Title of Invention	"AN ELECTROCHEMICAL PROCESS FOR THE PREPARATION OF NICKEL HYDROXIDE FROM NICKEL NITRATE SOLUTION "
Abstract	An electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution which comprises electrolysing a solution containing nickel nitrate, characterised in that passing a current of 100 to 600 A/m to a solution containing nickel nitrate in the range of 30 to 70 g/1 and ethanol in the range of 0.7 to 5.8 g/1 as an additive, at a temperature ranging between 30 to 70°C in a diaphragm cell to obtain the precipitate of nickel hydroxide, filtering the above said precipitate followed by washing with distilled water and drying to obtain the desired product.

Title of Invention

"AN ELECTROCHEMICAL PROCESS FOR THE PREPARATION OF NICKEL HYDROXIDE FROM NICKEL NITRATE SOLUTION "

Abstract

An electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution which comprises electrolysing a solution containing nickel nitrate, characterised in that passing a current of 100 to 600 A/m to a solution containing nickel nitrate in the range of 30 to 70 g/1 and ethanol in the range of 0.7 to 5.8 g/1 as an additive, at a temperature ranging between 30 to 70°C in a diaphragm cell to obtain the precipitate of nickel hydroxide, filtering the above said precipitate followed by washing with distilled water and drying to obtain the desired product.

Full Text	The present invention relates to an electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution. More particularly the present invention relates to an electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution useful for being used in batteries such as Nickel - Cadmium, Nickel Metal Hydride. The recent growth in the consumer electronics market has spurted the development of nickel metal hydride and nickel cadmium batteries. The emergence of lap-top computers, cellular telephones and other personnel electronic devices increases the demand of nickel hydroxide considerably in recent years. Nickel metal hydride batteries to-day represent the faster growing segment of this rechargeable battery market for consumer electronic industry due to its higher density and more environment friendly compared to lead acid batteries. Current estimate indicates that the total portable rechargeable battery market is expected to reach 5b$ by 2000. It is estimated about 50,000 tons of nickel is consumed for the production of nickel hydroxide. Nickel hydroxide exists in two forms. One anhydrous form with a brucite structure called ß- Ni (OH)2 and the other a hydrated form which is known as α- Ni (OH)2. Oxidation of ß- Ni (OH)2 produces ß- NiOOH and oxidation of a- Ni (OH)2 produces y- NiOOH. α- Ni (OH)2 could dehydrate in concentrated alkali to form as ß- Ni (OH)2 and as ß~ Ni (OH)2 could be converted to γ- Ni OOH. The addition of foreign ions like other metallic hydroxide improves the physio-chemical and electrochemical properties of Ni (OH)2. Several additives such as Co, Zn, Fe, Cd, etc. have been added to the solutions during precipitation of Ni (OH)2. The charge-discharge characteristics are one of the important properties of Ni (OH)2 for measurement of its capacity. Reference may be made to C. Faure, C Delmas. P. Willmann, J. Power Sources, 35 (1991) 263-77 , wherein turbostatic alpha-nickel hydroxide was obtained with an almost quauntative yield from NiSO4 solution. Delahaye etal. J. Power Sources, 35 (1991) 263-77 characterized α and ß type nickel hydroxides obtained chemically or electrochemically by different techniques like chemical analysis, x-ray diffraction, electron microscopy, and infrared spectroscopy. It was observed that the recrystallizaiicn of alpha and beta phase occurred by dissolution of a and nucleation of ß from the solution. The electrochemical impregnation of porous nickel sintered plates was studied by Rortmer etal. J. Electrochem. Soc. 139 (1992) 671-678 to gain a better understanding of the structure, texture and composition of the deposited active material. Chiba et al J. Mat. Science Let., 12 (1993) 620-22 reported that ultrasonic irradiation increases the mass transport rates in eiectrodeposition and increases the physical and chemical properties of electrodeposited metallic films. Two different methods for preparing i electrochromic nickel hydroxide films were tested by de Torresi et al., Thin Solid Films, 229 (1993) 180-6. The technology conditions of preparation of high activity nickel hydroxide and the effect of additives on activity of nickel hydroxide were studied by Qiangqing etal, Battery Bimonthly, 25 (1995) 55-8. Reference may be made to K. Watanabe, T. Kikuoka, N. Kumagai. J. Appl. Electrochem. 25 (1995) 219- 26 vherein physical properties of nickel hydroxide powders have been examined by laser diffraction, BET, X-ray diffraction, thermal analysis and SEM. Nickel hydroxide powder with a smaller crystalline size showed better charge-discharge cyclic characteristic . The tap density and activity of nickel hydroxide prepared under various conditions were studied by Hui et al. J. Power Sources, 57 (1995) 137-40. Yungchang et al. J. Power Sources, 56 (1995) 115-9, studied the effects of dopant and concluded from their results that the level of dopant has a great effect on the electrode performance. Nickel hydroxide are generally prepared by chemical precipitation, electrosynthesized and by using complexation precipitation techniques. Electrosynthsized nickel hydroxide (ESN) designated as a- Ni (OH)2 has been found to have supenor electrochemical properties compared to chemically prepared (3- Ni (OH)2. Different workers, already cited in the literature prepare chemical nickel hydroxide samples. Reference may be made to A. Merlin, C. R. Acad. Sci., Paris, 236 (1953) 1892 wherein nickel hydroxide was prepared by evaporation of a solution of nickel amine complex. The solid is filtered and washed free of nitrate and ammonium ions. Reference may be made to O. Giemser in 'Handbook of Preparative Inorganic Chemistry', vol. II. (Edited by G. Brauer), Academic Press, New York-London (1965) 1549 wherein nickel hydroxide was prepared by adding strong alkali (1 M KOH) to a nickel nitrate solution at 35 °C. Turbostatic nickel hydroxide was prepared by addition of ammonia to nickel nitrate and by rapid centrifugation of the precipitate. S. LeBihan, J. Guenot and M. Figlarz, C. R. Acad. Sci., Paris 270 (1970) 2131. In the present invention the nickel hydroxide is prepared electrochemically from nickel nitrate solution wherein ethanol has been used as an additive that improves the discharge capacity and also controlled the particle size and other physico-chemical and electrochemical properties and thereby makes the scaling up process easy. The main object of the present invention is to provide an electrochemical process for the precipitation of nickel hydroxide from nickel nitrate solution which obviate the drawbacks of the inventions cited in the above references. Accordingly the present invention provides an electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution which comprises electrolysing a solution containing nickel nitrate, characterised in that passing a current of 100 to 600 A/m2 to a solution containing nickel nitrate in the range of 30 to 70 g/1 and ethanol in the range of 0.7 to 5.8 g/1 as an additive, at a temperature ranging between 30 to 70°C in a diaphragm cell to obtain the precipitate of nickel hydroxide, filtering the above said precipitate followed by washing with distilled water and drying to obtain the desired product. In an embodiment of the present invention the nickel hydroxide obtained has the tap density ranging between 0.65 to 1.63 g/cc. In yet another embodiment the discharge characteristic of nickel hydroxide obtained is in the range of 180 to 190 mAh/g. The present patent relates to preparation of different tap density nickel hydroxide material ranging from 0.65 to 1.63 nickel hydroxide by electrochemical route with a current efficiency of 75% to 90% from nickel nitrate solution in a two compartment cell with mtcroporous diaphragm separator. Two-compartment cell having a microporous diaphragm had