The relationship between charge-density-wave(CDW) and superconductivity(SC), two vital physical phases in condensed matter physics, has always been the focus of scientists’ research over the past decades. Motivated b...The relationship between charge-density-wave(CDW) and superconductivity(SC), two vital physical phases in condensed matter physics, has always been the focus of scientists’ research over the past decades. Motivated by this research hotspot, we systematically studied the physical properties of the layered telluride chalcogenide superconductors CuIr_(2-x)Al_(x)Te_(4)(0 ≤x≤ 0.2). Through the resistance and magnetization measurements, we found that the CDW order was destroyed by a small amount of Al doping. Meanwhile, the superconducting transition temperature(T_(c)) kept changing with the change of doping amount and rose towards the maximum value of 2.75 K when x = 0.075. The value of normalized specific heat jump(△C/γT_(c)) for the highest T_(c) sample CuIr_(2-x)Al_(x)Te_(4)was 1.53, which was larger than the BCS value of 1.43 and showed the bulk superconducting nature. In order to clearly show the relationship between SC and CDW states,we propose a phase diagram of T_(c) vs. doping content.展开更多
The replacement of liquid organic electrolytes with solid-state electrolytes(SSEs)is a feasible way to solve the safety issues and improve the energy density of lithium batteries.Developing SSEs materials that can wel...The replacement of liquid organic electrolytes with solid-state electrolytes(SSEs)is a feasible way to solve the safety issues and improve the energy density of lithium batteries.Developing SSEs materials that can well match with high-voltage cathodes and lithium metal anode is quite significant to develop high-energy-density lithium batteries.Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)SSE with NASICON structure exhibits high ionic conductivity,low cost and superior air stability,which enable it as one of the most hopeful candidates for all-solidstate batteries(ASSBs).However,the high interfacial impedance between LATP and electrodes,and the severe interfacial side reactions with the lithium metal greatly limit its applications in ASSBs.This review introduces the crystal structure and ion transport mechanisms of LATP and summarizes the key factors affecting the ionic conductivity.The side reaction mechanisms of LATP with Li metal and the promising strategies for optimizing interfacial compatibility are reviewed.We also summarize the applications of LATP including as surface coatings of cathode particles,ion transport network additives and inorganic fillers of composite polymer electrolytes.At last,this review proposes the challenges and the future development directions of LATP in SSBs.展开更多
The Li_(4+x)Al_xSi_(1-x)O_(4-y)Al_2O_3 (x = 0 to 0.5, y = 0 to 0.5) ionconductors were prepared by the Sol-Gel method and examined in detail. The powder and sinteredsamples were characterized by TG-DTA, XRD, SEM, and ...The Li_(4+x)Al_xSi_(1-x)O_(4-y)Al_2O_3 (x = 0 to 0.5, y = 0 to 0.5) ionconductors were prepared by the Sol-Gel method and examined in detail. The powder and sinteredsamples were characterized by TG-DTA, XRD, SEM, and AC impedance techniques. The experimentalresults show that the conductivity and sinterability increase with the amount of excess Al_2O_3 inthe silicate. The particle size of the powder samples is about 0.13 μm. The maximum conductivity at18 ℃ is 3.057 * 10^(-5) s/cm for Li_(4.4)Al_(0.4)Si_(0.6)O_4-0.3 Al_2O_3.展开更多
NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定...NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定性好,但其立方相结构不稳定,影响其实际应用。采用溶液浇筑法,制备纯PVDF-LiTFSI电解质膜和以PVDF为基、3种不同质量比的Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)的固态电解质膜,并探讨纯PVDF-LiTFSI电解质膜和3种不同质量比的活性无机电解质填料对复合固态电解质离子电导率的影响。结果表明,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时,电解质膜的XRD图谱的衍射峰比纯PVDF-LiTFSI下降更为明显,电化学窗口为3.9 V左右,表现出更好的稳定性。在不同温度下分别测量其离子电导率发现,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时的电解质膜均高于纯PVDF-LiTFSI电解质膜和Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为2∶1和3∶1时的电解质膜。将其装配成电池后发现,0.1C下电池首次充放电比容量分别为90 m A·h/g和87 m A·h/g。以0.5C的电流循环25圈,放电比容量从57 mA·h/g衰减至51mA·h/g,容量保持率为99.7%。所以,以PVDF为基、Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1的固态电解质膜有优良的倍率性能和循环稳定性能。展开更多
基金the financial support by the National Natural Science Foundation of China (Grant No. 11922415)Guangdong Basic and Applied Basic Research Foundation, China (Grants No. 2019A1515011718)+8 种基金the Pearl River Scholarship Program of Guangdong Province Universities and Colleges (Grants No. 20191001)supported by the National Natural Science Foundation of China (Grants No. 11974432)the National Key R&D Program of China (Grant Nos. 2018YFA0306001 and 2017YFA0206203)the financial support by the National Key Laboratory Development Fund (No. 20190030)partial support by the National Key R&D Program of China (Grant No. 2017YFA0303000)National Natural Science Foundation of China (Grant No. 11827805)Shanghai Municipal Science and Technology Major Project, China (Grant No. 2019SHZDZX01)supported by the National Natural Science Foundation of China (Grant Nos. 11904414 and 12174454)the National Key R&D Program of China (Grant No. 2019YFA0705702)。
文摘The relationship between charge-density-wave(CDW) and superconductivity(SC), two vital physical phases in condensed matter physics, has always been the focus of scientists’ research over the past decades. Motivated by this research hotspot, we systematically studied the physical properties of the layered telluride chalcogenide superconductors CuIr_(2-x)Al_(x)Te_(4)(0 ≤x≤ 0.2). Through the resistance and magnetization measurements, we found that the CDW order was destroyed by a small amount of Al doping. Meanwhile, the superconducting transition temperature(T_(c)) kept changing with the change of doping amount and rose towards the maximum value of 2.75 K when x = 0.075. The value of normalized specific heat jump(△C/γT_(c)) for the highest T_(c) sample CuIr_(2-x)Al_(x)Te_(4)was 1.53, which was larger than the BCS value of 1.43 and showed the bulk superconducting nature. In order to clearly show the relationship between SC and CDW states,we propose a phase diagram of T_(c) vs. doping content.
基金Key-Area Research and Development Program of Guangdong Province,Grant/Award Number:2020B090919001National Natural Science Foundation of China,Grant/Award Number:U2001220+1 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center,Grant/Award Number:XMHT20200203006Shenzhen Technical Plan Project,Grant/Award Number:JCYJ20180508152210821,JCYJ20170817161221958,JCYJ20180508152135822。
文摘The replacement of liquid organic electrolytes with solid-state electrolytes(SSEs)is a feasible way to solve the safety issues and improve the energy density of lithium batteries.Developing SSEs materials that can well match with high-voltage cathodes and lithium metal anode is quite significant to develop high-energy-density lithium batteries.Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)SSE with NASICON structure exhibits high ionic conductivity,low cost and superior air stability,which enable it as one of the most hopeful candidates for all-solidstate batteries(ASSBs).However,the high interfacial impedance between LATP and electrodes,and the severe interfacial side reactions with the lithium metal greatly limit its applications in ASSBs.This review introduces the crystal structure and ion transport mechanisms of LATP and summarizes the key factors affecting the ionic conductivity.The side reaction mechanisms of LATP with Li metal and the promising strategies for optimizing interfacial compatibility are reviewed.We also summarize the applications of LATP including as surface coatings of cathode particles,ion transport network additives and inorganic fillers of composite polymer electrolytes.At last,this review proposes the challenges and the future development directions of LATP in SSBs.
基金theNaturalScienceFoundationofHebeiProvince (No .2 96 16 9)
文摘The Li_(4+x)Al_xSi_(1-x)O_(4-y)Al_2O_3 (x = 0 to 0.5, y = 0 to 0.5) ionconductors were prepared by the Sol-Gel method and examined in detail. The powder and sinteredsamples were characterized by TG-DTA, XRD, SEM, and AC impedance techniques. The experimentalresults show that the conductivity and sinterability increase with the amount of excess Al_2O_3 inthe silicate. The particle size of the powder samples is about 0.13 μm. The maximum conductivity at18 ℃ is 3.057 * 10^(-5) s/cm for Li_(4.4)Al_(0.4)Si_(0.6)O_4-0.3 Al_2O_3.
文摘NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定性好,但其立方相结构不稳定,影响其实际应用。采用溶液浇筑法,制备纯PVDF-LiTFSI电解质膜和以PVDF为基、3种不同质量比的Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)的固态电解质膜,并探讨纯PVDF-LiTFSI电解质膜和3种不同质量比的活性无机电解质填料对复合固态电解质离子电导率的影响。结果表明,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时,电解质膜的XRD图谱的衍射峰比纯PVDF-LiTFSI下降更为明显,电化学窗口为3.9 V左右,表现出更好的稳定性。在不同温度下分别测量其离子电导率发现,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时的电解质膜均高于纯PVDF-LiTFSI电解质膜和Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为2∶1和3∶1时的电解质膜。将其装配成电池后发现,0.1C下电池首次充放电比容量分别为90 m A·h/g和87 m A·h/g。以0.5C的电流循环25圈,放电比容量从57 mA·h/g衰减至51mA·h/g,容量保持率为99.7%。所以,以PVDF为基、Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1的固态电解质膜有优良的倍率性能和循环稳定性能。
