Stable aqueous carbon inks,with graphene sheets(GSs)and carbon black(CB)as conductive fillers,are prepared by a simple one-pot ball-milling method.The asprepared composite ink with 10 wt%GSs shows optimized rheologica...Stable aqueous carbon inks,with graphene sheets(GSs)and carbon black(CB)as conductive fillers,are prepared by a simple one-pot ball-milling method.The asprepared composite ink with 10 wt%GSs shows optimized rheological properties(viscosity and thixotropy)for screen printing.The as-printed coatings based on the above ink are uniform and dense on a polyimide substrate,and exhibit a sandwich-type conductive three dimensional network at the microscale.The resistivity of the typical composite coating is as low as 0.23±0.01Ωcm(92±4Ωsq^-1,25μm),which is 30%as that of a pure CB coating(0.77±0.01Ωcm).It is noteworthy that the resistivity decreases to 0.18±0.01Ωcm(72±4Ωsq^-1,25μm)after a further rolling compression.The coating exhibits good mechanical flexibility,and the resistance slightly increases by 12%after 3000 bending cycles.With the CB/GSs composite coatings as a flexible conductor,fascinating luminescent bookmarks and membrane switches were fabricated,demonstrating the tremendous potential of these coatings in the commercial production of flexible electronics and devices.展开更多
Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable electronics.However,the safety problem severely restricts the practical app...Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable electronics.However,the safety problem severely restricts the practical application of Li-S batteries because of the possible occurrence of thermal runaway caused by battery short circuits and combustible components,particularly under bending conditions.The development of advanced separators that can suppress lithium dendrite growth and are incombustible is the key to improving the safety of flexible Li-S batteries.In this work,a nonflammable multifunctional Janus separator with self-extinguishing capability,high thermal stability,high thermal conductivity,good electrolyte infiltration,uniform lithium deposition,and efficient polysulfide shuttling inhibition,is proposed.The separator is composed of polyacrylonitrile(PAN)fiber and decabromodiphenyl ethane(DBDPE)membrane as well as functional layers of boron nitride(BN)for suppressing lithium dendrite growth and reduced graphene oxide(rGO)for accelerating the sulfur convention kinetics.As a result,the Li-S battery with a sulfur mass loading of2.7 mg cm^(-2) delivers a specific capacity of 916.8 mA h g^(-1) after100 cycles at 0.1 C and maintains a stable performance during intermittent thermal shock.Moreover,the Li-S pouch cell with a sulfur mass loading of 8 mg exhibits a high capacity of6.3 mA h under bending conditions.展开更多
基金supported by the Scientific and Technological Key Project of Shanxi Province (MC2016-04 and MC2016-08)Natural Science Foundation of Shanxi Province (201801D221156)+2 种基金DNL Cooperation Fund of CAS (DNL180308)Science and Technology Service Network Initiative of CAS (KFJ-STS-ZDTP-068)Youth Innovation Promotion Association of CAS
文摘Stable aqueous carbon inks,with graphene sheets(GSs)and carbon black(CB)as conductive fillers,are prepared by a simple one-pot ball-milling method.The asprepared composite ink with 10 wt%GSs shows optimized rheological properties(viscosity and thixotropy)for screen printing.The as-printed coatings based on the above ink are uniform and dense on a polyimide substrate,and exhibit a sandwich-type conductive three dimensional network at the microscale.The resistivity of the typical composite coating is as low as 0.23±0.01Ωcm(92±4Ωsq^-1,25μm),which is 30%as that of a pure CB coating(0.77±0.01Ωcm).It is noteworthy that the resistivity decreases to 0.18±0.01Ωcm(72±4Ωsq^-1,25μm)after a further rolling compression.The coating exhibits good mechanical flexibility,and the resistance slightly increases by 12%after 3000 bending cycles.With the CB/GSs composite coatings as a flexible conductor,fascinating luminescent bookmarks and membrane switches were fabricated,demonstrating the tremendous potential of these coatings in the commercial production of flexible electronics and devices.
基金support from the National Natural Science Foundation of China(52072205)the National Key Research and Development Program of China(2019YFA0705700,2021YFB2500200)+1 种基金Shenzhen Stabilization Support Program(WDZC20200824091903001)the Start-up Funds of Tsinghua Shenzhen International Graduate School。
文摘Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable electronics.However,the safety problem severely restricts the practical application of Li-S batteries because of the possible occurrence of thermal runaway caused by battery short circuits and combustible components,particularly under bending conditions.The development of advanced separators that can suppress lithium dendrite growth and are incombustible is the key to improving the safety of flexible Li-S batteries.In this work,a nonflammable multifunctional Janus separator with self-extinguishing capability,high thermal stability,high thermal conductivity,good electrolyte infiltration,uniform lithium deposition,and efficient polysulfide shuttling inhibition,is proposed.The separator is composed of polyacrylonitrile(PAN)fiber and decabromodiphenyl ethane(DBDPE)membrane as well as functional layers of boron nitride(BN)for suppressing lithium dendrite growth and reduced graphene oxide(rGO)for accelerating the sulfur convention kinetics.As a result,the Li-S battery with a sulfur mass loading of2.7 mg cm^(-2) delivers a specific capacity of 916.8 mA h g^(-1) after100 cycles at 0.1 C and maintains a stable performance during intermittent thermal shock.Moreover,the Li-S pouch cell with a sulfur mass loading of 8 mg exhibits a high capacity of6.3 mA h under bending conditions.
