Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is considered as a promising solid-state electrolyte due to its high ionic conductivity,wide electrochemical window,and excellent electrochemical stability.However,its application in soli...Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is considered as a promising solid-state electrolyte due to its high ionic conductivity,wide electrochemical window,and excellent electrochemical stability.However,its application in solid-state lithium metal batteries(SSLMBs)is impeded by the growth of lithium dendrites in LLZO due to some reasons such as its high electronic conductivity.In this study,lithium fluoride(LiF)was introduced into Ta-doped LLZO(LLZTO)to modify its grain boundaries to enhance the performance of SSLMBs.A nanoscale LiF layer was uniformly coated on the LLZTO grains,creating a threedimensional continuous electron-blocking network at the grain boundaries.Benefiting from the electronic insulator LiF and the special structure of the modified LLZTO,the symmetric cells based on LLZO achieved a high critical current density(CCD)of 1.1 mA·cm^(-2)(in capacity-constant mode)and maintained stability over 2000 h at 0.3 mA·cm^(-2).Moreover,the full cells combined with a LiFePO_(4)(LFP)cathode,demonstrated excellent cycling performance,retaining 97.1% of capacity retention after 500 cycles at 0.5 C.Therefore,this work provides a facile and effective approach for preparing a modified electrolyte suitable for high-performance SSLMBs.展开更多
ZrO_(2) spherical nanometer powders containing 3.5 mol%Y_(2)O_(3) have been prepared via the coupling route of water/oil(W/O)emulsion with dimethyl oxalate homogenous precipitation.ZrO_(2) powders and their precursor ...ZrO_(2) spherical nanometer powders containing 3.5 mol%Y_(2)O_(3) have been prepared via the coupling route of water/oil(W/O)emulsion with dimethyl oxalate homogenous precipitation.ZrO_(2) powders and their precursor powders have been characterized by XRD,TEM and SEM.According to the XRD result,phase volume fractions of powders were calculated by comparing the peaks’intensities of spectrum.Furthermore,phase crystal lattice constants were obtained using crystal interplanar spacing formula and Bragg equation.With these results,the theoretical density of powders was analyzed.Finally,powders’spherical degree was revealed via the method of comparison between theoretical density and actual density.展开更多
Mesoporous TiO2 microspheres with flower-like morphology, high specific surface area, and high- crystallinity primary crystalline-phase of anatase have been prepared through a water-in-oil emulsion synthesis route ass...Mesoporous TiO2 microspheres with flower-like morphology, high specific surface area, and high- crystallinity primary crystalline-phase of anatase have been prepared through a water-in-oil emulsion synthesis route assisted by solvothermal treatment. The as-prepared powder microspheres, as well as their precursor, were characterized by various techniques. Thermogravimetry and differential thermal analysis indicated that the optimal sintering temperature of the TiO2 precursor was 550 ℃. Field emission scanning electron microscopy, laser particle size analysis, and X-ray diffractionjointly confirmed that the precursor powder with a spherical structure and main particle sizes ranging from 3 to 20 μm had the same primary crystalline-phase as the TiO2 microspheres obtained from the calcination of the precur- sor at 550 ℃ for 4 h. The specific surface area of the TiO2 microspheres was approximately 123.6 m2/g according to the Brunauer-Emmett-Teller (BET) nitrogen adsorption results. Compared with the com- mercial TiO2 powder (P25), the resulting TiO2 microspheres exhibited a higher photocatalytic activity. Based on the experimental results, a rational mechanism was proposed to elucidate the formation of the TiO2 microsoheres.展开更多
基金supported by the National Natural Science Foundation of China(No.52202231)the Natural Science Foundation of Hubei Province(No.2023AFB316)+1 种基金the Independent Innovation Projects of the Hubei Longzhong Laboratory(No.2022ZZ-16)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(No.2022-KF-23).
文摘Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is considered as a promising solid-state electrolyte due to its high ionic conductivity,wide electrochemical window,and excellent electrochemical stability.However,its application in solid-state lithium metal batteries(SSLMBs)is impeded by the growth of lithium dendrites in LLZO due to some reasons such as its high electronic conductivity.In this study,lithium fluoride(LiF)was introduced into Ta-doped LLZO(LLZTO)to modify its grain boundaries to enhance the performance of SSLMBs.A nanoscale LiF layer was uniformly coated on the LLZTO grains,creating a threedimensional continuous electron-blocking network at the grain boundaries.Benefiting from the electronic insulator LiF and the special structure of the modified LLZTO,the symmetric cells based on LLZO achieved a high critical current density(CCD)of 1.1 mA·cm^(-2)(in capacity-constant mode)and maintained stability over 2000 h at 0.3 mA·cm^(-2).Moreover,the full cells combined with a LiFePO_(4)(LFP)cathode,demonstrated excellent cycling performance,retaining 97.1% of capacity retention after 500 cycles at 0.5 C.Therefore,this work provides a facile and effective approach for preparing a modified electrolyte suitable for high-performance SSLMBs.
基金The authors acknowledge the support of the National Natural Science Foundation of China(Grant Nos.51004046 and 51075129)the State Key Development Program for Basic Research of China(Project No.2010CB635107)the National Natural Science Foundation of Hubei Province of China(Project No.2010CDB05806).
文摘ZrO_(2) spherical nanometer powders containing 3.5 mol%Y_(2)O_(3) have been prepared via the coupling route of water/oil(W/O)emulsion with dimethyl oxalate homogenous precipitation.ZrO_(2) powders and their precursor powders have been characterized by XRD,TEM and SEM.According to the XRD result,phase volume fractions of powders were calculated by comparing the peaks’intensities of spectrum.Furthermore,phase crystal lattice constants were obtained using crystal interplanar spacing formula and Bragg equation.With these results,the theoretical density of powders was analyzed.Finally,powders’spherical degree was revealed via the method of comparison between theoretical density and actual density.
基金The authors gratefully acknowledge the financial support for this work from State Key Development Program for Basic Research of China (No. 2010CB635107), The National Natural Science Foundation of China (Nos. 51004046, 51202064, 51302073), The National Natural Science Foundation of Hubei Province of China (No. 2010CDB05806), Wuhan Youth Chenguang Program of Sci- ence and Technology (No. 2013070104010016), and Middle-aged and Young Program of Educational Commission of Hubei Province (No. Q20101409).
文摘Mesoporous TiO2 microspheres with flower-like morphology, high specific surface area, and high- crystallinity primary crystalline-phase of anatase have been prepared through a water-in-oil emulsion synthesis route assisted by solvothermal treatment. The as-prepared powder microspheres, as well as their precursor, were characterized by various techniques. Thermogravimetry and differential thermal analysis indicated that the optimal sintering temperature of the TiO2 precursor was 550 ℃. Field emission scanning electron microscopy, laser particle size analysis, and X-ray diffractionjointly confirmed that the precursor powder with a spherical structure and main particle sizes ranging from 3 to 20 μm had the same primary crystalline-phase as the TiO2 microspheres obtained from the calcination of the precur- sor at 550 ℃ for 4 h. The specific surface area of the TiO2 microspheres was approximately 123.6 m2/g according to the Brunauer-Emmett-Teller (BET) nitrogen adsorption results. Compared with the com- mercial TiO2 powder (P25), the resulting TiO2 microspheres exhibited a higher photocatalytic activity. Based on the experimental results, a rational mechanism was proposed to elucidate the formation of the TiO2 microsoheres.