对锂离子电池脉冲充放电特性进行了实验研究,计算了电池在不同SoC(State of Charge)状态下的内阻和开路电压,建立了电池开路电压和内阻图谱。在5℃到45℃的温度范围内,研究了电池脉冲特性的变化规律。试验方法和电池脉冲特性参数计算方...对锂离子电池脉冲充放电特性进行了实验研究,计算了电池在不同SoC(State of Charge)状态下的内阻和开路电压,建立了电池开路电压和内阻图谱。在5℃到45℃的温度范围内,研究了电池脉冲特性的变化规律。试验方法和电池脉冲特性参数计算方法以及实验结果可用于电池特性评估或电池数学模型的建立。展开更多
Solid-state electrolytes in rechargeable all-solidstate Li-metal batteries,which have better safety and higher specific capacity than conventional rechargeable Liion batteries with liquid electrolytes,are limited by t...Solid-state electrolytes in rechargeable all-solidstate Li-metal batteries,which have better safety and higher specific capacity than conventional rechargeable Liion batteries with liquid electrolytes,are limited by the low Li-ion conductivity of the solid electrolyte and the large electrolyte/electrode interfacial resistance.Here,we report a new rhombohedral NAS ICON structure Li1.4Sr0.2Hf1.8(PO4)3 with a high Li-ion conductivity of 1.62×10-5 S·cm-1 at 25℃,and its conductivity can be improved to 3.4×10-5 S·cm-1 after the densification of the pellet by hot pressing.Li1.4Sr0.2Hf1.8(PO4)3 coated by a thin layer of polymer electrolyte showed a stable lowimpedance dendrite-free plating/stripping process in a symmetric Li/Li cell for 100 h;moreover,the Li1.4Sr0.2Hf1.8(PO4)3 electrolyte had a small interfacial resistance in all-solid-state Li/LiFePO4 cell,which allows a high Coulombic efficiency and good cycling of the cell.展开更多
储能系统是实现智能电网能量双向流动的重要支撑条件,而大规模成组技术是大规模锂电池储能系统的发展瓶颈。针对锂电池放电时电压特性,将小波分析理论与锂电池等效电路模型相结合,并对SOC(State Of Charge,电池剩余容量)、电池内阻、放...储能系统是实现智能电网能量双向流动的重要支撑条件,而大规模成组技术是大规模锂电池储能系统的发展瓶颈。针对锂电池放电时电压特性,将小波分析理论与锂电池等效电路模型相结合,并对SOC(State Of Charge,电池剩余容量)、电池内阻、放电时间之间的三维关系开展了研究,得出电池内阻随放电时间和SOC的变化在不同阶段有不同的变化趋势的结论,提出了电池管理系统中的单体电池切除的理论判断依据,预计对SOC的精确估计有较大的借鉴意义。展开更多
扩展卡尔曼滤波算法常被用来进行电池荷电状态(State of Charge,SOC)估计。该方法以等效电路模型为基础,因此模型准确度对于估计结果起到了非常关键的作用。随着电池的使用,电池老化加剧,内阻增大,模型准确度降低。通过实验考察了内阻...扩展卡尔曼滤波算法常被用来进行电池荷电状态(State of Charge,SOC)估计。该方法以等效电路模型为基础,因此模型准确度对于估计结果起到了非常关键的作用。随着电池的使用,电池老化加剧,内阻增大,模型准确度降低。通过实验考察了内阻老化对SOC估计算法的影响,并提出了一种修正方案。测试结果显示,该方法在电池寿命周期内具有较高的估计准确度。展开更多
We report a three-dimensional(3D)nanofiber-reinforced solid composite electrolyte with a 3D Li^(+)-conducting ceramic network of Li_(6.2)5Ga_(0.25)La_(3)Zr_(2)O_(12)(LLZO)nanofibers.Benefiting from the 3D structure,th...We report a three-dimensional(3D)nanofiber-reinforced solid composite electrolyte with a 3D Li^(+)-conducting ceramic network of Li_(6.2)5Ga_(0.25)La_(3)Zr_(2)O_(12)(LLZO)nanofibers.Benefiting from the 3D structure,the composite shows a high ionic conductivity of 3.2×10^(-4)S cm^(-1)and Li-ion transference number of 0.32 at room temperature.The interfacial resistance between the composite solid electrolyte and cathode is mitigated by creating an integrated interfacial structure,in which the polyethylene oxide(PEO)-lithiumbis(trifluoromethylsulphonyl)imide(LiTFSI)binder and ionic liquids(ILs)form a viscoelastic interface.Therefore,intimate contact,low interfacial impedance,and fast ion-transport between the cathode and the solid electrolyte are simultaneously achieved.Solid-state lithium metal batteries with the Li Fe PO_(4) cathode deliver a superior capacity(158.0 m A h g^(-1))and significant capacity retention(90.4%retention after 800 cycles)at 60℃.Moreover,the smooth and uniform Li surface after long-term cycling confirms the successful suppression of the dendrite formation.The integrated interfacial structure provides a solution to the interfacial problem and improves the cycling performance in solid-state Li-metal batteries.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51504127)。
