Polymer Electrolyte Research Articles

Optimization on the peroxide ratio control strategy of PEMFC system based on immune algorithm

The air supply system is an essential component of a proton exchange membrane fuel cell (PEMFC), and proper control of the oxygen stoichiometry ratio(λo2) is crucial to prevent oxygen starvation in the PEMFC while maintaining efficient and stable performance output. In response to the issues of poor dynamic performance and slow response in traditional λo2 control strategies, this study was conducted to establish a dynamic oxygen flow model of the PEMFC and proposed a λo2 control strategy based on an immune algorithm-fuzzy PID (IAFPID). The performance of the IAFPID control strategy in λo2 control was analyzed under different load requirements, simulated vehicle dynamic loads, and temperature disturbances. The results demonstrate that the IAFPID control strategy has advantages such as fast convergence speed, strong robustness, and good dynamic performance. The efficiency of achieving the optimal stoichiometry ratio for high power output in PEMFC under disturbances was nearly 50% higher with IAFPID control compared to traditional PID, Fuzzy-PID, Genetic Algorithm PID, and Immune Algorithm PID strategies. Furthermore, this method ensures a lower average error in maintaining stable λo2 under dynamic disturbances compared to the IAPID and PID control strategies, with reductions of 12.93% and 37.75%, respectively.

Self‐Extinguishing and Low‐Cost Quasi‐Solid Polymer Electrolyte for Room Temperature Lithium Metal Batteries

Most modification strategies of polyethylene oxide (PEO)‐based solid polymer electrolyte focus on improving the room temperature ionic conductivity, while disregarding its inherent flammability that poses substantial safety hazard. Herein, a self‐extinguishing quasi‐solid‐state polymer electrolyte (PTTF‐SPE), which combines excellent room temperature electrochemical properties and high safety, has been developed by introducing triethyl phosphate (TEP) as a low‐cost and highly effective flame retardant. The cross‐linking structure derived from ‐CH2‐CH2‐O‐ segments of tetramethylene glycol dimethyl ether (TEGDME) and PEO makes a contribution to a high amorphous state of polymer. A robust solid electrolyte interphase (SEI) formed by preferential decomposition of fluoroethylene carbonate (FEC) that acts as a film‐forming additive, which can prevent TEP from degradation at lithium metal anode. The optimized PTTF‐SPE exhibits high ionic conductivity (0.54×10‐3 S/cm) and lithium transference number (0.71) at room temperature. The LiFePO4||Li battery demonstrates excellent cycle life over 500 cycles at 0.5 C with a high average discharge capacity of 131 mAh/g. A symmetric Li||Li battery that operating for 850 hours indicates a good compatibility of PTTF‐SPE towards lithium metal. This work provides a new idea for developing high‐energy‐density and high‐safety lithium‐metal batteries (LMBs) for room temperature.

Metal bond strength regulation enables large-scale synthesis of intermetallic nanocrystals for practical fuel cells.

Structurally ordered L10-PtM (M = Fe, Co, Ni and so on) intermetallic nanocrystals, benefiting from the chemically ordered structure and higher stability, are one of the best electrocatalysts used for fuel cells. However, their practical development is greatly plagued by the challenge that the high-temperature (>600 °C) annealing treatment necessary for realizing the ordered structure usually leads to severe particle sintering, morphology change and low ordering degree, which makes it very difficult for the gram-scale preparation of desirable PtM intermetallic nanocrystals with high Pt content for practical fuel cell applications. Here we report a new concept involving the low-melting-point-metal (M' = Sn, Ga, In)-induced bond strength weakening strategy to reduce Ea and promote the ordering process of PtM (M = Ni, Co, Fe, Cu and Zn) alloy catalysts for a higher ordering degree. We demonstrate that the introduction of M' can reduce the ordering temperature to extremely low temperatures (≤450 °C) and thus enable the preparation of high-Pt-content (≥40 wt%) L10-Pt-M-M' intermetallic nanocrystals as well as ten-gram-scale production. X-ray spectroscopy studies, in situ electron microscopy and theoretical calculations reveal the fundamental mechanism of the Sn-facilitated ordering process at low temperatures, which involves weakened bond strength and consequently reduced Ea via Sn doping, the formation and fast diffusion of low-coordinated surface free atoms, and subsequent L10 nucleation. The developed L10-Ga-PtNi/C catalysts display outstanding performance in H2-air fuel cells under both light- and heavy-duty vehicle conditions. Under the latter condition, the 40% L10-Pt50Ni35Ga15/C catalyst delivers a high current density of 1.67 A cm-2 at 0.7 V and retains 80% of the current density after extended 90,000 cycles, which exceeds the United States Department of Energy performance metrics and represents among the best cathodic electrocatalysts for practical proton-exchange membrane fuel cells.

Structurally Tunable Graphitized Mesoporous Carbon for Enhancing the Accessibility and Durability of Cathode Pt‐Based Catalysts for Proton Exchange Membrane Fuel Cells

Low Pt utilization and intense carbon corrosion of cathode catalysts is a crucial issue for high‐efficiency proton exchange membrane fuel cells due to the highly demanded long‐term durability and less acquisition/application cost. Herein, structurally tunable graphitized mesoporous carbon (GMC) is obtained by direct high‐temperature pyrolysis and in situ‐controlled mesopore formation; the structure‐optimized GMC1300‐1800 exhibits a mesopore size of 7.54 nm and enhanced corrosion resistance. Functionalized GMC1300‐1800 is loaded with small‐sized Pt nanoparticles (NPs) (1.5 nm) uniformly by impregnation method to obtain Pt/GMC1300‐1800 and form an “internal platinum structure” to avoid sulfonic acid groups poisoning as well as ensure O2/proton accessibility. Hence, the electrochemically active surface area (ECSA) of Pt/GMC1300‐1800 reaches 106.1 m2 g−1Pt, while mass activity and specific activity at 0.9 V are 2.1 and 1.4 times those of commercial Pt/C, respectively. Notably, the ECSA decay is less than 17% for both 30 000 cycles’ accelerated durability tests (ADTs) of Pt attenuation and carbon attenuation. Accordingly, the optimized mesoporous structure of GMC1300‐1800 significantly decreases the coverage of sulfonic acid groups on Pt NPs, leading to the highest peak power density in the single‐cell test. Density functional theory calculations demonstrate the synergistic effect between graphitization and mesoporosity on enhancing the accessibility and durability of the catalysts.

Experimental Study on the Electrochemical Performance of PEMFC under Different Assembly Forces

Proton exchange membrane fuel cell (PEMFC) is of paramount significance to the development of clean energy. The components of PEMFC are assembled using many pairs of nuts and bolts. The assembly champing bolt torque is critical to the electrochemical performance and mechanical stability of PEMFC. In this paper, a PEMFC with the three-channel serpentine flow field was used and studied. The different assembly clamping bolt torques were applied to the PEMFC in three uniform assembly bolt torque and six non-uniform assembly bolt torque conditions, respectively. And then, the electrochemical performance experiments were performed to study the effect of the assembly bolt torque on the electrochemical performance. The test results show that the assembly bolt torque significantly affected the electrochemical performance of the PEMFC. In uniform assembly bolt torque conditions, the maximal power density increased initially as the assembly bolt torque increased, and then decreased on further increasing the assembly torque. It existed the optimum assembly torque which was found to be 3.0 N·m in this work. In non-uniform assembly clamping bolt torque conditions, the optimum electrochemical performance appeared in the condition where the assembly torque of each bolt was closer to be 3.0 N·m. This could be due to the change of the contact resistance between the gas diffusion layer and bipolar plate and mass transport resistance for the hydrogen and oxygen towards the catalyst layers. This work could optimize the assembly force conditions and provide useful information for the practical PEMFC stack assembly.

Nickel Decoration Promotes Pure Hydrogen Release from Sodium Zinc Borohydride

Sodium zinc borohydride (NaZn(BH4)3) is an attractive hydrogen storage material due to its ease of preparation and hydrogen release aligning well with the operational conditions of proton exchange membrane fuel cells. However, a critical limitation of NaZn(BH4)3 is the loss of boron as diborane (B2H6) during hydrogen release. Herein, this work presents a straightforward approach to address this challenge. NaZn(BH4)3 is stabilized in the form of nanorods and decorated with nickel (Ni) as a catalyst. Notably, Ni‐decorated NaZn(BH4)3 exhibits pure hydrogen release at a significantly lower temperature (50 °C) compared to pristine material, which releases a substantial amount of B2H6 alongside hydrogen at 100 °C. In‐depth structural analyses reveal that Ni decoration facilitates the decomposition of B2H6 (into B and H2) near the interfaces between the shell and borohydride core within the NaZn(BH4)3 nanorods. These findings pave the way for the development of novel strategies to achieve pure hydrogen generation from various mixed‐metal complex hydrides.

Design of adaptive hybrid MPPT controllers with universal input voltage DC–DC converter for RES’s

At present, conventional energy production is absent because of the more hazardous gases released into the environment, the high effect on human health, more cost required for maintenance, plus less usefulness for highly populated areas. So, the Renewable Energy Sources are more focused for the present automotive industry application. In this work, the Proton Exchange Membrane Fuel Stack is considered for analyzing the proposed DC–DC converter circuit. The advantages of this fuel stack are high energy density, fast functioning nature, more robustness, and more usefulness for the various water membrane conditions of the fuel stack. However, the disadvantages of the fuel stack are excessive current generation, plus more current conduction losses. So, the wide voltage supply single switch power converter is introduced in this work for optimizing the current production of the fuel stack network. The merits of this converter circuit are high stability, good reliability, low voltage appearing across the switches, plus a uniform power supply. Here, the converter switching pulses are obtained by proposing the Modified Continuous Step Change Adaptive Fuzzy Logic with Grey Wolf Optimization hybrid controller. This controller provides high maximum power extraction efficiency from the fuel stack which is equal to 99.421%. Also, this controller's Maximum Power Point Tracking time is 0.0285 s.

In-situ X-ray Fluorescence Analysis of In-plane Cerium-ion Distribution Under Humidity Gradients in Proton Exchange Membrane

Cerium ions are incorporated into proton exchange membranes (PEMs) of fuel cells to mitigate its chemical degradation caused by radical species. However, under fuel cell operating conditions, cerium ions move in in-plane direction in the cell by humidity gradient. This cerium ion transport results in cerium ion depletion leading to accelerated chemical degradation. This study developed an in-situ and operando measurement technique utilizing synchrotron high-energy X-ray fluorescence spectroscopy to monitor the cerium ion transport across the membrane under the in-plane humidity gradient. This method effectively tracks the dynamic behavior of cerium ions under fuel cell operating conditions.

Opening and Constructing Stable Lithium‐ion Channels within Polymer Electrolytes

Lithium‐ion batteries play an integral role in various aspects of daily life, yet there is a pressing need to enhance their safety and cycling stability. In this study, we have successfully developed a highly secure and flexible solid‐state polymer electrolyte (SPE) through the in‐situ polymerization of allyl acetoacetate (AAA) monomers. This SPE constructed an efficient Li+ transport channel inside and effectively improved the solid‐solid interface contact of solid‐state batteries to reduce interfacial impedance. Furthermore, it exhibited excellent thermal stability, an ionic conductivity of 3.82×10‐4 S cm‐1 at room temperature (RT), and a Li+ transport number (tLi+) of 0.66. The numerous oxygen vacancies on layered inorganic SiO2 created an excellent environment for TFSI‐ immobilization. Free Li+ migrated rapidly at the C=O equivalence site with the poly(allyl acetoacetate) (PAAA) matrix. Consequently, when cycled at 0.5 C and RT, it displayed an initial discharge specific capacity of 140.6 mAh g‐1 with a discharge specific capacity retention rate of 70% even after 500 cycles. Similarly, when cycled at a higher rate of 5 C, it demonstrated an initial discharge specific capacity of 132.3 mAh g‐1 while maintaining excellent cycling stability.

Durability Investigation of Low Pt-Loaded PEM Fuel Cells with Different Catalyst Layer Morphologies

This study investigates the durability of proton exchange membrane fuel cells against the Pt-dissolution degradation mechanism using a triangular accelerated stress test (AST) within the voltage range of 0.6-1 V. The electrochemical active surface area and polarization curves are reported throughout the AST for three different catalyst layers (CL), all featuring 0.1 mg/cm2 Pt loading but with different morphologies, which include the Pt/C weight percentages, dilution ratio, and thickness. In addition, a numerical model is employed to simulate the electrochemical performance of these samples at the beginning and end of life, considering the variations in the oxygen transport resistances and catalyst structure.

Parametric Optimization of Proton Exchange Membrane Fuel Cell Using Chaotic Swarm Intelligence Technique

AbstractThe proton exchange membrane fuel cell (PEMFC) converts chemical energy into electricity without pollution or noise. PEMFC has a stable electrolyte, reliable, fast start‐up, and lightweight portability. Optimal PEMFC parameter prediction is difficult. Due to inaccurate estimation, many meta‐heuristic models are inaccurate. Particle swarm, Ant colony, and grey wolf algorithms are tested for fuel cell parameter estimation. These traditional algorithms benefit from chaotic maps for exploitation and exploration. Analyzing V–I and P–I polarization curves, hybrid approaches estimate unknown parameters. Results are compared with others to support the identifying strategy. This project examined SR‐12 and NedSstack PS‐6 PEMFC stacks. The objective function was shown by the sum of square errors between the experiments, and once an appropriate map is identified, the single chaotic map inclusion method can perform better than the multiple chaotic map scheme, and the “Iterative” approach in chaotic swarm is the most promising for multidimensional challenges.

Improvement of corrosion resistance and electrical conductivity of a Cr–C coated heat-assisted forming stainless steel bipolar plate for proton exchange membrane fuel cell

Heat-assisted forming is gaining increasing attention for its potential in improving the formability and quality of metallic bipolar plate (BPP) of proton exchange membrane fuel cell (PEMFC). However, the effects of heat-assisted forming and the subsequent coating process on corrosion resistance and electrical conductivity of stainless steel BPP still remain unclear. This work proposes a way to improve simultaneously the corrosion resistance and electrical conductivity of heat-assisted forming stainless steel BPP by depositing a Cr–C coating directly on its surface without removing the oxide layer using the magnetron sputtering method. Potentiodynamic tests indicate that self-corrosion current density and corrosion current density at 1.0 V (vs. Ag/AgCl) of the Cr–C coated heat-assisted forming SS316L BPP prepared under 900 °C for 10 min are 0.021–0.040 μA cm−2 and 77.54 μA cm−2, respectively, both of which are smaller than those of coated SS316L BPP formed under room temperature. In addition, the contact resistance is close to that of the gold-plated copper plate under the same pressure. The corrosion resistant intermediate oxide layer and conductive network formed between Cr–C coating and metal substrate through defects of oxide layer may be the main reason for improvement of its corrosion resistance and electrical conductivity, respectively.

Recent advances in Pt catalysts and membrane electrode assemblies fabrication for proton exchange membrane fuel cells

Recent advances in Pt catalysts and membrane electrode assemblies fabrication for proton exchange membrane fuel cells

Optimisation and effect of ionomer loading on porous Fe–N–C-based proton exchange membrane fuel cells probed by emerging electrochemical methods

The next generation of proton exchange membrane fuel cells (PEMFCs) require a substantial reduction or elimination of Pt-based electrocatalyst from the cathode, where O2 reduction takes place. The most promising alternative to Pt is atomic Fe embedded in N-doped C (Fe–N–C). Successful incorporation of Fe–N–C in PEMFCs relies on a thorough understanding of the catalyst layer properties, both ex situ and in situ, with tailored electrode interface engineering. To help resolve this conundrum, we provide a quantitative protocol on the optimisation of I/C for Fe–N–Cs. It is demonstrated that a high pore volume (3.33 cm3 g−1FeNC) Fe–N–C catalyst requires a sufficiently high ionomer to catalyst mass ratio (I/C, 2.8≤I/C ≤ 4.2) for optimum PEMFC activity under H2/O2. Emerging electrochemical techniques (distribution of relaxation times and Fourier transformed alternating current voltammetry) were used to deconvolute for the first time the trade-off between proton and electron resistance and accessible FeNx active site density with increasing ionomer loading. These findings highlight the significant impact of tuning the I/C ratio based on the catalyst layer properties and feature the power of evolving electrochemical tools for optimising performance in PEMFCs and other electrochemical devices.

Coupling Global Parameters and Local Flow Optimization of a Pulsed Ejector for Proton Exchange Membrane Fuel Cells

Proton exchange membrane fuel cells (PEMFCs), as an important utilization of hydrogen energy, contribute to the sustainable development of global energy. Pulsed ejectors have a high potential for improving the hydrogen utilization of PEMFCs in the full operating range by circulating unconsumed hydrogen. In this study, a pulsed ejector applied to a 120 kW fuel cell was designed, and the flow characteristics were analysed using computational fluid dynamics (CFD). Based on the data from the CFD model, the global optimization of the ejector was carried out using the Gaussian process regression (GPR) surrogate model and the grey wolf optimization (GWO) algorithm. The local structure was then further optimized using an adjoint method coupling streamlining modification that takes into account the local flow characteristics. The CFD results showed that, under a fixed structure, increasing the pressure difference between the secondary flow and the ejector outlet would promote boundary layer separation, shorten the shockwave chain length, change the effective flow area of the secondary flow, and lower the entrainment ratio (ER). The analytical results from the GPR model indicated significant interactions among the structural parameters. The globally optimized ejector using GPR and GWO improved the hydrogen entrainment ratio from 1.42 to 3.12 at the design point. Furthermore, the results of streamlining local optimization show that the entrainment ratio increased by 1.67% at the design point and increased by up to 3.99% over the full operating range compared to the optimized ejector by global optimization.

Synthesis of low cost cathode electrocatalyst Pt‐Ni/CAB using DMSO as a solvent for low temperature proton exchange membrane fuel cell application

AbstractIn the present study, low cost platinum based bimetallic electrocatalyst Pt‐Ni/CAB with varying Pt to Ni atomic ratios 3:1, 1:1, and 1:3 were successfully synthesized for oxygen reduction reaction (ORR) of the developed proton exchange membrane fuel cell (PEMFC). The solvothermal process was adopted for the synthesis of Pt‐Ni(3:1)/CAB, Pt‐Ni(1:1)/CAB, and Pt‐Ni(1:3)/CAB using dimethyl sulfoxide (DMSO) as solvent at a temperature of 190°C which is very close to the boiling point. The Pt‐Ni/CAB exhibited the highest activity for the ORR in half‐cell and single cell PEMFC performance. The electrocatalysts Pt‐Ni(1:3)/CAB appeared with smallest crystalline FCC structures having crystallite size of 8.33 nm. The transmission electron microscopy (TEM) analysis also show that the Pt‐Ni(1:3)/CAB has smallest particle size of 1.67 ± 0.45 nm. The cyclic voltammetry (CV) analysis shows Pt‐Ni(1:3)/CAB electrocatalyst offers less activation loss at ORR peak at a potential of 0.16 V as compared to Pt‐Ni(3:1)/CAB (ORR peak – 0.12) and Pt‐Ni(1:1)/CAB (ORR peak – 0.11). The synthesized Pt‐Ni(1:3)/CAB produced a maximum power density of 18.86 mW/cm2 at a maximum current density of 44.8 mA/cm2 with an open‐circuit voltage of 0.914 V at a room temperature of 33°C. The power density improved around 1.34 times when the cell temperature was raised from 33 to 70°C. The Pt‐Ni(1:3)/CAB cathode electrocatalyst could be used as economical to substitute costly commercial pure platinum based electrocatalyst.

A Comparative Study on Electrochemical Performance of Single versus Dual Networks in Lithium Metal/Polysulfide-Polyoxide Co-Network/Lithium Titanium Oxide Cathode

The present article introduces a strategy for controlling oxidation and reduction reactions within polymer electrolyte membrane (PEM) networks as a means of enhancing storage capacity through the complexation of dissociated lithium cations with multifunctional groups of the polymer network. Specifically, co-polymer networks based on polysulfide (PS) and polyoxide (PO) precursors, photo-cured in the presence of succinonitrile (SCN) and lithium bis(trifluoro methane sulfonyl imide) (LiTFSI) salt, exhibited ionic conductivity on the order of mid 10−4 S/cm at ambient temperature in the 30/35/35 (weight %) composition. Lithium titanate (LTO, Li4Ti5O12) electrode was chosen as an anode (i.e., a potential source of Li ions) against lithium iron phosphate (LFP, LiFePO4) cathode in conjunction with polysulfide-co-polyoxide dual polyelectrolyte networks to control viscosity for 3D printability on conformal surfaces of drone and aeronautic vehicles. It was found that the PS-co-PO dual network-based polymer electrolyte containing SCN plasticizer and LiTFSI salt exhibited extra storage capacity (i.e., specific capacity of 44 mAh/g) with the overall specific capacity of 170 mAh/g (i.e., for the combined LTO electrode and PEM) initially that stabilized at 153 mAh/g after 50th cycles with a reasonable capacity retention of over 90% and Coulombic efficiency of over 99%. Of particular interest is the observation of the improved electrochemical performance of the polysulfide-co-polyoxide electrolyte dual-network relative to that of the polyoxide electrolyte single-network.

Green hydrogen prospects in Peninsular Malaysia: a techno-economic analysis via Monte Carlo simulations

According to Malaysia's National Energy Transition Roadmap, hydrogen is a critical component of the country's energy transition. However, there is a scarcity of hydrogen studies for Peninsular Malaysian states, which limits discussions on green hydrogen production. This study employs a Monte Carlo model to assess the economic and technical factors influencing the success of green hydrogen in Peninsular Malaysia. The study focuses on three target years: 2023, 2030, and 2050, representing various stages of technological development and market adoption. The levelized cost of hydrogen (LCOH) of a 1-MW Proton Exchange Membrane (PEM) electrolyzer system ranges from $5.39 to $10.97 per kg in 2023, highlighting early-stage challenges and uncertainties. A 6-MW PEM electrolyzer system could achieve an LCOH of $3.50 to $4.72 per kg by 2030, indicating better prospects. Because of technological advancements and cost reductions, a 20-MW PEM electrolyzer system could achieve an LCOH of $3.12 to $3.64 per kg in 2050. The findings indicate that the northern regions of Peninsular Malaysia have consistently low LCOH values due to favorable geographical conditions. Due to minor variations in solar capacity factors, uncertainty distributions in LCOH remain stable across different regions. Some states may face increased uncertainty, emphasizing the need for additional policy support mechanisms to mitigate risks associated with green hydrogen investments. The sensitivity analysis shows that key cost drivers are shifting, with early-stage electrolyzer investments dominating in 2023 and electricity prices becoming more important in 2030 and 2050. Future research could focus on optimizing green hydrogen systems for areas with underdeveloped green hydrogen industries. This study contributes to informed discussions about green hydrogen production by emphasizing the importance of tailored strategies that consider local conditions and highlighting the role of Peninsular Malaysia in the energy transition.

Breaking the Trade‐Off between Ionic Conductivity and Mechanical Strength in Solid Polymer Electrolytes for High‐Performance Solid Lithium Batteries

AbstractSolid polymer electrolytes (SPEs) are among the most promising candidates for solid‐state batteries due to their easy processibility, interface compatibility, and cost efficiency. However, the trade‐off between the ionic conductivity and mechanical strength of SPEs, which has persisted for decades, hinders their application in solid‐state lithium (Li) metal batteries. In this study, the aim is to break this trade‐off by utilizing poly(p‐phenylene benzobisoxazole) (PBO) nanofibers as a mechanically strong backbone and polyethylene oxide (PEO) as an ionically conductive network. The PBO/PEO composite electrolyte reduces the crystallinity of PEO while increasing the mechanical strength (74.4 MPa, ≈14 times that of PEO). Thus, PBO/PEO simultaneously improves ionic conductivity and mechanical strength both at room temperature and elevated temperatures, enabling uniform and smooth Li deposition. Thus, a long cycle life of solid‐state Li symmetric cells for 1000 h at 60 °C is achieved, and stable cycling of solid‐state Li metal full batteries at 60 °C and even 100 °C. Furthermore, the solid‐state pouch cell using this SPE exhibits excellent performance reliably after bending. The study clearly indicates that simultaneously improving mechanical properties and conductivity is the indispensable path to the practical application of solid‐state electrolytes.

Electrical behavior and water phase transformation in multi‐walled carbon nanotube/polytetrafluoroethylene composite films

AbstractMulti‐walled carbon nanotubes (MWCNTs) with excellent physiochemical properties have been recently applied to energy/power generation and storage systems encompassing polymer electrolyte membrane fuel cells (PEMFCs). However, there is a lack of investigations of the properties of MWCNT composites themselves under the actual operating conditions of systems. In this paper, MWCNTs/polytetrafluoroethylene (PTFE) composites were fabricated as electric and hydrophobic components for energy/power systems. The electrical properties, heating behavior, hydrophobicity, and water evaporation behavior of the composites are characterized within the operating voltage ranges of PEMFC. With 50% MWCNT content, the conductivity and the contact angle were 11.83 S/cm, and the contact angle 128.1°, respectively. The MWCNT/PTFE composite film showed a linear temperature rise with voltages and rapid temperature saturation within 40 s. The rate in the initial heating range was measured at 0.5°C/s for the voltage of 0.5 V. The voltage increase induced an exponential decrease in the height of water droplets on the composite surface. The evaporation rate increased almost 10‐fold, from 0.013 mm/min at 0.0 V to 0.12 mm/min at 1.0 V. The proposed characteristics of the functional composite provide insights into the material requirements for electrochemical devices, including PEMFC.Highlights Multi‐walled carbon nanotube/polytetrafluoroethylene composites can be applied to energy storage and power generation. Key properties of the composites are proposed for polymer electrolyte membrane fuel cell (PEMFC) operating conditions. The composite has a fast heating by high conductivity and temperature uniformity. Water‐vapor transformation under PEMFC operating voltage is quantified.