Local Electric‐Field‐Driven Fast Li Diffusion Kinetics at the Piezoelectric LiTaO₃ Modified Li‐Rich Cathode–Electrolyte Interphase

Abstract

As one of the most promising cathodes for next-generation lithium ion batteries (LIBs), Li-rich materials have been extensively investigated for their high energy densities. However, the practical application of Li-rich cathodes is extremely retarded by the sluggish electrode-electrolyte interface kinetics and structure instability. In this context, piezoelectric LiTaO₃ is employed to functionalize the surface of Li_1.2Ni_0.17Mn_0.56Co_0.07O₂ (LNMCO), aiming to boost the interfacial Li⁺ transport process in LIBs. The results demonstrate that the 2 wt% LiTaO₃-LNMCO electrode exhibits a stable capacity of 209.2 mAh g^-1 at 0.1 C after 200 cycles and 172.4 mAh g^-1 at 3 C. Further investigation reveals that such superior electrochemical performances of the LiTaO₃ modified electrode results from the additional driving force from the piezoelectric LiTaO₃ layer in promoting Li⁺ diffusion at the interface, as well as the stabilized bulk structure of LNMCO. The supplemented LiTaO₃ layer on the LNMCO surface herein, sheds new light on the development of better Li-rich cathodes toward high energy density applications.