While silicon/carbon(Si/C)is considered one of the most promising anode materials for the next generation of high-energy lithium-ion batteries(LIBs),the industrialization of Si/C anodes is hampered by high-cost and lo...While silicon/carbon(Si/C)is considered one of the most promising anode materials for the next generation of high-energy lithium-ion batteries(LIBs),the industrialization of Si/C anodes is hampered by high-cost and low product yield.Herein,a high-yield strategy is developed in which photovoltaic waste silicon is converted to cost-effective graphitic Si/C composites(G-Si@C)for LIBs.The introduction of a binder improves the dispersion and compatibility of silicon and graphite,enhances particle sphericity,and significantly reduces the loss rate of the spray prilling process(from about 25%to 5%).As an LIB anode,the fabricated G-Si@C composites exhibit a capacity of 605 mAh g^(-1) after 1200 cycles.The cost of manufacturing Si/C anode materials has been reduced to approximately$7.47 kg^(-1),which is close to that of commercial graphite anode materials($5.0 kg^(-1)),and significantly lower than commercial Si/C materials(ca.$20.74 kg^(-1)).Moreover,the G-Si@C material provides approximately 81.0 Ah/$of capacity,which exceeds the current best commercial graphite anodes(70.0 Ah/$)and Si/C anodes(48.2 Ah/$).The successful implementation of this pathway will significantly promote the industrialization of high-energydensity Si/C anode materials.展开更多
C/SiO_(x)anode with higher capacity and lower lithiation potential has been recognized as a nextgeneration alternative to graphite for high-energy-density lithium-ion batteries.However,C/SiO_(x)suffers from low initia...C/SiO_(x)anode with higher capacity and lower lithiation potential has been recognized as a nextgeneration alternative to graphite for high-energy-density lithium-ion batteries.However,C/SiO_(x)suffers from low initial Coulombic efficiency(ICE),which significantly hinders its practical application.Herein,we reported a straightforward iodine redox chemistry strategy to realize highly reversible Li storage behavior and remarkably enhanced ICE of high-capacity C/SiO_(x)anode toward long-life lithium-ion batteries.Specifically,I2is introduced into porous C/SiO_(x)via simple fumigation to synthesize their composite(C/SiO_(x)@I),in which I_(2)can effectively inhibit the irreversible lithiation reactions of SiO_(x)through redox reaction.Further,redox reaction intermediates of LiI_(3)and LiIO_(3)can inhibit the decomposition of electrolyte and LiPF6,thereby reducing the thickness of the solid-electrolyte interphase film.Consequently,the obtained C/SiO_(x)@I exhibits a considerable capacity of 1241 mAh g^(-1)with an improved ICE of 88.5%at 0.1 A g^(-1)and impressive cyclability,showing capacity retention of 95%after 700 cycles at5.0 A g^(-1).Besides,the C/SiO_(x)@I with a 12%addition ratio can greatly enhance the capacity of graphite from 352 to 454 mAh g^(-1),with negligible impact on its ICE.When the addition ratio is 9%,the energy density of the 18,650 cylindrical battery composed of graphite and Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)can be enhanced by approximately 25 Wh kg^(-1).This study opens a new avenue for developing high ICE in SiO_(x)-based anodes for high-energy-density lithium-ion batteries.展开更多
Severe volume expansion and inherently poor lithium ion transmission are two major problems of silicon anodes.To address these issues,we proposed a pomegranate-type Si/C composite anode with highly dispersed tiny sili...Severe volume expansion and inherently poor lithium ion transmission are two major problems of silicon anodes.To address these issues,we proposed a pomegranate-type Si/C composite anode with highly dispersed tiny silicon particles as the core assisted by small amount of SiC.Skillfully exploiting the high heat from magnesiothermic reduction,SiC can assist the good dispersion of silicon and provide good interface compatibility and chemical stability.The silicon anchored to the carbon shell provides multipoint contact mode,that together with the carbon shell frame,significantly promoting the transfer of dual charge.Besides,the pomegranate-type microcluster structure also improves the tap density of the electrode,reduces the direct contact area between active material and electrolyte,and enhances the electrochemical performance.展开更多
Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic ...Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic Ni/Co brought CoNiSe_(2)/C anodes with high specific surface area (172.79 m^(2)/g) and outstanding electrochemical performance.CoNiSe_(2)/C anodes obtained reversible discharge capacities of850.9 mAh/g at 0.1 A/g after cycling for 100 cycles.In addition,CoNiSe_(2)/C exhibits excellent cycle stability and reversibility in the rate test at a current density of 0.1–2.0 A/g.When the current density returns to 0.5 A/g for 150 cycles,its discharge ratio the capacity is 330.8 m Ah/g.Electrochemical impedance spectroscopy (EIS) tests suggested that CoNiSe_(2)/C anodes had a lower charge transfer impedance of 130.02Ωafter 30 cycles.In-situ X-ray diffraction (XRD) tests confirmed the alloying mechanism of CoNiSe_(2)/C which realized higher lithium storage capacity.This work affords substantial evidence for the extension of bimetallic selenides in secondary batteries,promoting the development of bimetallic selenides in anode materials for LIBs.展开更多
