Arrays of sealed silicon nanotubes as anodes for lithium ion batteries.
Nano Lett
; 10(5): 1710-6, 2010 May 12.
Article
in En
| MEDLINE
| ID: mdl-20369889
ABSTRACT
Silicon is a promising candidate for electrodes in lithium ion batteries due to its large theoretical energy density. Poor capacity retention, caused by pulverization of Si during cycling, frustrates its practical application. We have developed a nanostructured form of silicon, consisting of arrays of sealed, tubular geometries that is capable of accommodating large volume changes associated with lithiation in battery applications. Such electrodes exhibit high initial Coulombic efficiencies (i.e., >85%) and stable capacity-retention (>80% after 50 cycles), due to an unusual, underlying mechanics that is dominated by free surfaces. This physics is manifested by a strongly anisotropic expansion in which 400% volumetric increases are accomplished with only relatively small (<35%) changes in the axial dimension. These experimental results and associated theoretical mechanics models demonstrate the extent to which nanoscale engineering of electrode geometry can be used to advantage in the design of rechargeable batteries with highly reversible capacity and long-term cycle stability.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Electric Power Supplies
/
Silicon
/
Nanotechnology
/
Nanotubes
/
Electrodes
/
Lithium
Language:
En
Journal:
Nano Lett
Year:
2010
Type:
Article