been used as a separator of anolyte and catholyte chambers. The anode was a titanium substrate insoluble material of 0.3 ern thick, having dimensions 10 ern long and 5 em wide. The cathode was stainless steel sheet having the dimensions of 10 ern long and 5 em wide. Fresh electrodes were used for each experiment. The cathode was carefully polished with fine (600) grade emery paper, washed under running tap water, degreased with acetone and then washed again with distilled water followed by air drying. The electrodes were placed into the cell and connected to the circuit for nickel hydroxide precipitation. The electrolysis was carried out by applying DC current from a regulated power supply unit. All the reagents used in the present study were of analytical grade and the solution was prepared using distilled water. The initial composition of the catholyte and the anolyte were kept same in all experiments. The physical properties such as tap density and apparent density were measured by standard methods and particle size were measured by Malvern particle size analyser. The surface morphology of the nickel hydroxide was examined by SEM and crystallographic orientations of the material by X-ray diffractory. BET surface area had been measured by Coulter SA 3100. The charge and discharge characteristics had been studied in 100-ml cell using 30% KOH solution and Ni (OH)2 pellets having an area of 4.91 cm . The pellets were prepared by taking active nickel hydroxide material with 30 % of graphite powder and 4.00% of Ni powder in 3 drops of 10% PVA as binding material and pressed at a pressure of 4 t/cm for 2 min. Two cadmium hydroxide electrodes were used as The pellets were prepared by taking active nickel hydroxide material with 30 % of graphite powder and 4.00% of Ni powder in 3 drops of 10% PVA as binding material and pressed Particle size and other physico-chemical and electrochemical properties can at a pressure of 4 t/cm2 for 2 min. counter electrodes to study the charge discharge characteristics. The novelty of the present invention is that the nickel hydroxide is produced from nickel nitrate solution and ethanol has been used as an additive that improves the discharge capacity. Particle size and other physico-chemical and electrochemical properties can be controlled. Scaling up of the process is easy. The following examples are given by the way of illustration and should not construed to limit the scope of the invention. Example 1 100 ml of 70 gpl synthetic nickel nitrate solution is taken in each compartment of a diaphragm cell. 100 ml of 70 gpl synthetic nickel nitrate solution is taken in each compartment of a diaphragm cell. The solution is prepared by dissolving nickel nitrate of AR grade in distilled water. 0.5 ml of 90% ethanol is added to the catholyte compartment. The dipping area of the cathode is 31.5 cm2. The DC current of 0.93 A is applied between stainless steel cathode and titanium substrate insoluble anode. The cell voltage obtained is 2.3 V. The electrolysis continued for 3 hours. The precipitate thus obtained is filtered through Whatman (No.40) filter paper and washed thoroughly with distilled water. The nickel hydroxide obtained is dried in an oven at 70°C for 24 hours. The dried hydroxide is powdered and measured for physical properties. The tap density of the powder obtained is 1.58 g/cc. Charge-Discharge Studies: 2.52 g of nickel hydroxide powder is mixed with 1.32 g of graphite powder and 0.16 gm of nickel powder and mixed thoroughly. Three drops of aqueous suspension of 10% Poly Vinyl alcohol (PVA) is used as binder. The mixture is placed in nickel-plated stainless steel mesh and palletized under pressure of 4 ton/cm using 20 mm dye. Two cadmium hydroxide pellets of the same size as nickel hydroxide electrodes are used as counter electrodes. The pellets thus obtained is then charged at a current density of 5 mA/cm2 until the cell voltage is discharged down to 0.85 V. During charging the potential is raised up to 1.86 V and the open- circuit potential of 1.41 V is obtained. The discharge capacity of nickel hydroxide is 190 mAh/g of active material. Example 2 100 ml of 30 gpl synthetic nickel nitrate solution is taken in each compartment of a diaphragm cell. The solution is prepared by dissolving nickel nitrate of AR grade in distilled water. 0.5 ml of 90% ethanol is added to the catholyte compartment. The dipping area of the cathode is 31.5 cm2. The DC current of 0.49 A is applied between stainless steel cathode and titanium substrate insoluble anode. The cell voltage obtained is 3.2 V. The electrolysis continued for 3 hours. The precipitate thus obtained is filtered through Whatman (No.40) filter paper and washed thoroughly with distilled water. The nickel hydroxide obtained is dried in an oven at 70°C for 24 hours. The dried hydroxide is powdered and measured for physical properties. The tap density of the powder obtained is 1.54 g/cc. 2.52 g of nickel hydroxide powder is mixed with 1.32 g of graphite powder and 0.16 gm of nickel powder and mixed thoroughly. Three drops of aqueous suspension of 10% Poly Vinyl alcohol (PVA) is used as binder. The mixture is placed in nickel-plated stainless steel mesh and palletized under pressure of 4 ton/cm2 using 20 mm dye. Two cadmium hydroxide pellets of the same size as nickel hydroxide electrodes are used as counter electrodes. The pellets thus obtained is then charged at a current density of 5 mA/cm2 until the cell voltage is discharged down to 0.85 V. During charging the potential is raised up to 1.86 V and the open-circuit potential of 1.41 V is obtained. The discharge capacity of nickel hydroxide is 190 mAh/g of active material. Advantages The electrochemical route provides a cleaner and more effective method of producing and hence prefers to chemical process. This method is quite attractive and offers ease of production and better control over the particle size, specific surface area, tap density, and discharge capacity. Nickel hydroxide produced in this route provides high discharge capacity. We Claim 1. An electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution which comprises electrolysing a solution containing nickel nitrate, characterised in that passing a current of 100 to 600 A/m2 to a solution containing nickel nitrate in the range of 30 to 70 g/1 and ethanol in the range of 0.7 to 5.8 g/1 as an additive, at a temperature ranging between 30 to 70°C in a diaphragm cell to obtain the precipitate of nickel hydroxide, filtering the above said precipitate followed by washing with distilled water and drying to obtain the desired product. 2. An electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution substantially as herein described with reference to the examples.

