Synergy effects of Tb/Y/Zn for structural stability of high-voltage LiCoO2 cathode material

As a popular cathode material in rechargeable lithium-ion batteries, lithium cobalt oxide (LiCoO 2 ) is required to achieve high-level safety with high energy density to meet the ever-increasing energy demand for energy storage devices. The method of lifting the operating voltage of LiCoO 2 to release more capacity for higher energy density usually causes severe structural instability at the deeply delithiated state, resulting in capacity fade and limited lifespan. Herein, we present a series of zinc, yttrium and terbium modified LiCoO 2 through solid-state reaction to tackle this long-term issue of structure destruction cycling at high voltages. Compared with the mediocre electrochemical performance of LiCoO 2 doped with single elements of Zn, Y and Tb, respectively, the dual-doped LiCoO 2 exhibits better structural stability and capacity retention at high voltages. Furthermore, the prepared Zn–Y–Tb ternary-doped LiCoO 2 exhibits excellent electrochemical capability with a discharge capacity of 185mAh/g after 100 cycles and capacity retention of 98% at 4.55 V. These multiple dopants synergistically maintain structural integrity after 300 cycles and effectively promote the cycle stability of lithium cobalt oxide cathode material at high voltages. • Zn, Y, and Tb are incorporated into LCO by facile solid phase reaction. • Multiple dopants suppress irreversible phase transition and structural collapse. • Tb element doping plays a dominating role in enhancing cycling stability. • Improving capacity retention of LCO from 66% to 98% after 100 cycles at 4.55V.