Lithium diffusion study in Li 2 MnO 3 and Li 1.17 Ni 0.17 Mn 0.67 O 2 : a combined experimental and computational approach

• Published in: Physical chemistry chemical physics : PCCP Vol. 19; no. 47; pp. 31724 - 31730
• Main Authors: Sarkar, Tanmay, Prakasha, Kunkanadu R, Bharadwaj, Mridula Dixit, Prakash, Annigere S
• Format: Journal Article
• Language: English
• Published: England 06.12.2017
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/C7CP06458F

A theoretical and experimental diffusivity study of Li MnO and Li Ni Mn O has been carried out to investigate the effect of Mn, Ni and surrounding atoms on Li diffusion and to understand how the Li diffusion trajectory changes with different charge spheres. It is observed that due to the presence of Ni in Li Ni Mn O , the activation energy reduces in all the possible diffusion paths, which helps in faster Li diffusion. This study brings a new physical insight into Li diffusion based on elliptical and straight diffusion trajectories. In Li Ni Mn O , the Li diffusion mechanism in different paths based on 2b, 2c and 4h Wyckoff sites of Li has been discussed. Experimentally, the galvanostatic intermittent titration technique is adopted to identify the diffusion coefficient of Li . The diffusion coefficient of both the compounds varies in different voltage ranges. For L MnO , diffusion varies from 10 to 10 cm s , whereas for Li Ni Mn O , diffusion varies from 10 to 10 cm s in the voltage range of 3.7-4.7 V.