Full Text

The present invention relates to an electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution.
More particularly the present invention relates to an electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution useful for being used in batteries such as Nickel - Cadmium, Nickel Metal Hydride.
The recent growth in the consumer electronics market has spurted the development of nickel metal hydride and nickel cadmium batteries. The emergence of lap-top computers, cellular telephones and other personnel electronic devices increases the demand of nickel hydroxide considerably in recent years. Nickel metal hydride batteries to-day represent the faster growing segment of this rechargeable battery market for consumer electronic industry due to its higher density and more environment friendly compared to lead acid batteries. Current estimate indicates that the total portable rechargeable battery market is expected to reach 5b$ by 2000. It is estimated about 50,000 tons of nickel is consumed for the production of nickel hydroxide.

Nickel hydroxide exists in two forms. One anhydrous form with a brucite structure called ß- Ni (OH)2 and the other a hydrated form which is known as α- Ni (OH)2. Oxidation of ß- Ni (OH)2 produces ß- NiOOH and oxidation of a- Ni (OH)2 produces y- NiOOH. α- Ni (OH)2 could dehydrate in concentrated alkali to form as ß- Ni (OH)2 and as ß~ Ni (OH)2 could be converted to γ- Ni OOH.
The addition of foreign ions like other metallic hydroxide improves the physio-chemical and electrochemical properties of Ni (OH)2. Several additives such as Co, Zn, Fe, Cd, etc. have been added to the solutions during precipitation of Ni (OH)2. The charge-discharge characteristics are one of the important properties of Ni (OH)2 for measurement of its capacity.
Reference may be made to C. Faure, C Delmas. P. Willmann, J. Power Sources, 35 (1991) 263-77 , wherein turbostatic alpha-nickel hydroxide was obtained with an almost quauntative yield from NiSO4 solution. Delahaye etal. J. Power Sources, 35 (1991) 263-77 characterized α and ß type nickel hydroxides obtained chemically or electrochemically by

