Constructing Al@C-Sn pellet anode without passivation layer for lithium-ion battery

Al is considered as a promising lithium-ion battery(LIBs)anode materials owing to its high theoretical capacity and appropri-ate lithation/de-lithation potential.Unfortunately,its inevitable volume expansion causes the electrode structure instability,leading to poor cyclic stability.What’s worse,the natural Al2O3 layer on commercial Al pellets is always existed as a robust insulating barrier for elec-trons,which brings the voltage dip and results in low reversible capacity.Herein,this work synthesized core-shell Al@C-Sn pellets for LIBs by a plus-minus strategy.In this proposal,the natural Al2O3 passivation layer is eliminated when annealing the pre-introduced SnCl2,meanwhile,polydopamine-derived carbon is introduced as dual functional shell to liberate the fresh Al core from re-oxidization and alle-viate the volume swellings.Benefiting from the addition of C-Sn shell and the elimination of the Al2O3 passivation layer,the as-prepared Al@C-Sn pellet electrode exhibits little voltage dip and delivers a reversible capacity of 1018.7 mAh·g^(-1) at 0.1 A·g^(-1) and 295.0 mAh·g^(-1) at 2.0 A·g^(-1)(after 1000 cycles),respectively.Moreover,its diffusion-controlled capacity is muchly improved compared to those of its counterparts,confirming the well-designed nanostructure contributes to the rapid Li-ion diffusion and further enhances the lithium storage activity.

Low-Temperature Aging Provides 22% E cient Bromine-Free and Passivation Layer-Free Planar Perovskite Solar Cells

Previous reports of formamidinium/methylamine(FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface—for example,through the inclusion of bromine and surface passivation.In this paper,we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI3 halide perovskites via the control of intermediate phase.Through low-temperature aging growth(LTAG)of a freshly deposited perovskite film,α-phase perovskites can be seeded in the intermediate phase and,at the same time,prevent beta-phase perovskite to nucleate.After postannealing,large grain-size perovskites with significantly reduced PbI2 presence on the surface can be obtained,thereby eliminating the need of additional surface passivation step.Our pristine LTAG-treated solar cells could provide PCEs of greater than 22%without elaborate use of bromine or an additional passivation layer.More importantly,when using this LTAG process,the growth of the pure alpha-phase FAMAPbI3 was highly reproducible.

Improvement of Ge MOS Electrical and Interfacial Characteristics by using NdAlON as Interfacial Passivation Layer

The Ge metal-oxide-semiconductor (MOS) capacitors were fabricated with HfO2 as gate dielectric.AlON,NdON,and NdAlON were deposited between the gate dielectric and the Ge substrate as the interfacial passivation layer (IPL).The electrical properties (such as capacitance-voltage (C-V) and gate leakage current density versus gate voltage (J_(g)-V_(g))) were measured by HP4284A precision LCR meter and HP4156A semiconductor parameter analyzer.The chemical states and interfacial quality of the high-k/Ge interface were investigated by X-ray photoelectron spectroscopy (XPS).The experimental results show that the sample with the NdAlON as IPL exhibits the excellent interfacial and electrical properties.These should be attributed to an effective suppression of the Ge suboxide and HfGeOx interlayer,and an enhanced blocking role against inter-diffusion of the elements during annealing by the NdAlON IPL.

Significantly improved high k dielectric performance:Rare earth oxide as a passivation layer laminated with TiO_(2) film

In order to achieve a super gate dielectric performance,rare earth oxides featuring for large band gap,good thermodynamic stability and relatively high k value were selected to be laminated with TiO_(2)film to prepare bilayer dielectric films.As an example,the microstructure,morphology,band gap structure and electrical performance of TiO_(2)-Y_(2)O_(3)bilayer films were systematically investigated.Results show that stacking sequence of TiO_(2)and Y_(2)O_(3)sublayers has a significant impact on the dielectric performance and Y_(2)O_(3)film as a passivation layer can effectively improve electrical properties.Besides,the electrical behaviors analysis of TiO_(2)-Y_(2)O_(3),Y_(2)O_(3)-TiO_(2),Y_(2)O_(3)and TiO_(2)samples was carried out by impedance spectra and equivale nt circuit.The result shows that TiO_(2)-Y_(2)O_(3)/Si sample holds the largest internal re sistance of 74665Ωamong four samples.Moreover,the most outstanding properties of Pt/TiO_(2)-Y_(2)O_(3)/Si capacitor are achieved by varying the thickness of sublayers and annealing temperature.500℃-annealed bilayer film with 17 nm-TiO_(2)and 3-nm Y_(2)O_(3)displays a k value of 28.24,which is more than 1.4 times that of current commercial HfO_(2).Further,Schottky emission was determined to be leakage current transport mechanism for TiO_(2)-Y_(2)O_(3)bilayer films.Inspired by this result,the electrical performance of more general Pt/TiO_(2)-REOs/Si MOS capacitors(RE=Sc,La,Ce,Gd and Pr)was measured.The combination of TiO_(2)film and REOs passivation layer with the satisfying performance provides promising candidates for future Si-based integrated circuit(IC).

