Metallic Li is a promising anode material for high energy density batteries but it suffers from poor stability and formation of unsafe dendrites. Previous studies demonstrated that 3 D metal foams are able to improve ...Metallic Li is a promising anode material for high energy density batteries but it suffers from poor stability and formation of unsafe dendrites. Previous studies demonstrated that 3 D metal foams are able to improve the stability of Li metal but the properties of these foams are inherently limited. Here we report a facile surface modification approach via magnetron sputtering of mixed oxides that effectively modulate the properties of Cu foams for supporting Li metal with remarkable stability. We discovered that hybrid Li anodes with Li metal thermally infused to aluminum-zinc oxides(AZO) coated Cu foams have significantly improved stability and reactivity compared with pristine Li foils and Li infused to unmodified Cu foams. Full cells assembled with a Li Fe PO4 cathode and a hybrid anode maintained low and stable charge-transfer resistance(<50) during 500 cycles in carbonate electrolytes, and exhibited superior rate capability(~100 m Ah g-1 at 20 C) along with better electrochemical reversibility and surface stability. The AZO modified Cu foams had superior mechanical strength and afforded the hybrid anodes with minimized volume change without the formation of dendrites during battery cycling. The rational construction of surface architecture to precisely control Li plating and stripping may have great implications for the practical applications of Li metal batteries.展开更多
塑料-金属聚合物复合集流体(metallized plastic current collector,MPCC)通过减厚、减重可大幅提高电池的能量密度,且因聚合物自身绝缘、受热收缩、熔融等特性可提高电池的安全性,因此吸引了产业界研究者的诸多关注。了解聚合物基底和M...塑料-金属聚合物复合集流体(metallized plastic current collector,MPCC)通过减厚、减重可大幅提高电池的能量密度,且因聚合物自身绝缘、受热收缩、熔融等特性可提高电池的安全性,因此吸引了产业界研究者的诸多关注。了解聚合物基底和MPCC的特性及制备方法有利于高质量MPCC的研发,同时可促进高能量密度、高安全电池的发展,因此本文着重介绍了常用和亟待开发的聚合物的特性,阐明了目前市场生产的高质量PET、PP基复合集流体虽已应用于锂离子电池,但面临着各种挑战,例如PET的溶胀溶解反应,PP与金属层间的低黏结性等,并提出了相应的改进措施。此外,本文总结了聚合物表面沉积金属层的多种方法(磁控溅射、蒸镀、化学沉积和电镀等)的原理、优缺点和设备改良策略、注意事项,以期提高聚合物表面金属层的均匀性、一致性和导电率。最后,为提高MPCC在电池中的应用可行性,明确了MPCC未来研发的重点攻关问题,例如提高金属-聚合物界面黏结性,进一步提高电池安全性和导电率,并阐述了将来的发展趋势:功能化和精细化MPCC在电池中的应用。展开更多
Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, uns...Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, unstable solid electrolyte interphases, low Coulombic efficiencies, and safety hazards have significantly hindered the practical application of metallic Li anodes. Herein, we propose a three-dimensional （3D） carbon nanotube sponge （CNTS） as a Li deposition host. The high specific surface area of the CNTS enables homogenous charge distribution for Li nucleation and minimizes the effective current density to overcome dendrite growth. An additional conformal A1203 layer on the CNTS coated by atomic layer deposition （ALD） robustly protects the Li metal electrode/electrolyte interface due to the good chemical stability and high mechanical strength of the layer. The Li@ALD-CNTS electrode exhibits stable voltage profiles with a small overpotential ranging from 16 to 30 mV over 100 h of cycling at 1.0 mA·cm^-2. Moreover, the electrodes display a dendrite-free morphology after cycling and a Coulombic efficiency of 92.4% over 80 cycles at 1.0 mA·cm^-2 in an organic carbonate electrolyte, thus demonstrating electrochemical stability superior to that of planar current collectors. Our results provide an important strategy for the rational design of current collectors to obtain stable Li metal anodes.展开更多