different techniques like chemical analysis, x-ray diffraction, electron microscopy, and infrared spectroscopy. It was observed that the recrystallizaiicn of alpha and beta phase occurred by dissolution of a and nucleation of ß from the solution. The electrochemical impregnation of porous nickel sintered plates was studied by Rortmer etal. J. Electrochem. Soc. 139 (1992) 671-678 to gain a better understanding of the structure, texture and composition of the deposited active material.
Chiba et al J. Mat. Science Let., 12 (1993) 620-22 reported that ultrasonic irradiation increases the mass transport rates in eiectrodeposition and increases the physical and chemical properties of electrodeposited metallic films. Two different methods for preparing
i
electrochromic nickel hydroxide films were tested by de Torresi et al., Thin Solid Films, 229 (1993) 180-6. The technology conditions of preparation of high activity nickel hydroxide and the effect of additives on activity of nickel hydroxide were studied by Qiangqing etal, Battery Bimonthly, 25 (1995) 55-8. Reference may be made to K. Watanabe, T. Kikuoka, N. Kumagai. J. Appl. Electrochem. 25 (1995) 219- 26 vherein physical properties of nickel hydroxide powders have been examined by laser diffraction, BET, X-ray diffraction, thermal analysis and SEM. Nickel hydroxide powder with a smaller crystalline size showed better

charge-discharge cyclic characteristic . The tap density and activity of nickel hydroxide prepared under various conditions were studied by Hui et al. J. Power Sources, 57 (1995) 137-40. Yungchang et al. J. Power Sources, 56 (1995) 115-9, studied the effects of dopant and concluded from their results that the level of dopant has a great effect on the electrode performance.
Nickel hydroxide are generally prepared by chemical precipitation, electrosynthesized and by using complexation precipitation techniques. Electrosynthsized nickel hydroxide (ESN) designated as a- Ni (OH)2 has been found to have supenor electrochemical properties compared to chemically prepared (3- Ni (OH)2.
Different workers, already cited in the literature prepare chemical nickel hydroxide samples. Reference may be made to A. Merlin, C. R. Acad. Sci., Paris, 236 (1953) 1892 wherein nickel hydroxide was prepared by evaporation of a solution of nickel amine complex. The solid is filtered and washed free of nitrate and ammonium ions. Reference may be made to O. Giemser in 'Handbook of Preparative Inorganic Chemistry', vol. II. (Edited by G. Brauer), Academic Press, New York-London (1965) 1549 wherein nickel hydroxide was prepared by adding strong alkali (1 M KOH) to a nickel nitrate solution at 35 °C. Turbostatic nickel hydroxide

was prepared by addition of ammonia to nickel nitrate and by rapid centrifugation of the precipitate. S. LeBihan, J. Guenot and M. Figlarz, C. R. Acad. Sci., Paris 270 (1970) 2131.
In the present invention the nickel hydroxide is prepared electrochemically from nickel nitrate solution wherein ethanol has been used as an additive that improves the discharge capacity and also controlled the particle size and other physico-chemical and electrochemical properties and thereby makes the scaling up process easy.
The main object of the present invention is to provide an electrochemical process for the precipitation of nickel hydroxide from nickel nitrate solution which obviate the drawbacks of the inventions cited in the above references.
Accordingly the present invention provides an electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution which comprises electrolysing a solution containing nickel nitrate, characterised in that passing a current of 100 to 600 A/m2 to a solution containing nickel nitrate in the range of 30 to 70 g/1 and ethanol in the range of 0.7 to 5.8 g/1 as an additive, at a temperature ranging between 30 to 70°C in a diaphragm cell

