Claims:
1. A cathode (100) comprising:
a) a ceramic layer (101) having 15 to 35% by weight of a first inorganic
material, 45 to 65% by weight of a second inorganic material and 10
5 to 30% by weight of at least two water-soluble binders;
b) a current collector (102); and
c) an active material layer (103),
wherein the first inorganic material has a particle size in a range of 1.5 to
2.0 µm, and the second inorganic material has a particle size in a range of
10 0.1 to 0.15 µm;
wherein the first inorganic material and the second inorganic material are in
a weight ratio range of 1:1.5 to 1:4, with respect to combined weight of the
first and the second inorganic materials; and
wherein the current collector (102) is having the ceramic layer (101) on a
15 first portion of the current collector and the active material layer (103) on a
second portion of the current collector.
2. The cathode as claimed in claim 1, wherein the first inorganic material and
the second inorganic material are selected from AlO(OH), Al2O3, ZrO2,
ZnO, TiO2, BaTiO3, SiO2, or combinations thereof.
20 3. The cathode as claimed in claim 1, wherein the ratio of combined weight of
the first inorganic material and the second inorganic material to the weight
of at least two water-soluble binders is in a range of 70:30 to 90:10.
4. The cathode as claimed in claim 1, wherein the at least two water-soluble
binders comprises a polymeric binderselected from polyacrylic acid (PAA),
25 polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polycarboxylic acid,
polyimide, styrene-butadiene rubber (SBR), polyethylene oxide (PEO),
sodium alginate, polyvinyl pyrrolidone (PVP), or combinations thereof; and
a biopolymer-based binder selected from carboxymethyl cellulose (CMC),
cyclodextrin, hydroxypropyl methylcellulose (HPMC), starch, xanthan
30 gum, gelatin, or combinations thereof.
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5. The cathode as claimed in claim 4, wherein the polymeric binder and the
biopolymer-based binder are in a weight ratio range of 85:15 to 95:5.
6. The cathode as claimed in claim 1, wherein the ceramic layer has a thickness
in a range of 20 to 50 µm and a density in a range of 1.7 to 2 g/cc.
5 7. The cathode as claimed in claim 1, wherein the ceramic layer exhibits a
tensile strength in a range of 69 to 80 MPa and a peel strength in a range of
3.8 to 5 N/inch.
8. The cathode as claimed in claim 1, wherein the current collector (102) is
selected from aluminium foil, aluminium sheet, glossy aluminium sheet,
10 aluminium plate or aluminium rod.
9. The cathode as claimed in claim 1, wherein the active material layer (103)
comprises:
a) a cathode active material selected from layered oxides, nickel
manganese cobalt (NMC), nickel cobalt aluminium (NCA), lithium
15 iron phosphate (LFP), lithium manganese iron phosphate (LMFP), or
combinations thereof;
b) a conductive carbon selected from carbon black, graphene, mesoporous
carbon, acetylene black, activated carbon, super P, carbon nanofiber,
vapor grown carbon nanofiber, carbon nanotube, or combinations
20 thereof, and
c) an organic binder selected from polyvinylidene fluoride (PVDF),
vinylidene fluoride (VDF), poly(vinylidene-co-hexafluoropropylene)
(PVDF-HFP), polyamides, polytetrafluoroethylene, polyethylene
oxide, fluoroethylene vinyl ether (FEVE), fluoroethylene polymer
25 (FEP), or combinations thereof.
10. A process for preparing the cathode as claimed in claim 1, the process
comprising:
a) blending a first inorganic material and a second inorganic material to
obtain an inorganic mixture;
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b) adding the inorganic mixture into an aqueous solution of a biopolymerbased binder followed by adding a polymeric binder to obtain a
composition of ceramic layer;
c) mixing an active material, a conductive additive and an organic binder
5 to obtain a mixture of active material layer; and
d) applying the composition of ceramic layer on a first portion of the
current collector and the mixture of active material layer on a second
portion of the current collector, to obtain the cathode.
11. The process as claimed in claim 10, wherein the aqueous solution of a
10 biopolymer-based binder is prepared by stirring 1 to 5% w/w of a
biopolymer-based binder with water at a speed of 800 to 1000 rpm for a
period in a range of 8 to 15 h.
12. The process as claimed in claim 10, wherein adding the inorganic mixture
in step (b) is carried out by adding a first part of the inorganic mixture and
15 blending followed by adding a second part of the inorganic mixture and
blending.
13. The process as claimed in claim 12, wherein the first part of the inorganic
mixture is in a weight range of 40 to 60%, with respect to total weight of
the inorganic mixture.
20 14. The process as claimed in any one of the claims 10 or 12, wherein blending
is carried out at a speed in a range of 1500 to 2500 rpm for a period in a
range of 4 to 6 h.
15. The process as claimed in claim 10, wherein adding the polymeric binder is
carried out while stirring at a speed in a range of 1500 to 2500 rpm for a
25 period in a range of 4 to 6 h.
16. The process as claimed in claim 10, wherein the composition of ceramic
layer has a solid content in a range of 40% to 50% and a viscosity in a range
of 2000 to 5000 cP at 50 s-1
.
17. The process as claimed in claim 10, wherein applying the composition is
30 carried out by slot die coating, doctor blading, dip coating, drop casting, or
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spray coating, followed by drying at a temperature in a range of 60 to 120℃
for a period in a range of 10 to 20 h.
18. An electrochemical cell comprising:
a) an anode;
5 b) the cathode as claimed in claim 1; and
c) an electrolyte.