1. A cathode comprises:
a cathode current collector (200) having a planar structure with a
predetermined width and length, wherein a cathode active material layer is
5 coated onto a surface of the cathode current collector (200),
wherein a mass loading of the cathode active material layer is greater
than 45 mg/cm2
; and
wherein a density of the cathode active material layer is in the range
of 3.5 – 3.7 g/cc.
10
2. The cathode as claimed in claim 1, wherein divergence (D) along the
length of the cathode current collector (200) is such that when the cathode
current collector (200) is unfolded along a notional straight line (214) with a
first edge (216) of the cathode current collector (200) coinciding with a point
15 (218) on the notional straight line, a second edge (220) of the cathode
current collector (200) diverges from a corresponding point (222) on the
notional straight line (214) by a distance less than 10 mm.
3. The cathode as claimed in claim 1, wherein the mass loading of the
cathode active material layer is greater than 48.25 mg/cm2 20 , and wherein the
density of the cathode active material layer is greater than 3.57 g/cc.
4. The cathode as claimed in claim 1, wherein the cathode active
material layer comprises at least 97.5% cathode active materials and less
25 than or equal to 1.5% of one or more binders by weight.
5. The cathode as claimed in claim 4, wherein the cathode active
materials include Nickel Cobalt Manganese Oxide (NCM), Nickel Cobalt
Aluminum Oxide (NCA), Lithium Iron Phosphate (LFP), Lithium Manganese
30 Oxide (LMO), and Lithium Cobalt Oxide (LCO).
14
6. The cathode as claimed in claim 4, wherein the binder has a
molecular weight higher than at least 97.2 gm/mole.
7. The cathode as claimed in claim 4, wherein the binder is selected
5 from a group consisting of polyvinylidene fluoride (PVDF), polyacrylic acid
(PAA), polyimides (PI) and a combinations thereof.
8. A method (300) for manufacturing electrodes, the method
comprising:
10 preparing a cathode slurry mixture by mixing cathode active
materials and binders for a cathode active material layer;
coating the cathode active material layer onto a cathode current
collector (200), wherein the coating comprises distributing the cathode
active material layer onto the cathode current collector (200) forming at least
15 one uncoated region, wherein each of the at least one uncoated region is a
strip of a predefined width along a length of the cathode current collector;
and
wherein the at least one uncoated region is located such that a
coated region exists between an edge of the at least one uncoated region
20 and a side of the cathode current collector; and
calendaring the coated cathode current collector by applying
pressure with a set of plurality of rollers.
9. The method (300) as claimed in claim 8, wherein at least one
25 uncoated region comprises a first strip (204) and a second strip (206), such
that a first coated region (210) exists between a first side (202) of the
cathode current collector (200) and the first strip (204) and a second coated
region (212) exists between a second side (208) of the cathode current
collector and the second strip (206), the method (300) further comprising:
30 cutting the cathode current collector (200) along an outer edge of the
first strip (204) to remove the first coated region (210), the outer edge of the
15
first strip (204) being proximal to the first side (202) of the cathode current
collector (200);
cutting the cathode current collector (200) along an outer edge of the
second strip (206) to remove the second coated region (212), the outer edge
5 of the second strip (206) being proximal to the second side (208) of the
cathode current collector (200); and
slitting remaining width of the cathode current collector (200) to
obtain a first cathode and a second cathode.
10 10. The method (300) as claimed in claim 8, wherein the coating
comprises applying the cathode active material layer to achieve a mass
loading of the cathode active material layer greater than 45 mg/cm2 and a
density of the cathode active material layer in the range of 3.5 – 3.7 g/cc.