Delving into the dissimilarities in electrochemical performance and underlying mechanisms for sodium and potassium ion storage in N-doped carbon-encapsulated metallic Cu_(2)Se nanocubes

The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical performance.Herein,metallic Cu_(2)Se encapsulated with N-doped carbon(Cu_(2)Se@NC)was prepared using Cu_(2)O nanocubes as templates through a combination of dopamine polymerization and hightemperature selenization.The unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu_(2)Se@NC with excellent electrochemical performance in sodium ion batteries(SIBs)and potassium ion batteries(PIBs).The composite exhibited excellent rate performance(187.7 mA h g^(-1)at 50 A g^(-1)in SIBs and 179.4 mA h g^(-1)at 5 A g^(-1)in PIBs)and cyclic stability(246,8 mA h g^(-1)at 10 A g^(-1)in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction(XRD)and ex situ transmission electron microscope(TEM).In particular,the final products in PIBs of K_(2)Se and K_(2)Se_(3)species were determined after discharging,which is different from that in SIBs with the final species of Na_(2)Se.The density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu_(2)Se,leading to the introduction of built-in electric field on heterojunction to improve electron mobility.Significantly,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na~+diffusion with low energy barrier and moderate adsorption energy.These findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.

In situ luminescence measurements of GaN/Al_(2)O_(3) film under different energy proton irradiations

Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within the material.The energies of H^(+)were set to 500 keV,640 keV and 2 MeV,the Bragg peaks of which correspond to the GaN film,GaN/Al_(2)O_(3) heterojunction and Al_(2)O_(3) substrate,respectively.A photoluminescence measurement at 250 K was also performed for comparison,during which only near band edge(NBE) and yellow band luminescence in the GaN film were observed.The evolution of the luminescence of the NBE and yellow band in the GaN film was discussed,and both exhibited a decrease with the fluence of H^(+).Additionally,the luminescence of F centers,induced by oxygen vacancies,and Cr^(3+),resulting from the ^(2)E →^(4)A_(2) radiative transition in Al_(2)O_(3),were measured using 2 MeV H^(+).The luminescence intensity of F centers increases gradually with the fluence of H^(+).The luminescence evolution of Cr^(3+)is consistent with a yellow band center,attributed to its weak intensity,and it is situated within the emission band of the yellow band in the GaN film.Our results show that IBIL measurement can effectively detect the luminescence behavior of multilayer films by adjusting the ion energy.Luminescence measurement can be excited by various techniques,but IBIL can satisfy in situ luminescence measurement,and multilayer structural materials of tens of micrometers can be measured through IBIL by adjusting the energy of the inducing ions.The evolution of defects at different layers with ion fluence can be obtained.

Investigations on MoS_(2)plasma by infra-red pulsed laser irradiation in high vacuum

MoS_(2)targets were irradiated by infra-red(IR)pulsed laser in a high vacuum to determine hot plasma parameters,atomic,molecular and ion emission,and angular and charge state distributions.In this way,pulsed laser deposition(PLD)of thin films on graphene oxide substrates was also realized.An Nd:YAG laser,operating at the 1064 nm wavelength with a 5 ns pulse duration and up to a 1 J pulse energy,in a single pulse or at a 10 Hz repetition rate,was employed.Ablation yield was measured as a function of the laser fluence.Plasma was characterized using different analysis techniques,such as time-of-flight measurements,quadrupole mass spectrometry and fast CCD visible imaging.The so-produced films were characterized by composition,thickness,roughness,wetting ability,and morphology.When compared to the MoS_(2)targets,they show a slight decrease of S with respect to Mo,due to higher ablation yield,low fusion temperature and high sublimation in vacuum.The pulsed IR laser deposited Mo Sx(with 1<x<2)films are uniform,with a thickness of about 130 nm,a roughness of about 50 nm and a higher wettability than the MoS_(2)targets.Some potential applications of the pulsed IR laser-deposited Mo Sx films are also presented and discussed.

