Stabilizing surface chemistry and texture of single-crystal Ni-rich cathodes for Li-ion batteries

Abstract

The single-crystalline Ni-rich cathodes are believed to help improve the safety of Li-ion batteries (LIBs), however, the ion-diffusion limits their high-rate performance owing to large single-crystal particles. Herein, a dual-modification strategy of surface Li 2 TiO 3 -coating and bulk Ti-doping has been performed to achieve high-rate single crystal LiNi 0.83 Co 0.12 Mn 0.05 O 2 (NCM) cathode. The Li-ion conductive Li 2 TiO 3 coating layer facilitates the Li-ion transfer and prevents the electrolyte erosion. Meanwhile, the robust Ti-O bonds stabilize the cubic close-packed oxygen framework and mitigate the Li/Ni disorder. The synergy endows the dual-modified NCM with enhanced de-/lithiation reaction kinetics and stable surface chemistry. A high specific capacity of 128 mAh g -1 is delivered even at 10 C with an extended cycle life. This finding is reckoned to pave the way for developing high energy density LIBs for long-range electric vehicles.