A study on composite PtRu(1:1)-PtSn(3:1) anode catalyst for PEMFC

Composite PtRu(1:1)/C-PtSn(3:1)/C catalyst layers with various geometries and loadings were designed for a proton exchange membrane fuel cell (PEMFC) anode to improve carbon monoxide (CO) tolerance of the conventional PtRu(1:1)/C catalyst. The idea was based on an experimental finding that the onset potential of the PtSn for CO oxidation was lower than that of the PtRu and the resultant expectation that there seemed to be a possibility of using the PtSn as a CO filter. The CO tolerance of the composite catalyst of each design was judged by the cell performance obtained through a single cell test using H₂/CO gases of various CO concentrations and compared to that of the PtRu/C catalyst. The highest CO tolerance among the composite catalysts tested in this study was obtained for the one with geometry of double layers in the order of PtRu/C and PtSn/C from the electrolyte layer and with respective PtRu and PtSn loadings of 0.25 and 0.12 mg cm⁻². The cell with this composite catalyst showed better performance than the one with the PtRu/C catalyst. When a H₂/100 ppmCO gas was used as the fuel in the single cell test, the cell voltages were measured to be 0.49 and 0.44 V at a current density of 500 mA cm⁻², respectively for the cell with the composite and PtRu/C catalyst.     

Development of materials for mini DMFC working at room temperature for portable applications

Methanol permeability measurements and direct methanol fuel cell tests were performed at room temperature with different commercially available or recast Nafion^® membranes and sulfonated polyimide (SPI) membranes. Power densities as high as 20 mW cm⁻² could be obtained with Nafion^® 115. However, in order to meet the technological requirements for portable applications, thinner membranes have to be considered. As the MeOH crossover increases greatly (from (7 to 20) × 10⁻⁸ mol s⁻¹ cm⁻²) while Nafion^® membranes thickness decreases, non-perfluorinated polymers having high IEC are promising candidates for DMFC working at room temperature. The development catalysts tolerant to methanol is also relevant for this application. In spite of the low permeability to MeOH of SPI membranes, the obtained electrical performance with E-TEK electrodes based MEAs was lower than that obtained with Nafion^® membranes. No significant increase of performances was neither evidenced by using homemade PtCr(7:3)/C and PtRu(4:1)/C catalysts instead of E-TEK electrodes with recast Nafion^® based MEAs. However, MEAs composed with thin SPI membranes (50 μm) and homemade PtCr/C catalysts gave very promising results (18 mW cm⁻²). Based on experimental observations, a speculative explanation of this result is given.     

The effect of the MEA preparation procedure on both ethanol crossover and DEFC performance

In the present work, the changes of Nafion^®-115 membrane porosity in the presence of ethanol aqueous solutions of different concentrations were determined by weighing vacuum-dried and ethanol solution-equilibrated membranes. It was found that membrane porosity increases as ethanol concentration increases. Membrane electrode assemblies (MEAs) have been prepared by following both the conventional and the decal transfer method. The ethanol crossover through these two MEAs was electrochemically quantified by a voltammetric method. A 10 h stability test of direct ethanol fuel cell (DEFC) at a current density of 50 mA cm⁻² was carried out. It was found that the electrode preparation procedure has an obvious effect on ethanol crossover and direct ethanol fuel cell's performance and stability. The single DEFC test results showed that about 15 and 34% of the original peak power density was lost after 10 h of life test for the MEAs prepared by the decal transfer method and the conventional method, respectively. Electrochemical impedance spectrum (EIS) results of the MEAs showed that, in the case of the membrane electrode assembly prepared by the following decal transfer method, the internal cell resistance was almost the same, 0.236 Ω cm² before the life test and 0.239 Ω cm² after 10 h of life test, while the respective values for the membrane electrode assembly by the conventional method are 0.289 and 0.435 Ω cm². It is supposed that the improved cell performance with MEA by the decal transfer method could be resorted to both a better contact between the catalyst layer and the electrolyte membrane and higher catalyst utilization. Furthermore, based on the experimental results, the increased internal cell resistance and the degraded single DEFC performance could be attributed to the delamination of the catalyst layer from the electrolyte membrane.     

