FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1.TITLE OF THE INVENTION "A chemical synthesis process of cobalt-manganese phosphate thin films on conducting substrates"
2.APPLICANT:
NAME: Dr. Vishwanath Vithal Bhosale.
a)NATIONALITY: Indian
b)ADDRESS: i) APPLICANT: D. Y. Patil Education Society (Deemed to be university), Kasaba Bawada, Kolhapur 416 006, __
3.PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed
The following specification particularly describes and ascertains the nature of the present invention and the manner in which it is to be performed. Papers Related to work
1.P. Venkateswarlu, E. Umeshbabu, U. Naveen Kumar, P. Nagaraja, P. Tirupathi, G. Ranga Rao, P. Justin, Facile hydrothermal synthesis of urchin-like cobalt manganese spinel for high performance supercapacitor applications, J. Colloid Interface Sci., (2017), 503,17-27.
2.Y. Tang, Z. Liu,W. Guo, T. Chen,Y. Qiao, S. Mu, Y. Zhao, F. Gao, Honeycomb-like mesoporous cobalt nickel phosphate nanospheres as novel materials for high performance supercapacitor, Electrochem. Acta, (2016), 190, 118-125.
3.X. Li, A. M. Elshahawy, C. Guan, J. Wang, Metal phosphides and phosphates-based electrodes for electrochemical supercapacitors, Small, (2017), 13, 1-25.
4 H. Pang, S. Wang, W. Shao, S. Zhao, B. Yan, X. Li, S. Li, J. Chen. W. Du, Few-layered CoHP04.3H20 ultrathin nanosheets for high performance of electrode materials for supercapacitors, Nanoscale, (2013), 5, 5752-5757. 5. Y. H. Dai, L. B. Kong, K. Yan, M. Shi, Y. C. Luo, L. Kang, Facile fabrication of manganese phosphate nanosheets for supercapacitor applications, Ionics, (2016), 22,1461-1469.

6. X. J. Ma, W. B. Zhang, L. B. Kong, Y. C. Luo, L. Kang, Electrochemical performance in alkaline and neutral electrolytes of a manganese phosphate material possessing a broad potential window, RSC Adv., (2016), 6, 40077-40085.
7. K. V. Sankar, S.C. Lee, Y. Seo, C. Ray, S. Liu, A. Kundu, S.C. Jun, Binder-free cobalt phosphate one-dimensional nanograsses as ultrahigh performance cathode material for hybrid supercapacitor applications, J. Power Sources, (2018), 373, 211-219.
Patents
Sr. Patent Name of the patent Month and year Inventors
no. Number
1 7476467 Lithium secondary battery 13-January-2009 Hey Woong Park, Ji-Sang Yu,
with high power Sung-Woo Kim, Min Su Kim,
United States Patent
~2 8431271 Positive active material 30-April-2013 Yukiko Fujino, Yoshinobu
for lithium secondary Yasunaga, Akihiro Fujii, Yohei
battery and lithium Shibata, Mariko Kohmoto, .
secondary battery Takashi Egawa, Toru Tabuchi,
Hiroe Nakagawa, Tokuo Inamasu,
Toshiyuki Nukuda, United States
Patent
3 8597833 Rechargeable lithium 03-December- Cheol-Hee Hwang, Bong-
Battery 2013 Chull Kim, Dong-Yung Kim, Se-
Ho Park, United States Patent
4 9929402 Power storage device 27-March-2018 Kawakami, Takahiro, United
States Patent
Field of the Invention:
The present invention relates to a novel chemical synthesis method of positive electrode active material of a cobalt-manganese phosphate applicable in energy storage devices. Background Art of the Invention:
The elements in the centre of the periodic table, between II and III groups, are called the transition metals. They are good conductors of heat and electricity and their compounds such as oxides, hydroxides, sulphides show high energy and power densities in batteries and supercapacitors [1, 2]. Phosphorus is a multivalent non-metal of the nitrogen group, which is also one of the most useful and well-established donor atoms in coordination chemistry. There is a large group of phosphorus compounds, including metal

