查看更多>>摘要：Flexible conductive fibers are essential for wearable electronics and smart electronic textiles.However,in complex operating conditions,conductive fibers will inevitably fracture or damage.Herein,we have developed an elastic conductive self-healable fiber(C-SHF),of which the electrical and mechanical properties can efficiently heal in a wide operating range,including room temperature,underwater,and low temperature.This advantage can be owed to the combination of reversible covalent imine bond and disulfide bond,as well as the instantaneous self-healing ability of liquid metal.The C-SHF,with stretchability,conductivity stability,and universal self-healing properties,can be used as an electrical signal transmission line at high strain and under different operating conditions.Besides,C-SHF was assembled into a double-layer capacitor structure to construct a self-healable sensor,which can effectively respond to pressure as a wearable motion detector.
查看更多>>摘要：The poor contact and side reactions between Li1.3Al0.3Ti1.7(PO4)3(LATP)and lithium(Li)anode cause uneven Li plating and high interfacial impendence,which greatly hinder the practical application of LATP in high-energy density solid-state Li metal batteries.In this work,a multifunctional ferroelectric BaTiO3(BTO)/poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)(P[VDF-TrFE-CTFE])composite interlayer(B-TERB)is constructed between LATP and Li metal anode,which not only suppresses the Li dendrite growth,but also improves the interfacial stability and maintains the intimate interfacial contact to significantly decrease the interfacial resistance by two orders of magnitude.The B-TERB interlayer generates a uniform electric field to induce a uniform and lateral Li deposition,and therefore avoids the side reactions between Li metal and LATP achieving excellent interface stability.As a result,the Li/LATP@B-TERB/Li symmetrical batteries can stably cycle for 1800 h at 0.2 mA cm-2 and 1000 h at 0.5 mA cm-2.The solid-state LiFePO4/LATP@B-TERB/Li full batteries also exhibit excellent cycle performance for 250 cycles at 0.5 C and room temperature.This work proposes a novel strategy to design multifunctional ferroelectric interlayer between ceramic electrolytes and Li metal to enable stable room-temperature cycling performance.
查看更多>>摘要：Poly(3-hexylthiophene)(P3HT),as a traditional organic hole-transporting material(HTM),is widely used in thin-film solar cells due to its high charge mobility and good thermal stability.However,the P3HT films obtained by the traditional method are amorphous,which is unfavorable to hole extraction and transport.Here,a low-toxicity solvent 1,2,4-trimethylbenzene(TMB)was used as the solvent instead of the commonly used halogen solvent chlorobenzene(CB)to dissolve P3HT.Thus,the self-assembled nanofibrous P3HT film was prepared and applied as HTM in the newly emerged Sb2S3 solar cells.According to the density functional theory calculations,the interface contact between TMB-P3HT and Sb2S3 was enhanced via the bonding interaction of S in P3HT and Sb in Sb2S3.Through transient absorption spectroscopy characterization,the enhanced interface contact improves the charge extraction ability of TMB-P3HT when compared to the CB-P3HT film.Thus,the TMB-P3HT-based Sb2S3 solar cell delivers a power conversion efficiency of 6.21％,which is 9.7％higher than that of the CB-P3HT-based device.Furthermore,the dopant-free TMB-P3HT-based Sb2S3 devices exhibit excellent environmental stability compared with Spiro-OMeTAD-based devices.This work demonstrates that the application of P3HT and the solvent engineering of HTM are applicable strategies for developing Sb2S3 solar cells with high efficiency and stability.
查看更多>>摘要：Development of tin(Sn)-based perovskite solar cells(PSCs)largely lags behind that of lead counterparts due to fast crystallization process of Sn perovskite and numerous defects in both bulk and surface of Sn perovskite films.Herein,this work reports a facile strategy of introducing 4-fluorobenzylammonium iodide(FBZAI)as additives into Sn perovskite precursor to synergistically modulate the roles of benzylamine and fluorine in Sn-based PSCs.Incorporation of FBZAI can increase crystallinity,passivate defects,and inhibit the oxidation of Sn2+,leading to suppression of nonradiative recombination and enhancement of charge transport and collection in devices.As a result,the best-performing Sn-based PSC with the FBZAI additive achieves the maximum PCE of 13.85％with the enhanced fill factor of 77.8％and open-circuit voltage of 0.778 V.Our unencapsulated device exhibits good stability by maintaining 95％of its initial PCE after 160 days of storage.
