Title of Invention

"A PROCESS FOR THE SYNTHESIS OF LITHIUM NICKEL VENDATE(LiNIVO4) AS CATHODE MATERIAL FOR ROCKING CHAIR LITHIUM ION CELLS"

Abstract A process for the synthesis of lithium nickel vanadate (LiNiVO4) as cathode material for the rocking chair lithium ion cells A process for the synthesis of lithium nickel vanadate (LiNiV04) as cathode material for the rocking chair lithium ion cells by mixing, lithium oxide, nickel oxide, vanadium oxide in molar ratio 1:1:1, adding glycerol to the above mixture to get a paste, heating the above paste upto a temperature of 750°C for a maximum period of 12 hours and cooling to get lithium nickel vanadate.
Full Text The present invention relates to the novel process for the preparation of lithium nickel vanadate useful as a battery cathode material for lithium cells.
The present invention more particularly relates to the preparation of lithium nickel vanadate (LiNiV04) a composite, which is very useful for high voltage lithium cells, and can be prepared by mixing solid oxides of nickel, vanadium and lithium by solid state reaction. Nickel vanadate of lithium is useful as a positive electrode material for reversible rechargeable battery electrode for secondary cells based on lithium.
This invention more particularly relates to the preparation of lithium nickel vanadate a composite, which very useful for high voltage lithium cells and can be prepared by chemical combustion method.
Studies on the inverse spinel LiNiO4 was began from 1994 onwards. It was already established that this spinel compound was able to intercalate / deintercalate in a non-aqueous medium when used as an electrode in a lithium battery. This compound was prepared by heating LiNiO2 with vanadium trioxide V2O3 at 800°C in a furnace for 24 hours at about 800°C continuously. [George Ting - Kuofey, WU Li & J.R.Dahn, J Electrochem, Soc, 141 (1994) 2279],
This compound was also prepared by subjecting a uniform mixture of Li2CO3 NiCO3 and V2O5 at 600°C in a furnace for several hours [C.Gonzaler, M.Galtan, M.L.Veija, R.Saez - puche, C.Pico J.Mat.Sci.29 (1994) 3458].
In an interesting procedure reported recently LiNiV04 was prepared by heating freshly prepared LiNiO2 with NH4VO3. However, LiNiO2 was obtained by a thermal

procedure reported as LiOH + NiCO3 combination [Jooji, Teeinkew Fuel, JP 07, 320, 741 (95, 320, 741) (C1. H01M4/58)].
In a recent paper, LiNiV04 was obtained by heating an aqueous solution of LiNO3, Ni(NO3)2 & NH4VO3 of known composition [S.R.S. Prabaharan, M.S. Michael, S.Radhakrishnan and C.Julien, J.Mater.Chem,. 7(1997) 1791].
A solution precipitation procedure was evolved to get LiNiV04 by reacting LiNO3, Ni(NO3)2 and vanadium (III) acetyl acetonate at 450°C for 12 hours continuously [Geoge Ting - Kuo-Song Chen, J.Power Sources, 81 -82 (1999) 467].
Yet another method in a non-aqueous media viz isopropanol, LiOH, Ni(NO3)2 &, NH4VO3 were dissolved and heated to get the required product [Chung - Hsin Lu, Wei - Cheng Lee, Shaw - Jang Liou, George Ting - Kuo Fey, J.Power Sources, 81-82 (1999) 696].
In all the above mentioned methods any one of the following disadvantages is observed.
Phase purity
Longer duration of thermal preparation High temperature of operation Controlling of pH
The main objects of this present inventigation is to formulate a new process for
the synthesis of single thermal procedure for the synthesis of LiNiV04 cathode material for the rocking chair lithium ion cells which obviates the draw backs of the known methods.
The another object of this invention is to synthesis lithium nickelvanadate cathode material by solid state reaction procedure which obviates the defects and drawbacks hither to known in other methods of preparation of this compound from the known procedures available in literature.
Still another object is to use glycerol as binding agent to make an inform homogeneous mixture which permits was reaction to occur without any other side reaction or products.
Yet another object of this invention to prepare lithium nickel venadate with oxides of the components present in the system.
Accordingly the present invention provides a process for a simple thermal procedure for the synthesis of lithium nickel vanadate which comprises mixing, lithium oxide, nickel oxide, vanadium oxide in molar ratio 1:1:1, adding binding agent to the above mixture to get a paste, heating the above paste up to a temperature of 750°C a maximum period of 12 hours and cooling to get the product.
An embodiment of this invention glycerol may be used as a binding agent for complete reaction.
In another embodiment of this invention the temperature of preparation may be carried out in the range of 600oC to 750oC for 10 hrs to 12 hours.
In yet another embodiment of this invention optionally urea, succinic acid, fomamide, ammonium formate and ammonium nitrate, may be used
A novel method of preparing this compound viz LiNiVO4 was carried out by uniformly mixing the oxides of Li, Ni and Vanadium 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 product obtained formed in this lab was confirmed by x-ray analysis (Fig 1) and also found to be formed in single phase.
The present invention, describes the method of synthesis of the cathode material for a secondary battery, by heating a paste of fine particles of lithium oxide, nickel oxide and vanadium oxide made in glycerol. This paste was initially heated in a fiimace slowly to evaporate off the glycerol in order to get a dried mass. The dried mass obtained when the temperature recorded around 3000C. The dried mass was continuously heated to 750°C for 12 hours. The product formed was slowly cooled to room temperature and then examined. It was found that the prepared sample was deep yellow coloured and homogeneous. X-ray analysis confirmed the formation of LiNiVO4 according to Fig. 1 and Table 1.
Novelty of this process is the following:
This process gave pure product and leaves behind no unreacted components as evidenced from x-ray results.
This process does not produce partial reactions & side reaction.
This process does not involve any inncucous gas formation like No2, Co2.
This process is needless time of heating then other methods as evidenced from literature.
The following examples are given by the way of illustration & should not
be construed the scope of this invention.
Oxides of lithium, cobalt & nickel were ground well in a pestle and mortar arrangement. After the mixture was ground well glycerol was added slowly continuing the process of grinding till a fine paste was formed. The paste was transferred with a ceramic / crucible & strongly heated this material is a furnace initially at 300°C and then the temperature initially at 300°C and then the temperature was given to 750°C subsequently kept for 12 hours. The product was cooled after 12 hours & then was ground well & then x-rayed to identify its.
The following examples gives the way of synthesizing solid state LiNiVO4 cathode material
Example -1 Components
Li2O 0.596 gm
NiO 2.99 gm
V2O5 3.637 gm
Fuel No fuel added
Glycerol 1 ml
Precursor temperature 300°C - 750°C
Duration of heating 12hrs
Colour of the product Deep yellow
Efficiency of the product 98%
Phase Single
Single electrode potential of
LiNiVO4 w.r.t. in 1M LiC1O4 3.01v
In propylene carbonate
A standard procedure to measure the single elements potential of the cathode.
Example - 2 Components
Li2O 0.596 gm
NiO 2.99 gm
V2O5 3.637 gm
Fuel No fuel added
Glycerol 1 ml
Precursor temperature 300°C - 750°C
Duration of heating 12hrs
Colour of the product Yellow tint brown
Efficiency of the product 98%
Phase Single
Single electrode potential of
LiNiVO4 w.r.t. in 1M LiC1O4 3.01 v
In propylene carbonate
A standard procedure to measure the single elements potential of the cathode.
Oxides of lithium, cobalt & nickel were ground well in a pestle and mortar arrangement. After the mixture was ground well glycerol was added slowly continuing the process of grinding till a fine paste was formed. The paste was
transferred with a ceramic / crucible & strongly heated this material is a furnace initially at 300°C and then the temperature initially at 3000C and then the temperature was given to 750°C subsequently kept for 12 hours. The product was cooled after 12 hours & then was ground well & then x-rayed to identify its.
Table. 1 X -ray diffraction date of LiNiVO4
(Table Removed)
* The standard LiNiVO4 is from JCPDS 38-1395.





We Claim
1.A process for a simple thermalprocedure for the
synthesis of lithium nickel vanadate which comprises mixing, lithium oxide, nickel oxide, vanadium oxide in molar ratio 1:1:1, adding binding agent to the above mixture to get a paste, heating the above paste up to a temperamre of 750°C a maximum period of 12 hours and cooling to get the product(Li Ni VO4)
2. A process as claimed in claim1 wherein the reactants react uniformly in presence of mixture of glycerol as binding agent.
3 A process as claimed in claim1-2 a paste procedure is followed with fine particles of the reactants viz lithium oxide, nickel oxide and vanadium oxide to thermally prepare LiNiV04 for secondary rechargeable lithium cells.
4 A process as claimed in claimsl-3 wherein highly viscous glycerol is used as binding solution
to form a paste with the reactants viz oxides of Li, Ni &. vanadium. 5. A process as claimed in claims to 1 -4 wherein a single phase LiNiVO4 free form impurity in
produced as observed by x-ray pattern. 6 A process as claimed in claims 1-5 wherein the colour variation of the product depends on the
particle size and also on the absence / presence of precursor. 7.A novel process for the synthesis of Lithium nickel
vanadate material for the rocking chair lithium ion cells substantially as herein described with
reference to the examples and drawing accompanying the specification.

Documents:

367-del-2001-abstract.pdf

367-del-2001-claims.pdf

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

367-del-2001-correspondence-others.pdf

367-del-2001-correspondence-po.pdf

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

367-del-2001-drawings.pdf

367-del-2001-form-1.pdf

367-del-2001-form-18.pdf

367-del-2001-form-2.pdf


Patent Number 242954
Indian Patent Application Number 367/DEL/2001
PG Journal Number 39/2010
Publication Date 24-Sep-2010
Grant Date 21-Sep-2010
Date of Filing 27-Mar-2001
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI- 110 001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 ANGAIAH SUBRAMANIAN EXT. SRF. DEPT. OF INDUSTRIAL CHEMISTRY ALAGAPPA UNIVERSITY, KARAIKUDI-630 003
2 ARYANAN MANI SCIENTIST, CECRI, KARAIKUDI 630 006,
3 THIAGARAJAN VASUDEVAN PROF. & HEAD ALGAPPA UNIVERSITY, KARAIKUDI 630 003, INDIA
4 RAMAIYER GANGADHARAN EMERITUS SCIENTIST, ALGAPPA UNIVERSITY, KARAIKUDI 630 003, INDIA
PCT International Classification Number H01M 4/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA