查看更多>>摘要：Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23％by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80％of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.
查看更多>>摘要：Direct air capture(DAC)of CO2 plays an indispensable role in achieving carbon-neutral goals as one of the key negative emission technologies.Since large air flows are required to capture the ultradilute CO2 from the air,lab-synthesized adsorbents in powder form may cause unacceptable gas pressure drops and poor heat and mass transfer efficiencies.A structured adsorbent is essential for the implementation of gas-solid contactors for cost-and energy-efficient DAC systems.In this study,efficient adsorbent poly(ethy-leneimine)(PEI)-functionalized Mg-AI-CO3 layered double hydroxide(LDH)-derived mixed metal oxides(MMOs)are three-dimensional(3D)printed into monoliths for the first time with more than 90％adsor-bent loadings.The printing process has been optimized by initially printing the LDH powder into mono-liths followed by calcination into MMO monoliths.This structure exhibits a 32.7％higher specific surface area and a 46.1％higher pore volume,as compared to the direct printing of the MMO powder into a monolith.After impregnation of PEI,the monolith demonstrates a large adsorption capacity(1.82 mmol/g)and fast kinetics(0.7 mmol/g/h)using a CO2 feed gas at 400 ppm at 25 ℃,one of the high-est values among the shaped DAC adsorbents.Smearing of the amino-polymers during the post-printing process affects the diffusion of CO2,resulting in slower adsorption kinetics of pre-impregnation mono-liths compared to post-impregnation monoliths.The optimal PEI/MeOH ratio for the post-impregnation solution prevents pores clogging that would affect both adsorption capacity and kinetics.
查看更多>>摘要：Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a deficiency in understanding the structure-property relationship.Herein,we investigated two low-cost terthiophene-based electron acceptors,namely,3TC8 and 3TEH,with 3,4-bis(octan-3-yloxy)thiophene,differing only in the alkylated thiophene-bridges.Both acceptors exhibit low optical gaps(～1.43 eV)and possess deep highest occupied molecular orbital(HOMO)levels(～-5.8 eV).Notably,the single-crystal structure of 3TEH demonstrates highly planar conjugated backbone and strong π-π stacking between intermolecular terminal groups,attributed to the presence of the bulky alkylated non-covalently conformational locks.Upon utilizing both acceptors to fabricate OSCs,the 3TC8-based device exhibited a power conversion efficiency(PCE)of 11.1％,while the 3TEH-based OSC demonstrated an excellent PCE of 14.4％.This PCE is the highest among OSCs based on terthiophene-containing electron acceptors.These results offer a new strategy for designing low-cost electron acceptors for highly efficient OSCs.
查看更多>>摘要：Polyolefins such as polyethylene(PE)are one of the largest-scale synthetic plastics and play a key role in modern society.However,polyethylene is extremely inert to chemical recycling owing to its lack of chemical functionality and low polarity,making it one of the most challenging environmental hazards globally.Herein,we developed a phosphorylated CeO2 catalyst by an organophosphate precursor and fea-tured efficient photocatalysis of low-density polyethylene(LDPE)without the acid or alkaline pre-treatment.Compared to pristine CeO2,the surface phosphorylation allows to introduce Brønsted acid sites,which facilitate to form carbonium ions on LDPE via protonation.In addition,the suitable band structure of the phosphorylated CeO2 catalyst enables efficient photoabsorption and generates reactive oxygen species,leading to the C-C bond cleavage of LDPE.As a result,the phosphorylated CeO2 catalyst exhibited an outstanding carbon conversion rate of＞94％after 48 h of photocatalysis under 50 mW/cm2 of simulated sunlight,with a high CO2 product selectivity of＞99％.Furthermore,the PE microparticles with sizes larger than 10 μm released from LDPE plastic wrap were directly and completely degraded by photocatalysis within 12 h,suggesting an attractive and environmentally benign strategy of utilizing solar energy-based photocatalysis for reducing potential hazards of LDPE plastic trashes.
查看更多>>摘要：Bimetallic oxides are attractive anode materials for lithium-ion batteries(LIBs)due to their large theoret-ical capacity.However,the low conductivity,short cycle life,and poor rate capability are the bottlenecks for their further applications.To overcome above issues,the basket-like polymolybdate(NiP6Mo18)and carbon nanotubes(CNTs)were uniformly embedded on the urchin-shaped CoNiO2 nanospheres to yield a ternary composites CoNiO2@NiP6Mo18/CNTs via electrostatic adsorption.The multi-level morphology of urchin spinules accelerates the diffusion rate of Li+;CNT improves the conductivity and enhances cycle stability of the material;and heteropoly acid contributes more redox activity centres.Thus,CoNiO2@NiP6Mo18/CNTs as an anode of LIBs exhibits a high initial capacity(1396.7 mA h g-1 at 0.1 A g-1),long-term cycling stability(750.2 mA h g-1 after 300 cycles),and rate performance(450.3 mA h g-1 at 2 A g-1),which are superior to reported metallic oxides anode of LIBs.The density functional theory(DFT)and kinetic mechanism suggest that CoNiO2@NiP6Mo18/CNTs delivers an out-standing pseudocapacitance and rapid Li+diffusion behaviors,which is due to the rich surface area of the urchin-like CoNiO2 with the uniform embeddedness of NiP6Mo18 and CNTs.This study provides a new idea for optimizing the performance of bimetallic oxides and developing high-rate lithium-ion bat-tery composites.
