TY - JOUR
T1 - Revealing lithium–silicide phase transformations in nano-structured silicon-based lithium ion batteries via in situ NMR spectroscopy
AU - Ogata, K.
AU - Salager, E.
AU - Kerr, C.j.
AU - Fraser, A.e.
AU - Ducati, C.
AU - Hofmann, S.
AU - Grey, C.p.
AU - Morris, Andrew
PY - 2014/2/3
Y1 - 2014/2/3
N2 - Nano-structured silicon anodes are attractive alternatives to graphitic carbons in rechargeable Li-ion batteries, owing to their extremely high capacities. Despite their advantages, numerous issues remain to be addressed, the most basic being to understand the complex kinetics and thermodynamics that control the reactions and structural rearrangements. Elucidating this necessitates real-time in situ metrologies, which are highly challenging, if the whole electrode structure is studied at an atomistic level for multiple cycles under realistic cycling conditions. Here we report that Si nanowires grown on a conducting carbon-fibre support provide a robust model battery system that can be studied by 7Li in situ NMR spectroscopy. The method allows the (de)alloying reactions of the amorphous silicides to be followed in the 2nd cycle and beyond. In combination with density-functional theory calculations, the results provide insight into the amorphous and amorphous-to-crystalline lithium–silicide transformations, particularly those at low voltages, which are highly relevant to practical cycling strategies.
AB - Nano-structured silicon anodes are attractive alternatives to graphitic carbons in rechargeable Li-ion batteries, owing to their extremely high capacities. Despite their advantages, numerous issues remain to be addressed, the most basic being to understand the complex kinetics and thermodynamics that control the reactions and structural rearrangements. Elucidating this necessitates real-time in situ metrologies, which are highly challenging, if the whole electrode structure is studied at an atomistic level for multiple cycles under realistic cycling conditions. Here we report that Si nanowires grown on a conducting carbon-fibre support provide a robust model battery system that can be studied by 7Li in situ NMR spectroscopy. The method allows the (de)alloying reactions of the amorphous silicides to be followed in the 2nd cycle and beyond. In combination with density-functional theory calculations, the results provide insight into the amorphous and amorphous-to-crystalline lithium–silicide transformations, particularly those at low voltages, which are highly relevant to practical cycling strategies.
U2 - 10.1038/ncomms4217
DO - 10.1038/ncomms4217
M3 - Article
SN - 2041-1723
VL - 5
JO - Nature Communications
JF - Nature Communications
M1 - 3217
ER -
