Synthesis, structure and electrochemical properties of Al doped high entropy perovskite Lix(LiLaCaSrBa)Ti1-xAlxO3

In this work, the Al doped high entropy perovskite Li0.2La0.2Ca0.2Sr0.2Ba0.2TiO3 ceramic is synthesized by using a solid state reaction method, and the effect of different doping amount on the crystal structures and conductivity are also studied. The result proves that doping leads to a positive influence on the conductivity of ceramic. The material of Li0.1(LiLaCaSrBa)Ti0.9Al0.1O3 (LLCSBTA-0.1) exhibits a high total conductivity with approximately 3.92 × 10-7 S cm-1 at 30 °C and an activation energy of 0.39 eV. The beneficial result can be ascribed to the increase of Li + concentration. The Li0.2La0.2Ca0.2Sr0.2Ba0.2TiO3 presents a pure cubic perovskite structure, but with partial tetragonal structure due to the addition of Al2O3. However, these high entropy perovskite ceramics showed porous structures which are unfavourable for lithium ion conduction. The electrochemical property of the Li0.1(LiLaCaSrBa)Ti0.9Al0.1O3 as electrode is investigated as well. The results show that the Li0.1(LiLaCaSrBa)Ti0.9Al0.1O3 electrode exhibits good cyclability and stability for the insert-extraction of lithium ions with the specific capacity of 58.6 mA h g−1.