Multifunctional AlPO_(4)reconstructed LiMn_(2)O_(4)surface for electrochemical lithium extraction from brine

LiMn_(2)O_(4)(LMO)electrochemical lithium-ion pump has gained widespread attention due to its green,high efficiency,and low energy consumption in selectively extracting lithium from brine.However,collapse of crystal structure and loss of lithium extraction capacity caused by Mn dissolution loss limits its industrialized application.Hence,a multifunctional coating was developed by depositing amorphous AlPO_(4)on the surface of LMO using sol-gel method.The characterization and electrochemical performance test provided insights into the mechanism of Li^(+)embedment and de-embedment and revealed that multifunctional AlPO_(4)can reconstruct the physical and chemical state of LMO surface to improve the interface hydrophilicity,promote the transport of Li^(+),strengthen cycle stability.Remarkably,after 20 cycles,the capacity retention rate of 0.5AP-LMO reached 93.6%with only 0.147%Mn dissolution loss.The average Li^(+)release capacity of 0.5AP-LMO//Ag system in simulated brine is 28.77 mg/(g h),which is 90.4%higher than LMO.Encouragingly,even in the more complex Zabuye real brine,0.5AP-LMO//Ag can still maintain excellent lithium extraction performance.These results indicate that the 0.5AP-LMO//Ag lithium-ion pump shows promising potential as a Li^(+)selective extraction system.

Co-doped BaFe_(2)As_(2) Josephson junction fabricated with a focused helium ion beam

Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance.In this work,we have successfully fabricated Josephson junctions from Co-doped BaFe_(2)As_(2)thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam(FHIB).The electrical transport properties were investigated for junctions fabricated with various He^(+)irradiation doses.The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K,and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He^(+)irradiation.Significant J_c suppression by more than two orders of magnitude can be achieved by increasing the He^(+)irradiation dose,which is advantageous for the realization of low noise ion pnictide thin film devices.Clear Shapiro steps are observed under 10 GHz microwave irradiation.The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe_(2)As_(2)Josephson junction with high reproducibility using the FHIB technique,laying the foundation for future investigating the mechanism of iron-based superconductors,and also the further implementation in various superconducting electronic devices.

Hierarchically Structured Nb_(2)O_5 Microflowers with Enhanced Capacity and Fast-Charging Capability for Flexible Planar Sodium Ion Micro-Supercapacitors

Planar Na ion micro-supercapacitors(NIMSCs) that offer both high energy density and power density are deemed to a promising class of miniaturized power sources for wearable and portable microelectron-ics. Nevertheless, the development of NIMSCs are hugely impeded by the low capacity and sluggish Na ion kinetics in the negative electrode.Herein, we demonstrate a novel carbon-coated Nb_(2)O_5 microflower with a hierarchical structure composed of vertically intercrossed and porous nanosheets, boosting Na ion storage performance. The unique structural merits, including uniform carbon coating, ultrathin nanosheets and abun-dant pores, endow the Nb_(2)O_5 microflower with highly reversible Na ion storage capacity of 245 mAh g^(-1) at 0.25 C and excellent rate capability.Benefiting from high capacity and fast charging of Nb_(2)O_5 microflower, the planar NIMSCs consisted of Nb_(2)O_5 negative electrode and activated car-bon positive electrode deliver high areal energy density of 60.7 μWh cm^(-2),considerable voltage window of 3.5 V and extraordinary cyclability. Therefore, this work exploits a structural design strategy towards electrode materials for application in NIMSCs, holding great promise for flexible microelectronics.

Carrageenan Fiber Prepared by a New Process Route of Ba^(2+)Ion Pre-Crosslinking in the Spinning Solution

Ba^(2+)pre-crosslinked carrageenan fiber(Ba/CAF)was prepared by adding a small amount of Ba^(2+) to the carrageenan(CA)solution as the spinning solution.Ba/CAF-n/A,Ba/CAF-n/B and Ba/CAF-n/C were prepared with ethanol solution(combine A),high concentration BaCl_(2)solution(combine B)and low concentration BaCl_(2)solution(combine C),as coagulation bath and stretch bath,respectively.The combination of coagulation bath and stretch bath suitable for Ba^(2+) pre-crosslinking wet spinning was screened.The results showed that Ba^(2+) can induce the birefringence of the CA molecular chain,and the Ba^(2+) pre-crosslinking effect is the best when the CA mass fraction is 8.0 wt%.From the perspective of production safety,fiber performance and spinning cost,the coagulation bath of 3.5 wt%BaCl_(2)solution and stretch bath of 1.7 wt%BaCl_(2)solution,that is,combination C with low concentration BaCl_(2)solution,is the best choice.Ba/CAF-8.0/C was obtained under the best conditions.The linear intensity,water absorption and flame retardancy study showed that the breaking strength of Ba/CAF-8.0/C is as high as 1.61 cN/dtex,the water absorption was 649.2%and 574.3%,in deionized water and normal saline,respectively,and the LOI value reached 32.

High-performance magnesium/sodium hybrid ion battery based on sodium vanadate oxide for reversible storage of Na^(+)and Mg^(2+)

Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are an effective way to address these problems.Here,we report a new type of MSHBs that use layered sodium vanadate((Na,Mn)V_(8)O_(20)·5H_(2)O,Mn-NVO)cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide(PTCDI)anode in Mg^(2+)/Na^(+)hybrid electrolytes.During electrochemical cycling,Mg^(2+)and Na^(+)co-participate in the cathode reactions,and the introduction of Na^(+)promotes the structural stability of the Mn-NVO cathode,as cleared by several ex-situ characterizations.Consequently,the Mn-NVO cathode presents great specific capacity(249.9 mA h g^(−1)at 300 mA g^(−1))and cycling(1500 cycles at 1500 mA g^(−1))in the Mg^(2+)/Na^(+)hybrid electrolytes.Besides,full battery displays long lifespan with 10,000 cycles at 1000 mA g^(−1).The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method,and the mechanism for these improvements is discussed.

Interfacial built-in electric field and crosslinking pathways enabling WS_(2)/Ti_(3)C_(2)T_(x) heterojunction with robust sodium storage at low temperature

Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.

Solid-state NMR study on sodium intercalation at low voltage window for Na_(3)V_(2)(PO_(4))_(3) as an anode

In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.

Extending the solid solution range of sodium ferric pyrophosphate:Off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)as a novel cathode for sodium‐ion batteries

Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.

Determination of Ten Kinds of Alpha-2 Agonists Residues in Animal Derived Food by UHPLC-Triple Quadrupole/Composite Linear Ion Trap Mass Spectrometry

[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.

Sb_(2)S_(3)/石墨烯负极材料的制备及其储钠性能研究

钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量高被认为是较好的钠离子电池负极材料。本文使用简单水热法将Sb_(2)S_(3)与石墨烯复合,制备Sb_(2)S_(3)/石墨烯复合材料(Sb_(2)S_(3)/Gr)。结果表明:Sb_(2)S_(3)/Gr作为钠离子电池负极时,不仅表现出良好的电导率(3.5×10~(-3)S/cm)和钠离子扩散速率(4.853×10~(-13)cm~2/s),而且在0.5 A/g的电流密度下,首圈库伦效率为76.27%,经150次循环后的比容量稳定在488 m A·h/g,表现出较高的比容量。Sb_(2)S_(3)/Gr复合材料表现出了极大的应用潜力,为高性能钠离子电池负极材料的研发提供了一定的参考价值。

水系铵离子电池β-MnO_(2)正极材料的制备及性能研究

通过简单的水热法合成了隧道型β-MnO_(2)正极材料并应用于水系铵离子电池,并采用1 mol/L(NH4)2SO4水系电解液,在窗口电压为0~1.6 V范围内,测试其电化学性能。实验结果表明:β-MnO_(2)正极材料在0.1A/g电流密度下表现出109.8 mAh/g放电比容量,经过140次循环后,其放电比容量仍有101.9 mAh/g,容量保留率为92.8%,库伦效率接近100%,具有优异的循环稳定性能。同时还具有优异的倍率性能,β-MnO_(2)纳米棒正极材料即使在1.0 A/g大电流密度下仍有78.7 mAh/g。此外,通过非原位FTIR、XPS测试探索了其储铵机理,结果表明铵根离子具有良好的可逆性。

Ti_(3)C_(2)T_(x)超薄纳米片高效率去除废水中重金属的研究

通过刻蚀剥离法制备了Ti_(3)C_(2)T_(x)超薄纳米片,探究了其对废水中重金属离子的吸附特性。通过SEM、XRD、AFM、FT-IR、Raman对Ti_(3)C_(2)T_(x)超薄纳米片的形貌和结构进行了表征,通过ICP-MS对处理前后水体中重金属离子的含量进行了测试。结果表明剥离的Ti_(3)C_(2)T_(x)超薄纳米片表面含有结构缺陷和羟基,当水体中Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)初始浓度为50 mg/L时,47.5 mg Ti_(3)C_(2)T_(x)超薄纳米片对其的去除效率高达90%以上,尤其是对Pb(Ⅱ)的去除效率达到了98.81%,吸附性能远高于大孔树脂、硅藻土和活性炭等常见吸附试剂。在Na(Ⅰ)、Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)4种离子共存溶液中,Ti_(3)C_(2)T_(x)超薄纳米片对于Pb(Ⅱ)和Cr(Ⅵ)的去除依然可以达到92%以上。通过动力学和吸附等温拟合,Ti_(3)C_(2)T_(x)纳米片对Pb(Ⅱ)的吸附符合拟二级动力学模型和Langmuir等温模型,对Pb(Ⅱ)的最大吸附量和最低检出限分别为81.7 mg/g和0.0094 mg/L。Ti_(3)C_(2)T_(x)超薄纳米片对重金属离子的吸附特性在化学工业、食品加工的废水处理中具有良好的应用前景。

Li-richening strategy in Li_(2)ZrCl_(6) lattice towards enhanced ionic conductivity

All-solid-state Li batteries(ASSLBs) with solid-state electrolytes(SSEs) are exciting candidates for nextgeneration energy storage and receive considerable attention owing to their reliability. Halide SSEs are promising candidates due to their excellent stability against 4 V-class layered cathodes. Compared with Li3InCl6or Li_(3)ScCl_(6), the low ionic conductivity of Li_(2)ZrCl_(6)(LZC) is a challenge despite its low raw-material cost. Herein, we report a family of Li-Richened chloride, Li_(2+2x)Zr_(1–x)MxCl_(6), which can be used in highperformance ASSLBs owing to its high ionic conductivity(up to 0.62 mS cm^(-1)). The theoretical(ab initio molecular dynamics simulations) and experimental results prove that the strategy of aliovalent substitution with divalent metals to obtain Li-Richened LZC is effective in improving Li^(+)conductivity in SSEs. By combining Li_(2.1)Zr_(0.95)Mg_(0.05)Cl_(6)(Mg5-LZC) with a Li–In anode and a LiCoO_(2)cathode, a room-temperature ASSLBs with excellent long-term cycling stability(88% capacity retention at 0.3C for 100 cycles) and highrate capability(121 m A h g^(-1)at 1C) is reported. This exploratory work sheds light on improving the Li^(+)conductivity of low-cost LZC-family SSEs for constructing high performance ASSLBs.

Enabling High-Performance Sodium Battery Anodes by Complete Reduction of Graphene Oxide and Cooperative In-Situ Crystallization of Ultrafine SnO_(2)Nanocrystals

The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few-layer graphene sheets loaded with ultrafine SnO_(2)nanocrystals,using short exposure of microwave to xerogel of graphene oxide(GO)and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO(RGO).The resultant nanocomposites(SnO_(2)@MWG)enabled significantly quickened redox processes as SIB anode,which led to remarkable full anode-specific capacity reaching 538 mAh g^(−1)at 0.05 A g^(−1)(about 1.45 times of the theoretical capacity of graphite for the LIB),in addition to outstanding rate performance over prolonged charge–discharge cycling.Anodes based on the optimized SnO_(2)@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g^(−1),and capacity retention of over 70.4%was maintained at a high areal loading of 3.4 mg cm^(−2),highly desirable for high energy density SIBs to rival the current benchmark LIBs.

Unraveling the Role of Nitrogen-Doped Carbon Nanowires Incorporated with MnO_(2)Nanosheets as High Performance Cathode for Zinc-Ion Batteries

Manganese-based cathode materials are considered as a promising candidate for rechargeable aqueous zinc-ion batteries(ZIBs).Suffering from poor conductive and limited structure tolerance,various carbon matrix,especially N-doped carbon,were employed to incorporate with MnO_(2)for greatly promoted electrochemical performances.However,the related underlying mechanism is still unknown,which is unfavorable to guide the design of high performance electrode.Herein,by incorporating layered MnO_(2)with N-doped carbon nanowires,a free-standing cathode with hierarchical core-shell structure(denoted as MnO_(2)@NC)is prepared.Benefiting from the N-doped carbon and rational architecture,the MnO_(2)@NC electrode shows an enhanced specific capacity(325 mAh g^(−1)at 0.1 A g^(−1))and rate performance(90 mAh g^(−1)at 2 A g^(−1)),as well as improved cycling stability.Furthermore,the performance improvement mechanism of MnO_(2)incorporated by N-doped carbon is investigated by X-ray photoelectron spectroscopy(XPS),Raman spectrums and density functional theory(DFT)calculation.The N atom elongates the Mn-O bond and reduces the valence of Mn^(4+)ion in MnO_(2)crystal by delocalizing its electron clouds.Thus,the electrostatic repulsion will be weakened when Zn^(2+)/H^(+)insert into the host MnO_(2)lattices,which is profitable to more cation insertion and faster ion transfer kinetics for higher capacity and rate capability.This work elucidates a fundamental understanding of the functions of N-doped carbon in composite materials and shed light on a practical pathway to optimize other electrode materials.

固态电解质Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)中Li+的迁移特性

Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)是一种颇具前景的NASICON型锂离子固态电解质.本文通过第一性原理计算研究了不同Al掺杂浓度(x=0.00,0.16,0.33,0.50)对LATP的结构特性、电学特性以及Li^(+)迁移特性的影响.结果表明,Al能够稳定掺杂进入LiTi2(PO4)3(LTP)的晶体结构当中.当Al掺杂浓度x=0.16时,Li—O键的平均键长最长,成键强度最弱,而Ti—O键强度随Al掺杂浓度变化不大.Al掺杂浓度对LATP带隙的影响不大,但Al附近的O原子聚集了更多的负电荷,形成AlO6极化中心.Li^(+)不同的迁移方式(空位迁移、间隙位迁移和协同迁移)在Al掺杂浓度不同时展现出复杂的能垒变化,Li^(+)在空位迁移中迁移势垒随Al掺杂浓度的增大而升高,而在间隙位迁移中Li^(+)的迁移势垒变化相反,由于协同迁移中涉及空位和间隙位两种位点,Li^(+)的迁移势垒表现为随Al掺杂浓度的升高先降低后升高的复杂变化.当x=0.50时,LATP具有最低的Li^(+)迁移势垒0.342 eV,这个势垒值是间隙位迁移的结果.因此,通过改变Al掺杂浓度,可改变间隙Li^(+)浓度及迁移通道结构,进而调节Li^(+)的迁移性能,提高LATP中的Li^(+)导电性能.

Synthesis and Luminescence of SrZnO_2∶Eu^(3+), Li^+ Phosphor by Long Wavelength UV Excitation

SrZnO2 ： Eu^3 ＋ , Li^＋ phosphor powder by long wavelength UV excitation was synthesized by conventional solid-state reaction method. XRD and PL were employed to characterize their properties. The resuits show that Eu^3＋ ions preferentially occupy Sr^2＋ asymmetry cationic sites, thus emitting 612 nm red light originated from ^5D0 to ^7F2 transition. The luminescent intensity can be greatly enhanced with incorporation of Li^＋ ions. The excitation efficiency in range of 350 - 400 nm also increases greatly due to incorporating Li ^＋ ions. SrZnO2 ： Eu^3 ＋ , Li^＋ is a promising redemitting phosphor by long wavelength UV excitation.