phosphates, which have been studied for better performing electrodes for energy storage [3]. The thin films of transition metal phosphates have been prepared using chemical methods [1-3].
There are two types of thin film deposition methods, physical and chemical methods based on the ways of material deposition. In physical methods, vacuum evaporation and sputtering are the basic categories, which are further classified into laser evaporation, electron beam evaporation, RF sputtering, magnetron sputtering etc. Chemical methods are classified according to phase of initial precursor solutions. Solution and gas phases are subcategories of chemical methods, which are further classifies into chemical vapor deposition (CVD), electrodeposition, chemical bath deposition (CBD), hydrothermal etc. Physical methods require high working temperature, high vacuum and advanced instruments. Hence, these methods suffer from high cost. Also, material wastage, cleaning of deposition chamber and small area deposition are the things of concern in the physical methods. Comparatively, chemical methods are simple, cheap and convenient to deposit materials on large scale. Different preparative parameters of chemical method such as the pH of solution, concentration of reactants, deposition temperature, and time of deposition can be easily controlled. The inventors have found that, binary metal phosphate material can be prepared by a chemical hydrothermal method using cobalt, manganese and phosphate precursors.
The hydrothermal synthesis method is simple and convenient in fabrication of thin film for various nanostructures. It has various advantages over other conventional methods such as,
1) It is possible to grow crystals of compound with high melting point at lower temperature.
2) It is also particularly suitable for the growth of large and good-quality materials while maintaining control over their composition.
3) The environmental perspective, hydrothermal method is more environmentally benign than many other methods.
4) It can be easily controlled by manipulating various preparative parameters such as temperature of bath, time of deposition, concentrations of initial precursors, pH of solution bath, etc. and the material wastage is less as compared with resistive heating and sputtering methods.
Thin films of transition metal phosphates, such as, Co3(P04)2, Mn3(P04)2, Mn3(P04)2-3H20 have been prepared using simple chemical methods such as co-precipitation, sonochemical, chemical precipitation method, respectively. H. Pang et. al. [4] successfully synthesized Con(HP03)8(OH)6 by a mild hydrothermal method and applied as an electrode for electrochemical supercapacitor, Y. H. Dai et. al. [5] prepared Mn3(P04)2-3H20 by a facile chemical precipitation method at 70 °C, which showed excellent supercapacitive performance in 2 M KOH alkaline electrolyte. Furthermore, X. J. Ma et. al. [6] synthesized Mn3(P04)2 by hydrothermal method and studied its structural properties. Few reports are available on individual cobalt phosphate and manganese phosphate with various morphologies such as,

nanoribbons, nanosheets, nanograsses etc. However, there are no reports available on cobalt-manganese phosphate thin films either by physical or chemical methods. Prior Art:
U. S. patent No. 7476467, described a non-aqueous electrolyte-based high power lithium secondary battery having a long-term service life, superior safety at room temperature and high temperature, even after repeated high-current charging and discharging, wherein the battery comprises a mixture of a particular lithium manganese-metal composite oxide (A) having a spinal structure and a particular lithium nickel-manganese-cobalt composite oxide (B) having a layered structure, as a cathode active material.
U. S. patent No. 8431271, described positive active material is lithium iron cobalt phosphate for a lithium ion secondary battery represented by the general formula: LiyFe(1_x)CoxP04. By using the positive active material for a lithium secondary battery, high temperature storage stability and charge and discharge cycle with improved performance.
U. S. patent No. 8597833, described first positive active material selected from cobalt and manganese phosphate acid-based materials, and it used to making electrodes for rechargeable lithium battery.
U. S. patent No. 9929402, described a power storage device with a positive electrode. The positive electrode includes a first region active material which includes a compound containing lithium and one or more of manganese, cobalt, nickel and a second region which covers the first region and includes a compound containing lithium and iron.
The prior art describes the various methods of synthesis of individual cobalt and manganese phosphate for lithium ion batteries and energy storage devices and no one has tried to form cobalt-manganese phosphate thin films for energy storage applications. Objectives of Invention:
Primary objective of the invention is to deposit adhesive and compact cobalt-manganese phosphate thin films on large area stainless steel substrate.
Another primary objective of the invention is to produce cobalt-manganese phosphate thin films in the range of 90 to 150 °C bath temperature.
Another primary objective is to produce microstructured cobalt-manganese phosphate thin films by optimizing preparative parameters in chemical method namely, hydrothermal method.
Another objective is to deposit cobalt-manganese phosphate thin films having monoclinic crystal structure.
Yet another objective of invention is to produce cobalt-manganese phosphate thin films useful for various advanced applications such as supercapacitor, electrocatalysis, photocatalysis, and battery.