In-situ interfacial passivation and self-adaptability synergistically stabilizing all-solid-state lithium metal batteries

The function of solid electrolytes and the composition of solid electrolyte interphase(SEI)are highly significant for inhibiting the growth of Li dendrites.Herein,we report an in-situ interfacial passivation combined with self-adaptability strategy to reinforce Li_(0.33)La_(0.557)TiO_(3)(LLTO)-based solid-state batteries.Specifically,a functional SEI enriched with LiF/Li_(3)PO_(4) is formed by in-situ electrochemical conversion,which is greatly beneficial to improving interface compatibility and enhancing ion transport.While the polarized dielectric BaTiO_(3)-polyamic acid(BTO-PAA,BP)film greatly improves the Li-ion transport kinetics and homogenizes the Li deposition.As expected,the resulting electrolyte offers considerable ionic conductivity at room temperature(4.3 x 10~(-4)S cm^(-1))and appreciable electrochemical decomposition voltage(5.23 V)after electrochemical passivation.For Li-LiFePO_(4) batteries,it shows a high specific capacity of 153 mA h g^(-1)at 0.2C after 100 cycles and a long-term durability of 115 mA h g^(-1)at 1.0 C after 800 cycles.Additionally,a stable Li plating/stripping can be achieved for more than 900 h at 0.5 mA cm^(-2).The stabilization mechanisms are elucidated by ex-situ XRD,ex-situ XPS,and ex-situ FTIR techniques,and the corresponding results reveal that the interfacial passivation combined with polarization effect is an effective strategy for improving the electrochemical performance.The present study provides a deeper insight into the dynamic adjustment of electrode-electrolyte interfacial for solid-state lithium batteries.

Anionic passivation layer-assisted trapping of an icosahedral Ag_(13)kernel in a truncated tetrahedral Ag_(89)nanocluster

Isolating reductive silver kernel from shell is a challenging task but is quite important to understand the embryonic form during the formation of silver nanoclusters.The intercalation of suitable anionic species may be of benefit for passivating then capturing such highly active kernel.Herein,we successfully isolated a novel silver thiolate nanocluster[Ag_(13)@Ag_(76)S_(16)(Cyh S)_(42)(p-NH_(2)-Ph As O_(3))_(4)]^(3+)(SD/Ag89 a,Cyh SH=cyclohexanethiol)that contains a well-isolated icosahedral Ag_(13) kernel passivated by four Ag S_(4)^(7-) tetrahedra and four p-NH_(2) Ph As O_(3)^(2-) piercing from outer Ag_(72) shell.Of note,this Ag_(13) kernel is the largest isolable subvalent silver kernel beneath the silver shell with extremely legible core-shell boundary ever before and represents a precise embryonic model formed in the reducing Ag(I)to Ag(0)followed by aggregating to large silver nanoparticles.The reductive role of DMF and the introduction of anionic passivation layer(APL)synergistically modulate the reduction kinetics,facilitating the capture of ultrasmall subvalent silver kernel.SD/Ag89 a emits in near infrared(NIR)region(λ_(em)=800 nm)at low temperature.The synthetic strategy shown in this work opens up new opportunities for precisely capturing and recognizing diverse reductive silver kernels in different systems.

