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High-energy-density lithium manganese iron phosphate for lithium-ion batteries: Progresses, challenges, and prospects

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Journal of Energy Chemistry 2025年第1期100卷 1-17页

作者： Bokun Zhang Xiaoyun Wang Shuai Wang Yan Li Libo Chen Handong Jiao Zhijing Yu Jiguo Tu State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Research institute for Intelligent Wearable Systems The Hong Kong Polytechnic University institute of Advanced structure Technology Beijing Institute of Technology

The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion *** manganese iron phosphate (LiMnxFe1-xPO4) has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy *** LiMnxFe1-xPO4has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap *** review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMnxFe1-xPO4to analyze reaction processes accurately and guide material ***,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMnxFe1-xPO4,including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology ***,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are *** importantly,it is expected to provide key insights into the development of high-performance and stable LiMnxFe1-xPO4materials,to achieve practical energy storage requirements.

关键词： Semiconductor doping

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Laser induced broad band anti-Stokes white emission from LiYbF_4 nanocrystals

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Journal of Rare Earths 2016年第3期34卷 227-234页

作者： L.Marciniak R.Tomala M.Stefanski D.Hreniak W.Strek institute of low temperature and structure Research Polish Academy of Sciences

Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 nanocrystals was observed. Its intensity strongly depended on the excitation power, excitation wavelength and ambient pressure. temperature of the nanocrystals under 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF_4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the laser-induced charge transfer emission from Yb^（2＋） states.

关键词： fluorides white emission up-conversion rare earths

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Synthesis and optical properties of Eu^(3+) ion doped nanocrystalline hydroxya patites embedded in PMMA matrix

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Journal of Rare Earths 2011年第12期29卷 1111-1116页

作者： R.J.Wiglusz A.Bednarkiewicz W.Strek institute of low temperature and structure Research Polish Academy of Sciences

Transparent, luminescent and functional nanocomposites demonstrate interesting optical and mechanical properties suitable for many optoelectronic applications. Transparent polymethyl methacrylate （PMMA） polymer nanocornposites modified with thenoyl- trifluoroacetonate （TAA） were fabricated by in situ polymerization and used as hosts for homogenous dispersion of 3 mol.% Eu^3＋：Ca10（PO4）6（OH）2 （Eu^3＋：HA） hydroxyapatite -20 nm large nanocrystals. The emission, excitation and transmission spectra as well as the fluorescence decay rates of bare Eu^3＋：HA nanocrystallites, Eu^3＋：HA embedded in the PMMA and and Eu：HA embedded in the PMMA/TTA rtanocomposites were studied. The improvement of transparency was demonstrated with the addition of TTA as well as europium doped hydroxyapatites in comparison to pure PMMA matrix. The Judd-Ofelt analysis of f-f transitions of Eu^3＋：HA nanocrystallites, the PMMA/Eu^3＋：HA and the PMMA＋TTA/Eu^3＋：HA was performed to investigate the optical behavior of the polymeric composites.

关键词： photoluminescence hydroxyapatites Eu^3+ doping nanocrystallites nanocomposites PMMA Judd-Ofelt analysis rare earths

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Energy transfer processes from Yb^(3+) to Ln^(3+) (Ln=Er or Tm) in heavy metal glasses

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Journal of Rare Earths 2014年第3期32卷 273-276页

作者： A.Kos I.Czopek J.Pisarska W.A.Pisarski R.Lisiecki W.Ryba-Romanowski University of Silesia Institute of Chemistry institute of low temperature and structure Research