We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of elec...We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of electrochemical active sites,easy access of electrolyte ions,and facile charge transport for flexible wearable applications.The interconnected and compact electrode delivers a high volumetric capacitance(gravimetric capacitance)of 73 F cm−3(2446 F g−1),excellent rate capability,and cycle stability.The 3D-nickel cobalt-layered double hydroxide onto 3D-nickel wire(NiCo LDH/3D-Ni)//the 3D-manganese oxide onto 3D-nickel wire(Mn3O4/3D-Ni)hybrid supercapacitor exhibits energy density of 153.3 Wh kg−1 and power density of 8810 W kg−1.The red lightemitting diode powered by the as-prepared hybrid supercapacitor can operate for 80 min after being charged for tens of seconds and exhibit excellent electrochemical stability under various deformation conditions.The results verify that such wire-shaped 3D-hybrid supercapacitors are promising alternatives for batteries with long charge–discharge times,for smart wearable and implantable devices.展开更多
锂金属负极具有较高的理论比容量(3860 mAh/g)和较低的还原电势(-3.04 V vs.标准氢电势),被誉为最具发展潜力的负极材料,但是锂金属负极中的枝晶、死锂等问题阻碍了锂金属电池的商业化发展。针对锂金属负极中出现的问题,研究人员提出了...锂金属负极具有较高的理论比容量(3860 mAh/g)和较低的还原电势(-3.04 V vs.标准氢电势),被誉为最具发展潜力的负极材料,但是锂金属负极中的枝晶、死锂等问题阻碍了锂金属电池的商业化发展。针对锂金属负极中出现的问题,研究人员提出了大量的解决方案,其中,三维集流体不仅可以降低电流密度,缓解枝晶生长,还可以容纳锂沉积/溶解过程中发生的体积变化。而碳基三维集流体更是因其稳定的化学性质和较小的密度受到了极大的关注。从碳基三维集流体的制备、改性以及对锂沉积/溶解的影响进行介绍,并对其发展进行了展望。展开更多
基金The financial supports of the National Natural Science Foundation of China(Grant Nos.51572060,51702067 and 51671074)Special Financial Grant from the China Postdoctoral Science Foundation(No.2017T100239)+1 种基金General Financial Grant from the China Postdoctoral Science Foundation(No.2016M590279)the startup grants from Northern Illinois University。
文摘Metallic Li is a promising anode material for high energy density batteries but it suffers from poor stability and formation of unsafe dendrites. Previous studies demonstrated that 3 D metal foams are able to improve the stability of Li metal but the properties of these foams are inherently limited. Here we report a facile surface modification approach via magnetron sputtering of mixed oxides that effectively modulate the properties of Cu foams for supporting Li metal with remarkable stability. We discovered that hybrid Li anodes with Li metal thermally infused to aluminum-zinc oxides(AZO) coated Cu foams have significantly improved stability and reactivity compared with pristine Li foils and Li infused to unmodified Cu foams. Full cells assembled with a Li Fe PO4 cathode and a hybrid anode maintained low and stable charge-transfer resistance(<50) during 500 cycles in carbonate electrolytes, and exhibited superior rate capability(~100 m Ah g-1 at 20 C) along with better electrochemical reversibility and surface stability. The AZO modified Cu foams had superior mechanical strength and afforded the hybrid anodes with minimized volume change without the formation of dendrites during battery cycling. The rational construction of surface architecture to precisely control Li plating and stripping may have great implications for the practical applications of Li metal batteries.
