Alkali fuel cells, systems, and related methods, and flow-through, high-surface area electrodes, are employed to generate electricity. The electrode can include a porous substrate comprising a first side for fluid ingress, a second side for fluid egress, and a plurality of walls oriented in different directions between the first and second sides, with voids defined between the walls, which can include surfaces and micro-scale pores. A thin film comprising a catalytic material can be disposed on the surfaces. A fuel/electrolyte mixture can be flowable generally from the first side, through the voids and the pores of the substrate and in contact with the thin film, and to the second side. Additives can be included for refreshing the electrolyte and/or the electrode. A water/thermal/pressure management system includes a permeable membrane from which water can be removed from a fluid while retaining fuel and/or electrolyte in the fluid. The electrolyte can include an additive that cleans the electrodes. A refresh cycle can be implemented in which one or more electrodes are operated in a mode that refreshes catalytic material of the electrode.