Microbial fuel cells

A microbial fuel cell, comprising:

• an anode having an anode surface area, a cathode having a cathode surface area, a cation exchange membrane disposed between the anode and the cathode, and a plurality of electricigenic microbes disposed on the anode wherein the plurality of electricigenic microbes includes 0.075 milligrams of microbial protein or greater per square centimeter of the anode surface area, the plurality of electricigenic microbes forming a plurality of colonies having pillars spaced from each other in an amount greater than zero and up to 40 microns improving a mass transfer of the plurality of electricigenic microbes increasing a power density of the microbial fuel cell wherein the fuel cell has a power density of from 100 mA/m2 to 4.56 A/m and operates at a duration of greater than 24 hours.

A microbial fuel cell, comprising:

• an anode having an anode surface area, a cathode having a cathode surface area, a cation exchange membrane disposed between the anode and the cathode, and a plurality of electricigenic microbes disposed on the anode wherein the plurality of electricigenic microbes includes 0.075 milligrams of microbial protein or greater per square centimeter of the anode surface area, the plurality of electricigenic microbes forming a plurality of colonies spaced from each other in an amount greater than zero and up to 40 microns improving a mass transfer of the plurality of electricigenic microbes increasing a power density of the microbial fuel cell and wherein the plurality of electricigenic microbes form a bio film having a thickness greater than one micron wherein the fuel cell has a power density of from 100 mA/m2 to 4.56 A/m and operates at a duration of greater than 24 hours.