Plasma-Enhanced Atomic Layer Deposition of Amorphous Ga_(2)O_(3) for Solar-Blind Photodetection

Wide-bandgap gallium oxide(Ga_(2)O_(3))is one of the most promising semiconductor materials for solar-blind(200 nm to 280 nm)photodetection.In its amorphous form,amorphous gallium oxide(a-Ga_(2)O_(3))maintains its intrinsic optoelectronic properties while can be prepared at a low growth temperature,thus it is compatible with Si integrated circuits(ICs)technology.Herein,the a-Ga_(2)O_(3) film is directly deposited on pre-fabricated Au interdigital electrodes by plasma enhanced atomic layer deposition(PE-ALD)at a growth temperature of 250°C.The stoichiometric a-Ga_(2)O_(3) thin film with a low defect density is achieved owing to the mild PE-ALD condition.As a result,the fabricated Au/a-Ga_(2)O_(3)/Au photodetector shows a fast time response,high responsivity,and excellent wavelength selectivity for solar-blind photodetection.Furthermore,an ultra-thin MgO layer is deposited by PE-ALD to passivate the Au/a-Ga_(2)O_(3)/Au interface,resulting in the responsivity of 788 A/W(under 254 nm at 10 V),a 250-nm-to-400-nm rejection ratio of 9.2×10^(3),and the rise time and the decay time of 32 ms and 6 ms,respectively.These results demonstrate that the a-Ga_(2)O_(3) film grown by PE-ALD is a promising candidate for high-performance solar-blind photodetection and potentially can be integrated with Si ICs for commercial production.

Proton irradiation-induced dynamic characteristics on high performance GaN/AlGaN/GaN Schottky barrier diodes

Dynamic characteristics of the single-crystal Ga N-passivated lateral AlGaN/GaN Schottky barrier diodes(SBDs)treated with proton irradiation are investigated.Radiation-induced changes including idealized Schottky interface and slightly degraded on-resistance(RON)are observed under 10-Me V proton irradiation at a fluence of 10^(14)cm^(-2).Because of the existing negative polarization charges induced at GaN/AlGaN interface,the dynamic ON-resistance(RON,dyn)shows negligible degradation after a 1000-s-long forward current stress of 50 mA to devices with and without being irradiated by protons.Furthermore,the normalized RON,dynincreases by only 14%that of the initial case after a 100-s-long bias of-600 V has been applied to the irradiated devices.The high-performance lateral AlGaN/GaN SBDs with tungsten as anode metal and in-situ single-crystal GaN as passivation layer show a great potential application in the harsh radiation environment of space.

Stable sodium anodes for sodium metal batteries(SMBs) enabled by in-situ formed quasi solid-state polymer electrolyte

A high-performance quasi-solid polymer electrolyte for sodium metal batteries(SMBs)based on in-situ polymerized poly(1,3-dioxolane)(DOL)with 20%volume ratio of fluoroethylene carbonate(FEC),termed"PDFE-20",is proposed in this work.It is demonstrated PDFE-20 possesses a room-temperature ionic conductivity of 3.31×10^(-3) S cm^(-1),an ionic diffusion activation energy of 0.10 eV,and an oxidation potential of 4.4 V.SMBs based on PDFE-20 and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathodes were evaluated with an active material mass loading of 6.8 mg cm^(-2).The cell displayed an initial discharge specific capacity of 104 mA h g^(-1),and97.1%capacity retention after 100 cycles at 0.5 C.In-situ polymerization conformally coats the anode/-cathode interfaces,avoiding geometrical gaps and high charge transfer resistance with ex-situ polymerization of the same chemistry.FEC acts as a plasticizer during polymerization to suppress crystallization and significantly improves ionic transport.During battery cycling FEC promotes mechanical congruence of electrolyte-electrode interfaces while forming a stable NaF-rich solid electrolyte interphase(SEI)at the anode.Density functional theory(DFT)calculations were also performed to further understand the role FEC in the poly(DOL)-FEC electrolytes.This work broadens the application of in-situ prepared poly(DOL)electrolytes to sodium storage and demonstrates the crucial role of FEC in improving the electrochemical performance.

Spontaneous local redox reaction to passivate CNTs as lightweight current collector for high energy density lithium ion batteries

Extensive usage of highly conductive carbon materials with large specific surface area(e.g.,carbon nanotubes,CNTs)in lithium ion batteries(LIBs),especially as current collector of anodes,suffers from low initial coulombic efficiency(ICE),large interfacial resistance,and severe embrittlement,as the large specific surface area often results in severe interfacial decomposition of the electrolyte and the formation of thick and fluffy solid electrolyte interphase(SEI)during cycling of LIBs.Herein,we demonstrate that when the CNT-based current collector and Na foil(which are being stacked intimately upon each other)are being placed in Na+-based organic electrolyte,local redox reaction between the Na foil and the electrolyte would occur spontaneously,generating a thin and homogeneous NaF-based passivating layer on the CNTs.More importantly,we found that owing to the weak solvation behaviors of Na+in the organic electrolyte,the resulting passivation layer,which is rich in NaF,is thin and dense;when used as the anode current collector in LIBs,the pre-existing passivating layer can function effectively in isolating the anode from the solvated Li+,thus suppressing the formation of bulky SEI and the destructive intercalation of solvated Li+.The relevant half-cell(graphite as anode)exhibits a high ICE of 92.1%;the relevant pouch cell with thus passivated CNT film as current collectors for both electrodes(LiCoO_(2)as cathode,graphite as anode)displays a high energy density of 255 Wh kg^(-1),spelling an increase of 50%compared with that using the conventional metal current collectors.

