A brief outline of laboratory preparation of an experimental agarose/KOH gel electrolyte. I wish to test this material in supercapacitor designs. In "Chemical Engineering Journal" 472, (2023) 144870 Italian and Spanish researchers reported a facile approach to this novel gel.
Vitoriano et al are the authors. Before this work, see: Moon, et al, ACS Applied Material Interfaces ,7,(2015)3503-3511; a report on agarose use as gel electrolyte in certain supercapacitors.


A 2% (m/v) of 'agarose' polysaccharide ( not agar which is the seaweed source) in 100 ml. of 6-7 M KOH is stirred well and brought to 100-110 deg C in 10-15 minutes with efficient , rapid stirring. The solution will become homogeneous and yellow at it reaches 100 deg. C. At this point, the solution will slightly darken. It is poured in a silicone tray , while hot, and the balance was pored into a plastic weigh dish. No doctoring of the material was done to control thickness in this experiment.
A 6 M KOH concentration requires a curing time of about one hour (as it cools down) . Placing it in an oven at 37 deg C for 2-4 hours will optimize jellification.

An 8M KOH solution will cure quickly after casting and jellification time is not needed. The gel electrolyte. The researchers report that a "cage effect" occurs during this process and water retention (approx. 100%) for 200-250 hrs with use in a zinc/air cell. The conductivity is reported as 0.45 +/- .05 S -cm ^(-1) which is significant.
We will upload our experimental findings on supercapacitor designs using this novel gel electrolyte.

(I believe the cheaper material: "agar agar powder" can be used. i will confirm and upload my findings.)