Air-stable layered structured cathodes with high voltage and good cycling stability are highly desired for the practical application of Na-ion batteries.Herein,we report a P2-Na_(2/3)Ni_(2/3)Te_(1/3)O_(2) cathode that...Air-stable layered structured cathodes with high voltage and good cycling stability are highly desired for the practical application of Na-ion batteries.Herein,we report a P2-Na_(2/3)Ni_(2/3)Te_(1/3)O_(2) cathode that is stable in ambient air with an average operating voltage of~3.8 V,demonstrating excellent cycling stability with a capacity retention of more than 92.7%after 500 cycles at 20 mA g^(-1) and good rate capability with 91.9%capacity utilization at 500 mA g^(-1) with respect to capacity at 5 mA g^(-1) between 2.0 and 4.0 V.When the upper cutoff voltage is increased to 4.4 V,P2-Na_(2/3)Ni_(2/3)Te_(1/3)O_(2) delivers a reversible capacity of 71.9 mAh g^(-1) and retains 91.8%of the capacity after 100 cycles at 20 mA g^(-1).The charge compensation during charge/discharge is mainly due to the redox couple of Ni^(2+)/Ni^(3+)in the host with a small amount of contribution from oxygen.The stable structure of the material without phase transformation and with small volume change during charge-discharge allows it to give excellent cycle performance especially when the upper cutoff voltage is not higher than 4.2 V.展开更多
采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、...采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、微观形貌和电化学性能的影响。结果显示,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)表现出更低的阳离子混排和优异的电化学性能。经过Mo^(6+)掺杂后的正极,由于Li^(+)高速的迁移速率,使得首次不可逆容量损失降低,并展现出更好的高倍率性能和优异的循环稳定性。在0.5C倍率下循环100周后,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)的容量保持率达到92.2%,远远大于Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的87.5%。另外,当放电倍率增大到5C时,Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的放电比容量要比Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)低21.0 m A·h/g。因此,采用Mo^(6+)掺杂改性Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料,可以有效提高锂电池的循环保持率和高倍率放电性能。展开更多
Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/discharge.Researchers ha...Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/discharge.Researchers have used Ti substitution to improve the cathode, yet the chemical principles that underpin elemental substitution and functional improvement remain unclear. To clarify these principles, we used in situ Raman spectroscopy to monitor chemical changes in P2–Na2/3 Ni1/3 Mn1/3 Ti1/3 O2 and P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 during charge/discharge. Based on the change in the A_(1g) and E_g peaks during charge/discharge, we concluded that Ti substitution compressed the transition metal layer and expanded the planar oxygen layer in the unit cell. Titanium stabilized the P2 phase structure, which improved the cycling stability of P2–NaNMT. Our results provide clear theoretical support for future research on modifying electrodes by elemental substitution.展开更多
Multiple regression equations of liquidus temperature, electrical conductivity and bath density of the Na_3AlF_6-AlF_3-BaC1_2-NaCl system were obtained from experiments by using orthogonal regression method. The exper...Multiple regression equations of liquidus temperature, electrical conductivity and bath density of the Na_3AlF_6-AlF_3-BaC1_2-NaCl system were obtained from experiments by using orthogonal regression method. The experiments were carried out in 100A cell with low melting point electrolyte, the influences of cathodic current density, electrolytic temperature, density differences of bath and liquid aluminum on current efficiency (CE) were studied; when the electrolyte cryolite ratio was 2.5, w(BaC1_2) and w(NaCl) were 48% and 10%, respectively, CE reached 90% and specific energy consumption was 10.97k Wb/kg/kg. Because of the fact that aluminum metal obtained floated on the surface of molten electrolyte, this electrolysis method was then defined as low temperature aluminum floating electrolysis. The results showed that the new low temperature aluminum electrolysis process in the Na_3AlF_6-AlF_3-BaC1_2-NaCl bath system was practical and promising.展开更多
Na_(2)SiF_(6) was used as surface activating flux for laser welding of TC4 titanium alloy. The effect of Na_(2)SiF_(6) on TC4 titanium alloy laser welding was determined by observing the weld surface. The morphologica...Na_(2)SiF_(6) was used as surface activating flux for laser welding of TC4 titanium alloy. The effect of Na_(2)SiF_(6) on TC4 titanium alloy laser welding was determined by observing the weld surface. The morphological characteristics of the high temperature plasma above the workpiece was observed and analyzed by using high-speed digital camera system. The variation of weld depth,width and microstructure were analyzed by optical microscope. The experimental results show that laser weld of TC4 titanium alloy has good appearance with activating flux of Na_(2)SiF_(6), weld penetration increases by about 0.8%–12%, while weld surface width decrease by about 10%–29%, the depth to width ratio is effectively improved. The inhomogeneity of weld microstructure was improved, and the crystallization direction of β columnar crystals on the upper part of the weld was changed, the grain size and microstructure of the weld were refined by Na_(2)SiF_(6).展开更多
Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal w...Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies.Herein,a novel 3 D ternary Z-scheme heterojunction photocatalyst Ni_(2)P/Bi_(2)MoO_(6)/g-C_(3)N_(4)(Ni_(2)P/BMO/CN)was fabricated by a simple solvothermal method in which the broad spectrum antibiotics(mainly tetracyclines and supplemented by quinolones)were used as target pollution sources to evaluate its adsorption and photocatalytic performance.Notably,the Zscheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni_(2)P nanoparticles as electron conductor.Active species capture experiment and electron spin resonance(ESR)technology reveal the mechanism of Z-scheme Ni_(2)P/BMO/CN photocatalytic reaction in detail.In addition,based on the identification of intermediates by liquid chromatography–mass spectroscopy(LC–MS),the possible photocatalytic degradation pathways of TC were proposed.展开更多
Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a ...Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na_(3)KMg_(7)(PO_(4))6:Eu^(2+)phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li_(2)CO_(3)as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV(400 nm)diode chip excitation.The practical Eu^(2+)concentration is also enhanced by using Li_(2)CO_(3)as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL thermal stability,namely retains 94%integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu^(2+)blue,Sr_(2)SiO_(4):Eu^(2+)green,CaAlSiN_(3):Eu^(2+)red phosphors,and a 400 nm NUV diode chip.It shows a high color rendering index of R_(a)=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu^(2+)is a promising blue phosphor for full-spectrum WLED based on NUV diode chips.展开更多
Sodium-ion batteries(SIBs)are regarded as the ideal low-cost choice for next-generation large-scale energy storage system.Carbonyl-based organic salt-disodium rhodizonate(Na_(2)C_(6)O_(6))with high theoretical specifi...Sodium-ion batteries(SIBs)are regarded as the ideal low-cost choice for next-generation large-scale energy storage system.Carbonyl-based organic salt-disodium rhodizonate(Na_(2)C_(6)O_(6))with high theoretical specific capacity(501 mAh·g−1)is considered as a promising cathode material for SIBs.However,the dissolution of active material in electrolyte and low electronic conductivity lead to rapidly capacity decay and poor rate performance.Herein,a simple method is designed to construct free-standing and flexible Ti3C2Tx Na2C6O6/MXene paper via vacuum-assisted filtration and antisolvent approach.The MXene can form an electronic conductive network,adsorb the active materials,and offer additional active sites for Na storage.The binder-free Na_(2)C_(6)O_(6)/MXene paper delivers excellent electrochemical property with a high rate performance of 231 mAh·g−1 at 1,000 mA·g−1 and a high capacity of 215 mAh·g−1 after 100 cycles.This work provides an attractive strategy for designing high-performance organic electrode materials of SIBs.展开更多
P2-type layered oxides have been considered as promising cathode materials for Na-ion batteries,but the capac-ity decay resulting from the Na+/vacancy ordering and phase transformation limits their future large-scale ...P2-type layered oxides have been considered as promising cathode materials for Na-ion batteries,but the capac-ity decay resulting from the Na+/vacancy ordering and phase transformation limits their future large-scale applica-tions.Herein,the impact of Li-doping in different layers on the structure and electrochemical performance of P2-type Na_(0.7)Ni_(0.35)Mn_(0.65)O_(2) is investigated.It can be found that Li ions successfully enter both the Na and transition metal layers.The strategy of Li-doping can improve the cycling stability and rate capability of P2-type layered oxides,which promotes the development of high-performance Na-ion batteries.展开更多
A new P2-structured oxide Na0.8Ni0.4Mn0.6O2was synthesized using a solid reaction method in which Na2CO3, MnO2and NiO were used as starting materials.This oxide has a high amount of electrochemically active Ni and exh...A new P2-structured oxide Na0.8Ni0.4Mn0.6O2was synthesized using a solid reaction method in which Na2CO3, MnO2and NiO were used as starting materials.This oxide has a high amount of electrochemically active Ni and exhibits good electrochemical intercalation behavior of Na ions, including good rate capability and good cycle performance at both room temperature and elevated temperature. It displays two apparent voltage plateaus at about 3.6 and 3.3 V, and its discharge capacity reaches92 mAh·g-1at 0.1 C in the voltage range of 2.0-4.0 V. At1.0 C, its discharge capacity reaches 85.3 mAh·g-1. After80 cycles at different current rates, the as-prepared sample exhibits good capacity retention. At elevated temperature of 55 ℃, the discharge capacity remains the same at low current rate of 0.1 C, but at high current rate of 1.0 C, the discharge capacity is a little lower than that at room temperature.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52100084)Shenzhen Natural Science Fund(the Stable Support Plan Program GXWD20201230155427003-20200824094017001).
文摘Air-stable layered structured cathodes with high voltage and good cycling stability are highly desired for the practical application of Na-ion batteries.Herein,we report a P2-Na_(2/3)Ni_(2/3)Te_(1/3)O_(2) cathode that is stable in ambient air with an average operating voltage of~3.8 V,demonstrating excellent cycling stability with a capacity retention of more than 92.7%after 500 cycles at 20 mA g^(-1) and good rate capability with 91.9%capacity utilization at 500 mA g^(-1) with respect to capacity at 5 mA g^(-1) between 2.0 and 4.0 V.When the upper cutoff voltage is increased to 4.4 V,P2-Na_(2/3)Ni_(2/3)Te_(1/3)O_(2) delivers a reversible capacity of 71.9 mAh g^(-1) and retains 91.8%of the capacity after 100 cycles at 20 mA g^(-1).The charge compensation during charge/discharge is mainly due to the redox couple of Ni^(2+)/Ni^(3+)in the host with a small amount of contribution from oxygen.The stable structure of the material without phase transformation and with small volume change during charge-discharge allows it to give excellent cycle performance especially when the upper cutoff voltage is not higher than 4.2 V.
文摘采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、微观形貌和电化学性能的影响。结果显示,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)表现出更低的阳离子混排和优异的电化学性能。经过Mo^(6+)掺杂后的正极,由于Li^(+)高速的迁移速率,使得首次不可逆容量损失降低,并展现出更好的高倍率性能和优异的循环稳定性。在0.5C倍率下循环100周后,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)的容量保持率达到92.2%,远远大于Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的87.5%。另外,当放电倍率增大到5C时,Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的放电比容量要比Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)低21.0 m A·h/g。因此,采用Mo^(6+)掺杂改性Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料,可以有效提高锂电池的循环保持率和高倍率放电性能。
基金supported by the NSFC (21905239, 21925404, and 21775127)the Natural Science Foundation of Shanxi Province of China (201901D211265)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2019L0609)。
文摘Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/discharge.Researchers have used Ti substitution to improve the cathode, yet the chemical principles that underpin elemental substitution and functional improvement remain unclear. To clarify these principles, we used in situ Raman spectroscopy to monitor chemical changes in P2–Na2/3 Ni1/3 Mn1/3 Ti1/3 O2 and P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 during charge/discharge. Based on the change in the A_(1g) and E_g peaks during charge/discharge, we concluded that Ti substitution compressed the transition metal layer and expanded the planar oxygen layer in the unit cell. Titanium stabilized the P2 phase structure, which improved the cycling stability of P2–NaNMT. Our results provide clear theoretical support for future research on modifying electrodes by elemental substitution.
基金The project was financially supported by the National Natural Science Foundation of China! (Gmnt No.59574018)China Postdocto
文摘Multiple regression equations of liquidus temperature, electrical conductivity and bath density of the Na_3AlF_6-AlF_3-BaC1_2-NaCl system were obtained from experiments by using orthogonal regression method. The experiments were carried out in 100A cell with low melting point electrolyte, the influences of cathodic current density, electrolytic temperature, density differences of bath and liquid aluminum on current efficiency (CE) were studied; when the electrolyte cryolite ratio was 2.5, w(BaC1_2) and w(NaCl) were 48% and 10%, respectively, CE reached 90% and specific energy consumption was 10.97k Wb/kg/kg. Because of the fact that aluminum metal obtained floated on the surface of molten electrolyte, this electrolysis method was then defined as low temperature aluminum floating electrolysis. The results showed that the new low temperature aluminum electrolysis process in the Na_3AlF_6-AlF_3-BaC1_2-NaCl bath system was practical and promising.
基金National Natural Science Foundation of China (Grant No. 51165027)Inner Mongolia Natural Science Foundationt(2017MS(LH)0512)。
文摘Na_(2)SiF_(6) was used as surface activating flux for laser welding of TC4 titanium alloy. The effect of Na_(2)SiF_(6) on TC4 titanium alloy laser welding was determined by observing the weld surface. The morphological characteristics of the high temperature plasma above the workpiece was observed and analyzed by using high-speed digital camera system. The variation of weld depth,width and microstructure were analyzed by optical microscope. The experimental results show that laser weld of TC4 titanium alloy has good appearance with activating flux of Na_(2)SiF_(6), weld penetration increases by about 0.8%–12%, while weld surface width decrease by about 10%–29%, the depth to width ratio is effectively improved. The inhomogeneity of weld microstructure was improved, and the crystallization direction of β columnar crystals on the upper part of the weld was changed, the grain size and microstructure of the weld were refined by Na_(2)SiF_(6).
基金financially supported by the National Natural Science Foundation of China(No.21906072,22006057,21671084 and 51902140)the Natural Science Foundation of Jiangsu Province(BK20190982)+2 种基金Henan Postdoctoral Foundation(202003013)“Doctor of Mass entrepreneurship and innovation”Project in Jiangsu Province,Jiangsu 333 talents project funding(BRA2018342)Jiangsu provincial government scholarship for overseas studies,the Doctoral Scientific Research Foundation of Jiangsu University of Science and Technology(China)(1062931806 and 1142931803)。
文摘Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies.Herein,a novel 3 D ternary Z-scheme heterojunction photocatalyst Ni_(2)P/Bi_(2)MoO_(6)/g-C_(3)N_(4)(Ni_(2)P/BMO/CN)was fabricated by a simple solvothermal method in which the broad spectrum antibiotics(mainly tetracyclines and supplemented by quinolones)were used as target pollution sources to evaluate its adsorption and photocatalytic performance.Notably,the Zscheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni_(2)P nanoparticles as electron conductor.Active species capture experiment and electron spin resonance(ESR)technology reveal the mechanism of Z-scheme Ni_(2)P/BMO/CN photocatalytic reaction in detail.In addition,based on the identification of intermediates by liquid chromatography–mass spectroscopy(LC–MS),the possible photocatalytic degradation pathways of TC were proposed.
基金Project supported by the National Natural Science Foundation of China(11974351)。
文摘Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na_(3)KMg_(7)(PO_(4))6:Eu^(2+)phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li_(2)CO_(3)as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV(400 nm)diode chip excitation.The practical Eu^(2+)concentration is also enhanced by using Li_(2)CO_(3)as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL thermal stability,namely retains 94%integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu^(2+)blue,Sr_(2)SiO_(4):Eu^(2+)green,CaAlSiN_(3):Eu^(2+)red phosphors,and a 400 nm NUV diode chip.It shows a high color rendering index of R_(a)=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu^(2+)is a promising blue phosphor for full-spectrum WLED based on NUV diode chips.
基金This work was supported by the Natural Science Foundation of Shandong Province(No.ZR2020JQ19)Taishan Scholars Program of Shandong Province(Nos.tsqn201812002,ts20190908,and ts201511004)+2 种基金the Young Scholars Program of Shandong University(No.2016WLJH03)Shenzhen Fundamental Research Program(No.JCYJ20190807093405503)the National Natural Science Foundation of China(Nos.51972198 and 61633015).
文摘Sodium-ion batteries(SIBs)are regarded as the ideal low-cost choice for next-generation large-scale energy storage system.Carbonyl-based organic salt-disodium rhodizonate(Na_(2)C_(6)O_(6))with high theoretical specific capacity(501 mAh·g−1)is considered as a promising cathode material for SIBs.However,the dissolution of active material in electrolyte and low electronic conductivity lead to rapidly capacity decay and poor rate performance.Herein,a simple method is designed to construct free-standing and flexible Ti3C2Tx Na2C6O6/MXene paper via vacuum-assisted filtration and antisolvent approach.The MXene can form an electronic conductive network,adsorb the active materials,and offer additional active sites for Na storage.The binder-free Na_(2)C_(6)O_(6)/MXene paper delivers excellent electrochemical property with a high rate performance of 231 mAh·g−1 at 1,000 mA·g−1 and a high capacity of 215 mAh·g−1 after 100 cycles.This work provides an attractive strategy for designing high-performance organic electrode materials of SIBs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12105372 and 51991344)President's Foundation of China Institute of Atomic Energy(Grant No.16YZ202212000201)Chinese Academy of Sciences(Grant No.XDB33000000).
文摘P2-type layered oxides have been considered as promising cathode materials for Na-ion batteries,but the capac-ity decay resulting from the Na+/vacancy ordering and phase transformation limits their future large-scale applica-tions.Herein,the impact of Li-doping in different layers on the structure and electrochemical performance of P2-type Na_(0.7)Ni_(0.35)Mn_(0.65)O_(2) is investigated.It can be found that Li ions successfully enter both the Na and transition metal layers.The strategy of Li-doping can improve the cycling stability and rate capability of P2-type layered oxides,which promotes the development of high-performance Na-ion batteries.
基金financially supported by the National Natural Science Foundation of China (No. 51574081)the Natural Science Foundation of Liaoning Province(No. 2014020035)
文摘A new P2-structured oxide Na0.8Ni0.4Mn0.6O2was synthesized using a solid reaction method in which Na2CO3, MnO2and NiO were used as starting materials.This oxide has a high amount of electrochemically active Ni and exhibits good electrochemical intercalation behavior of Na ions, including good rate capability and good cycle performance at both room temperature and elevated temperature. It displays two apparent voltage plateaus at about 3.6 and 3.3 V, and its discharge capacity reaches92 mAh·g-1at 0.1 C in the voltage range of 2.0-4.0 V. At1.0 C, its discharge capacity reaches 85.3 mAh·g-1. After80 cycles at different current rates, the as-prepared sample exhibits good capacity retention. At elevated temperature of 55 ℃, the discharge capacity remains the same at low current rate of 0.1 C, but at high current rate of 1.0 C, the discharge capacity is a little lower than that at room temperature.