METHOD OF MANUFACTURING AN ION-CONDUCTING MEMBRANE
A method of manufacturing an ion-conducting membrane. comprising the steps of: (a) providing a substrate; (b) depositing a first dispersion onto the substrate to form a first layer, wherein the first dispersion comprises an ion-conducting polymer; (c) depositing a second dispersion onto the first dispersion to form a second layer on the first layer, wherein the second dispersion comprises an ion-conducting polymer; (d) providing a reinforcing component comprising pores so that the second dispersion impregnates at least some of the pores of the reinforcing component; and (e) drying the first and second layers, wherein step (e) is performed after steps (c) and (d).
1 . A method of manufacturing an ion-conducting membrane, wherein the method comprises the steps of:
(a) providing a substrate;
(b) depositing a first dispersion onto the substrate to form a first layer, wherein the first dispersion comprises an ion-conducting polymer;
(c) depositing a second dispersion onto the first dispersion to form a second layer on the first layer, wherein the second dispersion comprises an ion-conducting polymer;
(d) providing a reinforcing component comprising pores so that the second dispersion impregnates at least some of the pores of the reinforcing component; and
(e) drying the first and second layers,
wherein step (e) is performed after steps (c) and (d).
2 . The method according to claim 1 , wherein the first dispersion has a density that is greater than the density of the second dispersion.
3 . The method according to claim 1 , wherein the second dispersion has a surface tension that is less than the surface tension of the first dispersion.
4 . The method according to claim 1 , wherein the second dispersion has a higher degree of wetting towards the reinforcing component than the first dispersion.
5 . The method according to claim 1 , wherein the reinforcing component has a thickness that is substantially the same as a thickness of the second layer.
6 . The method according to claim 1 , wherein the first dispersion comprises a continuous phase comprising water, a polar solvent other than water, or a mixture thereof.
7 . The method according to claim 6 , wherein the continuous phase of the first dispersion comprises the polar solvent other than water in an amount in the range of <70 wt. %, preferably 10-50 wt. %, or more preferably 20-40 wt. % based on the total weight of the continuous phase.
8 . The method according to claim 1 , wherein the second dispersion comprises a continuous phase comprising water, a polar solvent other than water, or a mixture thereof.
9 . The method according to claim 8 , wherein the continuous phase of the second dispersion comprises the polar solvent other than water in an amount in the range of and including 50-100 wt. %, preferably 60-90 wt. %, or more preferably 70-80 wt. % based on the total weight of the continuous phase.
10 . The method according to claim 1 , in which the first dispersion and the second dispersion are deposited concurrently.
11 . The method according to claim 1 , in which the first dispersion and/or second dispersion is deposited using a slot-die coating process, knife-coating, bar coating, inkjet printing, gravure printing, curtain coating, or a spray coating process.
12 . The method according to claim 11 , in which the slot die coating process comprises providing a slot die head comprising a first outlet and a second outlet, wherein the first dispersion is deposited onto the substrate via the first outlet, and the second dispersion is deposited onto the first dispersion via the second outlet.
13 . The method according to claim 1 , further comprising the steps of:
(f) depositing a third dispersion onto the second layer to form a third layer, wherein the third dispersion comprises an ion-conducting polymer; and
(g) drying the third layer.
14 . The method according to claim 13 , wherein the step of depositing the third dispersion is performed after the step of drying the first and second layers.
15 . The method according to claim 13 , in which the third layer has a thickness that is substantially the same as a thickness of the first layer.
16 . The method according to claim 1 , further comprising the step of removing the substrate after the step of drying the first and second layers.
17 . The method according to claim 1 , wherein the substrate is a catalyst layer.
18 . A method of manufacturing a catalyst-coated ion-conducting membrane comprising the steps of:
providing an ion-conducting membrane manufactured using the method according to claim 1 ; and
applying a catalyst layer to the ion-conducting membrane.
19 - 20 . (canceled)
21 . A method of manufacturing a membrane-electrode assembly comprising the steps of:
providing a catalyst coated ion-conducting membrane manufactured using the method according to claim 18 ; and
applying a gas diffusion layer to the catalyst coated ion-conducting membrane.
22 - 23 . (canceled)