Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation d...Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs anode.Herein,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for SIBs.Moreover,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 cycles.This work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode.展开更多
电力电子化的直流配电网存在低惯性问题,不利于系统稳定运行。混合储能设备可向电网提供虚拟惯性,但不同类型的储能之间存在功率协调问题,并且储能的荷电状态(state of charge, SOC)对虚拟惯性的调节也有约束作用。针对上述问题,提出了...电力电子化的直流配电网存在低惯性问题,不利于系统稳定运行。混合储能设备可向电网提供虚拟惯性,但不同类型的储能之间存在功率协调问题,并且储能的荷电状态(state of charge, SOC)对虚拟惯性的调节也有约束作用。针对上述问题,提出了一种自适应时间常数的分频控制策略,时间常数根据混合储能系统(hybridenergy storage system, HESS)的SOC而动态调整以改变功率分配。首先,通过分析储能SOC与虚拟惯性的关系,并考虑储能充放电极限问题,研究兼顾SOC、电压变化率以及电压幅值的自适应虚拟惯性控制策略,提高系统惯性。然后,建立控制系统的小信号模型,分析虚拟惯性系数对系统的影响。最后,基于Matlab/Simulink搭建直流配电网仿真模型,验证了所提控制策略能合理分配HESS功率,提高超级电容器利用率,改善直流电压与功率稳定性。展开更多
新能源产业的飞速发展使磷酸铁锂电池广泛应用于储能领域。磷酸铁锂电池电解液固有的可燃性使其热稳定性和安全性问题不容忽视。为了更好地防控储能电站的爆炸事故,有必要开展储能电池的热失控过程研究,并对产气过程和产气组分的危害性...新能源产业的飞速发展使磷酸铁锂电池广泛应用于储能领域。磷酸铁锂电池电解液固有的可燃性使其热稳定性和安全性问题不容忽视。为了更好地防控储能电站的爆炸事故,有必要开展储能电池的热失控过程研究,并对产气过程和产气组分的危害性进行深入分析。开展了不同荷电状态(State of Charge, SOC)60 Ah磷酸铁锂电池热失控试验,根据电池温度演变曲线,将电池热失控过程分成三个阶段;依据电池产气曲线,将电池产气过程分为四个阶段;使用FLACS软件建模对预混气体进行了爆炸仿真,探索了SOC对可燃气体燃爆行为的影响规律,混合可燃气体的爆炸上下限和爆炸超压随着SOC的增大而增大。研究成果对储能电站的安全防护具有理论指导意义。展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.U1904173 and 52272219)the Key Research Projects of Henan Provincial Department of Education(No.19A150043)+2 种基金the Natural Science Foundation of Henan Province(Nos.202300410330 and 222300420276)the Nanhu Scholars Program for Young Scholars of Xinyang Normal Universitythe Xinyang Normal University Analysis&Testing Center。
文摘Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs anode.Herein,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for SIBs.Moreover,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 cycles.This work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode.
文摘新能源产业的飞速发展使磷酸铁锂电池广泛应用于储能领域。磷酸铁锂电池电解液固有的可燃性使其热稳定性和安全性问题不容忽视。为了更好地防控储能电站的爆炸事故,有必要开展储能电池的热失控过程研究,并对产气过程和产气组分的危害性进行深入分析。开展了不同荷电状态(State of Charge, SOC)60 Ah磷酸铁锂电池热失控试验,根据电池温度演变曲线,将电池热失控过程分成三个阶段;依据电池产气曲线,将电池产气过程分为四个阶段;使用FLACS软件建模对预混气体进行了爆炸仿真,探索了SOC对可燃气体燃爆行为的影响规律,混合可燃气体的爆炸上下限和爆炸超压随着SOC的增大而增大。研究成果对储能电站的安全防护具有理论指导意义。
