Tailoring crystal plane of short-process regenerated LiFePO_(4) towards enhanced rate properties

Captured by the environmental and economic value,the recycling of spent lithium iron phosphate(LFP)batteries has attracted numerous attentions.However,hydrometallurgical method still suffers from complex process,and hydrothermal method is limited by morphology control,ascribed to the strong polarity of water.Herein,supported by ethanol as crystal surface modifier,the regular(010)orientation and short b-axis are effectively tailored for regenerated LFP.As Li-storage cathode,the capacities of as-optimized LFP could reach up to 157.07 mA h g^(-1)at 1 C,and the stable capacity of 150.50 mA h g^(-1)could be remained with retention of 93.48%after 400 cycles at 1 C.Even at 10 C,their capacity could be still kept about 119.3 m A h g^(-1).Assisted by the detail analysis of adsorption energy,the clear growth mechanism is proposed,the lowest adsorbing energy(-4.66 eV)of ethanol on(010)crystal plane renders the ordered growth along(010)crystal plane.Given this,the work is expected to shed light on the tailoring mechanism of internal plane about regenerated materials,whilst providing effective strategies for highperformance regenerated LFP.

Enhancing the crystallinity and stability of perovskite solar cells with 4-tert-butylpyridine induction for efficiency exceeding 24%

Perovskite solar cells(PSCs)have emerged as a promising photovoltaic technology because of their high light absorption coefficient,long carrier diffusion distance,and tunable bandgap.However,PSCs face challenges such as hysteresis effects and stability issues.In this study,we introduced a novel approach to improve film crystallization by leveraging 4-tert-butylpyridine(TBP)molecules,thereby enhancing the performance and stability of PSCs.Our findings demonstrate the effective removal of PbI_(2)from the perovskite surface through strong coordination with TBP molecules.Additionally,by carefully adjusting the concentration of the TBP solution,we achieved enhanced film crystallinity without disrupting the perovskite structure.The TBP-treated perovskite films exhibit a low defect density,improved crystallinity,and improved carrier lifetime.As a result,the PSCs manufactured with TBP treatment achieve power conversion efficiency(PCE)exceeding 24%.Moreover,we obtained the PCE of 21.39%for the 12.25 cm^(2)module.

Mitigating kinetic hindrance of single-crystal Ni-rich cathodes through morphology modulation,nickel reduction,and lithium vacancy generation achieved by terbium doping

Single crystallization has proven to be effective in enhancing the capacity and stability of Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(SNCM)cathode materials,particularly at high cut-off voltages.Nevertheless,the synthesis of high-quality single-crystal particles remains challenging because of severe particle agglomeration and irregular morphologies.Moreover,the limited kinetics of solid-phase Li^(+)diffusion pose a significant concern because of the extended diffusion path in large single-crystal particles.To address these challenges,we developed a Tb-doped single-crystal LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(SNCM-Tb)cathode material using a straightforward mixed molten salt sintering process.The Tb-doped Ni-rich single crystals presented a quasi-spherical morphology,which is markedly different from those reported in previous studies.Tb^(4+)oping significantly enhanced the dynamic transport of Li^(+)ions in the layered oxide phase by reducing the Ni valence state and creating Li vacancies.A SNCM-Tb material with 1 at%Tb doping shows a Li^(+)diffusion coefficient up to more than 9 times higher than pristine SNCM in the non-diluted state.In situ X-ray diffraction analysis demonstrated a significantly facilitated H1-H2-H3 phase transition in the SNCM-Tb materials,thereby enhancing their rate capacity and structural stability.SNCM-Tb exhibited a reversible capacity of 186.9 mA h g^(-1)at 5 C,retaining 94.6%capacity after 100 cycles at 0.5 C under a 4,5 V cut-off.Our study elucidates the Tb^(4+)doping mechanisms and proposes a scalable method for enhancing the performance of single-crystal Ni-rich NCM materials.