Influence of pore structure on electric double-layer capacitance of template mesoporous carbons

The behavior of two types of mesoporous carbons with different pore structures (i.e. unimodal and bimodal) as electrode material in an electrochemical double-layer capacitor has been analyzed. The carbon samples were prepared using mesostructured silica materials (MSM) as templating agents. The unimodal mesoporous carbon has a BET surface area of 1550 m² g⁻¹, and a pore volume of 1.03 cm³ g⁻¹; the porosity is mainly made up of structural mesopores of ca. 3 nm that exhibit a narrow pore size distribution (PSD). The bimodal carbon shows larger surface area (1730 m² g⁻¹) and larger pore volume (1.50 cm³ g⁻¹); the porosity is composed of two types of mesopores: structural (size around 3 nm) and complementary (size around 16 nm) mesopores. Both carbons show a disordered 3-D pore structure. Heat treatments at high temperatures (1000 °C) for long times (11 h) do not significantly change the pore structure with respect to the two synthesised carbons (800 °C). From the synthesized and heat-treated carbons, electrodes were processed as composites in which the carbons, polivinilidene fluoride (PVDF) and carbon black (CB) were the components. The effect of the heat treatment and relative CB content on specific capacitance, energy density and power density were studied. We found a specific capacitance of 200 F g⁻¹ for low current density (1 mA cm⁻²) and 110 F g⁻¹ for high current density (150 mA cm⁻²). Moreover, the curve of the specific capacitance versus current density shows three regimes, which are related to the three types of pore: micropores, structural mesopores and complementary mesopores. An energy density of 3 Wh kg⁻¹ at a power density of 300 W kg⁻¹ was obtained in some particular cases.     

Electrodeposited PtRu on cryogel carbon–Nafion supports for DMFC anodes

For a high catalytic activity of the anodes in DMFC at low noble metal content a fine dispersion of PtRu on carbon supports is required and to this purpose we prepared and investigated high specific surface area cryogel carbons of controlled mesoporosity. Two carbons CC1 and CC2 with pore-size distribution centered at 6 and 20 nm were obtained by sol–gel polycondensation of resorcinol and formaldehyde, followed by a freeze-drying procedure, a versatile and low-cost method to provide after pyrolysis carbons of controlled porosity. Electrodeposited PtRu on CC2-Nafion support with ca. 100 μg cm⁻² of Pt displayed a good catalytic activity for methanol oxidation of 85 mA mg⁻¹ of Pt after 600 s at 492 mV versus NHE and 60 °C in H₂SO₄ 0.1 M–CH₃OH 0.5 M when the Pt-to-C mass ratio was ca. 10%. The catalytic activity tests and XRD and SEM analyses demonstrated the stability of the prepared electrodes upon catalysis in the time scale of our measurements. Strategies to further increase the catalytic activity of the PtRu/cryogel carbon–Nafion electrodes for methanol oxidation are discussed.     

Recycling of nickel from NiOOH/Ni(OH)2 electrodes of spent Ni–Cd batteries

In this work, nickel from the positive electrode of Ni–Cd batteries was recycled by chemical precipitation and electrodeposition. The structure of the material recovered by chemical precipitation is affected by temperature. Alfa nickel hydroxide is stable at low temperature but becomes beta nickel hydroxide with increasing of the synthesis temperature. Electrodeposition was accomplished by using the galvanostatic technique. The chronopotentiometric plots presented a plateau potential in the initial stage of the deposit growth due to the reduction of ionic nickel. Charge density of the plateau potential and charge efficiency decreased with increase in current density. Charge efficiency around 81.0% was the largest for current densities between 5.0 mA cm⁻² and 10.0 mA cm⁻² for q = 9.0 C cm⁻². As charge density increased to 90.0 C m⁻², the electrodeposition efficiency decreased. In this case, there is a second plateau potential at which the evolution of hydrogen on the nickel electrode, the principal reaction, is quickly reached. Charge density affects not only the reaction kinetics, but also the deposit morphology. A decrease in microporosity is observed with the increase in charge density. The microporosity increases as the current density increases for the same charge density.     

