Research On PANI-modified Anode's Influence Towards Power Production Capacity And Charge Storage Property In MFC

Microbial fuel cell (MFC) is one kind of environment-friendly electricity production technologies, and it utilizes microorganism to convert the chemical energy of organic matter into the electricity. The study of an integration of electricity generation and energy storage can not only enhance the electricity generation performance of MFC, but also increase the discharge current density of MFC. In this thesis, the preparation, modification and MFC application of PANI are investigated to improve the power output and discharge current density of MFC.With the substrate of carbon felt (CF), pulse electrodeposition and constant current electrodeposition were used to prepare P-PANI/CF and DC-PANI/CF electrodes. The two kinds of electrodes and the carbon felt were used as anodes in MFCs to study the electricity generation and energy storage in different MFC systems. PANI can stabilize the bio-anode performance and benefit to the power output. With the charge-discharge time of 60 min, the total discharge capacitances of P-PANI/CF and DC-PANI/CF anodes were 2.19 and 1.71 times as much as that of CF anode, respectively; the discharge current densities reached 0.73A/m2 and 0.59 A/m2,respectively. And the anode charge capacities were increased by 1.81 times and 1.11 times,respectively. Through polymerizing PANI on the CF substrate,the maximum specific power density was increased from 41.93 mW/m2 to 221.43 mW/m .The template method was used to synthesize PANI and then PANI was coated on the stainless steel felt (SF) to prepare PANI/CNTs/SF electrode. SF, CNTs/SF and PANI/CNTs/SF electrodes were studied as anodes in MFCs, and the results were: SF anode hardly possessed the ability of electricity generation and energy storage; the CNTs/SF anode was improved due to the good biocompatibility of CNTs; the anode was further improved through compositing PANI. Comparing with maximum output power of CNTs/SF anode, that of PANI composite anode was increased by 93.96 mW/m ; with the charge-discharge time of 60 min, the total discharge capacitance was increased from 999.44 C/m2 to 2101.38 C/m , and the current density was increased from 0.26 A/m2 to 0.53 A/m .With the sponge (S) substrate, CNTs, RGO and PANI were successively added to prepare CNTs/S, RGO/CNTs/S and PANI/RGO/CNTs/S electrodes, and the effects were studied. All of them exhibit great biocompatibility and good performance of electricity generation energy storage. With introducing PANI, the electron transfer rate was improved and the performance of PANI/RGO/CNTs/S anode displayed optimal. With thedischarge-charge time of 60 min,PANI/RGO/CNTs/S anode possessed a Qs of 905.70C/m2 and an output current density of 0.93A/m2. In addition, the maximum output power density reached 584.92 mW/m2, which was 1.24 times more than CNTs/S anode.