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Abstract: In this work, a hierarchically porous and ultrathick “breathable” wood‐based cathode for high‐performance Li‐O2 batteries is developed. The 3D carbon matrix obtained from the carbonized and activated wood (denoted as CA‐wood) serves as a superconductive current collector and an ideal porous host for accommodating catalysts. The ruthenium (Ru) nanoparticles are uniformly anchored on the porous wall of the aligned microchannels (denoted as CA‐wood/Ru). The aligned open microchannels inside the carbon matrix contribute to unimpeded oxygen gas diffusion. Moreover, the hierarchical pores on the microchannel walls can be facilely impregnated by electrolyte, forming a continuous supply of electrolyte. As a result, numerous ideal triphase active sites are formed where electrolyte, oxygen, and catalyst accumulate on the porous walls of microchannels. Benefiting from the numerous well‐balanced triple‐phase active sites, the assembled Li‐O2 battery with the CA‐wood/Ru cathode (thickness: ≈700 µm) shows a high specific area capacity of 8.58 mA h cm−2 at 0.1 mA cm−2. Moreover, the areal capacity can be further increased to 56.0 mA h cm−2 by using an ultrathick CA‐wood/Ru cathode with a thickness of ≈3.4 mm. The facile ultrathick wood‐based cathodes can be applied to other cathodes to achieve a super high areal capacity without sacrificing the electrochemical performance. [ABSTRACT FROM AUTHOR]

The performance of the proton exchange membrane fuel cell (PEMFC) is significantly improved through introducing nitrogen-doped carbon nanotubes (NCNTs) into the catalyst layer (CL) and microporous layer (MPL) of the membrane electrode assembly (MEA), it reveals by SEM images that the NCNTs are uniformly dispersed in CL and MPL, resulting in the more plenty of porosity, higher surface area, better conductivity, and better prevention of the layer cracks. The BET surface area and pore volume of MPL are increased by 88% and 77% respectively with the addition of 20 wt% of NCNTs in MPL. The membrane electrode assembly (MEA) with adding 20 wt% NCNTs both in cathode CL and in cathode GDL can yield the best cell performance. At a cell temperature of 70 °C and 30 psi back pressures, the current density is up to 1000 mA cm −2 at 0.7 V and 1600 mA cm −2 at 0.6 V, and the max power density reaches 997 mW cm −2 . [ABSTRACT FROM AUTHOR]