to obtain the precipitate of nickel hydroxide, filtering the above said precipitate followed by washing with distilled water and drying to obtain the desired product.
In an embodiment of the present invention the nickel hydroxide obtained has the tap density ranging between 0.65 to 1.63 g/cc.
In yet another embodiment the discharge characteristic of nickel hydroxide obtained is in the range of 180 to 190 mAh/g.
The present patent relates to preparation of different tap density nickel hydroxide material ranging from 0.65 to 1.63 nickel hydroxide by electrochemical route with a current efficiency of 75% to 90% from nickel nitrate solution in a two compartment cell with mtcroporous diaphragm separator. Two-compartment cell having a microporous diaphragm had been used as a separator of anolyte and catholyte chambers. The anode was a titanium substrate insoluble material of 0.3 ern thick, having dimensions 10 ern long and 5 em wide. The cathode was stainless steel sheet having the dimensions of 10 ern long and 5 em wide. Fresh electrodes were used for each experiment. The cathode was carefully polished with fine (600) grade emery paper, washed under running tap water, degreased with acetone and then washed again with

distilled water followed by air drying. The electrodes were placed into the cell and connected to the circuit for nickel hydroxide precipitation. The electrolysis was carried out by applying DC current from a regulated power supply unit. All the reagents used in the present study were of analytical grade and the solution was prepared using distilled water. The initial composition of the catholyte and the anolyte were kept same in all experiments. The physical properties such as tap density and apparent density were measured by standard methods and particle size were measured by Malvern particle size analyser. The surface morphology of the nickel hydroxide was examined by SEM and crystallographic orientations of the material by X-ray diffractory. BET surface area had been measured by Coulter SA 3100.
The charge and discharge characteristics had been studied in 100-ml cell using 30% KOH solution and Ni (OH)2 pellets having an area of 4.91 cm . The pellets were prepared by taking active nickel hydroxide material with 30 % of graphite powder and 4.00% of Ni powder in 3 drops of 10% PVA as binding material and pressed at a pressure of 4 t/cm for 2 min. Two cadmium hydroxide electrodes were used as The pellets were prepared by taking active nickel hydroxide material with 30 % of graphite powder and 4.00% of Ni powder in 3 drops of 10% PVA as binding

material and pressed Particle size and other physico-chemical and electrochemical properties can at a pressure of 4 t/cm2 for 2 min. counter electrodes to study the charge discharge characteristics.
The novelty of the present invention is that the nickel hydroxide is produced from nickel nitrate solution and ethanol has been used as an additive that improves the discharge capacity. Particle size and other physico-chemical and electrochemical properties can be controlled. Scaling up of the process is easy.
The following examples are given by the way of illustration and should not construed to limit the scope of the invention.
Example 1
100 ml of 70 gpl synthetic nickel nitrate solution is taken in each compartment of a diaphragm cell.
100 ml of 70 gpl synthetic nickel nitrate solution is taken in each compartment of a diaphragm cell. The solution is prepared by dissolving nickel nitrate of AR grade in distilled water. 0.5 ml of 90% ethanol is

added to the catholyte compartment. The dipping area of the cathode is 31.5 cm2. The DC current of 0.93 A is applied between stainless steel cathode and titanium substrate insoluble anode. The cell voltage obtained is 2.3 V. The electrolysis continued for 3 hours. The precipitate thus obtained is filtered through Whatman (No.40) filter paper and washed thoroughly with distilled water. The nickel hydroxide obtained is dried in an oven at 70°C for 24 hours. The dried hydroxide is powdered and measured for physical properties. The tap density of the powder obtained is 1.58 g/cc.
Charge-Discharge Studies:
2.52 g of nickel hydroxide powder is mixed with 1.32 g of graphite powder and 0.16 gm of nickel powder and mixed thoroughly. Three drops of aqueous suspension of 10% Poly Vinyl alcohol (PVA) is used as binder. The mixture is placed in nickel-plated stainless steel mesh and palletized under pressure of 4 ton/cm using 20 mm dye. Two cadmium hydroxide pellets of the same size as nickel hydroxide electrodes are used as counter electrodes. The pellets thus obtained is then charged at a current density of 5 mA/cm2 until the cell voltage is discharged down to 0.85 V. During charging the potential is raised up to 1.86 V and the open-

