Flexible yet highly thermoconductive materials are essential for the development of next-generation flexible electronic devices.Herein,we report a bioinspired nanostructured film with the integration of large ductilit...Flexible yet highly thermoconductive materials are essential for the development of next-generation flexible electronic devices.Herein,we report a bioinspired nanostructured film with the integration of large ductility and high thermal conductivity based on self-exfoliated pristine graphene and three-dimensional aramid nanofiber network.A self-grinding strategy to directly exfoliate flake graphite into few-layer and few-defect pristine graphene is successfully developed through mutual shear friction between graphite particles,generating largely enhanced yield and productivity in comparison to normal liquid-based exfoliation strategies,such as ultrasonication,high-shear mixing and ball milling.Inspired by nacre,a new bioinspired layered structural design model containing three-dimensional nanofiber network is proposed and implemented with an interconnected aramid nanofiber network and high-loading graphene nanosheets by a developed continuous assembly strategy of sol-gel-film transformation.It is revealed that the bioinspired film not only exhibits nacre-like ductile deformation behavior by releasing the hidden length of curved aramid nanofibers,but also possesses good thermal transport ability by directionally conducting heat along pristine graphene nanosheets.展开更多
Direct mass exfoliation of graphene from bulk graphite with high yield and productivity for commercial applications is challenging.This work proposes self-grinding exfoliation using the mutual shear friction of graphi...Direct mass exfoliation of graphene from bulk graphite with high yield and productivity for commercial applications is challenging.This work proposes self-grinding exfoliation using the mutual shear friction of graphite particles to fabricate graphene from microcrystalline graphite.The concept is implemented using microbeads as the grinding medium to drive the shear friction between graphite nanocrystals in a high-concentration paste.The proposed approach substantially improves graphene yield from 6.3% to 100% and simultaneously generates a record productivity of 7.5 g h^(-1)L^(-1),achieving total graphite-to-graphene conversion on the kilogram scale.The as-prepared graphene nanosheets have an average lateral size of 298 nm and the same C/O atomic ratio as the pristine graphite.In addition,the well-exfoliated,small nanosheets display good electrical conductivity and exhibit significant potential as conductive additives that improve the specific capacity and cyclic stability of Li-ion batteries better than commercial carbon-based conductive particles.展开更多
基金support from the National Natural Science Foundation of China(51973054)Young Talents Program in Hunan Province(2020RC3024)+2 种基金Natural Science Funds of Hunan Province for Distinguished Young Scholar(2021JJ10018)Science Research Project of Hunan Provincial Education Department(21B0027)High-level Innovative Talent Project in Hunan Province(2018RS3055).
文摘Flexible yet highly thermoconductive materials are essential for the development of next-generation flexible electronic devices.Herein,we report a bioinspired nanostructured film with the integration of large ductility and high thermal conductivity based on self-exfoliated pristine graphene and three-dimensional aramid nanofiber network.A self-grinding strategy to directly exfoliate flake graphite into few-layer and few-defect pristine graphene is successfully developed through mutual shear friction between graphite particles,generating largely enhanced yield and productivity in comparison to normal liquid-based exfoliation strategies,such as ultrasonication,high-shear mixing and ball milling.Inspired by nacre,a new bioinspired layered structural design model containing three-dimensional nanofiber network is proposed and implemented with an interconnected aramid nanofiber network and high-loading graphene nanosheets by a developed continuous assembly strategy of sol-gel-film transformation.It is revealed that the bioinspired film not only exhibits nacre-like ductile deformation behavior by releasing the hidden length of curved aramid nanofibers,but also possesses good thermal transport ability by directionally conducting heat along pristine graphene nanosheets.
基金supported by the National Natural Science Foundation of China(51973054)the High-level Innovative Talent Project in Hunan Province(2018RS3055)+2 种基金the Young Talents Program in Hunan Province(2020RC3024)the Natural Science Funds of Hunan Province for Distinguished Young Scholars(2021JJ10018)the Science Research Project of Hunan Provincial Education Department(21B0027)。
文摘Direct mass exfoliation of graphene from bulk graphite with high yield and productivity for commercial applications is challenging.This work proposes self-grinding exfoliation using the mutual shear friction of graphite particles to fabricate graphene from microcrystalline graphite.The concept is implemented using microbeads as the grinding medium to drive the shear friction between graphite nanocrystals in a high-concentration paste.The proposed approach substantially improves graphene yield from 6.3% to 100% and simultaneously generates a record productivity of 7.5 g h^(-1)L^(-1),achieving total graphite-to-graphene conversion on the kilogram scale.The as-prepared graphene nanosheets have an average lateral size of 298 nm and the same C/O atomic ratio as the pristine graphite.In addition,the well-exfoliated,small nanosheets display good electrical conductivity and exhibit significant potential as conductive additives that improve the specific capacity and cyclic stability of Li-ion batteries better than commercial carbon-based conductive particles.
