Self-template formation of porous yolk-shell structure Mo-doped NiCo2O4 toward enhanced lithium storage performance as anode material

Hollow ternary metal oxides have shown enormous potential in lithium-ion batteries (LIBs), which is ascribed to their complex chemical composition, abundant active defect sites, and the synergy effect between metals. In this work, we synthesized Mo-doped NiCo2O4 porous spheres with yolk-shell structure by using a simple self-templating method. Surprisingly, other than the yolk-shell structure we had obtained, the inner core of the yolk-shell was also porous, which could fully enhance the electrolyte infiltration and promote the transmission of lithium ions (Li+) and electrons (e(-)). The diameter of the porous core in the yolk-shell sphere was about 530 nm, and the outer shell's thickness was up to 110 nm. In addition, the unique pores in the core appeared in the diameter of about 85 nm. With this structure, the volume expansion of the anode could be well inhibited during charge/discharge. It exhibited prominent electrochemical performance with high reversible capacity (1338 mA h g(-1) at 100 mA g (-1)), satisfactory cycle life (1360 mA h g(-1) after 200 cycles at 100 mA g(-1)), and exceptional rate capability (820 mA h g(-1) at 2000 mA g(-1)) as anode material in LIBs. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Hollow ternary metal oxides, such as Mo-doped NiCo2O4 porous spheres with yolk-shell structure, show promising potential in LIBs due to their intricate composition and ample active defect sites. The porous core with unique pores of about 85 nm in diameter contributes to enhanced electrolyte infiltration and efficient transmission of Li+ and e(-), resulting in outstanding electrochemical performance with high reversible capacity, satisfactory cycle life, and exceptional rate capability.