文摘塑料-金属聚合物复合集流体(metallized plastic current collector,MPCC)通过减厚、减重可大幅提高电池的能量密度,且因聚合物自身绝缘、受热收缩、熔融等特性可提高电池的安全性,因此吸引了产业界研究者的诸多关注。了解聚合物基底和MPCC的特性及制备方法有利于高质量MPCC的研发,同时可促进高能量密度、高安全电池的发展,因此本文着重介绍了常用和亟待开发的聚合物的特性,阐明了目前市场生产的高质量PET、PP基复合集流体虽已应用于锂离子电池,但面临着各种挑战,例如PET的溶胀溶解反应,PP与金属层间的低黏结性等,并提出了相应的改进措施。此外,本文总结了聚合物表面沉积金属层的多种方法(磁控溅射、蒸镀、化学沉积和电镀等)的原理、优缺点和设备改良策略、注意事项,以期提高聚合物表面金属层的均匀性、一致性和导电率。最后,为提高MPCC在电池中的应用可行性,明确了MPCC未来研发的重点攻关问题,例如提高金属-聚合物界面黏结性,进一步提高电池安全性和导电率,并阐述了将来的发展趋势:功能化和精细化MPCC在电池中的应用。
文摘Lithium metal is considered the ideal anode material for Li-ion-based batteries because it exhibits the highest specific capacity and lowest redox potential for this type of cells. However, growth of Li dendrites, unstable solid electrolyte interphases, low Coulombic efficiencies, and safety hazards have significantly hindered the practical application of metallic Li anodes. Herein, we propose a three-dimensional （3D） carbon nanotube sponge （CNTS） as a Li deposition host. The high specific surface area of the CNTS enables homogenous charge distribution for Li nucleation and minimizes the effective current density to overcome dendrite growth. An additional conformal A1203 layer on the CNTS coated by atomic layer deposition （ALD） robustly protects the Li metal electrode/electrolyte interface due to the good chemical stability and high mechanical strength of the layer. The Li@ALD-CNTS electrode exhibits stable voltage profiles with a small overpotential ranging from 16 to 30 mV over 100 h of cycling at 1.0 mA·cm^-2. Moreover, the electrodes display a dendrite-free morphology after cycling and a Coulombic efficiency of 92.4% over 80 cycles at 1.0 mA·cm^-2 in an organic carbonate electrolyte, thus demonstrating electrochemical stability superior to that of planar current collectors. Our results provide an important strategy for the rational design of current collectors to obtain stable Li metal anodes.
基金supported by national research foundation of Korea(NRF)(No.NRF-2019R1H1A2039743)S-Oil corporation,and “Human Resources Program in Energy Technology” of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry and Energy,Republic of Korea(No.20194010201890)
文摘We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of electrochemical active sites,easy access of electrolyte ions,and facile charge transport for flexible wearable applications.The interconnected and compact electrode delivers a high volumetric capacitance(gravimetric capacitance)of 73 F cm−3(2446 F g−1),excellent rate capability,and cycle stability.The 3D-nickel cobalt-layered double hydroxide onto 3D-nickel wire(NiCo LDH/3D-Ni)//the 3D-manganese oxide onto 3D-nickel wire(Mn3O4/3D-Ni)hybrid supercapacitor exhibits energy density of 153.3 Wh kg−1 and power density of 8810 W kg−1.The red lightemitting diode powered by the as-prepared hybrid supercapacitor can operate for 80 min after being charged for tens of seconds and exhibit excellent electrochemical stability under various deformation conditions.The results verify that such wire-shaped 3D-hybrid supercapacitors are promising alternatives for batteries with long charge–discharge times,for smart wearable and implantable devices.
文摘锂金属负极具有较高的理论比容量(3860 mAh/g)和较低的还原电势(-3.04 V vs.标准氢电势),被誉为最具发展潜力的负极材料,但是锂金属负极中的枝晶、死锂等问题阻碍了锂金属电池的商业化发展。针对锂金属负极中出现的问题,研究人员提出了大量的解决方案,其中,三维集流体不仅可以降低电流密度,缓解枝晶生长,还可以容纳锂沉积/溶解过程中发生的体积变化。而碳基三维集流体更是因其稳定的化学性质和较小的密度受到了极大的关注。从碳基三维集流体的制备、改性以及对锂沉积/溶解的影响进行介绍,并对其发展进行了展望。
