Time: 03:30 p.m.
Place: ICAMS, Ruhr-Universität Bochum, Germany IC 02/718
Mansour Kanani, Shiraz University, Shiraz, Iran
Among different emerging cathode materials for high performance Li-ion batteries, LiNiO2 based systems have shown very promising result, especially when they are doped with Co and Al. The so-called NCA material system, LiNi0.75Co0.167Al0.083O2, has shown acceptable charge-discharge capacity as cathode material. However, its structural/thermal stability needs additional improvements. Recently, some of chemical composition engineering investigations showed significant improving impact on both efficiency and thermal stability. We have designed a systematic approach using quantum mechanics-based computation to predict efficient doping scenarios and get an insight to their underlying mechanisms. For this structure, a systematic DFT study is designed to dope the base LiNiO2 structure with Co and Al to reach LiNi0.75Co0.167Al0.083O2 chemical composition. Then, doping scenarios with Na and Y atoms were applied and structural as well as electronic properties were analysed. The results showed that the structure with both dopants has significant improvement. The results showed that simultaneous doping of NCA with Y and Na can increase the performance by two different, but constructive mechanisms. Accordingly, we proposed clear experimental procedures to resolve specific challenges on thermal stability issue and get an improved charge-discharge capacity at the same time. The predicted scenarios were verified by corresponding experiments with very good agreement.