Antimony(Sb)is an intriguing anode material for Li-ion batteries(LIBs)owing to its high theoretical capacity of 660 m Ah·g^(-1)and appropriate working potential of~0.8 V(vs.Li^(+)/Li).However,just like all alloyi...Antimony(Sb)is an intriguing anode material for Li-ion batteries(LIBs)owing to its high theoretical capacity of 660 m Ah·g^(-1)and appropriate working potential of~0.8 V(vs.Li^(+)/Li).However,just like all alloying materials,the Sb anode suffers from huge volume expansion(230%)during repeated insertion/extraction of Li+ions,resulting in structural deterioration and rapid capacity decay.In this work,a novel amorphous Sb/C composite with atomically dispersed Sb particles in carbon matrix is prepared via a straightforward high-energy ball milling approach.The intimate intermixing of amorphous Sb with C provides homogeneous element distribution and isotropic volume expansion during cycling,resulting in persistent structural stability.Meanwhile,the disordered structure of amorphous material shortens the diffusion distance of lithium ions/electrons,promoting fast reaction kinetics and rate capability.Benefiting from the aforementioned effects,the amorphous Sb/C exhibits a high reversible capacity of537.4 m Ah·g^(-1)at 0.1 A·g^(-1)and retains 201.0 m Ah·g^(-1)at an ultrahigh current rate of 10.0 A·g^(-1).Even after 1500deep cycles at 2.0 A·g^(-1),the amorphous Sb/C electrode still maintains 86.3%of its initial capacity,which outperforms all existing Sb-based anodes reported so far.Postmortem analysis further reveals a greatly reduced volume variation of merely 34.6%for the amorphous Sb/C electrode,much lower than that of 223.1%for crystalline Sb materials.This study presents a new approach to stabilizing Sb-based alloy anodes and contributes to the construction of high-performance amorphous anode materials for LIBs,enabling advanced energy storage.展开更多
Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging ...Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development.Here,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume change.As a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode conditions.In addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.展开更多
Anodized composite films containing Si C nanoparticles were synthesized on Ti6Al4 V alloy by anodic oxidation procedure in C4O6H4Na2 electrolyte. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) ...Anodized composite films containing Si C nanoparticles were synthesized on Ti6Al4 V alloy by anodic oxidation procedure in C4O6H4Na2 electrolyte. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS) were employed to characterize the morphology and composition of the films fabricated in the electrolytes with and without addition of Si C nanoparticles. Results show that Si C particles can be successfully incorporated into the oxide film during the anodizing process and preferentially concentrate within internal cavities and micro-cracks. The ball-on-disk sliding tests indicate that Si C-containing oxide films register much lower wear rate than the oxide films without Si C under dry sliding condition. Si C particles are likely to melt and then are oxidized by frictional heat during sliding tests. Potentiodynamic polarization behavior reveals that the anodized alloy with Si C nanoparticles results in a reduction in passive current density to about 1.54×10-8 A/cm2, which is more than two times lower than that of the Ti O2 film(3.73×10-8 A/cm2). The synthesized composite film has good anti-wear and anti-corrosion properties and the growth mechanism of nanocomposite film is also discussed.展开更多
Hierarchical mesoporous MoO2/Mo2C/C microspheres,which are composed of primary nanoparticles with a size of about 30 nm,have been designed and synthesized through polymer regulation and subsequent carbonization proces...Hierarchical mesoporous MoO2/Mo2C/C microspheres,which are composed of primary nanoparticles with a size of about 30 nm,have been designed and synthesized through polymer regulation and subsequent carbonization processes.The as-synthesized microspheres were characterized by XRD,Raman,SEM,TEM,XPS measurements and so on.It was found that polyethylene glycol acted as a structure-directing agent,mild reducing agent and carbon source in the formation of these hierarchical mesoporous Mo O2/Mo2C/C microspheres.Moreover,the electrochemical property of the microspheres was also investigated in this work.Evaluated as an anode material for lithium ion batteries,the hierarchical mesoporous Mo O2/Mo2C/C electrode delivered the discharge specific capacities of 665 and 588 m Ah/g after 100 cycles at current densities of 100 and 200 m A/g,respectively.The satisfactory cycling performance and controllable process facilitate the practical applications of the hierarchical mesoporous Mo O2/Mo2C/C as a potential anode material in high-energy density lithium-ion batteries.展开更多
Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell a...Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell and further constrained using graphene sheets.Hollow graphene oxide shells with abundant surficial hydrogen bonds,which were synthesized using a novel bottom-up method,were used as an intermediate material to anchor positively charged silicon nanoparticles via electrostatic attraction and achieve a rational spatial distribution.The inner hollow graphene shell anchorage and outer graphene constraint synergistically constituted a porous and robust conductive corn-like structure.The as-fabricated Si@GS@G anode afforded efficient electron and ion transport pathways and improved structural stability,thereby enhancing Li+storage capability(505 mAh·g^(−1)at 10 A·g^(−1))and extending the lifespan compared to the single hollow graphene shell or graphene sheet-protected Si anode(72%capacity retention after 500 cycles).The improved kinetics of the Si@GS@G anode were investigated using electro impedance spectroscopy,galvanostatic intermittent titration,and pseudocapacitance contribution rate analysis,and the structural evolution was analyzed using ex situ electron microscopy.This study proposes a novel hollow graphene oxide shell as an activated intermediate material for designing a porous electrode structure that facilitates an enhanced electrochemical performance.展开更多
基金supported by the Major Science and Technology Projects in Yunnan Province(Grant No.202402AF080005)National Natural Science Foundation of China(Grant Nos.52274408,22468029,52274412)+2 种基金Yunnan Fundamental Research Projects(Grant No.202201AW070014)the Program for Innovative Research Team in University of Ministry of Education of China(Grant No.IRT 17R48)the German Research Foundation(DFG,Project number 501766751).
文摘While silicon/carbon(Si/C)is considered one of the most promising anode materials for the next generation of high-energy lithium-ion batteries(LIBs),the industrialization of Si/C anodes is hampered by high-cost and low product yield.Herein,a high-yield strategy is developed in which photovoltaic waste silicon is converted to cost-effective graphitic Si/C composites(G-Si@C)for LIBs.The introduction of a binder improves the dispersion and compatibility of silicon and graphite,enhances particle sphericity,and significantly reduces the loss rate of the spray prilling process(from about 25%to 5%).As an LIB anode,the fabricated G-Si@C composites exhibit a capacity of 605 mAh g^(-1) after 1200 cycles.The cost of manufacturing Si/C anode materials has been reduced to approximately$7.47 kg^(-1),which is close to that of commercial graphite anode materials($5.0 kg^(-1)),and significantly lower than commercial Si/C materials(ca.$20.74 kg^(-1)).Moreover,the G-Si@C material provides approximately 81.0 Ah/$of capacity,which exceeds the current best commercial graphite anodes(70.0 Ah/$)and Si/C anodes(48.2 Ah/$).The successful implementation of this pathway will significantly promote the industrialization of high-energydensity Si/C anode materials.
基金financially supported by the National Natural Science Foundation of China(No.51962027,and 52262039)the Major Science and Technology Project of Inner Mongolia Autonomous Region(2021ZD0016)+3 种基金the National Key R&D Program of China(2020YFC1909105)the Fundamental Research Funds for Inner Mongolia University of Science&Technology(NO.2024QNJS071,2023QNJS052 and 2024QNJS064)the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT24002)the Central Guidance Fund for Local Scientific and Technological Development(2024ZY0012)。
文摘C/SiO_(x)anode with higher capacity and lower lithiation potential has been recognized as a nextgeneration alternative to graphite for high-energy-density lithium-ion batteries.However,C/SiO_(x)suffers from low initial Coulombic efficiency(ICE),which significantly hinders its practical application.Herein,we reported a straightforward iodine redox chemistry strategy to realize highly reversible Li storage behavior and remarkably enhanced ICE of high-capacity C/SiO_(x)anode toward long-life lithium-ion batteries.Specifically,I2is introduced into porous C/SiO_(x)via simple fumigation to synthesize their composite(C/SiO_(x)@I),in which I_(2)can effectively inhibit the irreversible lithiation reactions of SiO_(x)through redox reaction.Further,redox reaction intermediates of LiI_(3)and LiIO_(3)can inhibit the decomposition of electrolyte and LiPF6,thereby reducing the thickness of the solid-electrolyte interphase film.Consequently,the obtained C/SiO_(x)@I exhibits a considerable capacity of 1241 mAh g^(-1)with an improved ICE of 88.5%at 0.1 A g^(-1)and impressive cyclability,showing capacity retention of 95%after 700 cycles at5.0 A g^(-1).Besides,the C/SiO_(x)@I with a 12%addition ratio can greatly enhance the capacity of graphite from 352 to 454 mAh g^(-1),with negligible impact on its ICE.When the addition ratio is 9%,the energy density of the 18,650 cylindrical battery composed of graphite and Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)can be enhanced by approximately 25 Wh kg^(-1).This study opens a new avenue for developing high ICE in SiO_(x)-based anodes for high-energy-density lithium-ion batteries.