查看更多>>摘要：Water electrolysis poses a significant challenge for balancing catalytic activity and stability of oxygen evolution reaction(OER)electrocatalysts.In this study,we address this challenge by constructing asym-metric redox chemistry through elaborate surface OO-Ru-OH and bulk Ru-O-Ni/Fe coordination moi-eties within single-atom Ru-decorated defective NiFe LDH nanosheets(Ru@d-NiFe LDH)in conjunction with strong metal-support interactions(SMSI).Rigorous spectroscopic characterization and theoretical calculations indicate that single-atom Ru can delocalize the O 2p electrons on the surface and optimize d-electron configurations of metal atoms in bulk through SMSI.The 18O isotope labeling experiment based on operando differential electrochemical mass spectrometry(DEMS),chemical probe experiments,and theoretical calculations confirm the encouraged surface lattice oxygen,stabilized bulk lattice oxygen,and enhanced adsorption of oxygen-containing intermediates for bulk metals in Ru@d-NiFe LDH,leading to asymmetric redox chemistry for OER.The Ru@d-NiFe LDH electrocatalyst exhibits exceptional perfor-mance with an overpotential of 230 mV to achieve 10 mA cm-2 and maintains high robustness under industrial current density.This approach for achieving asymmetric redox chemistry through SMSI pre-sents a new avenue for developing high-performance electrocatalysts and instills confidence in its indus-trial applicability.
查看更多>>摘要：Electrochemical energy storage is a promising technology for the integration of renewable energy.Lead-acid battery is perhaps among the most successful commercialized systems ever since thanks to its excel-lent cost-effectiveness and safety records.Despite of 165 years of development,the low energy density as well as the coupled power and energy density scaling restrain its wider application in real life.To address this challenge,we optimized the configuration of conventional Pb-acid battery to integrate two gas dif-fusion electrodes.The novel device can work as a Pb-air battery using ambient air,showing a peak power density of 183 mW cm-2,which was comparable with other state-of-the-art metal-O2 batteries.It can also behave as a fuel cell,simultaneously converting H2 and air into electricity with a peak power density of 75 mW cm-2.Importantly,this device showed little performance degradation after 35 h of the long-evity test.Our work shows the exciting potential of lead battery technology and demonstrates the impor-tance of battery architecture optimization toward improved energy storage capacity.
Dan YuXingjun LiSamuel Simon ArayaSimon Lennart Sahlin...
544-558页
查看更多>>摘要：Utilizing machine learning techniques for data-driven diagnosis of high temperature PEM fuel cells is beneficial and meaningful to the system durability.Nevertheless,ensuring the robustness of diagnosis remains a critical and challenging task in real application.To enhance the robustness of diagnosis and achieve a more thorough evaluation of diagnostic performance,a robust diagnostic procedure based on electrochemical impedance spectroscopy(EIS)and a new method for evaluation of the diagnosis robust-ness was proposed and investigated in this work.To improve the diagnosis robustness:(1)the degrada-tion mechanism of different faults in the high temperature PEM fuel cell was first analyzed via the distribution of relaxation time of EIS to determine the equivalent circuit model(ECM)with better inter-pretability,simplicity and accuracy;(2)the feature extraction was implemented on the identified param-eters of the ECM and extra attention was paid to distinguishing between the long-term normal degradation and other faults;(3)a Siamese Network was adopted to get features with higher robustness in a new embedding.The diagnosis was conducted using 6 classic classification algorithms-support vec-tor machine(SVM),K-nearest neighbor(KNN),logistic regression(LR),decision tree(DT),random forest(RF),and Naive Bayes employing a dataset comprising a total of 1935 collected EIS.To evaluate the robustness of trained models:(1)different levels of errors were added to the features for performance evaluation;(2)a robustness coefficient(Roubust_C)was defined for a quantified and explicit evaluation of the diagnosis robustness.The diagnostic models employing the proposed feature extraction method can not only achieve the higher performance of around 100％but also higher robustness for diagnosis models.Despite the initial performance being similar,the KNN demonstrated a superior robustness after feature selection and re-embedding by triplet-loss method,which suggests the necessity of robustness evaluation for the machine learning models and the effectiveness of the defined robustness coefficient.This work hopes to give new insights to the robust diagnosis of high temperature PEM fuel cells and more comprehensive performance evaluation of the data-driven method for diagnostic application.
查看更多>>摘要：Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into elec-trolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS2 nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS2-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of poly-sulfides(e.g.,Na2S,Na2S6,and S8)and subsequent catalytic conversion of Na2S.Consequently,the MoS2-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional bin-ders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.
查看更多>>摘要：Development of a high-performance bifunctional catalyst is essential for the actual implementation of zinc-air batteries in practical applications.Herein,a bifunctional cathode of Co3S4/FeS heterogeneous nanoparticles embedded in Co/Fe single-atom-loaded nitrogen-doped carbon nanosheets is designed.Cobalt-iron sulfides and single atomic sites with Co-N4/Fe-N4 configurations are confirmed to coexist on the carbon matrix by EXAFS spectroscopy.3D self-supported super-hydrophobic multiphase compos-ite cathode provides abundant active sites and facilitates gas-liquid-solid three-phase interface reactions,resulting in excellent electrocatalytic activity and batteries performance,i.e.,an OER overpotential(η10)of 260 mV,a half-wave potential(E1/2)of 0.872 V for ORR,a ΔE of 0.618 V,and a discharge power density of 170 mW cm-2,a specific capacity of 816.3 mAh g-1.DFT analysis shows multiphase coupling of sulfide heterojunction through single-atomic metal doped carbon nanosheets reduces offset on center of elec-tronic density of states before and after oxygen adsorption,and spin density of adsorbed oxygen with same spin orientation,leading to weakened charge/spin interactions between adsorbed oxygen and sub-strate,and a lowered oxygen adsorption energy to accelerate OER/ORR.
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