Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode material doped with Ti and La co-doping were synthesized through a solid-state method.The bi-functions of the Ti and La co-doping is realized.On the one hand,the stability o...Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode material doped with Ti and La co-doping were synthesized through a solid-state method.The bi-functions of the Ti and La co-doping is realized.On the one hand,the stability of the LiNi_(0.5)Mn_(1.5)O_(4)crystal structure is enhanced and the Mn3t interference inside the material is reduced by the Ti doping.On the other hand,the co-doped La contributes to the formation of Li_(0.5)La_(0.5)TiO_(3)(LLTO)superionic conductor incorporated in the bulk LiNi_(0.5)Mn_(1.5)O_(4)phase,thereby enhancing the Li diffusion.With the help of XRD,FTIR,SEM and STEM techniques,La and Ti in the crystallographic structure and the dispersion of the LLTO superionic conductor in the bulk LNMO spinel are discussed.At the optimized molar ratio of 20:1 between LNMO and LLTO,the composite exhibits the best electrochemical performances in terms of the reversible capacity,rate capability and cycling stability.The lithium ion diffusion coefficient in the bulk LNMO phase is tripled by the LLTO superionic conductor incorporation.展开更多
Copper sulfide Cu2S is a p-type semiconducting compound that has attracted great attentions in the thermoelectric （TE） community most recently. Considering the intrinsic ultralow lattice thermal conductivity, the en...Copper sulfide Cu2S is a p-type semiconducting compound that has attracted great attentions in the thermoelectric （TE） community most recently. Considering the intrinsic ultralow lattice thermal conductivity, the enhancement of TE performance in CuzS should be achieved through improving its electrical transport properties. To achieve this goal, lithium element was doped into CuzS in this study. A series of Cu2_xLixS samples with different Li contents （x = 0, 0.005, 0.010, 0.050, and 0.100） was synthesized by the melting-annealing method. When x 〈 0.05, the Cuz_xLixS samples are stable and pure phases, having the same monoclinic structure with the pristine Cu2S at room temperature. The electrical conductivities in the Cu2_xLixS samples are greatly improved with the Li-doping content increasing due to the enhanced carrier concentrations. Meanwhile, doping Li into CuzS increases the ionic activation energy and lessens the influence of mobile Cu ions on the heat-carrying phonons. Thus, the thermal conductivities of the Li-doped Cu2S samples increase. A maximal figure of merit （zT） of 0.84 at 900 K is obtained in Cul.99Lio.018, about 133% improvement as compared with that in Cu2S matrix.展开更多
I. INTRODUCTIONIn recent years, people have conducted a lot of experiments and valuable theoretical studies on amorphous superionic conductors. From their results, the σ～ω property of amorphous superionic conductor...I. INTRODUCTIONIn recent years, people have conducted a lot of experiments and valuable theoretical studies on amorphous superionic conductors. From their results, the σ～ω property of amorphous superionic conductors can generally be concluded as follows:展开更多
Several emerging energy storage technologies and systems have been demonstrated that feature low cost,high rate capability,and durability for potential use in large-scale grid and high-power applications.Owing to its ...Several emerging energy storage technologies and systems have been demonstrated that feature low cost,high rate capability,and durability for potential use in large-scale grid and high-power applications.Owing to its outstanding ion conductivity,ultrafast Na-ion insertion kinetics,excellent structural stability,and large theoretical capacity,the sodium superionic conductor(NASICON)-structured insertion material NaTi2(PO4)3(NTP)has attracted considerable attention as the optimal electrode material for sodium-ion batteries(SIBs)and Na-ion hybrid capacitors(NHCs).On the basis of recent studies,NaTi2(PO4)3 has raised the rate capabilities,cycling stability,and mass loading of rechargeable SIBs and NHCs to commercially acceptable levels.In this comprehensive review,starting with the structures and electrochemical properties of NTP,we present recent progress in the application of NTP to SIBs,including non-aqueous batteries,aqueous batteries,aqueous batteries with desalination,and sodium-ion hybrid capacitors.After a thorough discussion of the unique NASICON structure of NTP,various strategies for improving the performance of NTP electrode have been presented and summarized in detail.Further,the major challenges and perspectives regarding the prospects for the use of NTP-based electrodes in energy storage systems have also been summarized to offer a guideline for further improving the performance of NTP-based electrodes.展开更多
Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis metho...Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, and transmission electron microscopy（TEM） as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.展开更多
基金This work is financially supported by the National Natural Science Foundation of China(NSFC,contract no.21875154 and 21473120)The authors also thank the Ministry of Science and Technology of the People's Republic of China,China(Contract No.2015AA034601).
文摘Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode material doped with Ti and La co-doping were synthesized through a solid-state method.The bi-functions of the Ti and La co-doping is realized.On the one hand,the stability of the LiNi_(0.5)Mn_(1.5)O_(4)crystal structure is enhanced and the Mn3t interference inside the material is reduced by the Ti doping.On the other hand,the co-doped La contributes to the formation of Li_(0.5)La_(0.5)TiO_(3)(LLTO)superionic conductor incorporated in the bulk LiNi_(0.5)Mn_(1.5)O_(4)phase,thereby enhancing the Li diffusion.With the help of XRD,FTIR,SEM and STEM techniques,La and Ti in the crystallographic structure and the dispersion of the LLTO superionic conductor in the bulk LNMO spinel are discussed.At the optimized molar ratio of 20:1 between LNMO and LLTO,the composite exhibits the best electrochemical performances in terms of the reversible capacity,rate capability and cycling stability.The lithium ion diffusion coefficient in the bulk LNMO phase is tripled by the LLTO superionic conductor incorporation.
基金financially supported by the National Natural Science Foundation of China (Nos. 51472262 and 51625205)the Key Research Program of Chinese Academy of Sciences (No.KFZD-SW-421)the Shanghai Government (No. 15JC1400301)
文摘Copper sulfide Cu2S is a p-type semiconducting compound that has attracted great attentions in the thermoelectric （TE） community most recently. Considering the intrinsic ultralow lattice thermal conductivity, the enhancement of TE performance in CuzS should be achieved through improving its electrical transport properties. To achieve this goal, lithium element was doped into CuzS in this study. A series of Cu2_xLixS samples with different Li contents （x = 0, 0.005, 0.010, 0.050, and 0.100） was synthesized by the melting-annealing method. When x 〈 0.05, the Cuz_xLixS samples are stable and pure phases, having the same monoclinic structure with the pristine Cu2S at room temperature. The electrical conductivities in the Cu2_xLixS samples are greatly improved with the Li-doping content increasing due to the enhanced carrier concentrations. Meanwhile, doping Li into CuzS increases the ionic activation energy and lessens the influence of mobile Cu ions on the heat-carrying phonons. Thus, the thermal conductivities of the Li-doped Cu2S samples increase. A maximal figure of merit （zT） of 0.84 at 900 K is obtained in Cul.99Lio.018, about 133% improvement as compared with that in Cu2S matrix.
文摘I. INTRODUCTIONIn recent years, people have conducted a lot of experiments and valuable theoretical studies on amorphous superionic conductors. From their results, the σ～ω property of amorphous superionic conductors can generally be concluded as follows:
基金supported by the National Natural Science Foundation of China (No. 51302079)the Natural Science Foundation of Hunan Province (No. 2017JJ1008)the Key Research and Development Program of Hunan Province of China under Grant 2018GK2031
文摘Several emerging energy storage technologies and systems have been demonstrated that feature low cost,high rate capability,and durability for potential use in large-scale grid and high-power applications.Owing to its outstanding ion conductivity,ultrafast Na-ion insertion kinetics,excellent structural stability,and large theoretical capacity,the sodium superionic conductor(NASICON)-structured insertion material NaTi2(PO4)3(NTP)has attracted considerable attention as the optimal electrode material for sodium-ion batteries(SIBs)and Na-ion hybrid capacitors(NHCs).On the basis of recent studies,NaTi2(PO4)3 has raised the rate capabilities,cycling stability,and mass loading of rechargeable SIBs and NHCs to commercially acceptable levels.In this comprehensive review,starting with the structures and electrochemical properties of NTP,we present recent progress in the application of NTP to SIBs,including non-aqueous batteries,aqueous batteries,aqueous batteries with desalination,and sodium-ion hybrid capacitors.After a thorough discussion of the unique NASICON structure of NTP,various strategies for improving the performance of NTP electrode have been presented and summarized in detail.Further,the major challenges and perspectives regarding the prospects for the use of NTP-based electrodes in energy storage systems have also been summarized to offer a guideline for further improving the performance of NTP-based electrodes.
基金Supported by the Major International Collaborative Project of the National Natural Science Foundation of China(No. 60574096)the Distinguished Young Scholars(No.60625301).
文摘Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, and transmission electron microscopy（TEM） as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.