基金the Shenzhen Science and Technology Projects(No.JCYJ20180306172957494)National Natural Science Foundation of China(No.5187224)for financial support.
文摘Severe volume expansion and inherently poor lithium ion transmission are two major problems of silicon anodes.To address these issues,we proposed a pomegranate-type Si/C composite anode with highly dispersed tiny silicon particles as the core assisted by small amount of SiC.Skillfully exploiting the high heat from magnesiothermic reduction,SiC can assist the good dispersion of silicon and provide good interface compatibility and chemical stability.The silicon anchored to the carbon shell provides multipoint contact mode,that together with the carbon shell frame,significantly promoting the transfer of dual charge.Besides,the pomegranate-type microcluster structure also improves the tap density of the electrode,reduces the direct contact area between active material and electrolyte,and enhances the electrochemical performance.
基金supported by National Natural Science Foundation, China (Nos. 52071132, 21773057 and U1904216)Zhongyuan Thousand People Plan-The Zhongyuan Youth Talent Support Program (in Science and Technology), China (No. ZYQR201810139)+1 种基金Innovative Funds Plan of Henan University of Technology, China (No. 2020ZKCJ04)Fundamental Research Funds for the Henan Provincial Colleges and Universities in Henan University of Technology, China (No. 2018RCJH01)。
文摘Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic Ni/Co brought CoNiSe_(2)/C anodes with high specific surface area (172.79 m^(2)/g) and outstanding electrochemical performance.CoNiSe_(2)/C anodes obtained reversible discharge capacities of850.9 mAh/g at 0.1 A/g after cycling for 100 cycles.In addition,CoNiSe_(2)/C exhibits excellent cycle stability and reversibility in the rate test at a current density of 0.1–2.0 A/g.When the current density returns to 0.5 A/g for 150 cycles,its discharge ratio the capacity is 330.8 m Ah/g.Electrochemical impedance spectroscopy (EIS) tests suggested that CoNiSe_(2)/C anodes had a lower charge transfer impedance of 130.02Ωafter 30 cycles.In-situ X-ray diffraction (XRD) tests confirmed the alloying mechanism of CoNiSe_(2)/C which realized higher lithium storage capacity.This work affords substantial evidence for the extension of bimetallic selenides in secondary batteries,promoting the development of bimetallic selenides in anode materials for LIBs.
基金supported by the National Natural Science Foundation of China(Nos.22279093 and 22075216)the Natural Science Foundation of Hubei Province,China(No.2022CFB096)the Fundamental Research Funds for Central University(Nos.2042022gf0005 and 2042021kf0194)。
文摘Antimony(Sb)is an intriguing anode material for Li-ion batteries(LIBs)owing to its high theoretical capacity of 660 m Ah·g^(-1)and appropriate working potential of~0.8 V(vs.Li^(+)/Li).However,just like all alloying materials,the Sb anode suffers from huge volume expansion(230%)during repeated insertion/extraction of Li+ions,resulting in structural deterioration and rapid capacity decay.In this work,a novel amorphous Sb/C composite with atomically dispersed Sb particles in carbon matrix is prepared via a straightforward high-energy ball milling approach.The intimate intermixing of amorphous Sb with C provides homogeneous element distribution and isotropic volume expansion during cycling,resulting in persistent structural stability.Meanwhile,the disordered structure of amorphous material shortens the diffusion distance of lithium ions/electrons,promoting fast reaction kinetics and rate capability.Benefiting from the aforementioned effects,the amorphous Sb/C exhibits a high reversible capacity of537.4 m Ah·g^(-1)at 0.1 A·g^(-1)and retains 201.0 m Ah·g^(-1)at an ultrahigh current rate of 10.0 A·g^(-1).Even after 1500deep cycles at 2.0 A·g^(-1),the amorphous Sb/C electrode still maintains 86.3%of its initial capacity,which outperforms all existing Sb-based anodes reported so far.Postmortem analysis further reveals a greatly reduced volume variation of merely 34.6%for the amorphous Sb/C electrode,much lower than that of 223.1%for crystalline Sb materials.This study presents a new approach to stabilizing Sb-based alloy anodes and contributes to the construction of high-performance amorphous anode materials for LIBs,enabling advanced energy storage.
