柔性钠离子电池(SIBs)在便携式和可穿戴设备中具有巨大的应用潜力,因为它们在特定情况下具有适用性和价格优势.在正极材料中,磷酸盐电极材料具有结构稳定性好、工作电位高和寿命长的优点.然而,由于对制造要求苛刻,反应复杂,以及柔性基...柔性钠离子电池(SIBs)在便携式和可穿戴设备中具有巨大的应用潜力,因为它们在特定情况下具有适用性和价格优势.在正极材料中,磷酸盐电极材料具有结构稳定性好、工作电位高和寿命长的优点.然而,由于对制造要求苛刻,反应复杂,以及柔性基材的缺失等问题,柔性磷酸盐电极材料的设计仍然是一个巨大的挑战.在此,我们报道了在柔性多孔碳纳米纤维上垂直生长的VO_(2)纳米片原位转化为三维氟磷酸钒钠纳米棒阵列(PCNF@NVOPF NR).PCNF@NVOPF NR实现了兼具柔性与高压正极电极的特点,并具有长期循环稳定性(4500次循环后容量保持率为87.6%).阵列结构可以确保快速的钠反应动力学和低界面电阻.此外,PCNF@NVOPF NR//PCNF@VO_(2)NS@C钠离子全电池表现出高能量和功率密度(220.5 W h kg^(-1)和9400 W kg^(-1)).这种用于柔性正极的材料设计策略可促进实用钠离子电池的商业化.展开更多
Na_(3)(VO)_(2)(PO_(4))_(2)F(NVPOF)has been considered as one potential candidate for sodium-ion batteries because of its high operating voltage and theoretical capacity.However,the poor intrinsic electronic conductivi...Na_(3)(VO)_(2)(PO_(4))_(2)F(NVPOF)has been considered as one potential candidate for sodium-ion batteries because of its high operating voltage and theoretical capacity.However,the poor intrinsic electronic conductivity significantly restricts its widespread application.In response to this drawback,we adopt the optimization strategy of tuning the morphology and structure to boost the electrical conductivity and mitigate the capacity fading.In this paper,NVPOF microspheres with unique porous yolk-shell structure were fabricated via a facile one-step solvothermal method for the first time.By monitoring the morphological evolution with time-dependent experiments,the self-sacrifice and Ostwald ripening mechanism from rough spheres to yolk-shell structure was revealed.Benefited from the favorable interwoven nanosheets shell,inner cavity and porous core structure,the resulting NVPOF electrode exhibits superior rate capability of 63 m A h g^(-1)at 20 C as well as outstanding long-cycling performance with the capacity retention up to 92.1%over 1000 cycles at 5 C.展开更多
基金supported by the National Natural Science Foundation of China(51874362 and 22209208)。
文摘柔性钠离子电池(SIBs)在便携式和可穿戴设备中具有巨大的应用潜力,因为它们在特定情况下具有适用性和价格优势.在正极材料中,磷酸盐电极材料具有结构稳定性好、工作电位高和寿命长的优点.然而,由于对制造要求苛刻,反应复杂,以及柔性基材的缺失等问题,柔性磷酸盐电极材料的设计仍然是一个巨大的挑战.在此,我们报道了在柔性多孔碳纳米纤维上垂直生长的VO_(2)纳米片原位转化为三维氟磷酸钒钠纳米棒阵列(PCNF@NVOPF NR).PCNF@NVOPF NR实现了兼具柔性与高压正极电极的特点,并具有长期循环稳定性(4500次循环后容量保持率为87.6%).阵列结构可以确保快速的钠反应动力学和低界面电阻.此外,PCNF@NVOPF NR//PCNF@VO_(2)NS@C钠离子全电池表现出高能量和功率密度(220.5 W h kg^(-1)和9400 W kg^(-1)).这种用于柔性正极的材料设计策略可促进实用钠离子电池的商业化.
基金financially supported by the National Natural Science Foundation of China(No.51972259)the Hubei Provincial Natural Science Foundation of China(No.2019CFB519)+1 种基金the Fundamental Research Funds for the Central Universities(No.WUT:2020Ⅲ015GX)the National innovation and entrepreneurship training program for Undergraduate(No.201910497011)。
文摘Na_(3)(VO)_(2)(PO_(4))_(2)F(NVPOF)has been considered as one potential candidate for sodium-ion batteries because of its high operating voltage and theoretical capacity.However,the poor intrinsic electronic conductivity significantly restricts its widespread application.In response to this drawback,we adopt the optimization strategy of tuning the morphology and structure to boost the electrical conductivity and mitigate the capacity fading.In this paper,NVPOF microspheres with unique porous yolk-shell structure were fabricated via a facile one-step solvothermal method for the first time.By monitoring the morphological evolution with time-dependent experiments,the self-sacrifice and Ostwald ripening mechanism from rough spheres to yolk-shell structure was revealed.Benefited from the favorable interwoven nanosheets shell,inner cavity and porous core structure,the resulting NVPOF electrode exhibits superior rate capability of 63 m A h g^(-1)at 20 C as well as outstanding long-cycling performance with the capacity retention up to 92.1%over 1000 cycles at 5 C.
