TY - JOUR
T1 - The effect of antisite disorder and particle size on Li intercalation kinetics in monoclinic LiMnBO3
AU - Kim, Jae Chul
AU - Seo, Dong Hwa
AU - Chen, Hailong
AU - Ceder, Gerbrand
N1 - Publisher Copyright:
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - In materials containing 1D lithium diffusion channels, cation disorder can strongly affect lithium intercalation processes. This work presents a model to explain the unusual transport properties of monoclinic LiMnBO3, a material determined by scanning electron microscopy and synchrotron X-ray diffraction to contain a wide particle size distribution and Mn/Li antisite disorder. First-principles calculations indicate that Mn occupying Li sites obstruct the 1D lithium diffusion channel along the [001] direction. While channel blockage by the antisites significantly lowers Li mobility in large particles, Li kinetics in small particles and particle surfaces are found to be less sensitive to the presence of antisite disorder. Thus, in an electrode containing a large particle size distribution, smaller particles have higher Li mobility, and the measured Li diffusivity as determined by potentiostatic intermittent titration test varies as a function of particle size. The Li capacity in monoclinic LiMnBO3 is kinetically controlled by the fraction of large particles with antisite disorder, but is not intrinsically limited. These results strongly suggest that particle nanosizing will significantly enhance the electrochemical performance of LiMnBO3. Mn/Li antisite disorder in monoclinic LiMnBO3 impedes 1D Li diffusion. This effect of channel-blocking on macroscopic Li transport and capacity is subject to particle size as large particles have a higher probability to contain at least two antisites within a single channel than small particles. Thus, in order to make a substantial amount of Li accessible and improve the capacity of LiMnBO3, its particle size should be minimized.
AB - In materials containing 1D lithium diffusion channels, cation disorder can strongly affect lithium intercalation processes. This work presents a model to explain the unusual transport properties of monoclinic LiMnBO3, a material determined by scanning electron microscopy and synchrotron X-ray diffraction to contain a wide particle size distribution and Mn/Li antisite disorder. First-principles calculations indicate that Mn occupying Li sites obstruct the 1D lithium diffusion channel along the [001] direction. While channel blockage by the antisites significantly lowers Li mobility in large particles, Li kinetics in small particles and particle surfaces are found to be less sensitive to the presence of antisite disorder. Thus, in an electrode containing a large particle size distribution, smaller particles have higher Li mobility, and the measured Li diffusivity as determined by potentiostatic intermittent titration test varies as a function of particle size. The Li capacity in monoclinic LiMnBO3 is kinetically controlled by the fraction of large particles with antisite disorder, but is not intrinsically limited. These results strongly suggest that particle nanosizing will significantly enhance the electrochemical performance of LiMnBO3. Mn/Li antisite disorder in monoclinic LiMnBO3 impedes 1D Li diffusion. This effect of channel-blocking on macroscopic Li transport and capacity is subject to particle size as large particles have a higher probability to contain at least two antisites within a single channel than small particles. Thus, in order to make a substantial amount of Li accessible and improve the capacity of LiMnBO3, its particle size should be minimized.
KW - 1D diffusion
KW - Li-ion batteries
KW - antisite disorder
KW - first-principles computation
KW - monoclinic LiMnBO cathodes
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U2 - 10.1002/aenm.201401916
DO - 10.1002/aenm.201401916
M3 - Article
AN - SCOPUS:84928211521
SN - 1614-6832
VL - 5
JO - Advanced Energy Materials
JF - Advanced Energy Materials
IS - 8
M1 - 1401916
ER -