The reviving use of lithium metal anode(LMA)is one of the most promising ways to upgrade the energy density of lithium ion batteries.In the roadmap towards the real use,besides the formation of the dendrite,various ad...The reviving use of lithium metal anode(LMA)is one of the most promising ways to upgrade the energy density of lithium ion batteries.In the roadmap towards the real use,besides the formation of the dendrite,various adverse reactions due to the high activity of LMA when exposed to air or the electrolyte limit its practical applications.Learning from the packaging technology in electronic industry,we propose a wax-based coating compositing with the ion conducting poly(ethylene oxide)by a simple dip-coating technology and the prepared LMA is featured with an air-stable and waterproof surface.The LMA thus remains stable for 24 h in ambient air even with the relative humidity of 70% while retaining about85% its electrochemical capacity.More importantly,the LMA is accessible to water and when dipping in water,no obvious adverse reactions or capacity decay is observed.With the composite coating,a steady cycling performance for 500 h in symmetrical cells and a low capacity decay rate of 0.075% per cycle after 300 cycles in lithium-sulfur batteries assembled with the packaged anode have been achieved.This work demonstrates a very simple and effective LMA package technology which is easily scalable and is very promising for speeding up the industrialization of lithium-sulfur batteries and shows potentials for the large-scale production of air-sensitive electrode materials not limited to LMAs.展开更多
Lithium(Li)metal has been regarded as one of the most promising anode materials to meet the urgent requirements for the next-generation high-energy density batteries.However,the practical use of lithium metal anode is...Lithium(Li)metal has been regarded as one of the most promising anode materials to meet the urgent requirements for the next-generation high-energy density batteries.However,the practical use of lithium metal anode is hindered by the uncontrolled growth of Li dendrites,resulting in poor cycling stability and severe safety issues.Herein,vertical graphene(VG)film grown on graphite paper(GP)as an all-carbon current collector was utilized to regulate the uniform Li nucleation and suppress the growth of dendrites.The high surface area VG grown on GP not only reduces the local current density to the uniform electric field but also allows fast ion transport to homogenize the ion gradients,thus regulating the Li deposition to suppress the dendrite growth.The Li deposition can be further guided with the lithiation reaction between graphite paper and Li metal,which helps to increase lithiophilicity and reduce the Li nucleation barrier as well as the overpotential.As a result,the VG film-based anode demonstrates a stable cycling performance at a current density higher than 5mAcm^(-2)in half cells and a small hysteresis of 50mV at 1mAcm^(-2)in symmetric cells.This work provides an efficient strategy for the rational design of highly stable Li metal anodes.展开更多
本文利用一种新的聚苯乙烯(PS)微乳液的凝胶化现象,制备了结构稳定的PS凝胶,并通过可控的毛细收缩过程获得了具有不同孔隙结构的PS块体.对PS微乳液的凝胶化机制的系统研究表明,在PS微乳液中加入适量特定的水溶性有机溶剂后,可实现PS微...本文利用一种新的聚苯乙烯(PS)微乳液的凝胶化现象,制备了结构稳定的PS凝胶,并通过可控的毛细收缩过程获得了具有不同孔隙结构的PS块体.对PS微乳液的凝胶化机制的系统研究表明,在PS微乳液中加入适量特定的水溶性有机溶剂后,可实现PS微乳液的破乳,PS乳胶粒子周围的表面活性剂完全解吸附,并自发团聚成二次颗粒,在适当温度条件下可通过分子链缠结组装形成三维多孔凝胶.不同溶剂实现PS微乳液凝胶化的能力可以通过d2T/η参数的大小衡量和评估.通过进一步调整成胶时间与溶剂置换程度,PS凝胶可在后续的干燥过程中实现不同程度的收缩,从而得到密度范围在0.06–1.14 g cm^(-3)的多孔或致密PS块体.这种PS凝胶化策略是一种简单高效的PS成型方法,避免了成型设备、模板、成孔剂以及大量表面活性剂的应用,有望成为制备功能高分子聚合物块体材料的新方法.展开更多
基金the financial support from the Guangdong Natural Science Funds for Distinguished Young Scholar (2017B030306006) the National Natural Science Foundation of China (51772164, U1601206 and U1710256)+1 种基金 the National Key Basic Research Program of China (2014CB932400)Shenzhen Technical Plan Project (JCYJ20150529164918734 and JCYJ20170412171359175)
基金supported by the National Science Fund for Distinguished Young Scholars, China (51525204)National Natural Science Foundation of China (51772164 and U1601206)+3 种基金Guangdong Natural Science Funds for Distinguished Young Scholar (2017B030306006)Guangdong Special Support Program (2017TQ04C664)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01N111)the Shenzhen Basic Research Project (JCYJ20170412171630020 and JCYJ20170412171359175)
文摘The reviving use of lithium metal anode(LMA)is one of the most promising ways to upgrade the energy density of lithium ion batteries.In the roadmap towards the real use,besides the formation of the dendrite,various adverse reactions due to the high activity of LMA when exposed to air or the electrolyte limit its practical applications.Learning from the packaging technology in electronic industry,we propose a wax-based coating compositing with the ion conducting poly(ethylene oxide)by a simple dip-coating technology and the prepared LMA is featured with an air-stable and waterproof surface.The LMA thus remains stable for 24 h in ambient air even with the relative humidity of 70% while retaining about85% its electrochemical capacity.More importantly,the LMA is accessible to water and when dipping in water,no obvious adverse reactions or capacity decay is observed.With the composite coating,a steady cycling performance for 500 h in symmetrical cells and a low capacity decay rate of 0.075% per cycle after 300 cycles in lithium-sulfur batteries assembled with the packaged anode have been achieved.This work demonstrates a very simple and effective LMA package technology which is easily scalable and is very promising for speeding up the industrialization of lithium-sulfur batteries and shows potentials for the large-scale production of air-sensitive electrode materials not limited to LMAs.
