Lithium cation exchange membrane for water electrolysis, and water electrolysis system using same
The present invention relates to a lithium cation exchange membrane, for water electrolysis, having high lithium cation conductivity, and a water electrolysis system using same, and a water electrolysis system using a lithium cation exchange membrane (LEM) for water electrolysis according to the present invention, comprising a hydrophilic polymer solution and a monomer solution having a sulfonic acid group, is an economically feasible water electrolysis system achieving lower costs than conventional proton exchange membrane (PEM) water electrolysis and a higher current density than alkali water electrolysis.
1 . A lithium cation exchange membrane (LEM) water electrolysis system, comprising:
a lithium cation exchange membrane including a perfluorosulfonic acid polymer having sulfonic acid groups and a hydrophilic polymer;
an anode catalyst layer on one side of the cation exchange membrane, the anode catalyst layer comprising Ni 3 Co alloy nanoparticles, and
a cathode catalyst layer on the opposite side of the cation exchange membrane, the cathode catalyst layer comprising nickel-based nanoparticles,
wherein an aqueous lithium hydroxide electrolyte is supplied to the anode side and lithium hydroxide is produced at the cathode side during water electrolysis.
2 . The LEM water electrolysis system of claim 1 , wherein the lithium hydroxide electrolyte is an aqueous solution having a concentration of 1 to 15 wt %.
3 . The LEM water electrolysis system of claim 1 , wherein the anode and the cathode each comprise an electrode body and a binder in the electrode body.
4 . The LEM water electrolysis system of claim 3 , wherein the anode catalyst comprises Ni 3 Co alloy nanoparticles present in an amount of 1 to 20 wt % relative to 100 wt % of the binder.
5 . The LEM water electrolysis system of claim 3 , wherein the cathode catalyst comprises nickel based nanoparticles present in an amount of 1 to 20 wt % relative to 100 wt % of the binder.
6 . The LEM water electrolysis system of claim 3 , wherein the binder is selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, and combinations thereof.
7 . The LEM water electrolysis system of claim 1 , wherein the lithium hydroxide produced at the cathode moves to an electrolyte supply reservoir at the anode, thereby providing for reuse of the lithium hydroxide in an anode compartment.