TY - JOUR
T1 - Structural and mechanistic insights into fast lithium-ion conduction in Li4SiO4-Li3PO4 solid electrolytes
AU - Deng, Yue
AU - Eames, Christopher
AU - Chotard, Jean Noël
AU - Laleìre, Fabien
AU - Seznec, Vincent
AU - Emge, Steffen
AU - Pecher, Oliver
AU - Grey, Clare P.
AU - Masquelier, Christian
AU - Islam, M. Saiful
PY - 2015/7/22
Y1 - 2015/7/22
N2 - Solid electrolytes that are chemically stable and have a high ionic
conductivity would dramatically enhance the safety and operating
lifespan of rechargeable lithium batteries. Here, we apply a
multi-technique approach to the Li-ion conducting system (1–z)Li4SiO4–(z)Li3PO4
with the aim of developing a solid electrolyte with enhanced ionic
conductivity. Previously unidentified superstructure and immiscibility
features in high-purity samples are characterized by X-ray and neutron
diffraction across a range of compositions (z = 0.0–1.0). Ionic
conductivities from AC impedance measurements and large-scale molecular
dynamics (MD) simulations are in good agreement, showing very low values
in the parent phases (Li4SiO4 and Li3PO4) but orders of magnitude higher conductivities (10–3
S/cm at 573 K) in the mixed compositions. The MD simulations reveal new
mechanistic insights into the mixed Si/P compositions in which Li-ion
conduction occurs through 3D pathways and a cooperative interstitial
mechanism; such correlated motion is a key factor in promoting high
ionic conductivity. Solid-state 6Li, 7Li, and 31P
NMR experiments reveal enhanced local Li-ion dynamics and atomic
disorder in the solid solutions, which are correlated to the ionic
diffusivity. These unique insights will be valuable in developing
strategies to optimize the ionic conductivity in this system and to
identify next-generation solid electrolytes.
AB - Solid electrolytes that are chemically stable and have a high ionic
conductivity would dramatically enhance the safety and operating
lifespan of rechargeable lithium batteries. Here, we apply a
multi-technique approach to the Li-ion conducting system (1–z)Li4SiO4–(z)Li3PO4
with the aim of developing a solid electrolyte with enhanced ionic
conductivity. Previously unidentified superstructure and immiscibility
features in high-purity samples are characterized by X-ray and neutron
diffraction across a range of compositions (z = 0.0–1.0). Ionic
conductivities from AC impedance measurements and large-scale molecular
dynamics (MD) simulations are in good agreement, showing very low values
in the parent phases (Li4SiO4 and Li3PO4) but orders of magnitude higher conductivities (10–3
S/cm at 573 K) in the mixed compositions. The MD simulations reveal new
mechanistic insights into the mixed Si/P compositions in which Li-ion
conduction occurs through 3D pathways and a cooperative interstitial
mechanism; such correlated motion is a key factor in promoting high
ionic conductivity. Solid-state 6Li, 7Li, and 31P
NMR experiments reveal enhanced local Li-ion dynamics and atomic
disorder in the solid solutions, which are correlated to the ionic
diffusivity. These unique insights will be valuable in developing
strategies to optimize the ionic conductivity in this system and to
identify next-generation solid electrolytes.
UR - http://www.scopus.com/inward/record.url?scp=84937796143&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1021/jacs.5b04444
U2 - 10.1021/jacs.5b04444
DO - 10.1021/jacs.5b04444
M3 - Article
AN - SCOPUS:84937796143
SN - 0002-7863
VL - 137
SP - 9136
EP - 9145
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 28
ER -