(a) Schematic of the hybrid electrolyte AAB built on a non-direct counter-flow microfluidic platform. (b) Photograph of a hybrid electrolyte AAB. (c and d) Specific capacities of Al foil in the hybrid electrolyte Al-air cells with (c) anolyte: neat methanol-based KOH solutions with KOH concentrations of 1 M, 2 M, 3 M and 4 M; catholyte: aqueous KOH solution with KOH concentrations of 1 M, 2 M, 3 M and 4 M. (d) Anolyte: 1 M KOH methanol-based solution with various water contents of 0 vol%, 20 vol%, 40 vol% and 60 vol%; catholyte: 1 M KOH aqueous solution. Adapt with permission from Ref. [153]. Copyright 2016 Elsevier B.V. (e and f) Schematics and experimental setups of (e) traditional AAB and (f) double electrolyte AAB. (g and h) Typical discharge curves at different current densities: (g) traditional AAB, (h) double electrolyte AAB [153,154]. Adapt with permission from Ref. [154]. Copyright 2014 Royal Society of Chemistry.