Synergistic effect of cation ordered structure and grain boundary engineering on long-term cycling of Li0.35La0.55TiO3-based solid batteries

Abstract

In this study, Li0.35La0.55TiO3 (LLTO) was coupled with Al-doped lithium lanthanum zirconate (LLZO) to improve the grain boundary and total conductivity. The obtained ceramic pellets (LLTZO) demonstrated a recordable grain boundary and total conductivity of 3.41 × 10−4 and 3.03 × 10−4 S/cm, respectively. The obtained results establish that the heteroatoms can perturb the cation ordered structure and improve the 3D conductivity in grain bulk. In addition, the residual Al-doped LLZO on the grain boundary led to a decline in the boundary resistance. An LiFeCoPO4 |Li cell was adopted to demonstrate the enhanced conductivity of LLTO. The solid state battery rendered a specific capacity of over 101.2 mAhg−1 after 300 cycles at a relatively high rate of 0.5C. It is established from the experiments that manufacturing a solid battery using the all-coating technique provides a promising approach to achieve a practical application.