In this work, an ordered membrane electrode assembly (MEA) based on a cone Nafion array with gradient Nafion distribution, tightly bonded catalytic layer/proton exchange membrane (CL/PEM) interface, and abundant vertical channels has been engineered by an anodic aluminum oxide template and magnetron sputtering method. Benefiting from a highly efficient CL/PEM interface, plentiful proton transfer highways, and rapid oxygen bubble release, this ordered MEA achieves an ultralow Ir loading of 20.0 μg cm −2 and a high electrochemical active area by 8.7 times compared to traditional MEA with Ir loading of 1.0 mg cm −2 . It yields a mass activity of 168 000 mA mg Ir −1 cm −2 at 2.0 V, which is superior to most reported PEM electrolyzers. Notably, this ordered MEA maintains excellent durability at a current density of 500 mA cm −2 . This work opens a simple, cost-effective, and scalable route to design ordered MEAs for proton exchange membrane water electrolysis.

The proton exchange membrane fuel cell (PEMFC) is one of the most promising energy conversion devices. However, a PEMFC is hindered by the serious problem of water management. Herein, a Janus gas diffusion layer (Janus GDL) that can spontaneously transport water from the hydrophobic side to the hydrophilic side was prepared by layer-by-layer filtration and laser drilling. The Janus GDL exhibits a remarkable antiflooding capability at the equivalent current density of 3.25 A cm–2 (2.3–2.5 times compared to the commercial GDL) in the half-cell. Because of the low water breakthrough pressure (29 Pa), the Janus GDL drains excessive water immediately, thus preventing heavy electrode floodings. As a result, the Janus GDL shows a higher peak power density (1.89 W cm–2 vs 1.17 W cm–2 of commercial GDL). Therefore, the Janus GDL is promising for use in PEMFCs and other electrochemical devices to get a good water management.

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In a proton exchange membrane fuel cell (PEMFC), the membrane electrode assembly (MEA) is the core component and the region of the oxidation−reduction. In order to obtain a great performance, Pt with excellent catalyst efficiency is usually adopted in PEMFC as the catalyst. However, the high cost and poor durability remain the two major challenges in the application of PEMFC; thus, it is worth paying attention to enhance the utilization of the Pt catalyst and the stability of PEMFC. In this work, the Nafion array membrane with a larger specific surface and higher proton conductivity was applied to the cathode catalyst layer (CL) to prepare the ordered MEA. In order to improve the three-phase interface of the cathode CL, Nafion was adsorbed on the Pt particles as the proton conductor to expedite the proton transfer efficiency based on the principle that sulfonic acid is easily adsorbed on the Pt surface. In this case, the peak power density of PEMFC with Nafion absorption on the Pt surface is up to 843 mW cm −2 at the Pt loading of 61.4 μg cm −2 , which is much higher than that of the fuel cell without a proton conductor on the Pt catalyst in the cathode CL (710 mW cm −2 ). Besides, the durability tests show that PEMFCs with Nafion absorption on the Pt catalyst surface can work continuously for 100 h without obvious voltage attenuation, which is more stable than that of the bare Pt for 70 h. In conclusion, Nafion as the proton conductor was adsorbed on the Pt catalyst surface of the cathode CL to enhance the triple-phase interface in PEMFC, which is expected to be a universal method to prepare PEMFCs with high stability and peak power density at a low preparation cost.

Hierarchically patterned proton-exchange membranes (PEMs) have the potential to significantly increase the specific surface area, thus improving the catalyst utilization rate and performance of proton-exchange membrane fuel cells (PEMFCs). In this study, we are inspired by the unique hierarchical structure of the lotus leaf and proposed a simple three-step strategy to prepare a multiscale structured PEM. Using the multilevel structure of the natural lotus leaf as the original template, and after structural imprinting, hot-pressing, and plasma-etching steps, we successfully constructed a multiscale structured PEM with a microscale pillar-like structure and a nanoscale needle-like structure. When applied in a fuel cell, the multiscale structured PEM resulted in a 1.96-fold increase in discharge performance and a significant improvement in mass transfer compared to the membrane electrode assembly (MEA) with a flat PEM. The multiscale structured PEM has the combined advantage of a nanoscale and a microscale structure, benefiting from the markedly reduced thickness, increased surface area, and improved water management inherited from the multiscale structured lotus leaf’s superhydrophobic characteristic. Using a lotus leaf as a multilevel structure template avoids the complex and time-consuming preparation process required by commonly used multilevel structure templates. Moreover, the remarkable architecture of biological materials can inspire novel and innovative applications in many fields through nature’s wisdom.

With the rapid development of portable and wearable electronics, safety concerns over flexible energy devices are inevitable. Therefore, it is important to develop energy supplies that are safe for use. In this work, a highly safe, durable, adaptable, and flexible air‐breathing direct methanol fuel cell (DMFC) is successfully prepared by synthesizing and applying a new composite material with agar gel and wood sponge, that is, a gel/sponge composite. The gel/sponge composite has a high absorption rate, high cyclic performance, high methanol absorption capacity, high energy content, and high flexibility. Moreover, the gel/sponge composite with 1.5% agar gel retains approximately 90% of the methanol solution at a pressure of 29.4 kPa, and the areal energy density of the proposed DMFC approaches 13.7 mWh cm−2. Both the single‐cell and stack of DMFC with the new composite material successfully survive a series of destructive tests, including needle penetration, cutting, and compression. Therefore, it is successfully demonstrated that absorbent materials can greatly boost the safety, adaptability, flexibility, and energy density of air‐breathing DMFCs. Furthermore, this concept shows promise in improving the safety of other fuel cells by using absorbent materials to solidify their gaseous or liquid fuels.

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