BaCe_(0.8)Fe_(0.1)Ni_(0.1)O_(3−δ)-impregnated Ni-GDC by phase-inversion as an anode of solid oxide fuel cells with on-cell dry methane reforming

BaCe_(0.8)Fe_(0.1)Ni_(0.1)O_(3−δ)(BCFN)in a perovskite structure is impregnated consecutively by BCFN solution and BCFN suspension into a phase-inversion prepared NiO–Gd_(0.1)Ce_(0.9)O_(2−δ)(GDC)scaffold as an anode for solid oxide fuel cells(SOFCs)with on-cell dry reforming of methane(DRM).The whole pore surface of the scaffold is covered by small BCFN particles formed by BCFN solution impregnation;the large pores near the scaffold surface are filled by BCFN aerogels with a high specific surface area produced by BCFN suspension impregnation,which act as a catalytic layer for on-cell DRM.After reduction,the anode consists of a Ni–GDC scaffold and BCFN particles with exsolved FeNi3 nanoparticles.This BCFN-impregnated Ni–GDC anode has higher electrical conductivity,electrochemical activity,and resistance to carbon deposition,with which the cell shows maximum power densities between 1.44 and 0.92 W·cm^(−2) when using H_(2) and between 1.09 and 0.50 W·cm^(−2) when using CO_(2)–CH_(4) at temperatures ranging from 750 to 600℃.A stable performance at 400 mA·cm^(−2) and 700℃is achieved using 45%CO_(2)–45%CH_(4)–10%N_(2) for more than 400 h without carbon deposition,benefiting from the impregnated BCFN aerogel with a high specific surface area and water adsorbability.

Electrochemical Properties of Tubular SOFC Based on a Porous Ceramic Support Fabricated by Phase-Inversion Method

In this work, a tubular ceramic-supported solid oxide fuel cell （SOFC） was successfully fabricated by a low cost and simple process involving phase-inversion, brush coating and co-sintering. Properties in- cluding sintering behavior, microstructure of the tubular support as well as the electrochemical properties of single cell were investigated. The results show that a porous tubular support with finger-like pores and macrovoids was obtained after phase-inversion process. The tubular support is proved to be gaspermeable after sintering at 1400 ℃ with shrinkage of about 34%. The maximum power density of single tubular SOFC is 100 mW/cm2 and 122 mW/cm2 at 850 ℃ when fed with wet methane and hydrogen, respectively. The current collection, thickness of electrolyte and gas permeability of tubular support should account for the large total resistance. The present tubular design could be expected to deliver a higher voltage for longer support with several segmented-in-series cell stacks.

3D vertically aligned microchannel structure to enhance piezoelectric energy harvesting performance of PZT/PVDF&CNTs piezoelectric composites

Piezoelectric energy harvesters(PEHs)have attracted significant attention with the ability of converting mechanical energy into electrical energy and power the self-powered microelectronic components.Generally,material's superior energy harvesting performance is closely related to its high transduction coefficient(d_(33)×g_(33)),which is dependent on higher piezoelectric coefficient d33 and lower dielectric constantεr of materials.However,the high d33 and lowεr are difficult to be simultaneously achieved in piezoelectric ceramics.Herein,lead zirconate titanate(PZT)based piezoelectric composites with vertically aligned microchannel structure are constructed by phase-inversion method.The polyvinylidene fluoride(PVDF)and carbon nanotubes(CNTs)are mixed as fillers to fabricate PZT/PVDF&CNTs composites.The unique structure and uniformly distributed CNTs network enhance the polarization and thus improve the d33.The PVDF filler effectively reduce theεr.As a consequence,the excellent piezoelectric coefficient(d_(33)=595 pC/N)and relatively low dielectric constant(ε_(r)=1,603)were obtained in PZT/PVDF&CNTs composites,which generated an ultra-high d_(33)×g_(33) of 24,942×10^(−15) m^(2)/N.Therefore,the PZT/PVDF&CNTs piezoelectric composites achieve excellent energy harvesting performance(output voltage:66 V,short current:39.22μA,and power density:1.25μW/mm^(2)).Our strategy effectively boosts the performance of piezoelectric-polymer composites,which has certain guiding significance for design of energy harvesters.