Journal
CHEMICAL ENGINEERING JOURNAL
Volume 451, Issue -, Pages -Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.cej.2022.138678
Keywords
Zn/Ti dual concentration-gradients; Stability; Kinetics; Cation doping; Li-rich layered oxides; Lithium-ion batteries
Categories
Ask authors/readers for more resources
We report a novel Zn/Ti dual concentration-gradients surface modification strategy for Li-rich layered oxides (LLOs) cathode materials. The strategy induces the formation of functionalized surfaces and stabilizes the structure, improving cycling performance and redox kinetics. The synergistic effect of double ion co-doping stabilizes the surface structure, improves the redox kinetics, and mitigates the degradation of electrochemical performance. Capacity retention increased by 24.1% compared to pristine LLOs after 150 cycles at 0.5 C.
Li-rich layered oxides (LLOs) with high specific capacity and low cost are potential cathode materials for next -generation lithium-ion batteries (LIBs). However, surface side reactions and structural instability at high operating voltages lead to poor cycling performance and sluggish kinetics. Herein, we report a novel Zn/Ti dual concentration-gradients surface modification strategy for LLOs, in which the Ti content gradually increases from the interface to the particle interior while the Zn content gradually decreases and finally remains at a relatively stable level. This strategy successfully induces the formation of functionalized surfaces and the Ti doping is more favorable to stabilize Mn4+, while the subsequent Zn doping is more benign to Ni3+. In addition, the strong Ti-O bond serves to stabilize the oxygen framework, while the blocking effect of Zn2+ in the Li layer inhibits the migration path of transition metal (TM) elements. In conclusion, the synergistic effect of double ion co-doping stabilizes the surface structure, improves the redox kinetics, and mitigates the degradation of electrochemical performance, with 24.1% increase in capacity retention compared to the pristine LLOs after 150 cycles at 0.5 C. This study provides an effective strategy for the design of robust LLOs cathode materials for LIBs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available