Li metal anode holds great promise to realize high-energy battery systems.However,the safety issue and limited lifetime caused by the uncontrollable growth of Li dendrites hinder its commercial application.Herein,an i...Li metal anode holds great promise to realize high-energy battery systems.However,the safety issue and limited lifetime caused by the uncontrollable growth of Li dendrites hinder its commercial application.Herein,an interlayer-bridged 3D lithiophilic rGO-Ag-S-CNT composite is proposed to guide uniform and stable Li plating/stripping.The 3D lithiophilic rGO-Ag-S-CNT host is fabricated by incorporating Ag-modified reduced graphene oxide(rGO)with S-doped carbon nanotube(CNT),where the rGO and CNT are closely connected via robust Ag-S covalent bond.This strong Ag-S bond could enhance the structural stability and electrical connection between rGO and CNT,significantly improving the electrochemical kinetics and uniformity of current distribution.Moreover,density functional theory calculation indicates that the introduction of Ag-S bond could further boost the binding energy between Ag and Li,which promotes homogeneous Li nucleation and growth.Consequently,the rGO-Ag-S-CNT-based anode achieves a lower overpotential(7.3 mV at 0.5 mA cm^(−2)),higher Coulombic efficiency(98.1%at 0.5 mA cm^(−2)),and superior long cycling performance(over 500 cycles at 2 mA cm−2)as compared with the rGO-Ag-CNT-and rGO-CNT-based anodes.This work provides a universal avenue and guidance to build a robust Li metal host via constructing a strong covalent bond,effectively suppressing the Li dendrites growth to prompt the development of Li metal battery.展开更多
In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. I...In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g^(-1) after 150 cycles at a current density of 400 mAg^(-1). It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.展开更多
Tailoring a rational structure to control the huge volume variation is practical in regulating alkali-ion battery performance on the basis of the anisotropic properties of crystallized anode materials.Here,a double-se...Tailoring a rational structure to control the huge volume variation is practical in regulating alkali-ion battery performance on the basis of the anisotropic properties of crystallized anode materials.Here,a double-serrated orthorhombic antimony oxide(Sb_(2)O_(3))microbelt was prepared by a thermally induced recrystallization/sublimation process.In situ transmission electron microscopy(TEM),in situ X-ray powder diffraction(XRD),and ex situ scanning electron microscopy(SEM)measurements demonstrate that Sb_(2)O_(3)microbelts exhibit a quasi-one-dimensional expansion perpendicular to the belt(along the[100]direction)during sodiation.The unconstrained microbelt surface space can appropriately accommodate the oriented volume variation.Thus,Sb_(2)O_(3)microbelts exhibit enhanced cycling and rate performance in half-cell sodium-ion batteries samples.Via support of reduced graphene oxide(RGO),Sb_(2)O_(3)@RGOcomposites deliver good rate capability(312.3 mAh g−1 at 3 A g−1)for sodium-ion full-cell batteries and good cycling performance(473.9 mAh g−1 at 100 mA g−1 after 100 cycles)for half-cell potassium-ion batteries.In situ Raman measurements reveal that the conversion/alloying-type Sb_(2)O_(3)anode undergoes a fully reversible alloying reaction and partially reversible conversion mechanism,which explains its irreversible capacity during the first cycle.The delicate structural design and clarification of the alkali-ion storage mechanisms facilitate the development of Sb_(2)O_(3)anodes for energy storage applications.展开更多
基金This work is supported by Singapore Ministry of Education academic research grant Tier 2 (MOE2019-T2-1-181).
文摘Li metal anode holds great promise to realize high-energy battery systems.However,the safety issue and limited lifetime caused by the uncontrollable growth of Li dendrites hinder its commercial application.Herein,an interlayer-bridged 3D lithiophilic rGO-Ag-S-CNT composite is proposed to guide uniform and stable Li plating/stripping.The 3D lithiophilic rGO-Ag-S-CNT host is fabricated by incorporating Ag-modified reduced graphene oxide(rGO)with S-doped carbon nanotube(CNT),where the rGO and CNT are closely connected via robust Ag-S covalent bond.This strong Ag-S bond could enhance the structural stability and electrical connection between rGO and CNT,significantly improving the electrochemical kinetics and uniformity of current distribution.Moreover,density functional theory calculation indicates that the introduction of Ag-S bond could further boost the binding energy between Ag and Li,which promotes homogeneous Li nucleation and growth.Consequently,the rGO-Ag-S-CNT-based anode achieves a lower overpotential(7.3 mV at 0.5 mA cm^(−2)),higher Coulombic efficiency(98.1%at 0.5 mA cm^(−2)),and superior long cycling performance(over 500 cycles at 2 mA cm−2)as compared with the rGO-Ag-CNT-and rGO-CNT-based anodes.This work provides a universal avenue and guidance to build a robust Li metal host via constructing a strong covalent bond,effectively suppressing the Li dendrites growth to prompt the development of Li metal battery.
基金supported by the National Natural Science Foundation of China(NO.91434203,21276257,91534109)"Strategic Priority Research Program" of the Chinese Academy of Sciences(Grant No.XDA09010103)External Cooperation Program of BIC of the Chinese Academy of Sciences(Grant No.GJHZ201306)
文摘In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g^(-1) after 150 cycles at a current density of 400 mAg^(-1). It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.
基金This study is supported by the National Natural Science Foundation of China(nos.21701163,21671181,and 21831006)the Anhui Provincial Natural Science Foundation(no.1808085QB25).
文摘Tailoring a rational structure to control the huge volume variation is practical in regulating alkali-ion battery performance on the basis of the anisotropic properties of crystallized anode materials.Here,a double-serrated orthorhombic antimony oxide(Sb_(2)O_(3))microbelt was prepared by a thermally induced recrystallization/sublimation process.In situ transmission electron microscopy(TEM),in situ X-ray powder diffraction(XRD),and ex situ scanning electron microscopy(SEM)measurements demonstrate that Sb_(2)O_(3)microbelts exhibit a quasi-one-dimensional expansion perpendicular to the belt(along the[100]direction)during sodiation.The unconstrained microbelt surface space can appropriately accommodate the oriented volume variation.Thus,Sb_(2)O_(3)microbelts exhibit enhanced cycling and rate performance in half-cell sodium-ion batteries samples.Via support of reduced graphene oxide(RGO),Sb_(2)O_(3)@RGOcomposites deliver good rate capability(312.3 mAh g−1 at 3 A g−1)for sodium-ion full-cell batteries and good cycling performance(473.9 mAh g−1 at 100 mA g−1 after 100 cycles)for half-cell potassium-ion batteries.In situ Raman measurements reveal that the conversion/alloying-type Sb_(2)O_(3)anode undergoes a fully reversible alloying reaction and partially reversible conversion mechanism,which explains its irreversible capacity during the first cycle.The delicate structural design and clarification of the alkali-ion storage mechanisms facilitate the development of Sb_(2)O_(3)anodes for energy storage applications.