Graphite tailings produced by natural graphite is usually regarded as garbage to be buried underground,which would result in a certain waste of resources.Here,in order to explore the utilization of natural graphite ta...Graphite tailings produced by natural graphite is usually regarded as garbage to be buried underground,which would result in a certain waste of resources.Here,in order to explore the utilization of natural graphite tailings(NGT),a liquid-polyacrylonitrile(LPAN)is used to modify the NGT fragments and aggregate them together to form secondary graphite particles with low surface area and high tap density.Moreover,the modified NGT show much better electrochemical performances than those of original one.When tested in full cells coupled with NMC532 cathode,the material achieves a high rate capability and cycle stability at the cutoff voltage of 4.25 V as well as 4.45 V,which maintains 84.32%capacity retention after 500 cycles at 1 C rate(4.25 V),higher than that of the pristine one(73.65%).The enhanced performances can be attributed to the use of LPAN to create a unique carbon layer upon graphite tailings to reconstruct surface and repair defects,and also to granulate an isotropic structure of secondary graphite particles,which can help to weaken the anisotropy of Li^(+)diffusion pathway and form a uniform,complete and stable solid-electrolyte-interface(SEI)on the surface of primary NGT fragments to promote a fast Li+diffusion and suppress lithium metal dendrites upon charge and discharge.展开更多
Reasonable design and applications of graphene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side re...Reasonable design and applications of graphene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side reactions,stabilization of electrode architecture,and improvement of conductive component.Therefore,extensive fundamental research on this aspect has been performed so far.However,when it comes to large-scale industrial applications,the utilization of graphene-based materials progresses at a very slow pace.Namely,there presents a severe technological decoupling between academic research and industrial application,and there is an urgent need to link them.Herein,in order to address current issues of graphene-based materials used in lithium batteries,we present their latest advancements with stateof-the-art technologies.Potential applications of graphenebased materials in practical lithium batteries are highlighted and predicted to bridge the gap between the academic progress and industrial manufacture,thereby paving the way for accelerating the development of graphenebased material as well as lithium battery industry.展开更多
In this study,the morphological distribution of Ru on nitrogen-doped graphene(NG)could be rationally regulated via modulating the combination mode between Ru precursor and the zeolite imidazolate framework-8(ZIF-8).Th...In this study,the morphological distribution of Ru on nitrogen-doped graphene(NG)could be rationally regulated via modulating the combination mode between Ru precursor and the zeolite imidazolate framework-8(ZIF-8).The cation exchange and host-guest strategies respectively resulted in two different combination modes between Ru precursor and ZIF-8 anchored on graphene.Following pyrolysis of the above precursors,Ru single-atom sites(SASs)with and without Ru nanoparticles(NPs)were formed selectively on NG(denoted as Ru SASs+NPs/NG and Ru SASs/NG,respectively).Ru SASs+NPs/NG exhibited excellent hydrogen evolution reaction(HER)performance in alkaline solutions(η_(10)=12 mV,12.57 A mg^(-1)_(Ru) at 100 mV),which is much better than Ru SASs/NG.The experimental and theoretical study revealed that Ru SASs could adsorb hydrogen with optimal adsorption strength,while Ru NPs could lower the barrier of water molecule dissociation,and thus Ru SASs and Ru NPs could synergistically promote the catalytic performance of HER in alkaline solutions.展开更多
In this study,dual-metal atomic pairs of manganese(Mn)-iron(Fe)binuclear sites(BNSs)with two conjoint MnN4 and FeN4 moieties(MnFeN8)anchored onto a graphite-like structure(GLS)(Mn-Fe BNSs/GLS)were constructed.The binu...In this study,dual-metal atomic pairs of manganese(Mn)-iron(Fe)binuclear sites(BNSs)with two conjoint MnN4 and FeN4 moieties(MnFeN8)anchored onto a graphite-like structure(GLS)(Mn-Fe BNSs/GLS)were constructed.The binuclear MnFeN8 structure was verified experimentally and theoretically.Magnetic measurements and Gaussian calculations reveal that this unique Mn-Fe BNSs exhibit strong short-range electronic interaction between Mn and Fe sites,which decouples two paired d electrons in Fe sites,thereby transforming Fe sites from an intermediate to a high spin state.The optimal electronic configuration of Fe sites and their binuclear structure facilitate an oxygen reduction reaction(ORR)thermodynamically and dynamically,respectively,endowing Mn-Fe BNSs with improved ORR performance.展开更多
基金the financial support of National Key Research and Development Program of China(No.2020YFC1909604)National Natural Science Foundation(NNSF)of China(Nos.52202269,52002248)+1 种基金Shenzhen Key Projects of Technological Research(No.JSGG20200925145800001)and Shenzhen Basic Research Project(Nos.JCYJ20190808145203535,JCYJ20190808163005631)for providing financial support for this work.We are also grateful to the Instrumental Analysis Center of Shenzhen University(Xili Campus)for providing the facilities for our material analyzes。
文摘Graphite tailings produced by natural graphite is usually regarded as garbage to be buried underground,which would result in a certain waste of resources.Here,in order to explore the utilization of natural graphite tailings(NGT),a liquid-polyacrylonitrile(LPAN)is used to modify the NGT fragments and aggregate them together to form secondary graphite particles with low surface area and high tap density.Moreover,the modified NGT show much better electrochemical performances than those of original one.When tested in full cells coupled with NMC532 cathode,the material achieves a high rate capability and cycle stability at the cutoff voltage of 4.25 V as well as 4.45 V,which maintains 84.32%capacity retention after 500 cycles at 1 C rate(4.25 V),higher than that of the pristine one(73.65%).The enhanced performances can be attributed to the use of LPAN to create a unique carbon layer upon graphite tailings to reconstruct surface and repair defects,and also to granulate an isotropic structure of secondary graphite particles,which can help to weaken the anisotropy of Li^(+)diffusion pathway and form a uniform,complete and stable solid-electrolyte-interface(SEI)on the surface of primary NGT fragments to promote a fast Li+diffusion and suppress lithium metal dendrites upon charge and discharge.
