Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes h...Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes have not satisfactorily addressed the challenges of poor rate performance and short cycle life.To fill this scientific gap,we herein pioneer incorporating the sodium fast ionic conductorβ"-Al_(2)O_(3)into ball-milled BP with carbon,which facilitates the formation of three-dimensional mass transfer channels in the resulting composite.To stabilize these channels,we develop a novel and environmentally friendly functional binder that outperforms traditional binders in thermal stability,wettability,and mechanical properties.The newly established binder is capable of remarkably mitigating volume expansion and interfacial side reactions in the BP/β"-Al_(2)O_(3)/C composite anode.Additionally,we identify synergistic effects of the binder interacting with the BP/β"-Al_(2)O_(3)/C composite during cycling,characterized by the in-situ formation of P-O-C bonds,which is the first instance of a strong,durable chemical bond between the binder and the active material to the best of our knowledge.These advancements allow the composite electrode to exhibit exceptional sodium storage,including high initial Coulombic efficiency and long-term cycling stability,which surpasses most previous phosphorus-based anodes fabricated via traditional approaches.Notably,when paired with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_7(NFPP)cathode,the full cell exhibits unexpectedly high energy and power densities,highlighting the BP potential in SIBs.The findings presented in the present work contribute to the promotion of economical and efficient applications of phosphorus-based anode materials.展开更多
The ceramic composite separators coated with silica or alumina particles have been used in power batteries due to their better electrolyte wettability and better thermal stability compared with bare polymer separators...The ceramic composite separators coated with silica or alumina particles have been used in power batteries due to their better electrolyte wettability and better thermal stability compared with bare polymer separators.However,these oxide ceramics are Liþion insulators,which increase internal resistance and hinder the improvement of rate capability of batteries.Herein,we report a strategy to further improving the performance of lithium-ion batteries(LIBs)by using fast ionic conductor ceramic composite separator as an alternative to traditional ceramic coated separators.Lithium lanthanum titanate(LLTO),a fast ionic conductor with excellent room temperature bulk conductivity,are coated on the common polyethylene(PE)separators.Our results demonstrate that such a novel LLTO-coated separator possess excellent electrolyte wettability and thermal stability;and the assembled NCM523/graphite lithium-ion pouch cells with LLTO-coated separator show better rate capability and cyclic performance with 88.7%capacity retention after 1000 cycles at room temperature compared with the pouch cells with Al2O_(3)-coated separators.The fast ionic conductor ceramic composite separators will be a potential competitor to the next-generation novel separators for high-performance Li-ion power batteries.展开更多
Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3-LaPO_4 fast ionic conductor was synthesized by high temperature solid state reaction. A.C. impedance measurements show that the system has higher conductivity in low doping content ...Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3-LaPO_4 fast ionic conductor was synthesized by high temperature solid state reaction. A.C. impedance measurements show that the system has higher conductivity in low doping content of Sr^(2+), but the conductivity goes down from 5.78×10^(-5) to 3.11×10^(-7) S·cm^(-1) with increasing the content of Sr^(2+). The activation energy is about 20 kJ·mol^(-1) in the temperature range of 25～400 ℃. X-ray powder diffraction shows that the doping Sr^(2+) would not affect the structure of compositions in the system. The main phase is Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3 perovskite solid solution, LaPO_4 as a second phase can also be found. With increasing the content of Sr^(2+) (x>0.05), another phase SrTiO_3 appears. IR measurement also indicates that the structure of compositions in the system would not be affected by Sr^(2+) doping. The decomposition voltage of Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3-LaPO_4 remain unchanged (1.5 V).展开更多
Resistive switching devices with a high self-rectifying ratio are important for achieving the crossbar memristor array that overcomes the sneak current issue.Herein,we demonstrate a single amorphous lithium lanthanum ...Resistive switching devices with a high self-rectifying ratio are important for achieving the crossbar memristor array that overcomes the sneak current issue.Herein,we demonstrate a single amorphous lithium lanthanum titanium oxide(LLTO)layer based Pt/LLTO/Pt device possessing a self-rectifying ratio higher than 1 × 10^(4) that is comparable to the reported devices with complicated multi-layer stacking structures.Moreover,the device shows forming-free and highly uniform bipolar resistive switching(BRS)characteristic that facilitates the potential applications.The trap-controlled and trap-free space charge limited conductions are demonstrated to dominate the high and low resistance states of the device,respectively.The fast migration of lithium ions under external voltage accelerates the electron injection across the Pt/LLTO interface and also the space charge accumulation in the LLTO layer,and as a result,the high performance of the Pt/LLTO/Pt device was achieved.As demonstrated Pt/LLTO/Pt device sheds a light on the potential applications of the lithium ionic conductors in self-rectifying resistive switching devices.展开更多
Li0.24＋2xLa0.59-xMxTiO3-LaPO4（M = K, Na） fast ionic conductor was synthesized by high temperature solid state reaction. A.C. Impedance measurements show that the compositions of system have better conductivities in...Li0.24＋2xLa0.59-xMxTiO3-LaPO4（M = K, Na） fast ionic conductor was synthesized by high temperature solid state reaction. A.C. Impedance measurements show that the compositions of system have better conductivities in low doping content of Na^＋ and K^＋ , as the doping content increases, the conductivity goes down in Na^＋ doping system. But in doping K^＋ system, the conductivity goes down and then goes up with the increasing content of K^＋. The activation energies of different doped ions are about 20 kJ·mol^-1 in the temperature range of 25 - 400℃. X-ray powder diffraction shows that the doped Na^＋ and K^＋ would not affect the structure of compositions in the system. The main phase is Li0.24＋2xLa0.59-x MxTiO3 perovskite solid solution, LaPO4 as a second phase also can be found. With increasing the content of M （x 〉 0.04）, unknown phase appears. IR measurement also indicates that the structure of compositions in the system would not be affected by doping alkali ion.展开更多
基金supported by the National Key R&D Program of China(2022YFB3807700)the National Natural Science Foundation of China(52072217,22179071,51772169,and 52104313)+3 种基金the Hubei Provincial Natural Science Foundation of China(2023AFB618 and 2024AFB993)the Hubei Natural Science Foundation Innovation Group Project(2022CFA020)the Joint Funds of the Hubei Natural Science Foundation Innovation and Development(2022CFD034)the Major Technological Innovation Project of Hubei Science and Technology Department(2019AAA164)。
文摘Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes have not satisfactorily addressed the challenges of poor rate performance and short cycle life.To fill this scientific gap,we herein pioneer incorporating the sodium fast ionic conductorβ"-Al_(2)O_(3)into ball-milled BP with carbon,which facilitates the formation of three-dimensional mass transfer channels in the resulting composite.To stabilize these channels,we develop a novel and environmentally friendly functional binder that outperforms traditional binders in thermal stability,wettability,and mechanical properties.The newly established binder is capable of remarkably mitigating volume expansion and interfacial side reactions in the BP/β"-Al_(2)O_(3)/C composite anode.Additionally,we identify synergistic effects of the binder interacting with the BP/β"-Al_(2)O_(3)/C composite during cycling,characterized by the in-situ formation of P-O-C bonds,which is the first instance of a strong,durable chemical bond between the binder and the active material to the best of our knowledge.These advancements allow the composite electrode to exhibit exceptional sodium storage,including high initial Coulombic efficiency and long-term cycling stability,which surpasses most previous phosphorus-based anodes fabricated via traditional approaches.Notably,when paired with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_7(NFPP)cathode,the full cell exhibits unexpectedly high energy and power densities,highlighting the BP potential in SIBs.The findings presented in the present work contribute to the promotion of economical and efficient applications of phosphorus-based anode materials.