Summary of Invention:
This invention generally relates to chemical hydrothermal method for the synthesis of cobalt-manganese phosphate, (CoxMn3.x(P04)2.nH20). The hydrothermal chemical deposition method is a relatively uncommon, but inexpensive, convenient, low temperature, and cost effective method for large area deposition of cobalt-manganese phosphate thin films at low temperature on any substrates. In the process of invention, solution containing cobalt and manganese salts are complexed using urea. The thin films of cobalt-manganese phosphate are deposited on conducting substrates using various precursors of cobalt, manganese and phosphates. This invention provides process for deposition of large area and almost uniform cobalt-manganese phosphate thin films from the solution concentration range 0.02-0.5 M for cobalt, manganese and phosphate precursors and 0.02-0.2 M urea on metallic conducting substrates at the temperature 90-150°C. These different concentrations of cobalt, manganese and phosphate are made in an aqueous solution. The thin films of cobalt-manganese phosphate are adherent. The morphology of prepared material varies from microflowers, microrods-like structure with different concentration of cobalt and manganese. The present invention shows supercapacitive performance of prepared novel material. The specific capacitance of cobalt manganese phosphate thin films increased with increase in cobalt or manganese content discussed in following examples.
The following examples, according to preferred embodiments of the invention, demonstrate the features thereof. However, it is understood that such examples are not to be interpreted as limiting the scope of the invention as defined in the claims. Following are typical experiments given to illustrate the invention.
Example No. 1:
0.02 M CoCl2.6H20, 0.02 M MnCl2.4H20, 0-02 M NH4H2P04 and 0.02 M CO(NH2)2 are prepared in 50 ml double distilled water (DDW) and taken in the glass beaker of 100 cc volume. A 304 grade well cleaned stainless steel as conducting substrate is immersed vertically in the glass beaker containing bath solution and kept at the 120°C for 180 min in hydrothermal autoclave. After 180 min, the stainless steel substrate is removed from autoclave. The violet colored deposition of CoxMn1_x(P04)2.nH20 is formed on stainless steel substrate. From the X ray diffraction study, peak positions observed at 20 values of 11.06, 19.48, 28.33, 29.92, 35.01, 41.57, 59.07° correspond to plane of (110), (001), (13-1), (201), (330), (-222) and (620), respectively of monoclinic phase CoxMn3.x(P04)2.nH20 [Figure 1J.
Composition I CoCl2.6H20 (0.02 M), MnCl2.4H20 (0.02 M), NH4H2PO4 (0.02 M)
and CO(NH2)2 (0.02 M).
Temperature 120°C

Deposition time 180 min
Substrate Stainless steel (1×5 cm2)
Crystal structure Monoclinic
Morphology Microcrystalline with Microrods
Example No. 2:
0.1 M CoCl2.6H20, 0.1 M MnCl2.4H20, 0.1 M NH4H2P04 and 0.1 M CO(NH2)2 are prepared in 50 ml DDW. Stainless steel substrate (10 cm2) is immersed in the solution and it kept at the 90°C for 300 min. After 300 min cobalt-manganese phosphate thin film is taken out of the bath, washed with distilled water and dried at room temperature. The violet colored deposition of CoxMn3.x(P04)2.nH20 is formed on stainless steel substrate. Field emission scanning electron microscopy (FESEM) study showed adherent distribution of microparticles depositing over the surface of stainless steel substrate, with microrods like morphology [Figure 2].
Composition I CoCl2.6H20 (0.1 M), MnCl2.4H20 (0.1 M), NH4Po4 (0.1 M) and
CO(NH2)2(0.1 M).
Temperature 90°C
Deposition time 300 min
Substrate Stainless steel (1x10 cm2)
Crystal structure Monoclinic
Morphology Microcrystalline with Microrods
Example No. 3:
0.25 M CoCl2.6H20, 0.75 M MnCl2.4H20, 0.1 M NH4H2P04 and 0.1 M CO(NH2)2 are prepared in 50 ml DDW. Stainless steel substrate (5 cm2) is immersed in the solution and it kept at the 100°C for 180 min. After 180 min cobalt-manganese phosphate film deposited on stainless steel substrate is taken out of the bath, washed with distilled water and dried at room temperature. The violet colored CoxMn3. x(P04)2.nH20 films are formed on stainless steel.
Composition I CoCl2.6H20 (0.25 M), MnCl2.4H20 (0.75 M),NH4 H2PO4 (0.1 M) and
CO(NH2)2(0.1 M).
Temperature ! 100°C
Deposition time 180 min
Substrate stainless steel (l×l cm2 )

Crystal structure Monoclinic
Morphology Microcrystalline with microrods
Example No. 4:
0.5 M Co(N03)2.6H20, 0.5 M Mn(N03)2.H20, 0.5 M KH2P04 and 0.2 M CO(NH2)2 are prepared in 50 ml DDW. Stainless steel substrate (5 cm2) is immersed in the solution and it kept at the 150°C for 30 min. After 30 min cobalt-manganese phosphate film deposited on stainless steel substrate is taken out of the bath, washed with distilled water and dried at room temperature. The violet colored deposition of CoxMn3.x(P04)2.nH20 is formed on stainless steel substrate.
Composition I Co(N03)2.6H20 (0.5 M), Mn(N03)2.H20 (0.5 M), KH2P04 (0.5 M)
andCO(NH2)2(0.2M).
Temperature 150°C
Deposition time 30 minute
Substrate stainless steel (1x5 cm^)
Crystal structure Monoclinic
Morphology Microcrystalline with Nanorods
Example 5:
Cobalt-manganese phosphate thin films deposited on stainless steel substrate in example 1 are evaluated for supercapacitive properties. Supercapacitance evaluation was carried out electrochemically, using three electrodes cell setup. Three electrodes cell consists of working electrode as cobalt-manganese phosphate deposited on stainless steel, counter electrode as platinum plate, and reference electrode as saturated calomel electrode. Cyclic voltammetry (CV) and galvanostatic charge discharge analyses [Figure 3(A), (B)] of cobalt-manganese phosphate is carried out to test charge storage application of material. The cyclic voltammetry study of cobalt-manganese phosphate materials are scanned at 5-100 mVs'1 scan rate in the voltage range of 0.0-0,5 V/SCE in 1 M KOH electrolyte, to assess the charge storage capacity as shown in Fig. 3 (A). Further, highest specific capacitance of 142.91 Fg"1 at scan rate of 5 mVs"1 is calculated for cobalt-manganese phosphate thin film using following equation,