基金This work was supported by the National Natural Science Fund for the Distinguished Young Scholars,China(51525204)the National Natural Science Foundation of China(51702229 and 51872195)the CAS Key Laboratory of Carbon Materials(KLCM KFJJ1704).
基金supported by the National Natural Science Foundation of China (51772164 and U1601206)Guangdong Natural Science Funds for Distinguished Young Scholar (2017B030306006)+2 种基金Guangdong Special Support Program (2017TQ04C664)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01N111)Shenzhen Technical Plan Project (JCYJ20170412171630020 and JCYJ20170412171359175)
基金We appreciate support from the National Key Research and Development Program of China(2018YFE0124500 and 2019YFA0705700)the National Natural Science Foundation of China(Nos.51972190 and 51932005)+4 种基金the National Science Fund for Distinguished Young Scholars,China(No.51525204)the Guangdong Natural Science Funds for Distinguished Young Scholars(2017B030306006)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01N111)the Shenzhen Basic Research Project(Grant Nos.JCYJ20170412171359175 and JCYJ20180508152037520)the Shenzhen Graphene Manufacturing Innovation Center(201901161513 and 201901171523).
文摘Lithium(Li)metal has been regarded as one of the most promising anode materials to meet the urgent requirements for the next-generation high-energy density batteries.However,the practical use of lithium metal anode is hindered by the uncontrolled growth of Li dendrites,resulting in poor cycling stability and severe safety issues.Herein,vertical graphene(VG)film grown on graphite paper(GP)as an all-carbon current collector was utilized to regulate the uniform Li nucleation and suppress the growth of dendrites.The high surface area VG grown on GP not only reduces the local current density to the uniform electric field but also allows fast ion transport to homogenize the ion gradients,thus regulating the Li deposition to suppress the dendrite growth.The Li deposition can be further guided with the lithiation reaction between graphite paper and Li metal,which helps to increase lithiophilicity and reduce the Li nucleation barrier as well as the overpotential.As a result,the VG film-based anode demonstrates a stable cycling performance at a current density higher than 5mAcm^(-2)in half cells and a small hysteresis of 50mV at 1mAcm^(-2)in symmetric cells.This work provides an efficient strategy for the rational design of highly stable Li metal anodes.
基金financially supported by the National Science Fund for Distinguished Young Scholars of China(51525204)the National Natural Science Foundation of China(51702229)。
文摘本文利用一种新的聚苯乙烯(PS)微乳液的凝胶化现象,制备了结构稳定的PS凝胶,并通过可控的毛细收缩过程获得了具有不同孔隙结构的PS块体.对PS微乳液的凝胶化机制的系统研究表明,在PS微乳液中加入适量特定的水溶性有机溶剂后,可实现PS微乳液的破乳,PS乳胶粒子周围的表面活性剂完全解吸附,并自发团聚成二次颗粒,在适当温度条件下可通过分子链缠结组装形成三维多孔凝胶.不同溶剂实现PS微乳液凝胶化的能力可以通过d2T/η参数的大小衡量和评估.通过进一步调整成胶时间与溶剂置换程度,PS凝胶可在后续的干燥过程中实现不同程度的收缩,从而得到密度范围在0.06–1.14 g cm^(-3)的多孔或致密PS块体.这种PS凝胶化策略是一种简单高效的PS成型方法,避免了成型设备、模板、成孔剂以及大量表面活性剂的应用,有望成为制备功能高分子聚合物块体材料的新方法.