Performance of membrane electrode assemblies based on proton exchange membranes prepared by pre-irradiation induced grafting

Proton exchange membranes (PEMs) were prepared by pre-irradiation induced grafting of styrene (S) or styrene/divinylbenzene (S/DVB) into the radiation-crosslinked polytetrafluoroethylene (RX-PTFE) films and then sulfonated. The thicknesses of the obtained PEMs were lower than 20 μm and the ion exchange capacity (IEC) values were around 2 meq g⁻¹. The surfaces of the PEMs and carbon electrodes were coated with Nafion^® dispersion, and then membrane electrode assembles (MEAs) were prepared by hot-pressing them together. A MEA based on a Nafion^® 112 membrane was also prepared under same procedure for comparison. The performances of the MEAs in a single cell were tested under different cell temperatures and humidifications. Electrochemical impedance spectra (EIS) were measured with ac frequencies which ranged from 100 kHz to 1 Hz at a dc density of 0.5 A cm⁻². The obtained impedance curves in Nyquist representation were semicircular.     

Enhanced electrocatalytic performance for methanol oxidation of a novel Pt-dispersed poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonic acid) electrode

A new catalyst electrode was prepared in which Pt particles were homogeneously distributed into a poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonic acid) (PEDOT–PSS) matrix. Catalytic activity and stability for the oxidation of methanol were studied by using cyclic voltammetry and chronoamperometry. For comparative purposes, bulk Pt and PEDOT–PSS based electrodes were fabricated and tested. Enhanced electrocatalytic activity toward the oxidation of methanol was noticed when Pt particles were embedded into the PEDOT–PSS matrix. A high catalytic current for methanol oxidation (2.51 mA cm⁻²) was found for the PEDOT–PSS–Pt electrode in comparison to bulk Pt electrode (0.45 mA cm⁻²) at +0.6 V (versus Ag/AgCl). The enhanced electrocatalytic activity might be due to the dispersion of Pt particles into the PEDOT–PSS matrix and the synergistic effects between the dispersed Pt particles and the PEDOT–PSS matrix. The morphology and crystalline behavior of PEDOT–PSS–Pt and simple ITO/Pt films were determined by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) and correlated with the enhanced electrocatalytic activity for the Pt-dispersed PEDOT–PSS electrode.     

Electrochemical lithium insertion in TiO2 with the ramsdellite structure

The electrochemical insertion of lithium in the ramsdellite polymorph of titanium dioxide, TiO₂ (R), is studied by electrochemical methods. At room temperature the maximal Li uptake under constant current densities of 0.1, 0.5 and 1.0 mA cm⁻² is 0.85, 0.8 and 0.7 Li/Ti, respectively. Between 2.3 and 1.3 V versus lithium, the specific capacity achieved is as high as 285 A h kg⁻¹ at 0.5 mA cm⁻². This corresponds to 85% of the maximum theoretical capacity (336 A h kg⁻¹), which may be reached by incorporation of one lithium per titanium under equilibrium conditions.     

Ammonia fuel cell using doped barium cerate proton conducting solid electrolytes

Proton-conducting solid electrolytes composed of gadolinium-doped barium cerate (BCG) or gadolinium and praseodymium-doped barium cerate (BCGP) were tested in an intermediate-temperature fuel cell in which hydrogen or ammonia was directly fed. At 700 °C, BCG electrolytes with porous platinum electrodes showed essentially no loss in performance in pure hydrogen. Under direct ammonia at 700 °C, power densities were only slightly lower compared to pure hydrogen feed, yielding an optimal value of 25 mW cm⁻² at a current density of 50 mA cm⁻². This marginal difference can be attributed to a lower partial pressure of hydrogen caused by the production of nitrogen when ammonia is decomposed at the anode.A comparative test using BCGP electrolyte showed that the doubly doped barium cerate electrolyte performed better than BCG electrolyte. Overall fuel cell performance characteristics were enhanced by approximately 40% under either hydrogen or ammonia fuels using BCGP electrolyte. At 700 °C using direct ammonia feed, power density reached 35 mW cm⁻² at a current density of approximately 75 mA cm⁻². Minimal loss of performance was noted over approximately 100 h on-stream in alternating hydrogen/ammonia fuels.     

