High Rate Capability and Excellent Thermal Stability of Li+-Conductive Li2ZrO3-Coated LiNi1/3Co1/3Mn1/3O2 via a Synchronous Lithiation Strategy

A novel synchronous lithiation route has been successfully used to coat Lit-conductive Li2ZrO3 on the surface of LiNi1/3Co1/3Mn1/3O2 (Li2ZrO3@LNCMO). In this strategy, Li2ZrO3 layer and LiNi1/3Co1/3Mn1/3O2 host simultaneously form from ZrO2@Ni1/3Co1/3Mn1/3C2O4 center dot xH(2)O precursor. In compared to bare LNCMO, the reversible capacity, cycling performance, thermal stability, rate capability, and polarization of Li2ZrO3@LNCMO have all been greatly improved. At 0.1 and 10 C, the specific capacity of Li2ZrO3@LNCMO is 192 and 106 mAh g(-1), respectively, while they are 178 and 46 mAh g(-1) for bare LNCMO. At a current density of 55 degrees C, the capacity retention of Li2ZrO3@LNCMO at 25 and 55 C after 400 cycles is enhanced to 93.8% and 85.1%, respectively, compared to 69.2% and 37.4% of bare LNCMO. The largely enhanced electrochemical performances of Li2ZrO3@LNCMO cathode can be attributed to the high Li-ion conductivity as well as the proctection of Li2ZrO3 coating. Li+ conductivity of Li2ZrO3@LNCMO is about 20 times higher than that of bare LNCMO. Moreover, the migration of partial Zr4+ to the host LNCMO phase not only benefits Li-ion or electron conductivity but also alleviates the Li-Ni cation mixing and improves the structure stability. The cations migration, doping effect, and the reduced cation mixing further contribute to the electrochemical performance enhancement.