circuit potential of 1.41 V is obtained. The discharge capacity of nickel hydroxide is 190 mAh/g of active material.
Example 2
100 ml of 30 gpl synthetic nickel nitrate solution is taken in each compartment of a diaphragm cell. The solution is prepared by dissolving nickel nitrate of AR grade in distilled water. 0.5 ml of 90% ethanol is added to the catholyte compartment. The dipping area of the cathode is 31.5 cm2. The DC current of 0.49 A is applied between stainless steel cathode and titanium substrate insoluble anode. The cell voltage obtained is 3.2 V. The electrolysis continued for 3 hours. The precipitate thus obtained is filtered through Whatman (No.40) filter paper and washed thoroughly with distilled water. The nickel hydroxide obtained is dried in an oven at 70°C for 24 hours. The dried hydroxide is powdered and measured for physical properties. The tap density of the powder obtained is 1.54 g/cc.
2.52 g of nickel hydroxide powder is mixed with 1.32 g of graphite powder and 0.16 gm of nickel powder and mixed thoroughly. Three drops of aqueous suspension of 10% Poly Vinyl alcohol (PVA) is used as binder. The mixture is placed in nickel-plated stainless steel mesh and

palletized under pressure of 4 ton/cm2 using 20 mm dye. Two cadmium hydroxide pellets of the same size as nickel hydroxide electrodes are used as counter electrodes. The pellets thus obtained is then charged at a current density of 5 mA/cm2 until the cell voltage is discharged down to 0.85 V. During charging the potential is raised up to 1.86 V and the open-circuit potential of 1.41 V is obtained. The discharge capacity of nickel hydroxide is 190 mAh/g of active material.
Advantages
The electrochemical route provides a cleaner and more effective method of producing and hence prefers to chemical process. This method is quite attractive and offers ease of production and better control over the particle size, specific surface area, tap density, and discharge capacity. Nickel hydroxide produced in this route provides high discharge capacity.

We Claim
1. An electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution which comprises electrolysing a solution containing nickel nitrate, characterised in that passing a current of 100 to 600 A/m2 to a solution containing nickel nitrate in the range of 30 to 70 g/1 and ethanol in the range of 0.7 to 5.8 g/1 as an additive, at a temperature ranging between 30 to 70°C in a diaphragm cell to obtain the precipitate of nickel hydroxide, filtering the above said precipitate followed by washing with distilled water and drying to obtain the desired product.
2. An electrochemical process for the preparation of nickel hydroxide from nickel nitrate solution substantially as herein described with reference to the examples.

Documents:

907-del-2001-abstract.pdf

907-del-2001-claims.pdf

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

907-del-2001-correspondence-others.pdf

907-del-2001-correspondence-po.pdf

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

907-del-2001-form-1.pdf

907-del-2001-form-18.pdf

907-del-2001-form-2.pdf

907-del-2001-form-3.pdf

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Patent Number

242167

Indian Patent Application Number

907/DEL/2001

PG Journal Number

34/2010

Publication Date

20-Aug-2010

Grant Date

17-Aug-2010

Date of Filing

03-Sep-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	TONDEPU SUBBAIAH	REGIONAL RESEARCH LABORATORY, BHUBANESWAR-751013, ORISSA, INDIA
2	SUBASH MALLICK	REGIONAL RESEARCH LABORATORY, BHUBANESWAR-751013, ORISSA, INDIA
3	RADHANATH PRASAD DAS	REGIONAL RESEARCH LABORATORY, BHUBANESWAR-751013, ORISSA, INDIA
4	KRUSHNA GOPAL MISHRA	REGIONAL RESEARCH LABORATORY, BHUBANESWAR-751013, ORISSA, INDIA

PCT International Classification Number

C01G 53/04

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA