VO4^3- anion was used to partially substitute for PO43 in the Nasicon compound of LiSn2(PO4)3 via a sol-gel method. XRD analysis revealed that the VO4^3-substituted samples did not have a single LiSn2(PO4)3 phase,...VO4^3- anion was used to partially substitute for PO43 in the Nasicon compound of LiSn2(PO4)3 via a sol-gel method. XRD analysis revealed that the VO4^3-substituted samples did not have a single LiSn2(PO4)3 phase, and some secondary phases like SnO2 and SnP2O7 appeared. Introduction of the VO4^3- anion did not prevent the LiSn2(PO4)3 compound from decomposing during the initial lithiation; however the VO4^3- anion substitution remarkably enhanced the rate capability and cycling performance of the products because they reduced the charge transfer hnpedance, increased the lithium ion diffusion, and strengthened the role of the Li3PQ matrix due to the precipitation of the Li3V04 phase, Of the substituted samples, the sample with a nominal composition of LiSn2(PO4)2.5(VO4)0.5 delivered a capacity of 449.2 mA-h/g at a rate of 0.25 C after 25 cycles and 373.8 mA.h/g at 2 C rate. Those values surpassed some previous reports on LiSn2(PO4)3 and the LiSnz(PO4)3/C composites. Accordingly, the partial substitution of phosphorus by vanadium in LiSn2(PO4)3 is a feasible technique to remarkably improve its electrochemical properties.展开更多
针对DC-DC变换电路差模传导电磁干扰信号难以提取的问题,通过分析直流人工电源网络(DCLISN,DC line impedance stabilization network)的网络特性,建立基于PSpice的差模传导干扰预测模型。该模型采用的DC-LISN可实现直流信号的正向传输...针对DC-DC变换电路差模传导电磁干扰信号难以提取的问题,通过分析直流人工电源网络(DCLISN,DC line impedance stabilization network)的网络特性,建立基于PSpice的差模传导干扰预测模型。该模型采用的DC-LISN可实现直流信号的正向传输、高频干扰信号在测试段无衰减提取的功能。通过PSpice仿真和实验分别提取了电源侧差模传导干扰的时域波形并进行频谱分析,结果表明,基于DCLISN的PSpice差模传导干扰预测模型与实际测试结果在幅值和频谱成分方面吻合较好,从而证明了该模型对预测实际变换器产生的差模干扰是有效的。展开更多
基金Supported by the Natural Science Foundation of Hebei Province, China(No.E2016202358).
文摘VO4^3- anion was used to partially substitute for PO43 in the Nasicon compound of LiSn2(PO4)3 via a sol-gel method. XRD analysis revealed that the VO4^3-substituted samples did not have a single LiSn2(PO4)3 phase, and some secondary phases like SnO2 and SnP2O7 appeared. Introduction of the VO4^3- anion did not prevent the LiSn2(PO4)3 compound from decomposing during the initial lithiation; however the VO4^3- anion substitution remarkably enhanced the rate capability and cycling performance of the products because they reduced the charge transfer hnpedance, increased the lithium ion diffusion, and strengthened the role of the Li3PQ matrix due to the precipitation of the Li3V04 phase, Of the substituted samples, the sample with a nominal composition of LiSn2(PO4)2.5(VO4)0.5 delivered a capacity of 449.2 mA-h/g at a rate of 0.25 C after 25 cycles and 373.8 mA.h/g at 2 C rate. Those values surpassed some previous reports on LiSn2(PO4)3 and the LiSnz(PO4)3/C composites. Accordingly, the partial substitution of phosphorus by vanadium in LiSn2(PO4)3 is a feasible technique to remarkably improve its electrochemical properties.
文摘针对DC-DC变换电路差模传导电磁干扰信号难以提取的问题,通过分析直流人工电源网络(DCLISN,DC line impedance stabilization network)的网络特性,建立基于PSpice的差模传导干扰预测模型。该模型采用的DC-LISN可实现直流信号的正向传输、高频干扰信号在测试段无衰减提取的功能。通过PSpice仿真和实验分别提取了电源侧差模传导干扰的时域波形并进行频谱分析,结果表明,基于DCLISN的PSpice差模传导干扰预测模型与实际测试结果在幅值和频谱成分方面吻合较好,从而证明了该模型对预测实际变换器产生的差模干扰是有效的。