文摘Solid-state electrolytes in rechargeable all-solidstate Li-metal batteries,which have better safety and higher specific capacity than conventional rechargeable Liion batteries with liquid electrolytes,are limited by the low Li-ion conductivity of the solid electrolyte and the large electrolyte/electrode interfacial resistance.Here,we report a new rhombohedral NAS ICON structure Li1.4Sr0.2Hf1.8(PO4)3 with a high Li-ion conductivity of 1.62×10-5 S·cm-1 at 25℃,and its conductivity can be improved to 3.4×10-5 S·cm-1 after the densification of the pellet by hot pressing.Li1.4Sr0.2Hf1.8(PO4)3 coated by a thin layer of polymer electrolyte showed a stable lowimpedance dendrite-free plating/stripping process in a symmetric Li/Li cell for 100 h;moreover,the Li1.4Sr0.2Hf1.8(PO4)3 electrolyte had a small interfacial resistance in all-solid-state Li/LiFePO4 cell,which allows a high Coulombic efficiency and good cycling of the cell.
文摘储能系统是实现智能电网能量双向流动的重要支撑条件,而大规模成组技术是大规模锂电池储能系统的发展瓶颈。针对锂电池放电时电压特性,将小波分析理论与锂电池等效电路模型相结合,并对SOC(State Of Charge,电池剩余容量)、电池内阻、放电时间之间的三维关系开展了研究,得出电池内阻随放电时间和SOC的变化在不同阶段有不同的变化趋势的结论,提出了电池管理系统中的单体电池切除的理论判断依据,预计对SOC的精确估计有较大的借鉴意义。
文摘扩展卡尔曼滤波算法常被用来进行电池荷电状态(State of Charge,SOC)估计。该方法以等效电路模型为基础,因此模型准确度对于估计结果起到了非常关键的作用。随着电池的使用,电池老化加剧,内阻增大,模型准确度降低。通过实验考察了内阻老化对SOC估计算法的影响,并提出了一种修正方案。测试结果显示,该方法在电池寿命周期内具有较高的估计准确度。
基金supported by the National Natural Science Foundation of China(51672096)China Postdoctoral Science Foundation funded project(2020M682403)the National Natural Science Foundation of China and the Israeli Science Foundation for funding this research within the framework of the joint NSFC-ISF(51961145302)。
文摘We report a three-dimensional(3D)nanofiber-reinforced solid composite electrolyte with a 3D Li^(+)-conducting ceramic network of Li_(6.2)5Ga_(0.25)La_(3)Zr_(2)O_(12)(LLZO)nanofibers.Benefiting from the 3D structure,the composite shows a high ionic conductivity of 3.2×10^(-4)S cm^(-1)and Li-ion transference number of 0.32 at room temperature.The interfacial resistance between the composite solid electrolyte and cathode is mitigated by creating an integrated interfacial structure,in which the polyethylene oxide(PEO)-lithiumbis(trifluoromethylsulphonyl)imide(LiTFSI)binder and ionic liquids(ILs)form a viscoelastic interface.Therefore,intimate contact,low interfacial impedance,and fast ion-transport between the cathode and the solid electrolyte are simultaneously achieved.Solid-state lithium metal batteries with the Li Fe PO_(4) cathode deliver a superior capacity(158.0 m A h g^(-1))and significant capacity retention(90.4%retention after 800 cycles)at 60℃.Moreover,the smooth and uniform Li surface after long-term cycling confirms the successful suppression of the dendrite formation.The integrated interfacial structure provides a solution to the interfacial problem and improves the cycling performance in solid-state Li-metal batteries.
