Compton scattering study of strong orbital delocalization in a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LiNiO</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> cathode
Veenavee Nipunika Kothalawala, Kosuke Suzuki, Johannes Nokelainen, Arttu Hyvönen, Ilja Makkonen, B. Barbiellini, Hasnain Hafiz, Pekka Tynjälä, Petteri Laine, Juho Välikangas, Tao Hu, Ulla Lassi, Kodai Takano, Naruki Tsuji, Yosuke Amada, Assa Aravindh Sasikala Devi, M. Alatalo, Y. Sakurai, Hiroshi Sakurai, Arun Bansil
Abstract
Cobalt is used in Li-ion batteries, but it is expensive and could be replaced by nickel to deliver better performance at a lower cost. With this motivation, we discuss how the character of redox orbitals of ${\mathrm{LiNiO}}_{2}$ can be ascertained through x-ray Compton scattering measurements combined with parallel first-principles simulations. Our analysis reveals the nature of hole states in Li-doped NiO resulting from the hybridization of $\text{O}\phantom{\rule{4.pt}{0ex}}2p$ and $\text{Ni}\phantom{\rule{4.pt}{0ex}}3d$ orbitals. Our study also gives insight into the ferromagnetic ground state and provides a pathway toward the rational design of next-generation battery materials.