查看更多>>摘要：Aqueous zinc ion batteries have been considered as the prominent candidate in the next-generation batteries for its low cost,safety and high theoretical capacity.Nonetheless,formation of zinc dendrites and side reactions at the electrode/electrolyte interface during the zinc plating/stripping process affect the cycling reversibility of the zinc anode.Regulation of the zinc plating/stripping process and realizing a highly reversible zinc anode is a great challenge.Herein,we applied a simple and effective approach of controlled-current zinc pre-deposition at copper mesh.At the current density of 40 mA cm-2,where the electron/ion transfers are both continuous and balanced,the Zn@CM-40 electrode with the(002)crystal plane orientation and the compactly aligned platelet morphology was successfully obtained.Compared with the zinc foil,the Zn@CM-40 exhibits greatly enhanced reversibility in the repeated plating/stripping(850 h at 1 mA cm-2)for the symmetric battery test.A series of characterization techniques including electrochemical analyses,XRD,SEM and optical microscopy observation,were used to demonstrate the correlation between the structure of pre-deposited zinc layer and the cycling stability.The COSMOL Multiphysics modeling demonstrates a more uniform electric field distribution in the Zn@CM than the zinc foil due to the aligned platelet morphology.Furthermore,the significant improvement is also achieved in a Zn||MnO2 full battery with a high capacity-retention(87％vs 47.8％).This study demonstrates that controlled-current electrodeposition represents an important strategy to regulate the crystal plane orientation and the morphology of the pre-deposited zinc layer,hence leading to the highly reversible and dendrite-free zinc anode for high-performance zinc ion batteries.
查看更多>>摘要：Lithium-ion batteries with polymer electrolytes(PEs)are promising candidates for high safety performance batteries.However,conventional PEs suffer from poor compatibility and high impedance of electrolyte-electrode interfaces.Herein,we present a method of the interfacial modification for PEs to inhibit lithium dendrites based on the solution to the interfacial compatibility.Our strategy is to improve the interfacial properties and inhibit the dendrite generation by coating a modified layer on PEs of the anode side with acetylene black(AB)and MXene.The mixed conductive layer(MCL)can promote the generation of Li3N and LiF with a uniform arrangement of electrons to form a dense solid electrolyte interphase layer and the even lithium-ion deposition for improving the performance and stability of the battery during cycling.After adding the MCL,the discharge capacity of solid lithium-ion batteries(SLIBs)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)/organic modified montmorillonite(OMMT)/soybean isolate protein(SPI)/poly(vinylidene fluoride)(PVDF)(LOSP)PE from 74.2 mAh g-1 up to 111.1 mAh g-1(AB-LiTFSI/OMMT/SPI/PVDF(AB-LOSP))and 111.6 mAh g-1(AB/MXene-LiTFSI/OMMT/SPI/PVDF(AB/MXene-LOSP)).The polarization voltage dropped by 0.06 and 0.12 V,respectively.This work represents a milestone in the dendrite-free SLIBs with good performances.
