solvent) as a binding material for oxides does not affect the quality of the end product

We claim :
1. A process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells which comprises preparing a paste by mixing lithium source with oxides of boron & cobalt in a ratio 1:0.5:0.5 respectively, heating the paste prepared above at a temperature upto 800°C for a period upto 12 hours, followed by cooling to give lithium cobalt borate (LiCo0.5B0.5O2).
2. A process as claimed in claim 1 where the oxides of boron & cobalt are mixed with lithium source selected from carbonate of lithium and LiOH.
3. A process as claimed in claims 1-2 wherein a cathode in the product used as secondary lithium cells (in solid state, nonaqueous & polymer electrolyte cells).
4. A process for the synthesis of lithium cobalt borate useful as cathode material for reversible lithium ion cells substantially as herein desribed with reference to the examples and drawing accompanying the specification.

Documents:

530-del-2001-abstract.pdf

530-del-2001-claims.pdf

530-del-2001-complete specification (granted).pdf

530-del-2001-corresponence-others.pdf

530-del-2001-corresponence-po.pdf

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

530-del-2001-drawings.pdf

530-del-2001-form-1.pdf

530-del-2001-form-18.pdf

530-del-2001-form-2.pdf

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Patent Number

259532

Indian Patent Application Number

530/DEL/2001

PG Journal Number

12/2014

Publication Date

21-Mar-2014

Grant Date

15-Mar-2014

Date of Filing

26-Apr-2001

Name of Patentee

COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	ANGAIAH SUBRAMANIAM	INDUSTRIAL CHEMISTRY ALAGAPPA UNIVERSITY, KARAIKUDI 630 003, INDIA.
2	ARIYANAN MANI	SCIENTIST, CECRI, KARAIKUDI 630 006, INDIA.
3	THIAGARAJAN VASUDEVAN	ALAGAPPA UNIVERSITY, KARAIKUDI 630 003, INDIA.
4	RAMAIYER GANGADHARAN	ALAGAPPA UNIVERSITY, KARAIKUDI 630 003, INDIA.

PCT International Classification Number

C01B 35/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA