Proton Exchange Membrane Fuel Cell (PEMFC) has the characteristics of high energy conversion efficiency, high power density, fast start-up at room temperature, low noise and zero pollution, which is expected to alleviate the energy crisis and reduce carbon dioxide emissions. It has broad application prospects in rail transit, aerospace and other fields. Catalyst is one of the key materials of PEMFC. Moreover, Pt catalysts are widely used and considered difficult to be replaced because of their good activity and stability in oxygen reduction reaction. Pt is expensive because of its limited storage. However, Pt loading could be significantly lessened by Pt support to improve PEMFC utilization. Carbon materials are widely used as Pt supports because of their low cost, high specific surface area, pore structure, adjustable conductivity and surface properties, but commercial carbon black supports have low utilization efficiency and poor electrochemical corrosion resistance for Pt. For realizing the large-scale application of PEMFC, it is necessary to develop new carbon supports which can uniformly disperse Pt, efficiently utilize Pt, be resistant to electrochemical corrosion, and have good conductivity, thus the performance and sustainability of PEMFC are improved. Carbon aerogels, carbon nanotubes, graphene and other new carbon supports with unique structures and properties, which are expected to improve PEMFC performance and life, have attracted the attention of many researchers. In this paper, the research progress on new carbon material as Pt support for PEMFC in recent years is reviewed systematically, and the development trend is also commented appropriately.

Mn ²⁺ intercalation strategy to optimize the sodium storage performance of V₂C MXene was studied. The intercalated Mn ²⁺ not only enlarged the interlayer spacing of V₂C MXene but also formed a V-O-Mn covalent bond, which was beneficial to stabilize the structure of V₂C and inhibit the structural collapse caused by volume change during Na ⁺ decalation or intercalation. As a result, the intercalated V₂C MXene (V₂C@Mn) electrode showed a high specific capacity of 425 mAh·g ^-1 at the current density of 0.05 A·g ^-1, and 70% retention after 1200 cycles. This result clearly suggests that cations intercalated MXene has a great prospect in Na ⁺ storage.

Ge nanoparticles were synthesized uniformly on MXene sheets via a one-step chemical solution method. Morphology of Ge/MXene was characterized by SEM and TEM. Formation process and optimized synthesis condition was analyzed carefully. Ge/MXene was used as anode for lithium-ion batteries. Their electrochemical performances, including capacity, rate and cycling stability, were tested and evaluated. Ge/MXene exhibited a greatly improved capacity of 1200 mAh/g during the first hundred cycles at 0.2C with a loading of 1 mg/cm ². A capacity of 450 mAh/g at a higher loading of 2 mg/cm ² was obtained after 100 cycles. The excellence in electrochemistry is attributed to the high conductivity of MXene and its accommodable interlayer space.

Manganese-based oxides are promising cathode materials for zinc-ion batteries. However, these materials often suffer from rapid capacity fade due to structure collapse during charge and discharge processes. Here, we report that core-shell structured Mn₃O₄@ZnO nanosheet arrays are synthesized on the carbon cloth, combining microwave hydrothermal process with atomic layer deposition. With an optimized thickness of ZnO coating layer, the capacity retention of the as-formed Mn₃O₄@ZnO nanosheet arrays exhibits 60.3% over 100 discharge-charge cycles at a current density of 100 mA·g ^-1. It is demonstrated that the introduction of ZnO layers is beneficial to maintain the microstructure and improve the structural stability of the Mn₃O₄ electrode material during the discharge-charge process, benefiting from avoiding direct contact with the electrolyte. The design of the well-defined core-shell structure provides an effective way to develop high-performance manganese-based oxide cathode materials for zinc-ion batteries.

Carbon nanospheres enriched with α-MoC_1-x nanocrystalline (α-MoC_1-x/CNS) were synthesized by self-assembly and applied as a mediator for the surface of commercial polypropylene (PP) separator. Compared with pristin PP separator, the cycling stability and rate performance of the lithium-sulfur batteries with the modified α-MoC_1-x/CNS-PP separator are significantly improved and the battery with α-MoC_1-x/CNS-PP separator exhibits an initial discharge capacity of 1129.7 mAh/g at 0.5C and retains 855.5 mAh/g after 100 cycles with above 98% Coulombic efficiency. Remarkably, the capacity loss rate is only 7.7% after 48 h static storage. Combined with the morphology and XPS analysis of α-MoC_1-x/CNS, it is found that the designed α-MoC_1-x/CNS-PP separator prevents the migration of lithium polysulfide to the anode during the process of charge and discharge in lithium sulfur batteries. Formations of Mo-S bonds, thiosulfate and polythionate are attributed to the contact between lithium polysulfide and α-MoC_1-x/CNS, which further restrains active material in cathode region and improves the performance of lithium- sulfur batteries consequently.

Lanthanum-substituted La_xSr_2-3x/2Fe_1.5Ni_0.1Mo_0.4O_6-δ (La_xSFNM, x=0, 0.1, 0.2, 0.3, 0.4) oxides were synthesized by the solid-state reaction method, and investigated as potential anodes for Solid Oxide Fuel Cells(SOFC). X-ray diffraction patterns of as-synthesized powders confirm the formation of the cubic perovskite structure. Reduction in H₂ promotes the segregation of nano-scale metallic Fe-Ni alloy particles on the grain surfaces. Scanning electron microscopy observations indicate that increasing La ³⁺ dopants results in a decrease in the density of the exsolved nanoparticulates. Based upon impedance measurements on symmetrical fuel cells, the anode polarization resistance decreases with the La ³⁺ dopant increasing, and attains a minimal value of 0.16 W?cm ² for La_0.3SFNM at 750 ℃, followed by a slight increase to 0.17 W?cm ² for La_0.4SFNM. The highest catalytic activity of La_0.3SFNM toward electro- oxidation of hydrogen fuels could be ascribed to the synergy between the exsolved Fe-Ni alloy nanoparticulates and the supporting La_xSFNM oxides. Thin La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ (LSGM) electrolyte fuel cells with La_0.3SFNM anodes and SmBa_0.5Sr_0.5Co₂O₆ cathodes exhibit the highest power densities, e.g., 1.26, 0.90 and 0.52 W?cm ^-2 at 750, 650 and 550 ℃, respectively. These results demonstrate La_0.3SFNM oxide as a promising high performance SOFC anode.