TY - JOUR
T1 - Effect of composition on the structure of lithium- and manganese-rich transition metal oxides
AU - Shukla, Alpesh Khushalchand
AU - Ramasse, Quentin
AU - Ophus, Colin
AU - Kepaptsoglou, Despoina Maria
AU - Hage, Fredrik Sydow
AU - Gammer, Christoph
AU - Bowling, Charles
AU - Gallegos, Pedro Alejandro Hern ?andez
AU - Venkatachalam, Subramanian
N1 - © The Royal Society of Chemistry, 2018. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details
PY - 2018/4
Y1 - 2018/4
N2 - The choice of chemical composition of lithium- and manganese-rich transition metal oxides used as cathode materials in lithium-ion batteries can significantly impact their long-term viability as storage solutions for clean energy automotive applications. Their structure has been widely debated: conflicting conclusions drawn from individual studies often considering different compositions have made it challenging to reach a consensus and inform future research. Here, complementary electron microscopy techniques over a wide range of length scales reveal the effect of lithium-to-transition metal-ratio on the surface and bulk structure of these materials. We found that decreasing the lithium-to-transition metal-ratio resulted in a significant change in terms of order and atomic-level local composition in the bulk of these cathode materials. However, throughout the composition range studied, the materials consisted solely of a monoclinic phase, with lower lithium content materials showing more chemical ordering defects. In contrast, the spinel-structured surface present on specific crystallographic facets exhibited no noticeable structural change when varying the ratio of lithium to transition metal. The structural observations from this study warrant a reexamination of commonly assumed models linking poor electrochemical performance with bulk and surface structure.
AB - The choice of chemical composition of lithium- and manganese-rich transition metal oxides used as cathode materials in lithium-ion batteries can significantly impact their long-term viability as storage solutions for clean energy automotive applications. Their structure has been widely debated: conflicting conclusions drawn from individual studies often considering different compositions have made it challenging to reach a consensus and inform future research. Here, complementary electron microscopy techniques over a wide range of length scales reveal the effect of lithium-to-transition metal-ratio on the surface and bulk structure of these materials. We found that decreasing the lithium-to-transition metal-ratio resulted in a significant change in terms of order and atomic-level local composition in the bulk of these cathode materials. However, throughout the composition range studied, the materials consisted solely of a monoclinic phase, with lower lithium content materials showing more chemical ordering defects. In contrast, the spinel-structured surface present on specific crystallographic facets exhibited no noticeable structural change when varying the ratio of lithium to transition metal. The structural observations from this study warrant a reexamination of commonly assumed models linking poor electrochemical performance with bulk and surface structure.
UR - http://www.scopus.com/inward/record.url?scp=85045936129&partnerID=8YFLogxK
U2 - 10.1039/C7EE02443F
DO - 10.1039/C7EE02443F
M3 - Article
SN - 1754-5692
VL - 11
SP - 830
EP - 840
JO - Energy & Environmental Science
JF - Energy & Environmental Science
IS - 4
ER -
