A flow redox battery system comprising an electrochemical cell , an anolyte tank , a catholyte tank , a first anolyte carrier slurry , a second anolyte carrier slurry , a first catholyte carrier slurry , a second catholyte carrier slurry , and a power generation circuit , wherein: the electrochemical cell comprises an ion-exchange membrane positioned between and electrochemically engaged with an anode and a cathode ; the power generation circuit is electrically coupled to the anode and the cathode ; the anolyte tank comprises an anolyte upper end fluidly coupled to the anode and an anolyte lower end fluidly coupled to the anode ; the catholyte tank comprises a catholyte upper end fluidly coupled to the cathode and a catholyte lower end fluidly coupled to the cathode ; the first anolyte carrier slurry comprises a density that is less than a density of the second anolyte carrier slurry and an electronegativity that is different than an electronegativity of the second anolyte carrier slurry , wherein the first and second anolyte carrier slurries each comprise a plurality of slurry grains, each slurry grain comprising an inert core and one or more active particles chemically engaged with the inert core; the first catholyte carrier slurry comprises a density that is less than a density of the second catholyte carrier slurry and an electronegativity that is different than an electronegativity of the second catholyte carrier slurry , wherein the first and second catholyte carrier slurries each comprise a plurality of slurry grains, each slurry grain comprising an inert core and one or more active particles chemically engaged with the inert core; the first anolyte carrier slurry floats above the second anolyte carrier slurry when the first and second anolyte carrier slurries are housed within the anolyte tank; and the first catholyte carrier slurry floats above the second catholyte carrier slurry when the first and second catholyte carrier slurries are housed within the catholyte tank. the electrochemical cell comprises an ion-exchange membrane positioned between and electrochemically engaged with an anode and a cathode ; the power generation circuit is electrically coupled to the anode and the cathode ; the anolyte tank comprises an anolyte upper end fluidly coupled to the anode and an anolyte lower end fluidly coupled to the anode ; the catholyte tank comprises a catholyte upper end fluidly coupled to the cathode and a catholyte lower end fluidly coupled to the cathode ; the first anolyte carrier slurry comprises a density that is less than a density of the second anolyte carrier slurry and an electronegativity that is different than an electronegativity of the second anolyte carrier slurry , wherein the first and second anolyte carrier slurries each comprise a plurality of slurry grains, each slurry grain comprising an inert core and one or more active particles chemically engaged with the inert core; the first catholyte carrier slurry comprises a density that is less than a density of the second catholyte carrier slurry and an electronegativity that is different than an electronegativity of the second catholyte carrier slurry , wherein the first and second catholyte carrier slurries each comprise a plurality of slurry grains, each slurry grain comprising an inert core and one or more active particles chemically engaged with the inert core; the first anolyte carrier slurry floats above the second anolyte carrier slurry when the first and second anolyte carrier slurries are housed within the anolyte tank; and the first catholyte carrier slurry floats above the second catholyte carrier slurry when the first and second catholyte carrier slurries are housed within the catholyte tank. <EOS>