Methoxy methane (dimethyl ether) as an alternative fuel for direct fuel cells

The electrooxidation of methoxy methane (dimethyl ether) was studied at different Pt-based electrocatalysts in a standard three-electrode electrochemical cell. It was shown that alloying platinum with ruthenium or tin leads to shift the onset of the oxidation wave towards lower potentials. On the other hand, the maximum current density achieved was lower with a bimetallic catalyst compared to that obtained with a Pt catalyst. The direct oxidation of dimethoxy methane in a fuel cell was carried out with Pt/C, PtRu/C and PtSn/C catalysts. When Pt/C catalyst is used in the anode, it was shown that the pressure of the fuel and the temperature of the cell played important roles to enhance the fuel cell electrical performance. An increase of the pressure from 1 to 3 bar leads to multiply by two times the maximum achieved power density. An increase of the temperature from 90 to 110 °C has the same effect. When PtRu/C catalyst is used in the anode, it was shown that the electrical performance of the cell was only a little bit enhanced. The maximum power density only increased from 50 to 60 mW cm⁻² at 110 °C using a Pt/C anode and a Pt_0.8Ru_0.2/C anode, respectively. But, the maximum power density is achieved at lower current densities, i.e. higher cell voltages. The addition of ruthenium to platinum has other effect: it introduces a large potential drop at relatively low current densities. With the Pt_0.5Ru_0.5/C anode, it has not been possible to applied current densities higher than 20 mA cm⁻² under fuel cell operating conditions, whereas 250 and almost 400 mA cm⁻² were achieved with Pt_0.8Ru_0.2/C and Pt/C anodes. The Pt_0.9Sn_0.1/C anode leads to higher power densities at low current densities and to the same maximum power density as the Pt/C anode.     

Electrodeposition synthesis and electrochemical properties of nanostructured γ-MnO2 films

The thin films of carambola-like γ-MnO₂ nanoflakes with about 20 nm in thickness and at least 200 nm in width were prepared on nickel sheets by combination of potentiostatic and cyclic voltammetric electrodeposition techniques. The as-prepared MnO₂ nanomaterials, which were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), were used as the active material of the positive electrode for primary alkaline Zn/MnO₂ batteries and electrochemical supercapacitors. Electrochemical measurements showed that the MnO₂ nanoflake films displayed high potential plateau (around 1.0 V versus Zn) in primary Zn/MnO₂ batteries at the discharge current density of 500 mA g⁻¹ and high specific capacitance of 240 F g⁻¹ at the current density of 1 mA cm⁻². This indicated the potential application of carambola-like γ-MnO₂ nanoflakes in high-power batteries and electrochemical supercapacitors. The growth process for the one- and three-dimensional nanostructured MnO₂ was discussed on the basis of potentiostatic and cyclic voltammetric techniques. The present synthesis method can be extended to the preparation of other nanostructured metal-oxide films.     

Sulfonated poly(ether sulfone) for universal polymer electrolyte fuel cell operations

The performances of the proton exchange membrane fuel cell (PEMFC), direct formic acid fuel cell (DFAFC) and direct methanol fuel cell (DMFC) with sulfonated poly(ether sulfone) membrane are reported. Pt/C was coated on the membrane directly to fabricate a MEA for PEMFC operation. A single cell test was carried out using H₂/air as the fuel and oxidant. A current density of 730 mA cm⁻² at 0.60 V was obtained at 70 °C. Pt–Ru (anode) and Pt (cathode) were coated on the membrane for DMFC operations. It produced 83 mW cm⁻² maximum power density. The sulfonated poly(ether sulfone) membrane was also used for DFAFC operation under several different conditions. It showed good cell performances for several different kinds of polymer electrolyte fuel cell applications.     

Dependence of high-temperature PEM fuel cell performance on Nafion® content

Operating a proton exchange membrane (PEM) fuel cell at elevated temperatures (above 100 °C) has significant advantages, such as reduced CO poisoning, increased reaction rates, faster heat rejection, easier and more efficient water management and more useful waste heat. Catalyst materials and membrane electrode assembly (MEA) structure must be considered to improve PEM fuel cell performance. As one of the most important electrode design parameters, Nafion^® content was optimized in the high-temperature electrodes in order to achieve high performance. The effect of Nafion^® content on the electrode performance in H₂/air or H₂/O₂ operation was studied under three different operation conditions (cell temperature (°C)/anode (%RH)/cathode (%RH)): 80/100/75, 100/70/70 and 120/35/35, all at atmospheric pressure. Different Nafion^® contents in the cathode catalyst layers, 15–40 wt%, were evaluated. For electrodes with 0.5 mg cm⁻² Pt loading, cell voltages of 0.70, 0.68 and 0.60 V at a current density of 400 mA cm⁻² were obtained at 35 wt% Nafion^® ionomer loading, when the cells were operated at the three test conditions, respectively. Cyclic voltammetry was conducted to evaluate the electrochemical surface area. The experimental polarization curves were analyzed by Tafel slope, catalyst activity and diffusion capability to determine the influence of the Nafion^® loading, mainly associated with the cathode.     