文摘The ceramic composite separators coated with silica or alumina particles have been used in power batteries due to their better electrolyte wettability and better thermal stability compared with bare polymer separators.However,these oxide ceramics are Liþion insulators,which increase internal resistance and hinder the improvement of rate capability of batteries.Herein,we report a strategy to further improving the performance of lithium-ion batteries(LIBs)by using fast ionic conductor ceramic composite separator as an alternative to traditional ceramic coated separators.Lithium lanthanum titanate(LLTO),a fast ionic conductor with excellent room temperature bulk conductivity,are coated on the common polyethylene(PE)separators.Our results demonstrate that such a novel LLTO-coated separator possess excellent electrolyte wettability and thermal stability;and the assembled NCM523/graphite lithium-ion pouch cells with LLTO-coated separator show better rate capability and cyclic performance with 88.7%capacity retention after 1000 cycles at room temperature compared with the pouch cells with Al2O_(3)-coated separators.The fast ionic conductor ceramic composite separators will be a potential competitor to the next-generation novel separators for high-performance Li-ion power batteries.
文摘Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3-LaPO_4 fast ionic conductor was synthesized by high temperature solid state reaction. A.C. impedance measurements show that the system has higher conductivity in low doping content of Sr^(2+), but the conductivity goes down from 5.78×10^(-5) to 3.11×10^(-7) S·cm^(-1) with increasing the content of Sr^(2+). The activation energy is about 20 kJ·mol^(-1) in the temperature range of 25～400 ℃. X-ray powder diffraction shows that the doping Sr^(2+) would not affect the structure of compositions in the system. The main phase is Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3 perovskite solid solution, LaPO_4 as a second phase can also be found. With increasing the content of Sr^(2+) (x>0.05), another phase SrTiO_3 appears. IR measurement also indicates that the structure of compositions in the system would not be affected by Sr^(2+) doping. The decomposition voltage of Li_(0.2375+x)La_(0.5875-x)Sr_xTiO_3-LaPO_4 remain unchanged (1.5 V).
基金supported by the National Key Research and Development Program of China(No.2019YFB2005801)the National Natural Science Foundation of China(Nos.52061135205,51731003,51971024,51971023,51971027,51927802)the Beijing Natural Science Foundation Key Program(No.Z190007)。
文摘Resistive switching devices with a high self-rectifying ratio are important for achieving the crossbar memristor array that overcomes the sneak current issue.Herein,we demonstrate a single amorphous lithium lanthanum titanium oxide(LLTO)layer based Pt/LLTO/Pt device possessing a self-rectifying ratio higher than 1 × 10^(4) that is comparable to the reported devices with complicated multi-layer stacking structures.Moreover,the device shows forming-free and highly uniform bipolar resistive switching(BRS)characteristic that facilitates the potential applications.The trap-controlled and trap-free space charge limited conductions are demonstrated to dominate the high and low resistance states of the device,respectively.The fast migration of lithium ions under external voltage accelerates the electron injection across the Pt/LLTO interface and also the space charge accumulation in the LLTO layer,and as a result,the high performance of the Pt/LLTO/Pt device was achieved.As demonstrated Pt/LLTO/Pt device sheds a light on the potential applications of the lithium ionic conductors in self-rectifying resistive switching devices.
基金Project supported bythe Science Technology Development Foundation of Fuzhou University (2002-XY-06)
文摘Li0.24＋2xLa0.59-xMxTiO3-LaPO4（M = K, Na） fast ionic conductor was synthesized by high temperature solid state reaction. A.C. Impedance measurements show that the compositions of system have better conductivities in low doping content of Na^＋ and K^＋ , as the doping content increases, the conductivity goes down in Na^＋ doping system. But in doping K^＋ system, the conductivity goes down and then goes up with the increasing content of K^＋. The activation energies of different doped ions are about 20 kJ·mol^-1 in the temperature range of 25 - 400℃. X-ray powder diffraction shows that the doped Na^＋ and K^＋ would not affect the structure of compositions in the system. The main phase is Li0.24＋2xLa0.59-x MxTiO3 perovskite solid solution, LaPO4 as a second phase also can be found. With increasing the content of M （x 〉 0.04）, unknown phase appears. IR measurement also indicates that the structure of compositions in the system would not be affected by doping alkali ion.