Surface deterioration dependent on the crystal facets of spinel LiNi_(0.5)Mn_(1.5)O_(4) cathode active material

The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notable safety and high energy density,particularly in their single-crystal type.Nevertheless,the industrial application of the LNMO CAMs is severely inhibited due to the interfacial deterioration and corrosion under proton-rich and high-voltage conditions.This study successfully designed and synthesized two typical types of crystal facets-exposed single-crystal LNMO CAMs.By tracking the electrochemical deterioration and chemical corrosion evolution,this study elucidates the surface degradation mechanisms and intrinsic instability of the LNMO,contingent upon their crystal facets.The(111)facet,due to its elevated surface energy,is found to be more susceptible to external attack compared to the(100)and(110)facets.Our study highlights the electrochemical corrosion stability of crystal plane engineering for spinel LNMO CAMs.

Analyses of Reaction Mechanisms among Different Sulfonation Reagents and m-Diphenylamine and Crystal Structures of the Formed Compounds

In the traditional process, m-phenylenediamine reacts with fuming sulfuric acid at high temperature to get intermediates, and then after dehydration occurs intramolecular rearrangement to get 2,4-diaminobenzenesulfonic acid. Traditional methods need to consume a lot of fuming sulfuric acid or concentrated sulfuric acid, resulting in high industrial large-scale production cost, more waste, and posing a serious environmental pollution risk. In this thesis, three different sulfonation reagents were used for the sulfonation reaction of m-phenylenediamine, and the reaction mechanisms and crystal structures of the three pathways were investigated. The three routes are: 1) one-step synthesis of monosulfonated compound 1 from raw material and sulfur trioxide (SO3);2) rapid reaction of raw material and chlorosulfonic acid to synthesize bisulfonated compound 2;3) direct eutectic crystallization of raw material and ordinary sulfuric acid to obtain compound 3. The crystal structure of the compounds synthesized by three paths was analyzed by X-ray single crystal diffraction, and compound 1 was characterized by NMR, Fourier infrared spectra, UV-visible spectrum and Mass spectrometry. The one-step synthesis of SO3 as a sulfonation reagent has the advantages of mild reaction conditions, simple operation and low cost.

ZnWO_4晶体着色和消色机理的研究

生长不掺杂但原料纯度不同的ZnwO_4晶体和掺人Sb_2O_2、CeO_2、Ag_2O等杂质的掺杂znwO_4晶体。晶体在氧气中高温退火,测试晶体退火前后的性能,探讨ZnwO_4晶体着色和消色机理;提出ZoWO_4晶体的颜色是由于色心复合体“Fe^(2+)+[O^(2-)]+电子”引起的。

提拉法Cr：ZnWO_4晶体晶场光谱的研究

本文报道了提拉法Ｃｒ：ＺｎＷＯ＿４晶体的吸收和反射光谱。分析了ＺｎＷＯ＿４基质中Ｃｒ￣（３＋）离子的能级结构，计算了它的晶场参数，据此讨论了Ｃｒ￣（３＋）：ＺｎＷＯ＿４发射红移的机制。在空气气氛下，以提拉法生长并经退火的Ｃｒ：ＺｎＷＯ＿４晶体中，除三价Ｃｒ￣（３＋）离子以外，还可能存在少量的四价的Ｃｒ￣（４＋）离子，初步计算了它的晶场参数。

ZnWO_4∶Cr^(3+)激光晶体在固体介质中退火处理

ZnWO_4∶Cr^(3+)激光晶体在固体介质中退火后,在490和700nm 处的吸收明显下降,在916nm 的荧光强度明显增强。研究了退火对晶体光谱特性的影响,对退火机制与氧扩散和相变之间的关系进行了分析。

闪烁晶体ZnWO_4:Ge^(4+)单晶研究

我们成功地生长出无色的掺Ge钨酸锌单晶,发光效率有所提高。研究了不同浓度下Ge在钨酸锌晶体中的分凝系数。研究了沿a、b和c轴方向提拉对生长速率和生长形貌的影响。

ZnWO_4:Tm^(3+)单晶的上转换研究

上转换发光的本质是一种反斯托克斯发光。由于可以用低能量的长波长光激发获得能量较高的短波长光 ,因此作为紧凑高效短波长的固体激光器的工作物质 ,上转换材料的前景十分看好。在实验室中用丘克拉斯基法成功地生长出了质量较好的单晶 ,名义掺杂浓度分别为 0 .2 %、0 .5 %和 1 .0 % (摩尔比 )。对样品进行了系统的光谱测试。从吸收谱可以看出 :样品的吸收峰位于 80 7nm( 3 H63 H4)左右 ,且谱线较宽。与吸收峰长位于 75 0nm ,谱线线宽Δλ =4nm的YAG :Tm3 +单晶相比 ,可以看出 :ZnWO4:Tm3 +更适合于激光二极管泵浦。值得注意的是基底在40 0nm左右的光吸收较强 ,退火可以在一定程度上消除基底的影响。对样品的荧光强度测试表明 :在 80 7nmLD泵浦下 ,样品主要有三个上转换荧光峰 ,分别位于 40 5、486和 6 95nm左右 ,其中以 6 95nm的峰为最强。荧光强度受出入射方向影响较大 ,在a轴方向接受时光的强度为最大 ,而且受激发方向影响较小。还测定了样品的荧光 ( 6 95nm)强度与激发功率之间的关系—线性关系。

表面活性剂对ZnWO_4:Tb^(3+)绿色荧光粉发光性能的影响

采用水热法合成应用于荧光灯的绿色荧光粉ZnWO_4:Tb^(3+).通过X射线粉末衍射分析仪(XRD),扫描电子显微镜(SEM)和荧光光谱仪,系统考察不同表面活性剂条件下合成的ZnWO_4:Tb^(3+)绿色荧光粉.结果表明,不同表面活性剂条件下,采用水热法合成的产品均为纯ZnWO_4结构,Tb^(3+)掺杂并不改变钨酸锌结构;荧光光谱仪对样品的激发和发射以及荧光衰减曲线测定表明,表面活性剂PEG-2000条件下合成的荧光粉,其发光强度增强最有效,采用PVP为表面活性剂合成ZnWO_4:Tb^(3+)的荧光粉寿命较采用PEG-2000和CTAB为表面活性剂合成的长.综合发光强度和荧光寿命的影响,选PVP为表面活性剂最佳.

Bi：ZnWO_4晶体的生长及其闪烁性能研究

在ＺｎＷＯ＿４晶体的原料中掺入ＢｉＯ＿３生长了Ｂｉ：ＺｎＷＯ＿４晶体。对Ｂｉ：ＺｎＷＯ＿４晶体的光谱和能量分辨率的测量表明，Ｂｉ离子能有效地消除ＺｎＷＯ＿４晶体的颜色，提高晶体的发光效率和能量分辨率。

高光束质量平-凸谐振腔Nd∶YVO_(4)激光器

采用一种由878.6 nm激光二极管(LD)端面抽运Nd∶YVO_(4)晶体,获得高光束质量的1064 nm脉冲激光输出。使用Matlab软件对晶体热透镜焦距进行模拟分析,并通过软件计算选取合适的平-凸谐振腔腔型,缓解热效应的同时获得最佳输出状态。泵浦功率为48 W时获得平均输出功率15.03 W的1064 nm连续光输出。通过磷酸钛氧铷(RTP)电光调Q的方式,在重复频率为10 kHz时获得了稳定的1064 nm脉冲激光输出,最大输出平均功率为8.78 W,动-静转化比为72.9%,脉宽为8.70 ns,光束质量因子为1.2。实验结果表明:利用波长878.6 nm作为泵浦源并采用平-凸谐振腔的方式,有利于缓解晶体的热效应、提高光束质量、获得基模脉冲激光输出。

Efficient Near-Infrared Quantum Cutting in Tm3＋/yb3＋ Codoped LiYF4 Single Crystals for Solar Photovoltaic

Downconversion （DC） with emission of two near-infrared photons about 1000 nm for each blue photon absorbed was obtained in thulium （Tm3＋） and ytterbium （Yb3＋） codoped yt- trium lithium fluoride （LiYF4） single crystals grown by an improved Bridgman method. The luminescent properties of the crystals were measured through photoluminescence excitation, emission spectra and decay curves. Luminescence between 960 and 1050 nm from yb3＋： 2Fs/2--＋2FT/2 transition, which was originated from the DC from Tm3＋ ions to Yb3＋ ions, was observed under the excitation of blue photon at 465 nm. Moreover, the energy transfer processes were studied based on the Inokuti-Hirayama model, and the results indicated that the energy transfer from Tm3＋ to Yb3＋ was an electric dipole-dipole interaction. The max- imum quantum cutting efficiency approached with 0.49mo1% Tm3＋ and 5.99mo1% Yb3＋. increasing the energy efficiency of crystalline energy part of the solar spectrum. up to 167.5% in LiYF4 single crystal codoped Application of this crystal has prospects for Si solar cells by photon doubling of the high

Synthesis,Crystal Structure and Antimicrobial Study of a New Schiff Base 2-{(2'-Benzyl)iminoethyl}-5-methoxyphenol

The Schiff base, 2-{（2′-benzyl）iminoethyl}-5-methoxyphenol （C6H4CH2N=C（CH3）C6H3- （OMe-5）OH） 1, was synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The compound crystallizes in the orthorhombic system, space group Pbca with a = 8.9849（10）, b = 13.2699（15）, c = 22.975（2） A ,V= 2739.3（5） A^3, Mr= 255.31, Z= 8, F（000） = 1088, Dc = 1.238 g/cm^3, T= 293 K, μ = 0.082 mm^-1, λ = 0.71073 .A, the final R = 0.0596 and wR = 0.1575 for 1934 observed reflections with I 〉 2σ（I）. The complex was valued for its antimicrobial activity against bacterial strands using the agar diffusion method, and found to be active against the four test bacterial organisms.

Syntheses and Crystal Structures of 3,5-Diiodo-salicylalidehyde and 3,5-Diiodo-salicylalidene-4-nitroaniline

The title compounds, C7H4I2O2 1 and C13H7I2N2O3 2, have been synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a = 9.802（2）, b = 13.867（3）, c = 7.364（2） A, β = 109.74（3）°, V= 942.1（3） A^3, Dc= 2.636 g/cm^3, C7H4I2O2, Mr= 373.90, F（000） = 672, μ = 6.627 mm^-1, Z = 4, R = 0.0459 and wR = 0.1018 for 1805 observed reflections （I 〉 2 σ（I））. Compound 2 belongs to the monoclinic system, space group P21/n with a = 9.015（2）, b = 12.024（2）, c = 14.072（3） A, β = 103.91（3）°, V = 1480.6（5） A^3, Dc= 2.216 g/cm^3, C13H7I2N2O3, Mr= 494.01, F（000） = 920, p = 4.255 mm^-1, Z = 4, R = 0.0777 and wR = 0.1757 for 2896 observed reflections （I 〉 2σ（I））. Compounds 1 and 2 were assayed for antibacterial activities against three Gram positive bacterial strains （B. subtilis, S. aureus and S. faecalis） and three Gram negative bacterial strains （E. coli, P. aeruginosa and E. cloacae） by MTr method. Fortunately, compound 2 is found to show potent antibacterial activity against these six bacterial strains.

Synthesis and Crystal Structure of 2(1-Phenyl-3-methyl-5-chloro-1H-pyrazol- 4-yl)-3-(1-naphthoylamido)-4-thiazolidinone

The crystal structure of 2(1-phenyl-3-methyl-5-chloro-1H-pyrazol-4-yl)-3-(1- naphthoylamido)-4-thiazolidinone (C24H19ClN4O2S, Mr = 462.94) has been determined by single- crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 11.623(5), b = 11.579(5), c = 16.619(7) ? b = 90.112(8), V = 2237(2) 3, Z = 4, Dc = 1.375 g/cm3, m = 0.294 mm-1, F(000) = 960, R = 0.0492 and wR = 0.0768 for 3932 unique reflections with 1897 observed ones (I > 2s(I)). X-ray analysis reveals that there exist both intra-and intermolecular hydrogen bonds in the crystal lattice.