Performance of direct methanol fuel cell using carbon nanotube-supported Pt–Ru anode catalyst with controlled composition

The performance of a single-cell direct methanol fuel cell (DMFC) using carbon nanotube-supported Pt–Ru (Pt–Ru/CNT) as an anode catalyst has been investigated. In this study, the Pt–Ru/CNT electrocatalyst was successfully synthesized using a modified polyol approach with a controlled composition very close to 20 wt.%Pt–10 wt.%Ru, and the anode was prepared by coating Pt–Ru/CNT electrocatalyst on a wet-proof carbon cloth substrate with a metal loading of about 4 mg cm⁻². A commercial gas diffusion electrode (GDE) with a platinum black loading of 4 mg cm⁻² obtained from E-TEK was employed as the cathode. The membrane electrode assembly (MEA) was fabricated using Nafion^® 117 membrane and the single-cell DMFC was assembled with graphite endplates as current collectors. Experiments were carried out at moderate low temperatures using 1 M CH₃OH aqueous solution and pure oxygen as reactants. Excellent cell performance was observed. The tested cell significantly outperformed a comparison cell using a commercial anode coated with carbon-supported Pt–Ru (Pt–Ru/C) electrocatalyst of similar composition and loading. High conductivity of carbon nanotube, good catalyst morphology and suitable catalyst composition of the prepared Pt–Ru/CNT electrocatalyst are considered to be some of the key factors leading to enhanced cell performance.     

Cresol–formaldehyde based carbon aerogel as electrode material for electrochemical capacitor

Carbon aerogels have been prepared through a polycondensation of cresol (Cm) with formaldehyde (F) and an ambient pressure drying followed by carbonization at 900 °C. Modification of the porous structures of the carbon aerogel can be achieved by CO₂ activation at various temperatures (800, 850, 900 °C) for 1–3 h. This process could be considered as an alternative economic route to the classic RF gels synthesis. The obtained carbon aerogels have been attempted as electrode materials in electric double-layer capacitors. The relevant electrochemical behaviors were characterized by constant current charge–discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy in an electrolyte of 30% KOH aqueous solution. The results indicate that a mass specific capacitance of up to 78 F g⁻¹ for the non-activated aerogel can be obtained at current density 1 mA cm⁻². CO₂ activation can effectively improve the specific capacitance of the carbon aerogel. After CO₂ activation performed at 900 °C for 2 h, the specific capacitance increases to 146 F g⁻¹ at the same current. Only a slight decrease in capacitance, from 146 to 131 F g⁻¹, was observed when the current density increases from 1 to 20 mA cm⁻², indicating a stable electrochemical property of carbon aerogel electrodes in 30% KOH aqueous electrolyte with various currents.     

Electrochemical properties of silicon deposited on patterned wafer

An amorphous silicon thin-film deposited on a patterned wafer is prepared by radio-frequency (rf) magnetron sputtering and is characterized by X-ray diffraction, galvanostatic cycle testing and field emission scanning electron microscopy. The specimen is assembled in cell of configuration: silicon working electrode/1 M LiPF₆ in EC/DMC, electrolyte/lithium metal, counter electrode (EC = ethylenecarbonate; DMC = dimethyl carbonate). A patterned silicon (1 0 0) wafer prepared by photolithography and KOH etching is used as the electrode substrate. The size of the patterns, which are composed of arrays of the negative square pyramids, is 5 μm/side.The patterned specimen (silicon film on patterned substrate) is compared with a normal specimen (silicon deposited on a flat substrate). The rate of capacity fade on cycling is monitored as a function of the voltage window and current density. The patterned specimen displays better cycle behaviour at a high current density (high C-rate).During the cycle tests at 200 μA cm⁻², the silicon electrodes yield an initial capacity of 327 μAh (cm² μm)⁻¹. After 100 cycles, the capacity is 285 μAh (cm² μm)⁻¹ and the capacity retention is 86%. Capacity retention is 76 and 61% at cycles 200 and 300, respectively.     

