Limits...
Facile synthesis of ultrahigh-surface-area hollow carbon nanospheres for enhanced adsorption and energy storage.

Xu F, Tang Z, Huang S, Chen L, Liang Y, Mai W, Zhong H, Fu R, Wu D - Nat Commun (2015)

Bottom Line: Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions.The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries.The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

View Article: PubMed Central - PubMed

Affiliation: Materials Science Institute, PCFM Lab and GDHPPC Lab, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.

ABSTRACT
Exceptionally large surface area and well-defined nanostructure are both critical in the field of nanoporous carbons for challenging energy and environmental issues. The pursuit of ultrahigh surface area while maintaining definite nanostructure remains a formidable challenge because extensive creation of pores will undoubtedly give rise to the damage of nanostructures, especially below 100 nm. Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions. The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries. The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

No MeSH data available.


Related in: MedlinePlus

Li–S battery performances of HCN/S nanocomposites.(a) Discharge–charge curves recorded at different cycles for HCN-900-10H5R/S; (b) cycle performances at 0.5 C for HCN-900-10H5R/S (red) and mixture of HCN-900-10H5R and S before melt infiltration (blue) and coulombic efficiency (black) for HCN-900-10H5R/S; (c) rate performances, (d) discharge–charge curves at various rates and (e) capacity (red) and coulombic efficiency (black) over 500 cycles at 1 C after stopping the rate performance test for one month for HCN-900-10H5R/S.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4490369&req=5

f7: Li–S battery performances of HCN/S nanocomposites.(a) Discharge–charge curves recorded at different cycles for HCN-900-10H5R/S; (b) cycle performances at 0.5 C for HCN-900-10H5R/S (red) and mixture of HCN-900-10H5R and S before melt infiltration (blue) and coulombic efficiency (black) for HCN-900-10H5R/S; (c) rate performances, (d) discharge–charge curves at various rates and (e) capacity (red) and coulombic efficiency (black) over 500 cycles at 1 C after stopping the rate performance test for one month for HCN-900-10H5R/S.

Mentions: Fig. 7a presents galvanostatic discharge–charge curves at a rate of 0.5 C for 100 cycles (n C represents full delivery of the theoretical capacity in 1/n h, 1 C=1,675 mA g−1). Two plateaus at 2.3 and 2.0 V are observed in the discharge curves, which are assigned to the reduction of cyclic S8 to long-chain lithium polysulphides (Li2Sx, 4≤x≤8) and further reduction to short-chain lithium polysulphides (Li2Sx, x≤3) and Li2S, respectively525354. During the charging process, only one plateau at 2.4 V assignable to the oxidation of Li2S is observed. The nanostructured composite shows a capacity of 1,043 mAh g−1 at the initial discharge, whereas simply mixing the sulphur with HCN-900-10H5R gives only a low capacity of 652 mAh g−1 (Fig. 7b and Supplementary Fig. 17). The plateaus retain their shapes after 100 cycles, and the coulombic efficiency keeps at 100% throughout 100 cycles, implying that only little fraction of polysulphide anions diffuse into the electrolyte due to efficient sequestering. The capacity is rather stable upon 100 cycles with a slight decrease of 0.07% per cycle and capacity retention ratio of 93%. This value is superior to that of previously reported HCNs and many other porous carbon substrates (Supplementary Table 6). HCN-900-10H5R/S electrode still keeps the spherical morphology with little change in surface structure after 100 cycles (Supplementary Fig. 18). The stable performance can be also reflected from the electrochemical impedance spectra, where the charge transfer resistance, determined by the semicircle at high-frequency region41, is quite stable upon 100 cycles, except for a larger resistance in the initial cycle because of the electrolyte penetration effect for activation (Supplementary Fig. 19 and refs 55, 56).


Facile synthesis of ultrahigh-surface-area hollow carbon nanospheres for enhanced adsorption and energy storage.

Xu F, Tang Z, Huang S, Chen L, Liang Y, Mai W, Zhong H, Fu R, Wu D - Nat Commun (2015)

Li–S battery performances of HCN/S nanocomposites.(a) Discharge–charge curves recorded at different cycles for HCN-900-10H5R/S; (b) cycle performances at 0.5 C for HCN-900-10H5R/S (red) and mixture of HCN-900-10H5R and S before melt infiltration (blue) and coulombic efficiency (black) for HCN-900-10H5R/S; (c) rate performances, (d) discharge–charge curves at various rates and (e) capacity (red) and coulombic efficiency (black) over 500 cycles at 1 C after stopping the rate performance test for one month for HCN-900-10H5R/S.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490369&req=5

f7: Li–S battery performances of HCN/S nanocomposites.(a) Discharge–charge curves recorded at different cycles for HCN-900-10H5R/S; (b) cycle performances at 0.5 C for HCN-900-10H5R/S (red) and mixture of HCN-900-10H5R and S before melt infiltration (blue) and coulombic efficiency (black) for HCN-900-10H5R/S; (c) rate performances, (d) discharge–charge curves at various rates and (e) capacity (red) and coulombic efficiency (black) over 500 cycles at 1 C after stopping the rate performance test for one month for HCN-900-10H5R/S.
Mentions: Fig. 7a presents galvanostatic discharge–charge curves at a rate of 0.5 C for 100 cycles (n C represents full delivery of the theoretical capacity in 1/n h, 1 C=1,675 mA g−1). Two plateaus at 2.3 and 2.0 V are observed in the discharge curves, which are assigned to the reduction of cyclic S8 to long-chain lithium polysulphides (Li2Sx, 4≤x≤8) and further reduction to short-chain lithium polysulphides (Li2Sx, x≤3) and Li2S, respectively525354. During the charging process, only one plateau at 2.4 V assignable to the oxidation of Li2S is observed. The nanostructured composite shows a capacity of 1,043 mAh g−1 at the initial discharge, whereas simply mixing the sulphur with HCN-900-10H5R gives only a low capacity of 652 mAh g−1 (Fig. 7b and Supplementary Fig. 17). The plateaus retain their shapes after 100 cycles, and the coulombic efficiency keeps at 100% throughout 100 cycles, implying that only little fraction of polysulphide anions diffuse into the electrolyte due to efficient sequestering. The capacity is rather stable upon 100 cycles with a slight decrease of 0.07% per cycle and capacity retention ratio of 93%. This value is superior to that of previously reported HCNs and many other porous carbon substrates (Supplementary Table 6). HCN-900-10H5R/S electrode still keeps the spherical morphology with little change in surface structure after 100 cycles (Supplementary Fig. 18). The stable performance can be also reflected from the electrochemical impedance spectra, where the charge transfer resistance, determined by the semicircle at high-frequency region41, is quite stable upon 100 cycles, except for a larger resistance in the initial cycle because of the electrolyte penetration effect for activation (Supplementary Fig. 19 and refs 55, 56).

Bottom Line: Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions.The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries.The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

View Article: PubMed Central - PubMed

Affiliation: Materials Science Institute, PCFM Lab and GDHPPC Lab, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.

ABSTRACT
Exceptionally large surface area and well-defined nanostructure are both critical in the field of nanoporous carbons for challenging energy and environmental issues. The pursuit of ultrahigh surface area while maintaining definite nanostructure remains a formidable challenge because extensive creation of pores will undoubtedly give rise to the damage of nanostructures, especially below 100 nm. Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions. The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries. The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

No MeSH data available.


Related in: MedlinePlus