| Abstract Scope |
Nanoscale cathode materials for high rate applications in lithium ion batteries are particularly unstable due to the high concentration of surfaces and interfaces. This work studied the interfaces of lithium cobalt oxide to fundamentally understand the stability of nanomaterials for cathode applications. The impact of dopant segregation on stability was explored through computational and experimental techniques. The segregation energies of dopants (La, Gd, Y, Sc, Sn, Zr, Ti, Mg, Ca, Sr) to surfaces and grain boundaries was studied using molecular dynamics with a Coulomb-Buckingham potential. The segregation energy of the dopants to a Sigma 3 and Sigma 5 grain boundary and a {001} and a {104} surface were compared to illustrate a trend of increasing segregation energy with ionic radii and ionic charge. Experimentally, doped samples of LiCoO2 were synthesized to confirm the impact of dopants on the interfacial energies and stability of the nanoparticles. |