Battery performance constraints

At present, the main output power as a measure of microbial fuel cell performance of the merits of an important criterion. Output power depends largely on the size of electrons in micro-organisms and the transfer efficiency between the electrode,battery,the electrode surface area, the electrolyte (the anode and cathode fluid and fluid PEM) of the resistance and cathode areas factors such as reaction kinetics.

This can be classified as Class 3 [28]: (1) kinetic factors, the anode and cathode reaction activation energy factor; (2) the internal resistance of the factors, mainly from the electrolyte ionic resistance, the electrode and contact resistance of the material generated , as well as generated by PEM internal resistance; (3) transmission factors, the reaction to the microbial activity places of mass transfer resistance and the cathode area of the proliferation of electronic final receptor. 1 Kinetic factors Microbial hp laptop battery from the dynamics of the main constraints are higher activation potential, resulting in the anode or cathode on the surface reaction rate relatively low, access to higher output power.

Therefore, it is one of the study focus. In the hp f2024a anode areas, ways to solve the kinetic constraints include:
First, although the choice of strains to a certain extent, affect the speed of micro-organisms enrichment, omnibook xe3 battery,but should not a final decision on the final output power of the battery, into a decisive role in the electricity production is to select efficient strains. For example, the literature [30] pointed out that the choice of anaerobic sludge mixed aerobic bacteria as a source of glucose for fuel cells, by 3 months of microbial cultivation and domestication, the energy conversion rate of 8 times the initial stage.
Second, the use of certain strains of other bacteria may be the generation of substances as a mediator of the characteristics of the material,hp 346970-001, by choosing suitable to carry out co-culture of different bacteria to set up the battery in the so-called symbiotic and mutually beneficial role, but also obtain a higher output power, the current density of single bacteria are cultured 6-fold [8]. Successful examples in this regard also, Rabaey, etc. [30] with electron transfer to the electrode capacity of Geobacteraceae, Desulfuromonaceae, Alteromonadaceae, Enterobacteriaceae, Pasteurellaceae, Clostridiaceae, Aeromonadaceae and Comamonadaceae posed by genus, such as bacteria to carry out co-culture, but also achieved good results.
Third, for those who pass the membrane directly to the electronic transmission of the bacteria to the anode [31],hp hstnn-db02, can use a larger surface area of the anode. This accompanied by the growth of micro-organisms will be greater in the anode surface area of biofilm, energy conversion rate will also improve Express.

There are studies [32] showed that an area of 30 6cm2 in PEM, the anode area of increased 4-fold, power density increases 3 times. Logan [1] will also work electrode biofilm from transplanted into the new electrode can significantly improve the new electrode micro-organisms of biological activity, improve output power. In the hp hstnn-ub02 cathode region, the electronic end-receptor in the electrode is also a decision to restore the rate of the battery output power of an important factor. Literature [29,33] involved in the study showed that the use of platinum-plated by platinum or graphite electrode modified with a high catalytic activity, can significantly reduce the activation potential.

In addition, studies show that the stainless steel electrode biofilm load of sea water [34], using modified Nafion membrane electrode fixed in bilirubin oxidase and mediator [35], are able to promote the cathodic reaction. 2 resistance factors Mench [36] pointed out that the slight decrease of internal resistance will significantly improve the output power, indicating the battery internal resistance in raising the output power plays an important role. Resistance mainly for high performance super-Ohmic electric potential. Super-Ohmic electric potential [28,29] from the electron flow and proton flow in direct mass transfer resistance, the resistance was mainly due to the electrode and contact material between the contact resistance,hp dp390a, the electrolyte membrane and PEM proton constitute resistance. Therefore, the rational design of electrode and membrane, or a better selection of performance-exchange membrane to reduce the mass transfer resistance are an effective way [33]. (1) PEM on the impact resistance. Logan, etc. [32] electrodes and PEM in the same nature, the experimental determination of the PEM surface area changes in size of the internal resistor.

The results show that the experimental conditions, if the PEM area less than the electrode area, will increase the hp pp2100, presario r3000 battery's internal resistance, thus limiting the output power of the battery; if the PEM surface area is large enough, PEM on the impact of power can be neglected, that is, the internal resistance of PEM on the the impact of close to zero. Liu, etc. [37] designed a non-PEM air cathode system to glucose and sewage as fuel, because of the strengthening of the protons between the anode and cathode flow, making the battery from the maximum output power increases, respectively, 1 9 and 2 times 5. As can be seen from the experimental results, PEM output power of the impact of electrode surface area and the impact on the power comparison, PEM size is also affected microbial fuel cell maximum output power of one of the important factors. Liu, etc. [4] the design of membrane fixed on the cathode microbial fuel cell, in the continuous process of sewage treatment has been the output power of 26mW m2; and they designed without PEM systems, internal resistance is reduced, too, have been 146mW m2 the maximum output power. (2) PEM and electrode distance on the space of impact resistance.

Anode and cathode closer to the more favorable to lower the internal resistance [29]. Min, etc. [38] developed a flat-panel system, the anode and cathode, respectively,pavilion dv1000 battery , pf723a, fixed at the both sides of the PEM, in the continuous flow of sewage treatment process, are able to receive the output power of 76mW m2. Although we do not reach non-PEM cell output power, but proved to electrode location and the availability of space affect the output power of PEM are an important factor. (3) the distance between electrodes and electrode surface area of the system, the impact resistance.

Zhen [3] designed upflow microbial fuel cell (UMFC), use of and Rabaey [30] the same as the PEM and the electrode material, but its presario x6000 battery , pavilion zv5000 battery internal resistance is 27 times the latter. UMFC resistance is mainly due to two inter-electrode distance, so that proton transfer in the electrolyte resistance encountered become larger. In addition, the cathode surface [40] and electrode solution ionic strength is also affected an important factor in battery internal resistance. Logan, etc. [32] through the medium to add to KCl, to increase the medium's ionic strength to enhance the conductivity of solution, thereby enhancing the output power. 3 Transfer factors Reactant to the active microbial mass transfer resistance between the cathode region and the proliferation of electronic end-receptor rate electron transfer process are the main constraints.

Although the cathode reaction of oxygen as electron acceptor when, with easy access to, pavilion zv6000 battery, hp 367759-001the reaction of the final product does not exist for the water and after the deal's advantages, but its biggest problem is the low solubility in water, mass transfer rate of a smaller impact on cathodic reaction rate. So the study [3,40] used iron cyanate as a final electron acceptor in order to obtain greater output power and current. Is generally perceived to be because of iron relative to oxygen isocyanates for greater mass transfer efficiency. Rabaey, etc. [30] the use of iron cyanide as a cathode mediator was 3 6W m2 of output power. In addition, the design of air cathode microbial fuel cell solution are an effective way to transfer problem is also an important future direction of development. Liu, etc. [4,37] have designed a single-chamber air cathode placed in the system and the air cathode of PEM systems, and one system in the post-glucose and sewage as fuel, have been 146mW m2 maximum output power.

In addition, the mixing reactor, the maximum growth rate of micro-organisms, micro-organisms on substrate affinity, pm579a , pavilion dv4000 battery, biomass load, operating temperature and pH on the microbial fuel cell within the influential mass transfer [30].