Robust ZnS interphase for stable Zn metal anode of high-performance aqueous secondary batteries

Although Zn metal is an ideal anode candidate for aqueous batteries owing to its high theoretical capacity,lower cost,and safety,its service life and efficiency are damaged by severe hydrogen evolution reaction,self-corrosion,and dendrite growth.Herein,a thickness-controlled ZnS passivation layer was fabricated on the Zn metal surface to obtain Zn@ZnS electrode through oxidation–orientation sulfuration by the liquid-and vapor-phase hydrothermal processes.Benefiting from the chemical inertness of the ZnS interphase,the as-prepared Zn@ZnS electrode presents an excellent anti-corrosion and undesirable hydrogen evolution reaction.Meanwhile,the thickness-optimized ZnS layer with an unbalanced charge distribution represses dendrite growth by guiding Zn plating/stripping,leading to long service life.Consequently,the Zn@Zn S presented 300 cycles in the symmetric cells with a 42 mV overpotential,200 cycles in half cells with a 78 mV overpotential,and superb rate performance in Zn||NH;V;O;full cells.

Recent advances based on Mg anodes and their interfacial modulation in Mg batteries

Magnesium(Mg)batteries(MBs),as post-lithium-ion batteries,have received great attention in recent years due to their advantages of high energy density,low cost,and safety insurance.However,the formation of passivation layers on the surface of Mg metal anode and the poor compatibility between Mg metal and conventional electrolytes during charge-discharge cycles seriously affect the performance of MBs.The great possibility of generating Mg dendrites has also caused controversy among researchers.Moreover,the regulation of Mg deposition and the enhancement of battery cycle stability is largely limited by interfacial stability between Mg metal anode and electrolyte.In this review,recent advances in interfacial science and engineering of MBs are summarized and discussed.Special attention is given to interfacial chemistry including passivation layer formation,incompatibilities,ion transport,and dendrite growth.Strategies for building stable electrode/interfaces,such as anode designing and electrolyte modification,construction of artificial solid electrolyte interphase(SEI)layers,and development of solid-state electrolytes to improve interfacial contacts and inhibit Mg dendrite and passivation layer formation,are reviewed.Innovative approaches,representative examples,and challenges in developing high-performance anodes are described in detail.Based on the review of these strategies,reference is provided for future research to improve the performance of MBs,especially in terms of interface and anode design.

具有超薄Al_(2)O_(3)钝化层的高性能近红外PtSe_(2)/n-Ge异质结光电探测器

二维(2D)材料正被广泛用于宽带响应光电探测器(PD).然而,基于2D材料的宽带响应PD通常对红外波长的响应较差.在此,我们报告了垂直PtSe_(2)/超薄Al_(2)O_(3)/Ge PD在近红外照明下的优异光响应性能.我们直接硒化沉积在Al_(2)O_(3)/Ge上的Pt膜以形成PtSe_(2)层.超薄Al_(2)O_(3)钝化层起到表面改性的作用,有效地削弱了光生载流子的复合.在1550 nm的光照下,我们的PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的工作面积为50μm×50μm,并在零偏压下获得了4.09 A W^(-1)、32.6/18.9μs的大响应度和快速上升/下降时间.在-5 V的外加电压下,PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的响应度和响应速度分别高达38.18 A W^(-1)和9.6/7.7μs.我们发现器件的工作面积对光响应特性有很大的影响.此外,我们证明PtSe_(2)/超薄Al_(2)O_(3)/Ge PD阵列在室温下显示出了优异的紫外、可见光和红外成像能力.我们的研究表明,PtSe_(2)/超薄Al_(2)O_(3)/Ge异质结在设计具有优异近红外响应性能的新兴宽带光电子器件方面具有巨大的应用前景.