Title of Invention

A SOLID STATE CELL

Abstract A solid cell comprises novel zeolite anode and zeolite catiode having prepared according to the process as herein described and sandwiched by the parent zeolite as herein described acting both as the electrolyte and the separator between the electrodes.
Full Text The present invention relates to a solid state cell.
The main object of the present invention is to provide an efficient and simple procedure of modifying zeolite as electrode which enables encapsulation of a wide variety of electroactive species and which possess ordered structures and stability over a wide range of temperatures for different electrochemical applications, thus ensuring production of zeolitic electrodes with a consistent and well defined stoichiometric compositions. These electrodes are further adaptable for use as active materials in the fabrication of all solid state cells with appreciable power output which is a new solid state power source.
To meet the above requirement, the process of the present invention
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consists of;
a) preparation of zeolitic anode by encapsulation of different
electroactive species,
b) preparation of zeolitic cathodes by encapsulation of different
electroactive species,
c) fabrication of cell assembly
containing the above zeolitic electrodes in combination with parent zeolite as electrolyte cum separator.
The preparation of zeolite electrode useful in a solid state cell comprises encapsulating an electroactive metal ion either in bivalent or in a monovalent state into different types of zeolites by dispersing the zeolite with a solution of the salt of the corresponding metal such as herein described and converting the metal ions into their respective metal oxides by known methods, filtering the said dispersion to isolate the metal ion encapsulated

zeolite and metal oxide, encapsulated zeolite, washing the metal ion encapsulated zeolite product repeatedly with water, drying under dynamic vacuum at 60 to 80°C and converting in to the form of a disc compacting the said disc on one side with pure metal or carbon preparation of electrode is made a subject matter of our copending application No. 161 /DEL/92 from which this application has been divided out.
Accordingly, the present invention provides a solid state cell comprising
novel zeolite anode and zeolite cathode^prepared according to the process as
herein described and sandwiched by the parent zeolite acting (jxtth as the electrolyte and the separator between the electrodes.
Fabrication of solid state cell assembly
According to another feature of the invention there is provided a cell employing the zeolite electrodes prepared by the above described process of the present invention.
Accordingly, the present invention provides a solid state cell comprises novel zeolite anode and zeolite cathode having prepared according to the process as herein described and sandwiched by the parent zeolite as herein described acting both as the electrolyte and the separator between the electrodes.
The cell can be prepared by building up layer by layer the electrodes and electrolytes as shown in Fig.1 of the drawing accompanying the provisional specification. The partent zeolite is also made as a disc and sandwiched between zeolite anode and zeolite cathode, by pressing all the three discs together. The thickness of partent zeolite layer can be in the

range of 0.15-0.30 mm. The thickness of the zeolitic electrode layers can be in the range of 0.12 - 0.175 mm, while the thickness of the corresponding metal/carbon layer used to compact zeolitic electrodes can be in the range of 0.02 - 0.025 mm. In a preferred embodiment of the present invention, these layers may be sealed using polypropylene film or polyethylene film with appropriate lead.
This invention is further illustrated by the following examples which should not, however, be construed to limit the scope of the invention.
Example-1
Preparation of Zeolitic Manganese dioxide Cathode

Zeolite used
Amount of zeolite used for encapsulation Total volume of the solution Concentration of MnCIa used Concentration of KMnCu used
Time required for drying the Mn2
encapsulated zeolite under vacuum
Temperature for drying of Mn2+ encapsulated zeolite
Time required for oxidation of Mn2+ encapsulated zeolite
Temperature for the oxidation of Mn2+ into MnOa in zeolite
Time required for drying MnO2 encapsulated zeolite
Temperature for drying MnO2 encapsulated zeolite

(Na56 AI56 Silae C-384), 250 H2O
10g
1 litre
10 mM
100mM
20 hours 80°C 22 hours 35°C 42 hours 100°C

Composition of the MnO2 (MnO2) Na-i2 AI56 Sii36
encapsulated zeolite O384xH2O (NaY based)
Pressure used for compacting MnO2
encapsulated zeolite as disc 5 ton/cm2
Thickness of carbon layer used 0.02 mm
The preparation of zeolitic lead oxide cathode can be similarly carried out as indicated in the above example, except that in place of MnCI2, Pb(NO3)2 is used and the rest of the conditions remain same.
Example-2
Performance of Mg/Mg2+ NaY/NaY/MnO2-NaY/C Cell
Anode Zeolitic Magnesium electrode (NaY based)
Composition of the anode Mg23 Naio Alse Sii3e O384 250 H2O
Thickness of the layer 0.15 mm
Size of the anode 2.7 x 2.2 cm
Cathode Zeolitic Manganese dioxide
Composition of the cathode (MnO2)22 Na-i2 AI56 Sii3e O384 xH2O
Thickness of the cathode layer 0.15 mm
Size of the cathode 2.7 x 2.2 cm
Composition of the electrolyte
Parent zeolite Y Na56 AI56 Sii36 O384 250 H2O (NaY)
Thickness of the electrolyte layer 0.2 mm
Total thickness of the cell 0.5 mm
Open circuit voltage 1.8 V
Load used for discharge 1.0 M Q
Capacity obtained 4.0 M Ah
Operating voltage 1.5V