查看更多>>摘要：Lithium-rich layered oxides(LLOs)are promising candidate cathode materials for safe and inexpensive high-energy-density Li-ion batteries.However,oxygen dimers are formed from the cathode material through oxygen redox activity,which can result in morphological changes and structural transitions that cause performance deterioration and safety concerns.Herein,a flake-like LLO is prepared and aberration-corrected scanning transmission electron microscopy(STEM),in situ high-temperature X-ray diffraction(HT-XRD),and soft X-ray absorption spectrum(sXAS)are used to explore its crystal facet degradation behavior in terms of both thermal and electrochemical processes.Void-induced degradation behavior of LLO in different facet reveals significant anisotropy at high voltage.Particle degradation originates from side facets,such as the(010)facet,while the close(003)facet is stable.These results are further understood through ab initio molecular dynamics calculations,which show that oxygen atoms are lost from the {010} facets.Therefore,the facet degradation process is that oxygen molecular formed in the interlayer and accumulated in the ab plane during heating,which result in crevice-voids in the ab plane facets.The study reveals important aspects of the mechanism responsible for oxygen-anionic activity-based degradation of LLO cathode materials used in lithium-ion batteries.In particular,this study provides insight that enables precise and efficient measures to be taken to improve the thermal and electrochemical stability of an LLO.
查看更多>>摘要：Developing cost-effective and facile methods to synthesize efficient and stable electrocatalysts for large-scale water splitting is highly desirable but remains a significant challenge.In this study,a facile ambient temperature synthesis of hierarchical nickel-iron(oxy)hydroxides nanosheets on iron foam(FF-FN)with both superhydrophilicity and superaerophobicity is reported.Specifically,the as-fabricated FF-FN electrode demonstrates extraordinary oxygen evolution reaction(OER)activity with an ultralow overpotential of 195 mV at 10 mA cm-2 and a small Tafel slope of 34 mV dec-1 in alkaline media.Further theoretical investigation indicates that the involved lattice oxygen in nickel-iron-based-oxyhydroxide during electrochemical self-reconstruction can significantly reduce the OER reaction overpotential via the dominated lattice oxygen mechanism.The rechargeable Zn-air battery assembled by directly using the as-prepared FF-FN as cathode displays remarkable cycling performance.It is believed that this work affords an economical approach to steer commercial Fe foam into robust electrocatalysts for sustainable energy conversion and storage systems.
查看更多>>摘要：All-solid-state lithium batteries(ASSLBs)based on sulfide solid electrolytes(SEs)are one of the most promising strategies for next-generation energy storage systems and electronic devices.However,the poor chemical/electrochemical stability of sulfide SEs with oxide cathode materials and high interfacial impedance,particularly due to physical contact failure,are the major limiting factors to the development of sulfide SEs in ASSLBs.Herein,the composite cathode of MOF-derived Fe7S8@C and Li6PS5Br fabricated by an infiltration method(IN-Fe7S8)with dissoluble sulfide electrolyte(dissoluble SE)is reported.Dissoluble SE can easily infiltrate the porous sheet-type Fe7S8@C cathode to homogeneously contact with Fe7S8 nanoparticles that are embedded in the surrounding carbon matrixes and form a fast ionic transport network.Benefiting from applying dissoluble SE and Fe7S8@C,the IN-Fe7S8-based cells displayed a reversible capacity of 510 mAh g-1 after 180 cycles at 0.045 mA cm-2 at 30 ℃.This work demonstrates a novel and practical method for the development of high-performance all-sulfide-based solid state batteries.
查看更多>>摘要：Sodium-and potassium-ion batteries have exhibited great application potential in grid-scale energy storage due to the abundant natural resources of Na and K.Conversion-alloying anodes with high theoretical capacity and low-operating voltage are ideal option for SIBs and PIBs but suffer the tremendous volume variations.Herein,a hierarchically structural design and sp2 N-doping assist a conversion-alloying material,Sb2Se3,to achieve superior life span more than 1000 cycles.It is confirmed that the Sb2Se3 evolves into nano grains that absorb on the sp2 N sites and in situ form chemical bonding of C-N-Sb after initial discharge.Simulation results indicate that sp2 N has more robust interaction with Sb and stronger adsorption capacities to Na+and K+than that of sp3 N,which contributes to the durable cycling ability and high electrochemical activity,respectively.The ex situ transmission electron microscopy and X-ray photoelectron spectroscopy results suggest that the Sb2Se3 electrode experiences conversion-alloying dual mechanisms based on 12-electron transfer per formula unit.
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