基金financially supported by Guangdong Basic and Applied Basic Research Foundation (No.2020A1515110762)。
文摘Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development.Here,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume change.As a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode conditions.In addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.
基金Project(51271012)supported by the National Natural Science Foundation of China
文摘Anodized composite films containing Si C nanoparticles were synthesized on Ti6Al4 V alloy by anodic oxidation procedure in C4O6H4Na2 electrolyte. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS) were employed to characterize the morphology and composition of the films fabricated in the electrolytes with and without addition of Si C nanoparticles. Results show that Si C particles can be successfully incorporated into the oxide film during the anodizing process and preferentially concentrate within internal cavities and micro-cracks. The ball-on-disk sliding tests indicate that Si C-containing oxide films register much lower wear rate than the oxide films without Si C under dry sliding condition. Si C particles are likely to melt and then are oxidized by frictional heat during sliding tests. Potentiodynamic polarization behavior reveals that the anodized alloy with Si C nanoparticles results in a reduction in passive current density to about 1.54×10-8 A/cm2, which is more than two times lower than that of the Ti O2 film(3.73×10-8 A/cm2). The synthesized composite film has good anti-wear and anti-corrosion properties and the growth mechanism of nanocomposite film is also discussed.
基金supported by the National Natural Science Foundation of China(No.21376251 and 21406233)the National Basic Research Development Program of China(2013CB632600)
文摘Hierarchical mesoporous MoO2/Mo2C/C microspheres,which are composed of primary nanoparticles with a size of about 30 nm,have been designed and synthesized through polymer regulation and subsequent carbonization processes.The as-synthesized microspheres were characterized by XRD,Raman,SEM,TEM,XPS measurements and so on.It was found that polyethylene glycol acted as a structure-directing agent,mild reducing agent and carbon source in the formation of these hierarchical mesoporous Mo O2/Mo2C/C microspheres.Moreover,the electrochemical property of the microspheres was also investigated in this work.Evaluated as an anode material for lithium ion batteries,the hierarchical mesoporous Mo O2/Mo2C/C electrode delivered the discharge specific capacities of 665 and 588 m Ah/g after 100 cycles at current densities of 100 and 200 m A/g,respectively.The satisfactory cycling performance and controllable process facilitate the practical applications of the hierarchical mesoporous Mo O2/Mo2C/C as a potential anode material in high-energy density lithium-ion batteries.
基金the National Natural Science Foundation of China(Nos.52071225 and 51672181)the Czech Republic through ERDF“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)M.H.R.acknowledges the Sino-German Research Institute for their support(Project GZ 1400).
文摘Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell and further constrained using graphene sheets.Hollow graphene oxide shells with abundant surficial hydrogen bonds,which were synthesized using a novel bottom-up method,were used as an intermediate material to anchor positively charged silicon nanoparticles via electrostatic attraction and achieve a rational spatial distribution.The inner hollow graphene shell anchorage and outer graphene constraint synergistically constituted a porous and robust conductive corn-like structure.The as-fabricated Si@GS@G anode afforded efficient electron and ion transport pathways and improved structural stability,thereby enhancing Li+storage capability(505 mAh·g^(−1)at 10 A·g^(−1))and extending the lifespan compared to the single hollow graphene shell or graphene sheet-protected Si anode(72%capacity retention after 500 cycles).The improved kinetics of the Si@GS@G anode were investigated using electro impedance spectroscopy,galvanostatic intermittent titration,and pseudocapacitance contribution rate analysis,and the structural evolution was analyzed using ex situ electron microscopy.This study proposes a novel hollow graphene oxide shell as an activated intermediate material for designing a porous electrode structure that facilitates an enhanced electrochemical performance.