Synthesis,Crystal Structure and Biological Activity of N-(2,6-Difluorobenzoyl)-N'-[5-(4-trifluoromethyl-phenyl)-1,3,4-thiadiazol-2-yl]ure

The title compound N-（2,6-difluorobenzoyl）-N＇-[5-（4-trifluoromethylphenyl）-1,3,4-thiadiazol-2-yl]urea（C17H9F5N4O2S,Mr = 428.34） has been synthesized by the reaction of 2-amino-5-（4-trifluoromethylphenyl）-1,3,4-thiadiazole with 2,6-difluorobenzoyl isocyanate,and its crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/n with a = 10.7316（13）,b = 10.5617（13）,c = 16.037（2） ,β = 106.408（2）°,V = 1743.6（4） 3,Z = 4,Dc = 1.632 g/cm3,μ = 0.260 mm-1,F（000） = 864,the final R = 0.0599 and wR = 0.1420 for 3467 observed reflections with I〉 2σ（I）.The urea group,which adopts a planar configuration mediated by the intramolecular N-H...O hydrogen bond,is nearly coplanar with the thiadiazole and 4-trifluoromethylbenzene rings.The title compound was found to exhibit good fungicidal activity against Rhizoctonia solani and Botrytis cinerea.

Synthesis and Crystal Structure of Calix[4]arene Bearing a 1,8-Bis(propoxy)anthracene-9,10-dione

The title complex （C50H44C14O8） was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/n with a = 19.7768（4）, b =10.2085（2）, c = 21.2721（4）A,β= 97.153（1）°, V = 4261.23（14）A^3, Z = 4, Mr = 914.65, F（000） = 1904, Dc = 1.426 g/cm^3,μ = 0.336, the final R = 0.0550 and wR = 0.1647. The compound was structurally characterized by IR and ^1H NMR. The molecules are stacked through C-H...π interactions and intermolecular C-H...O hydrogen bonds.

Ce∶La∶ZnWO_4晶体的生长及其闪烁性能的研究

钨酸锌 (ZnWO4)晶体属单斜晶系 ,点群为 2 ,熔点 1 2 0 0℃ ,ZnWO4晶体具有优良的闪烁性能 ,晶体的密度大 ,辐射长度短 ,发光效率高 ,抗辐照操作性能好的特点。但ZnWO4晶体易于着色 ,衰减时间长 ( 2 1 μs) ,在ZnWO4晶体中掺进CeO2 和La2 O3 生长Ce∶La∶ZnWO4晶体 ,能够改善晶体的闪烁性能。在ZnWO4中掺进质量分子数为 1 0 -4 的CeO2 和La2 O3 ,采用Czochralski法生长Ce∶La∶LiNb3 晶体。测试晶体的尺寸为 1 0mm× 1 0mm× 5mm ,采用SPEX1 0 0 0M型光谱仪测试晶体的透过率 ,Ce∶La∶ZnWO4晶体的透过率为 70 % ,纯ZnWO4晶体的透过率为 6 7% ,且在 46 0nm处有一吸收带。Ce∶La∶ZnWO4晶体的发射光谱在波长为 31 5nm的激光激发下 ,最强的吸收峰为在 480nm和纯ZnWO4发射谱一致。发光效率是衡量闪烁体将射线能量转变为光能的程度。在测量Ce∶La∶ZnWO4晶体的实验中 ,以NaI(Tl)晶体作为标准而进行比较。在S— 1 1阴极条件下 ,测量出相对输出脉冲 ,对信号进行积分的方法处理 ,测得Ce∶La∶ZnWO4晶体相对于Na(I)Tl晶体的发光效率 ,晶片样品对13 7Cs放射源的能量为 0 .6 6 2MeV的γ射线的测量结果 :Ce∶La∶ZnWO4晶体样品对13 7Cs放射源的能量为 0 .6 6 2MeV的γ射线的能量分辨率为 1 7.2 % 。