Three-dimensional printing MXene/polyaniline microlattices as high-efficiency anode for supercapacitive microbial fuel cells

The development of high-performance integrated anodes is essential for advancing supercapacitive microbial fuel cells (SC-MFCs), which hold great promise for autonomous micro-power systems. Herein, we employ three-dimensional (3D) printing to fabricate hierarchically porous MXene/polyaniline composite (MX/PANI) anodes for SC-MFCs. Component optimization of MX/PANI anode revealed that both the active surface area and capacitance increased with MX content up to 6%, beyond which the rising charge-transfer resistance suppressed PANI redox activity and reduced the active area. The 3D-printed MX/PANI anode with optimized component content delivers an specific capacitance of 639.65 F g −1 , as well as a peak volumetric power density of 2388 W m −3 and excellent self-charging-discharging behavior in SC-MFCs. These high performances arise from a combination of the superior spatial configuration of the 3D-printed scaffold, the enhanced capacitance from MX incorporation, and the favorable surface properties of PANI. This work not only develops a capacitive anode with opened 3D structure and excellent surface properties, but also demonstrates the application potential of 3D printing technology in SC-MFCs.