Heavy metal glasses doubly doped with Yb3＋ and Ln3＋ ions （Ln=Er or Tm） were studied. Glass host matrices were limited to lead borate glass and lead germanate glass. Efficient resonant （yb3＋-Er3＋） and non-resonant （yb3＋-Tm3＋） energy transfer was ob- served for the studied systems. Near-infrared luminescence spectra at 1.53 μm （Er3＋） and 1.9 gm （Tm3＋） were detected under excita- tion of Yb3＋ by 975 nm diode laser line. They corresponded to 4I13/2→4115/2 （Er3＋） and 3F4→3H6 （Tm3＋） transitions of rare earth ions, respectively. The unusual large spectral linewidth nearly close to 110 nm for 4I13/2→4I15/2 transition of Er3＋ ions in lead borate glass was obtained, whereas long-lived near-infrared luminescence at 1.53 gm was detected in lead germanate glass. Quite different situa- tion was observed for yb3＋-Tm3＋ doubly doped glasses. In contrast to lead borate glass, near-infrared （3F4→3H6） luminescence spectra were registered for Tm3＋ ions in lead germanate glasses, only. These phenomena strongly depended on stretching vibrations of glass host, which was confirmed by FT-IR spectroscopy.

关键词： heavy metal glasses rare earth ions energy transfer NIR luminescence

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Influence of concentration and sintering temperature on luminescence properties of Eu^(3+):SnO_2 nanocrystallites

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Journal of Rare Earths 2012年第7期30卷 627-631页

作者： P. Psuja W. Strek institute of low temperature and structure Research of Polish Academy of Sciences

The nanopowders of SnO2 doped with different Eu^3＋ concentrations were synthesized using the modified Pechini method. The Eu^3＋ concentrations were high above solubility limit. The average size of crystallites was controlled by the sintering temperatures. The structure and the morphology of obtained powders were examined using the XRD （X-ray diffraction） and TEM （transmission electron microscopy） analyses. The Eu2Sn2O7 phase separation was observed at relatively high concentration of Eu^3＋ ions. The ZnS：Ag micropowders were mixed with the Eu^3＋：SnO2 powders and their normalized emission was used to measure a relative efficiency of Eu3＋：SnO〉 The photoluminescence spectra of mixed powders were measured in function of Eu^3＋ concentration and average size of nanocrystallites. The reference peak method was used for comparison of intensities of the samples and selection of optimal one. The influence of the average grain size and Eu^3＋ concentration on the phosphor＇s efficiency was discussed. The presented results confirmed the rightness of synthesis of the Eu^3＋：SnO2 in form of nanocrystalites with relatively high Eu^3＋ concentration.

关键词： SnO2 nanocrystallites Eu^3+ luminescence phosphors rare earths

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Synthesis,structure and luminescence properties of KEu_(0.01)Gd_(0.19)Yb_(0.8)(WO_4)_2 powder

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Journal of Rare Earths 2009年第4期27卷 564-568页

作者： A.Lukowiak R.J.Wiglusz R.Pazik K.Lemanski W.Strek institute of low temperature and structure Research Polish Academy of Sciences

The synthesis of co-doped KEu0.01Gd0.19Yb0.8（WO4）2 was achieved by a modified Pechini method at 750℃. The structure of obtained compound was confirmed using X-ray diffraction measurement and Raman spectroscopy. The Scherrer＇s formula was used to confirm the grain sizes visualized by TEM technique. The grain sizes of about 100 nm of monoclinic KGW were successfully obtained by this meth- odology. In order to study spectroscopic properties of the prepared system the emission spectra were measured. The effective down- and up-conversion processes in non-resonant system were investigated.

关键词： sol-gel method tungstates doped by rare earth ions nanoctystals spectroscopy rare earths

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Luminescent properties of dysprosium(III) ions in LaAlO_3 nanocrystallites

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Journal of Rare Earths 2011年第12期29卷 1195-1197页

作者： K.Lemański P.J.Dereń institute of low temperature and structure Research Polish Academy of Sciences

The absorption and emission spectra as well as decay time profile of Dy^3＋ ions in LaAlO3 nanocrystals were analyzed. The crystal structure of LaAlO3 was confirmed from XRD measurement. The emission peaks from blue to red came from main emitting level of dysprosium ^4F9/2 to the ground and other excited levels of Dy^3＋ ions. Cross relaxation process led to non-radiative quenching of luminescence, so that the lifetime of the ^4F9/2 energy level ions decreased with increasing amount of doped Dy^3＋ ions. The cross relaxation transfer rates were experimentally determined as a fimction of Dy^3＋ concentration.

关键词： LaAlO3 dysprosium luminescence nanocrystals cross relaxation rare earths

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Governing of down-shifting processes in LiLaP_4O_(12):Tb^(3+),Yb^(3+) for enhancement of its near-infrared emission

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Journal of Rare Earths 2016年第8期34卷 833-836页

作者： K.Grzeszkiewicz L.Marciniak D.Hreniak institute of low temperature and structure Research Polish Academy of Sciences

Downshifting behavior of the Tb3＋-gb3＋ co-doped nanocrystalline LiLaP4012 powders synthesized by co-precipitation method was presented and discussed. The structural phase purity of obtained material was confirmed by X-ray diffraction （XRD） measurements. Strong enhancement of ytterbium 2 2 - 3＋ F5/2- F7/2 emission intensity was observed with decreasing Tb concentration un- der UV excitation. Dependence of efficiency of energy transfer between dopants on pumping wavelength was investigated due to bet- ter understanding of down-shifting mechanism. It was found that luminescence intensity of Yb3＋ decreased above 10 tool.% dopant con- tent, what was caused by concentration quenching. The power dependence measurements were carried out at 77 and 300 K. The re- sulting slopes had the same value of 1, what indicated the existence of linear down-shifting process, independent of the temperature.

关键词： downshifting LiLaP4O12 rb3+ yb3+ rare earths

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Magnetic studies of GaN nanoceramics doped with 1% of cerium

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Journal of Rare Earths 2011年第12期29卷 1183-1187页

作者： K.Oganisian P.Gluchowski W.Strek institute of low temperature and structure Research Polish Academy of Sciences

The magnetization measurements of gallium nitride nanoceramics doped with 1% of cerium and sintered under various pressures were reported. It was found that GaN nanoceramics doped with cerium showed paramagnetic behavior in the wide temperature range. Nanoceramics of GaN with 1% of Ce （as undoped GaN） was diamagnetic one, but under certain temperature the paramagnetic properties started to dominate. This crossover temperature was nonlinearly dependent on the pressure applied during the sintering. The fitting of molar magnetic susceptibility allowed to estimate the Curie temperature, Curie constant and diamagnetic part of susceptibility. As it was found, all the samples showed the antiferromagnetic ordering with θp≈-1 K. Also, the effective magnetic moment was estimated for all of the samples. As a result, magnetic moments in terms of Ce ion were notably larger in comparison with those obtained within the Russell-Saunders cou- pling model. We suggested that it was the strong influence of amorphous shell which was rising with the pressure applied during the sintering. Finally, we presented dependences of magnetization as a function of applied field. All the samples manifested weak ferromagnetism at high temperatures and paramagnetic behavior in low temperature region.

关键词： gallium nitride magnetism nanoceramics rare earths

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Laser induced broadband white emission of Y2Si2O7 nanocrystals

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Journal of Rare Earths 2019年第11期37卷 1196-1199页

作者： Robert Tomala Dariusz Hreniak Wieslaw Strek institute for low temperature and structure Research Polish Academy of Sciences

The generation of broadband white emission of theα-Y2Si2O7 nanocrystals was observed upon excitation by focused beam ofCW lasers operating in near infrared,visible and blue *** influence of excitation energy on order of process is *** temperature of sample emitting laser induced white emission(LIWE)was determined by luminescence nanothermometry *** is found that the temperature is much lower than that predicted by blackbody model characterized with the same *** is shown that the LIWE is accompanied by efficient *** origin of white emission is discussed in terms of multiphoton ionization process leading to the inter valence charge transfer emission.

关键词： White light Photoconductivity Laser induced emission Nanocrystals

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