Example-3
Performance of Zn/Zn2+ NaY/NaY/MnO2 NaY/C
Anode Zeolitic zinc electrode (NaY based)
Composition of the anode Zn2o Naie AI56 Si3e 0334 250 H2O
Thickness of the anode 0.15 mm
Size of the anode 2.7 x 2.2 cm
Cathode Zeolitic Manganese dioxide (NaY based)
Composition of the cathode (MnO2)22 Nai2 AI56 Si-i36 O384 xH2O
Thickness of the cathode layer 0.15 mm
Size of the cathode 2.7 x 2.2 cm
Composition of the electrolyte
Parent zeolite Y Na56 AI56 Sii36 O384 250 H2O (NaY)
Thickness of the electrolyte layer 0.2 mm
Total thickness of the cell 0.5 mm
Open circuit voltage 1.7V
Load used for discharge 1.0 M Q
Capacity obtained 5.0 M Ah
Operating voltage 1.4 V
Example-4
Performance of Pb/Pb2+ NaY/H.NaY/PbO2 NaY/C
Anode Zeolitic lead electrode (NaY)
Composition of the anode Pb20 Na-i6 AI5e Sii36 O384 250 H2O
Thickness of the anode 0.15 mm
Size of the anode 2.7 x 2.2 cm
Cathode Zeolitic lead dioxide

Composition of the cathode (PbO2)23 Na-io AI5e Si136 O384 xH2O
(NaY based)
Thickness of the cathode layer 0.15 mm
Size of the cathode 2.7 x 2.2 cm
Composition of the zeolite Y
Converted into acid form H4o Nai6 Sii3e O384 250 H2O (NaY based)
Thickness of the electrolyte layer 0.2 mm
Total thickness of the cell 0.5 mm
Open circuit voltage 1.9 V
Load used for discharge 1.0 M Q
Capacity obtained 6.0 M Ah
Operating voltage 1.7 V
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The following are the main advantages of this invention:
1. Zeolitic electrodes provide high surface area supports for active
materials.
2. Zeolite acts as template which facilitates the use of only smaller amount
of active materials for use as electrodes.
3. Zeolitic electrodes provide options to encapsulate a variety of species
and so also the mixed electroactive material.
4. An all solid state cell is possible with the use of the parent zeolite as solid
electrolyte.
5. Zeolitic environment offers structure stabilisation and ordering of the
electroactive species resulting into better performance.
6. Zeolitic electrodes provide the use of resultant solid state cell for the high
temperature and low temperature applications.




WE CLAIM
1. A solid state cell comprises novel zeolite anode and zeolite cathode
prepared according to the process as herein described and sandwiched
by the parent zeolite acting both as the electrolyte and the separator
between the electrodes.
2. A process as claimed in claim 1, wherein the thickness of zeolitic
electrode layer ranges from 0.1 - 0.2 mm of which metal layer ranges
from 0.02 to 0.025 mm.
3. A process as claimed in claims 1 & 2 wherein the thickness of the parent
zeolite layer in the solid state cell ranges from 0.15 - 0.3 mm.
4. A process as claimed in claims 1 to 3 wherein the sealing of the solid
state cell is done either with polypropylene film or polyethylene film.
5. A solid state cell substantially as herein described.


Documents:

384-del-1998-abstract.pdf

384-del-1998-claims.pdf

384-del-1998-complete specificaation (granted).pdf

384-del-1998-correspondence-others.pdf

384-del-1998-correspondence-po.pdf

384-del-1998-description (complete).pdf

384-del-1998-form-1.pdf

384-del-1998-form-2.pdf


Patent Number 186898
Indian Patent Application Number 384/DEL/1998
PG Journal Number 48/2001
Publication Date 01-Dec-2001
Grant Date 19-Jul-2002
Date of Filing 13-Feb-1998
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 SARIKAI KRISHNAMACHARI RANGRAJAN CENTRAL ELECTROCHEMICAL RESEARCH INSTITUTE KARAIKUDI,INDIA.
2 SUBBIAH RAVICHANDRAN CENTRAL ELECTROCHEMICAL RESEARCH INSTITUTE KARAIKUDI,INDIA.
3 SETHURAMAN PITCHUMANI CENTRAL ELECTROCHEMICAL RESEARCH INSTITUTE,KARAIKUDI,INDIA.
4 KANALA LAKSHMI NARSIMHA PHANI CENTRAL ELECTROCHEMICAL RESEARCH INSTITUTE, KARAIKUDI,INDIA.
PCT International Classification Number C04B 21/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA