Passive Direct Methanol Fuel Cell Research Articles

Self-sustainable, self-healable sulfonated graphene oxide incorporated nafion/poly(vinyl alcohol) proton exchange membrane for direct methanol fuel cell applications

Nafion, a perfluorosulfonic acid polymer, has been the standard membrane material for direct methanol fuel cells (DMFCs) due to its proton-carrying capabilities, despite its shortcomings as a methanol barrier. To attain self-healing and methanol-blocking properties, the incorporation of poly(vinyl alcohol) (PVA) polymer into Nafion was pursued. However, this strategy resulted in low proton conductivity. Thus, acid functional groups were added to a secondary modifier to boost proton conductivity. In this work, sulfonated graphene oxide (SGO) was assembled with Nafion and PVA through a simple freezing-thawing method to demonstrate a self-healable proton exchange membrane (PEM) without compromising the proton conductivity of Nafion. The synergistic effect of SGO in methanol-blocking and proton transport successfully strode over recast Nafion by hampering 33.2 % of methanol permeation and increasing 19.5 % of proton conductivity. As a result, the selectivity of the best hybrid PEM (N/PVA/SGO1.0) was increased by 1.8 times in comparison to recast Nafion. A single cell passive DMFC made using the novel hybrid membrane exhibited a power density of 6.07 mW cm−2 at a current density of 26.48 mA cm−2, and an open circuit voltage of 0.55 V at room temperature using 4 M methanol. This performance was essentially higher than that achieved by recast Nafion and commercial Nafion 117. The N/PVA/SGO1.0 hybrid membrane also showed remarkable self-healing properties, with 89 % recovery of methanol blocking function through reversible hydrogen bonding, illustrating its tremendous sustainable potential for use in DMFCs.

Research on design strategies and sensing applications of energy storage system based on renewable methanol fuel

The rapid depletion of traditional non-renewable fossil fuels has increased energy sustainability threats. Methanol is recognized as one of the viable alternatives to conventional fossil fuels mainly due to its high energy density and abundant raw materials. Direct methanol fuel cells (DMFCs) can convert the chemical energy of methanol into electricity in real time, which is one of the most effective ways to utilize methanol energy. However, DMFCs have undesirable performance, such as low fuel utilization, low cell voltage, and unstable output voltage, hindering the development of methanol energy technology. Herein, we design an energy storage system with high methanol energy efficiency based on passive micro DMFCs. This system with low power consumption (only uW scale) can extract the high chemical energy in methanol, efficiently convert it into electric energy, and store it to output a stable voltage for load. Moreover, application research on this system has been carried out. A self-powered methanol concentration sensor is designed and implemented on a printed circuit board. It can detect methanol solution with a concentration of 3 M–12 M, only requiring it to be tested as fuel without an additional power supply. The sensor has about 1.1 mW total power consumption and 0.34 s response time. This study on the energy conversion and storage of sustainable methanol fuel aims to provide a reference to explore the application of renewable energy.

Comparison of the Anode Side Catalyst Supports with and without Incorporation of Liquid Electrolyte Layer on the Performance of a Passive Direct Methanol Fuel Cell

In the passive direct methanol fuel cell (DMFC) operation, the catalyst plays an important role in electrical energy production. Efficient catalyst support increases the power output and simultaneously decreases irreversible losses in the fuel cell (FC). Effective utilization of methanol at the anode end reduces methanol crossover by selecting good anode catalyst supports. In the present study, two types of anode catalyst support of carbon and carbon black are used. The two types of anode catalysts are Pt-Ru/C+ Pt-Ru/black and Pt-Ru/C along with a 2 mm thick liquid electrolyte (LE) layer placed in the middle of the two half MEAs. The LE layer is made of piled hydrophilic filter papers, which are soaked in a solution of 1 M H2SO4 concentration. The methanol concentration is varied from 1 M to 12 M and from 1 M to 5 M with and without LE-inserted FC, respectively. The passive DMFC with Pt-Ru/C+ Pt-Ru/black anode catalyst and the LE layer exhibit the best performance, producing an MPD of 5.328 mWcm-2 at a 5 M methanol concentration. The MPD produced by the anode catalyst of Pt-Ru/C+ Pt-Ru/black and Pt-Ru/C along with the 2 mm thickness LE layer incorporated fuel cell is 75.26% higher than conventional-based FC of anode catalyst of single-layer catalyst of Pt-Ru/C.

Fuel cells operating as an immunosensor for cancer biomarker screening

This work presents the first integration of antibodies into one of the electrodes of a passive direct methanol fuel cell (DMFC) to create an autonomous immunosensor for cancer antigen 15–3 (CA15-3). The anode of the fuel cell was first made of carbon cloth with carbon black, platinum and ruthenium nanoparticles and then modified with anti-CA15-3, while the cathode was made of carbon cloth with carbon black and platinum nanoparticles. This hybrid DMFC (hDMFC), which works as an immunosensor, was fed with dilute methanol to generate a concentration-dependent current.The hDMFC device was calibrated in different media (buffer and serum), by incubating increasing concentrations of CA15-3 standard solutions, ranging from 47 to 750 U/mL. The linear response ranged from 188 to 563 U/mL, and the limit of detection (LoD) was 39.8 U/mL. The selectivity of the biosensor was also evaluated with competing cancer biomarkers, such as carcinoembryonic antigen (CEA), and cancer antigen 125 (CA-125), as well as with other compounds normally present in blood plasma (ascorbic acid, glucose, uric acid and urea), adjusted to the normal range of concentrations in serum. The results obtained indicate good selectivity of the immunosensor in the fuel cell.In general, the immunosensor showed a good response considering its integration into a passive DMFC. It is a good sensor for point-of-care (PoC) diagnosis because it has a good performance in human serum and, most importantly, it pursues electrical autonomy.

Green synthesis of polyvinyl-alcohol-montmorillonite clay cation exchange membrane for alkaline direct methanol fuel cell

The present study looked into a sustainable approach for synthesizing sodium ion conducting cation exchange membrane, in addition to addressing the methanol permeability, ionic conductivity, and cost of the direct methanol fuel cell (DMFC). The polyvinyl alcohol (PVA)-based sodium ion conducting membranes were synthesized by the sustainable modified phase inversion technique using a green nonsolvent coagulation bath composed of sodium hydroxide and sodium sulfate. Alkaline medium operating sulfonated polyvinyl alcohol (SPVA)-montmorillonite clay (MMT) was developed to overcome the drawbacks of a proton exchange membrane working in an acidic medium and an anion exchange membrane used in an alkaline medium. The SPVA-MMT membrane exhibited ionic conductivity of 0.0751 S cm−1 due to the presence of inorganic salts in the coagulation bath and the cation exchange capacity of the clays. Passive alkaline DMFC studies conducted using SPVA-MMT membrane showed a peak power density of 7.51 mW cm−2 at ambient conditions.

Water and heat management of vapor-fed direct methanol fuel cells with a non-isothermal triple-phase mass transfer model

Direct methanol fuel cells (DMFCs) operating with methanol vapor tends to operate under higher temperature, which contributes to improve cell performance and specific energy. However, the design of vapor-fed DMFCs with high performance and adaptability are still hindered by the complex water and heat management. To provide a comprehensive understanding of the critical multiphase heat and mass transfer, we develop a two-dimensional non-isothermal triple-phase mass transfer model for a passive vapor-fed DMFC. Effects of the electrochemical reactions and related thermal effect are fully investigated. Increasing the current density raises the operating temperature, thus enhancing the generation rate of methanol vapor and reducing concentration polarization under high current densities. With the enlargement of the open area ratio (from 0.1 to 0.3), an excessive methanol supply rate may cause deteriorated methanol crossover rates and excessively high temperatures, resulting in severe dehydration of polymer electrolytes and a degraded cathode overpotential (from −0.48V to −0.54V). For the DMFC with Nafion 112 membrane, the maximum current density and peak power density are 33.3% and 36.0% greater than that of Nafion 117 membrane. The simulation work will provide an exhaustive theoretical guidance for the efficient management of water and heat in DMFCs fed with neat methanol.

Passive direct methanol fuel cells acting as fully autonomous electrochemical biosensors: Application to sarcosine detection

This work describes an innovative electrochemical biosensor that advances its autonomy toward an equipment-free design. The biosensor is powered by a passive direct methanol fuel cell (DMFC) and signals the response via an electrochromic display. Briefly, the anode side of the DMFC power source was modified with a biosensor layer developed using molecularly imprinted polymer (MIP) technology to detect sarcosine (an amino acid derivative that is a potential cancer biomarker). The biosensor layer was anchored on the surface of the anode carbon electrode (carbon black with Pt/Ru, 40:20). This was done by bulk radical polymerization with acrylamide, bis-acrylamide, and vinyl phosphonic acid. This layer selectively interacted with sarcosine when integrated into the passive DMFC (single or multiple, in a stack of 4), which acted as a transducer element in a concentration-dependent process. Serial assembly of a stack of hybrid DMFC/biosensor devices triggered an external electrochromic cell (EC) that produced a colour change. Calibrations showed a concentration-dependent sarcosine response from 3.2 to 2000 µM, which is compatible with the concentration of sarcosine in the blood of prostate cancer patients. The final DMFC/biosensor-EC platform showed a colour change perceptible to the naked eye in the presence of increasing sarcosine concentrations. This colour change was controlled by the DMFC operation, making this approach a self-controlled and self-signalling device. Overall, this approach is a proof-of-concept for a fully autonomous biosensor powered by a chemical fuel. This simple and low-cost approach offers the potential to be deployed anywhere and is particularly suitable for point-of-care (POC) analysis.

Experimental investigations on passive direct methanol fuel cell using variable membrane electrode assembly dynamic regions by altering gasket shapes

PurposeThe purpose of this paper is to investigate the performance of Passive Direct Methanol Fuel Cell (PDMFC) experimentally using various Membrane Electrode Assembly (MEA) shapes such as square, rectangle, rhombus, and circle with equal areas and equal perimeters. The variation in MEA shape/size is achieved by altering gasket openings in the dynamic regions.Design/methodology/approachIn the equal areas of MEA shapes, gasket opening areas of 1963.5 (+/−0.2) mm2 are used. Whereas in the equal perimeters of shapes, gasket opening perimeters of 157.1 (+/−0.2) mm are used. In this experimentation, Nickel-201 current collectors with 45.3% of circular openings are used on both the anode and cathode sides. The experiment is carried out at a 5 molar methanol concentration to find out the highest power density of the cell.FindingsIn the equal areas, among the shapes that are chosen for investigation, the square shape opening consisting of a perimeter of 177.2 mm has developed a maximum power density of 6.344 mWcm−2 and a maximum current density of 65.2 mAcm−2. Similarly, in equal perimeters, the rhombus shape opening with an area of 1400 mm2 has developed a maximum power density of 7.714 mWcm−2 and a maximum current density of 85.3 mAcm−2.Originality/valueThe novelty of this research work is instead of fabricating various shapes and sizes of highly expensive MEAs, the desired shapes and sizes of the MEA are achieved by altering gasket openings over dynamic regions to find out the highest power density of the cell.

Recent Advances in the Development of Nanocatalysts for Direct Methanol Fuel Cells

Direct methanol fuel cells (DMFCs) have attracted much attention due to their potential application as a power source for portable devices. Their simple construction and operation, associated with compact design, high energy density, and relatively high energy-conversion efficiency, give the DMFCs an advantage over other promising energy production technologies in terms of portability. Nowadays, research on DMFCs has received increased attention in both academics and industries. However, many challenges remain before these systems become commercial, including their costs and durability. As a key material with a high-value cost, noble metal catalysts for both the anode and cathode sides face several problems, which hinder the commercialisation of DMFCs. This paper provides a detailed comprehensive review of recent progress in the development of nanocatalysts (NCs) for the anode and cathode reactions of DMFCs, based on Platinum, Platinum-hybrid, and Platinum-free materials. Particular attention is devoted to the systematisation of published experimental results tested in DMFC devices since 2015, with an emphasis on passive DMFC systems. In addition, a dedicated section was created to include modelling/theoretical studies. Some open problems and remaining challenges are also highlighted in the final section.

Passive Direct Methanol Fuel Cells Acting as Fully Autonomous Electrochemical Biosensors: Application to Sarcosine Detection

Passive Direct Methanol Fuel Cells Acting as Fully Autonomous Electrochemical Biosensors: Application to Sarcosine Detection

Evolution of oxygen reduction property by the role of CeO2 in CeO2/MnO2 cathode catalyst for passive direct methanol fuel cells

The oxygen reduction reaction (ORR) efficiency of direct methanol fuel cell (DMFC) is of great significance. In this work, MnO2 supported on CeO2-QDs (CeO2-QDs@MnO2) and CeO2-QDs supported on MnO2 (MnO2@CeO2-QDs) composite with different loading method were synthesized to investigate the role of CeO2 for ORR, according to the excellent oxygen adsorption and oxygen ion conductivity of CeO2 quantum dots (CeO2-QDs). A passive DMFC was assembled by CeO2-QDs@MnO2 or MnO2@CeO2-QDs as cathodic catalyst and PtRu/C as anodic catalyst. The maximum power densities for CeO2-QDs@MnO2 and MnO2@CeO2-QDs-based DMFCs were 9.4 and 7.8 mW·cm−2, while 8.5 and 7.0 mW·cm−2 for air-breathing DMFCs, respectively. CeO2-QDs@MnO2 showed a more superior ORR activity and stability in the high discharge currents especially for air-breathing DMFCs. The temporary storage and timely replenishment mechanism of oxygen in CeO2-QDs@MnO2 catalyst could significantly enhance the ORR efficiency at cathode. This work developed a new thought about the loading method of CeO2 on the ORR catalytic activity for CeO2/MnO2 catalysts.

Modification and Optimization of Rice Husk Ash Bio-Filler in Sulfonated Polyimide Membrane for Direct Methanol Fuel Cell

Direct methanol fuel cell (DMFC) is a very high potential renewable and sustainable energy for portable devices as it has very high energy density and more environmentally friendly. Adding filler into the membrane matrix had reported in improved performance of the DMFC. However, addition of filler will lead to the decrease of the ion exchange capacity of the membrane, which will in turn reduce the fuel cell performance. Hence, this work studies the modification of rice husk ash via sulfonation process and the effect of the synthesis parameter of novel sulfonated polyimides/sulfonated rice husk ash (SPI/sRHA) composite membrane towards fuel cell performance where filler sRHA had been synthesized via the mixing reaction between rice husk ash (RHA) with chloroform and chlorosulfonic acid. The composition of filler in membranes was optimized with different synthesis parameters such as different types of filler used, loading of filler in membrane and membrane annealing temperature. Investigation of the effects for these three parameters on the physicochemical properties of the composite membranes produced was carried out using response surface methodology (RSM) approach to optimize the synthesis parameters of the composite membrane. The fillers and composite membranes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller (BET) analysis and transmission electron microscopy. Different synthesis parameters had shown different influences on the physicochemical properties of the composite membranes and consequently, gave different passive fuel cell performances of DMFCs too. The optimized membrane (S-12-sR) showed enhanced physicochemical performance as well as the passive single cell performance as compared to pure SPI and Nafion 117 membranes. The water uptake, proton conductivity and IEC that had been achieved by the optimized membrane were 90.97%, 0.1891 S cm−1 and 0.2608 mmol g−1 respectively. The maximum power density of the passive DMFC was improved from 8.1 mW cm−2 to 16.4 mW cm−2 under ambient conditions.

Effect of cathode end plate on passive direct methanol fuel cell performance

Direct methanol fuel cell (DMFC) belongs to the class of fuel cells that use polymer electrolyte membrane and operate on methanol-water mixture. The low overall performance of passive DMFC compared to active DMFC is due to the slow anode reaction combined with inefficient cathode reaction. In this work, an attempt was made to augment the passive DMFC performance by modifying the structural design of the cathode end plate (CEP). The passive DMFC was fabricated and the performance was investigated experimentally. Three different CEP duct configurations were studied using 1 to 5 M methanol mass fraction. The results indicated higher performance for square duct CEP configuration, with 5 M methanol mixture.

Experimental Evaluation of the Effect of the Anode Diffusion Layer Properties on the Performance of a Passive Direct Methanol Fuel Cell

Passive direct methanol fuel cells (pDMFCs) are promising devices to replace the conventional batteries in portable electronic devices, due to their higher energy densities, autonomies, and instant recharging. However, some challenges, such as their costs, efficiency, and durability, need to be overcome before their commercialization. Towards that, this work presents the effect of the anode diffusion layer (ADL) properties on the performance of a pDMFC using a membrane electrode assembly (MEA) with reduced loadings on both anode and cathode catalysts (3 mg/cm2 Pt/Ru on the anode and 1.3 mg/cm2 of Pt on the cathode). The pDMFC behavior was evaluated through polarization and electrochemical impedance spectroscopy measurements, which allow identifying and quantifying the different losses that affect these systems. The results showed better performances when a diffusion layer with a dual-layer structure was used using higher methanol concentrations. The maximum power density achieved was 3.00 mW/cm2, using carbon cloth with a microporous layer, CC_MPL, as ADL, and a methanol concentration of 5 M. In this work, a tailored and low-cost MEA, using the materials available in the market, was proposed to achieve higher performances working under higher methanol concentrations. This work demonstrates that performing modifications on the fuel cell structure/design is an efficient way to achieve optimized performances.

Numerical simulation on mass transport in a passive vapor-fed direct methanol fuel cell operating with neat methanol

A direct methanol fuel cell (DMFC) operating with neat methanol is a promising power candidate for electronic and portable devices because of its high specific energy. But complex mass transport continues to hinder the reliability of such a DMFC. In this work, a two-dimensional isothermal model for a passive vapor-fed DMFC operating with neat methanol is developed to explore the triple-phase (gas, liquid and dissolved phases) mass transport and phase change. The simulation results indicate that the addition of water management layer at the cathode effectively facilitates the water recovery to the anode, especially under lower relative humidity condition. The increase of the methanol vapor supply rate alleviates the concentration polarization at high current densities, but the aggravated methanol crossover by an excessive fuel supply decreases the cathode performance. The elevated operating temperature enhances the electrochemical kinetics and mass transport, while excessively high temperature leads to the degradation of the cell performance due to significant water loss. The present work provides an effective theoretical guidance for the design and operation of a passive vapor-fed DMFC operating with neat methanol.

Performance evaluation of the incorporation of different wire meshes in between perforated current collectors and membrane electrode assembly on the Passive Direct methanol fuel cell

Passive Direct methanol fuel cells (DMFC) are more suitable for charging small capacity electronic devices. In passive DMFC, the fuel and oxidant are supplied by diffusion and natural convection process on the anode and cathode sides respectively. Current collectors (CC) play a vital importance in fuel cell performance. This paper presents the combined impact of perforated and wire mesh current collectors (WMCC) on passive DMFC performance. Three types of open ratios of perforated current collectors (PCC), such as 45.40%, 55.40% and 63.40% and two types of wire mesh current collectors with open ratios of 38.70% and 45.40% were chosen for the experimental work. A combination of Taguchi-L9 rule is considered. A combination of three PCC and two WMCC on both anode and cathode was used. Methanol concentration was varied from 1 mol·L −1 –5 mol·L −1 for nine combinations of PCC and WMCC. From the experimental results, it is noticed that the combination of PCC and WMCC with an open ratio of 55.40% and 38.70% incorporated passive DMFC produced peak power density at 5 mol·L −1 of methanol concentration. The passive DMFC performance was evaluated in terms of maximum power density and maximum current density. The combined current collectors of PCC and WMCC open ratios of 55.40% + 38.70% have more stable voltage than single PCC of open ratio 63.40% at 4 mol·L −1 of methanol concentration. This paper presents the combined impact of perforated and wire mesh current collectors (WMCC) on passive DMFC performance. Three types of open ratios of perforated current collectors (PCC) such as 45.40%, 55.40% and 63.40% and two types of wire mesh current collectors with open ratios of 38.70% and 45.40% were chosen for the experimental work.

Application of N-doped carbon nanotube-supported Pt-Ru as electrocatalyst layer in passive direct methanol fuel cell

In this research, nitrogen-doped carbon nanotubes (N-CNT) were prepared through the low-temperature thermal method and used as the support material for the bimetallic catalyst PtRu and Pt nanoparticles. A passive single-cell direct methanol fuel cell (DMFC) was designed and fabricated to investigate and compare the performance of three discrete membrane electrode assemblies (MEA) with carbon black (CB), CNT, and N-CNT as the catalyst support, respectively. Adding N to the structure of CNTs remarkably improves the physical and electrochemical characteristics of the catalyst. More active sites and stronger interaction between support and metal particles lead to the formation of smaller metal clusters and higher surface area as well as superior electrochemical activity. Compared to PtRu/CB and PtRu/CNT, PtRu/N-CNT illustrate 32% and 12% higher surface area, 3 and 1.9 times higher MOR activity, and 62% and 18% higher power output (26.1 mW/cm2), respectively. Moreover, it is revealed that PtRu/N-CNT has long-term stability in the MOR. The research work presented in this paper exhibits the outstanding performance of Pt and PtRu supported on N-CNT in a passive single-cell DMFC.

Evaluation of Quaternized polyvinyl alcohol/graphene oxide‐based membrane towards improving the performance of air‐breathing passive direct methanol fuel cells

Graphene oxide (GO) nanosheets are introduced to a Quaternized polyvinyl alcohol (QPVA) polymer matrix to obtain an anion exchange membranes (AEMs) for application of fuel cells. QPVA/GO nanocomposite membranes provide desirable properties such as low fuel uptake and permeability, excellent ionic conductivity, and cell performance, all of which are favorable for AEMs based on our previous works. Passive direct methanol fuel cells (DMFCs) are recognized as suitable technologies for use in portable devices. Nevertheless, the commercialization of DMFCs remains restricted due to a number of issues related to the conventional membrane; one of these issues is high fuel crossover problems due to high fuel uptake and permeability of Nafion membrane. This study aimed to expand the potential applications of QPVA/GO nanocomposite membranes in air-breathing passive DMFCs. The ionic conductivity, methanol uptakes (MUs), and permeabilities of self-synthesis QPVA/GO nanocomposites are examined to evaluate the ability to operate in methanol atmosphere. At 30°C, the ionic conductivity of the membranes reached 1.74 × 10−2 S cm−1. The MUs and permeabilities were as low as 35% and 7.6 × 10−7 cm2 s−1, respectively. The performance of air-breathing passive DMFCs bearing QPVA/GO nanocomposite membrane is much higher compared to conventional membranes. The maximum power density of air-breathing passive DMFCs was achieved 27.2 mW cm−2 under the optimum condition of 2 M methanol + 4 M KOH at 70°C. Single-cells could be sustained for 1000 hours. This article is the first to optimize and highlight the performance air-breathing passive DMFCs by using a QPVA-based membrane.

Fabrication of MEA from Biomass-Based Carbon Nanofibers Composited with Nickel-Cobalt Oxides as a New Electrocatalyst for Oxygen Reduction Reaction in Passive Direct Methanol Fuel Cells

Biomass has some advantages including renewability, abundant resources, being eco-friendly, easy processing, and low cost; and it is an important step in designing electrocatalysts in fuel cells as clean energy sources. In this study, a biomass-based carbon nanofiber of Typha domingensis, as available biomass source, and nickel-cobalt oxides is synthesized. The physicochemical techniques including X-ray powder diffraction, Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, Barrett-Joyner-Halenda, and Brunauer-Emmett-Teller as well as electrochemical techniques are used to evaluate the surface morphology, crystal structure, and electrochemical performance of composites. The biomass-derived composite is used as a new electrocatalyst for the oxygen reduction reaction and oxygen evaluation reaction. A membrane electrode assembly is prepared by employing of the produced composite for alkaline passive direct methanol fuel cell, which characterized by polarization, power density curves, methanol crossover test, and stability test for 8 h. Electrochemical results show that the composite is an appropriate electrode material for oxygen reduction reaction in passive direct methanol fuel cells.

Highly Durable Passive Direct Methanol Fuel Cell with Three‐Dimensional Ordered Porous NiCo2O4 as Cathode Catalyst

AbstractThe performance of durability in direct methanol fuel cell (DMFC) is of great significance. In this study, NiCo2O4 with three‐dimensional ordered hierarchical pore was applied as oxygen reduction reaction electrocatalyst to enhance the long‐term stability in passive DMFC. The peak power densities of NiCo2O4‐based DMFC were 14.78 and 26 mW cm−2 at 15 and 40 °C, respectively. In the durability test, NiCo2O4‐based DMFC could operate continually for 1406 hours, which is approximately 6 times higher than the highest values reported in literature. And the outstanding durability could be mainly ascribed to the interconnected and ordered macropores channel in NiCo2O4, which could act as a structural buffer to mitigate the structural changes in porous nano‐catalysts, and also significantly facilitate the mass transport and the rapid elimination of cathodic product to solve the problem of “water flooding” at the cathode.