Effects of sputtering parameters on the performance of electrodes fabricated for proton exchange membrane fuel cells

One way to alleviate the emission of air pollutants and CO₂ due to burning fossil fuels is the use of fuel cells. Sputter deposition techniques are good candidates for the fabrication of electrodes used for proton exchange membrane fuel cells (PEMFCs). Input power and sputtering-gas pressure are two important parameters in a sputtering process. However, little is known about the effects of these sputtering parameters on the performance of PEMFC electrodes. Therefore, this study applied a radio frequency (RF) magnetron sputter deposition process to prepare PEMFC electrodes and investigated the effects of RF power and sputtering-gas pressure in electrode fabrication on electrode/cell performance. At a Pt loading of 0.1 mg cm⁻², the electrode fabricated at 100 W, 10⁻³ Torr was found to exhibit the best performance mainly due to its lowest kinetic (activation) resistance (dominating the cell performance) in comparison to those fabricated by 50 and 150 W at 10⁻³ Torr, as well as by 10⁻⁴ and 10⁻² Torr at 100 W. In the tested ranges, the control of sputtering-gas pressure seems to be more critical than that of RF power for the activation loss. In addition to electrochemically active surface area, electrode microstructure should also be responsible for electrode/cell polarization, particularly the activation polarization.     

Studies of performance degradation of a high temperature PEMFC based on H3PO4-doped PBI

In this paper, a 600 h life test of a high temperature PEMFC based on phosphoric acid (H₃PO₄)-doped polybenzimidazole (PBI) (H₃PO₄/PBI HT-PEMFC) at a current density of 714 mA cm⁻² (the beginning 510 h continuous test) and 300 mA cm⁻² (the last 90 h intermittent test) was carried out. After the life test, degradation of the MEA occurred. The H₂ crossover rate through the PBI membrane and the open circuit voltage (OCV) of the cell were tested with time. The results showed that, at the beginning of 510 h continuous test, the PBI membrane did not show much physical degradation, but during the last 90 h test there was a remarkable physical degradation which resulted in a higher H₂ crossover. The catalysts, PBI membranes and the membrane electrode assemblies (MEAs) before and after the life test were comprehensively examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). TEM results showed that the particle size of the Pt/C catalysts in the anode and cathode increased from 3.72 to 7.40 and 8.39 nm, respectively. SEM images of MEA in cross-section revealed that the PBI membrane became thin after the life test. EDS analysis implied the leaching of H₃PO₄ from the PBI membrane had occurred. Therefore, we conclude that physical degradation of PBI membrane, agglomeration of the electrocatalysts (both anode and cathode) and the leaching of H₃PO₄ from the PBI membrane were responsible for the performance degradation of the H₃PO₄/PBI HT-PEMFC.     

Performance of a polyaniline(DMcT)/carbon fiber composite as cathode for rechargeable lithium batteries

The redox reaction of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) is slow at room temperature, but it can be accelerated when the electron transfer reaction is coupled with that of polyaniline (Pani). Films of polyaniline were electrosynthesized onto carbon fiber substrates by cyclic voltammetry from a 0.5 mol L⁻¹ H₂SO₄/0.1 mol L⁻¹ aniline aqueous solution; DMcT was incorporated into the films by two different procedures: A – previous adsorption on the carbon fiber substrate, and B – electropolymerization onto a Pani film from a 20 mmol L⁻¹ DMcT solution in acetonitrile. The Pani(DMcT)/carbon fiber composites were tested as cathodes at 0.1 mA cm⁻² in a cell containing lithium as anode in a 0.5 mol L⁻¹ LiClO₄ solution in propylene carbonate, in a dry box under an argon atmosphere at 25 ± 2 °C. Discharge capacity values of 159 mA h g⁻¹ (after 90 cycles) and 39 mA h g⁻¹ (after 50 cycles) were obtained for the composites prepared by procedures A and B, respectively. The high capacity value and the high electrochemical stability during the cycling indicate that there is a synergetic effect of Pani and DMcT in the composites prepared by procedure A.