where,

is area under the CV curve for corresponding scan rate of V within potential window

of (Vc-Va), and 'm' is deposited mass of material on steel substrate of 1 cm2 area.

Galvanostatic charge discharge (GCD) technique [Figure 3(B)] is used to test supercapacitor
nature of cobalt-manganese phosphate. GCD measurement of cobalt-manganese phosphate electrode is
carried for current density of 1-5 mAcm-2as shown in Fig. 3 (B). Initial sudden potential drop observed
in each GCD curve relates to intrinsic resistance of deposited material and subsequent non-linear curve
indicates pseudocapacitive behavior of material.
Entity parameter
Electrode material CoxMn3.x(P04)2.nH20 deposited on stainless steel (1x5 cm ) plate
Electrolyte 1 M KOH
Voltage range 0.0-0.5 V
Scan rate 5 mVs"
Highest specific capacitance 124.91 Fg"
In conclusion, we have successfully developed a chemical synthesis process of cobalt-manganese phosphate electrode material on stainless steel substrate for energy storage and related application. Cobalt-manganese phosphate (CoxMn3.x(P04)2.nH20) is useful in various advanced applications such as electrocatalysis, battery, photocatalysis and supercapacitor.

We Claim:
1. A new process for deposition of large area thin film of cobalt-manganese phosphate material, from aqueous bath containing cobalt and manganese salts, phosphate and urea compound on conducting substrate by heating solution bath at different temperature at different deposition time.
2. A chemical process as claimed in claim 1, wherein the chemical method used for thin film deposition is a hydrothermal method.
3. A chemical process as claimed in claim 1, wherein the heating of solution bath is performed for temperature range of 90-150°C.
4. A chemical process as claimed in claim 1, wherein said phosphate precursors are selected as ammonium phosphate monobasic (NH4H2P04) and potassium dihydrogen orthophosphate (KH2P04).
5. A chemical process as claimed in claim 1, wherein said cobalt and manganese salts used as cobalt chloride and cobalt nitrate and manganese chloride and manganese nitrate.
6. A chemical process as claimed in claim 1, wherein the cobalt-manganese phosphate is represented by the general formula CoxMn3.x(P04)2.nH20.
7. A chemical process as claimed in claim 6, wherein the factor 'x' varies from 0.1 to 2.9 range.
8. A chemical process as claimed in claim 1, wherein concentration of cobalt and manganese salts, phosphate and urea compound range from 0.02 to 0.5 M.
9. A chemical process as claimed in claim 1, wherein precursors of cobalt-manganese phosphate are water soluble.
10. A chemical process as claimed in claim 1, wherein conducting substrate is stainless steel.
11. A chemical process as claimed in claim 1, wherein area of stainless steel substrate used for thin film deposition ranges from 1 to 10 cm .
12. A chemical process as claimed in claim 1, wherein the films are adherent and compact over the substrates.
13. A chemical process as claimed in claim 1, wherein crystal structure of deposited cobalt-manganese phosphate thin film is monoclinic.
14. A chemical process as claimed in claim 1, wherein the morphology of cobalt-manganese phosphate consists of microcrystalline with microrods.
15. A process as claimed in claim 1, wherein cobalt-manganese phosphate deposition on stainless steel surface shows supercapacitive properties.

16. A process as claimed in claim 1, for thin film deposition of cobalt-manganese phosphate material using hydrothermal process on stainless steel substrate substantially as herein described with reference to the examples.

"A chemical synthesis process of cobalt-manganese phosphate thin films on
conducting substrates"
Dr. Umakant M. Patil, Mr. Pranav K. Katkar, Miss Supriya J. Marje,
Dr. Vishwanath Vithal Bhosale and Prof. Chandrakant D. Lokhande
D. Y. Patil Education Society (Deemed to be University), Kasaba Bawada, Kolhapur 416 006
Maharashtra (India).