基金financially supported by the National Key Research and Development Program of China(No.2020YFC1909604)the Natural Science Foundation of China(Nos.52202269 and 52002248)+1 种基金Shenzhen Science and Technology program(No.20220810155330003)Shenzhen Basic Research Program(No.JCYJ20190808163005631)。
文摘Reasonable design and applications of graphene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side reactions,stabilization of electrode architecture,and improvement of conductive component.Therefore,extensive fundamental research on this aspect has been performed so far.However,when it comes to large-scale industrial applications,the utilization of graphene-based materials progresses at a very slow pace.Namely,there presents a severe technological decoupling between academic research and industrial application,and there is an urgent need to link them.Herein,in order to address current issues of graphene-based materials used in lithium batteries,we present their latest advancements with stateof-the-art technologies.Potential applications of graphenebased materials in practical lithium batteries are highlighted and predicted to bridge the gap between the academic progress and industrial manufacture,thereby paving the way for accelerating the development of graphenebased material as well as lithium battery industry.
基金supported by the National Key Research and Development Program of China(2020YFC1909604)Shenzhen Key Projects of Technological Research(JSGG20200925145800001)+1 种基金Shenzhen Basic Research Project(JCYJ20190808145203535,JCYJ20190808144413257)the Project of Natural Science Foundation of Guangdong Province(2020A1515010379)。
文摘In this study,the morphological distribution of Ru on nitrogen-doped graphene(NG)could be rationally regulated via modulating the combination mode between Ru precursor and the zeolite imidazolate framework-8(ZIF-8).The cation exchange and host-guest strategies respectively resulted in two different combination modes between Ru precursor and ZIF-8 anchored on graphene.Following pyrolysis of the above precursors,Ru single-atom sites(SASs)with and without Ru nanoparticles(NPs)were formed selectively on NG(denoted as Ru SASs+NPs/NG and Ru SASs/NG,respectively).Ru SASs+NPs/NG exhibited excellent hydrogen evolution reaction(HER)performance in alkaline solutions(η_(10)=12 mV,12.57 A mg^(-1)_(Ru) at 100 mV),which is much better than Ru SASs/NG.The experimental and theoretical study revealed that Ru SASs could adsorb hydrogen with optimal adsorption strength,while Ru NPs could lower the barrier of water molecule dissociation,and thus Ru SASs and Ru NPs could synergistically promote the catalytic performance of HER in alkaline solutions.
基金supported by the National Key Research and Development Program of China (2020YFC1909604)Shenzhen Key Projects of Technological Research (JSGG20200925145800001)Shenzhen Science and Technology Program (CJGJZD20210408092801005)。
基金financially supported by the National Natural Science Foundation of China(11921006)the National Key Research and Development Program of China(2020YFC1909604)+1 种基金Shenzhen Key Projects of Technological Research(JSGG20200925145800001)Shenzhen Science and Technology Program(CJGJZD20210408092801005)。
基金support of Shenzhen Basic Research Project(Nos.JCYJ20170818092720054,JCYJ20190808145203535,and JCYJ20190808144413257)National Natural Science Foundation of China(No.21671136)+3 种基金Postdoctoral Science Foundation of China(No.2019M663085)Major Programs for Science and Technology Development of Shenzhen(Nos.JSGG20160328151657828 and XCL201110060)Major Industrial Projects of Shenzhen(No.s2017001850011)the Project of Natural Science Foundation of Guangdong Province(Nos.2020A1515010380 and 2014A030311028).
文摘In this study,dual-metal atomic pairs of manganese(Mn)-iron(Fe)binuclear sites(BNSs)with two conjoint MnN4 and FeN4 moieties(MnFeN8)anchored onto a graphite-like structure(GLS)(Mn-Fe BNSs/GLS)were constructed.The binuclear MnFeN8 structure was verified experimentally and theoretically.Magnetic measurements and Gaussian calculations reveal that this unique Mn-Fe BNSs exhibit strong short-range electronic interaction between Mn and Fe sites,which decouples two paired d electrons in Fe sites,thereby transforming Fe sites from an intermediate to a high spin state.The optimal electronic configuration of Fe sites and their binuclear structure facilitate an oxygen reduction reaction(ORR)thermodynamically and dynamically,respectively,endowing Mn-Fe BNSs with improved ORR performance.
