Enabling High-Performance Li-Rich Single-Crystalline Cathode via Mo-Doping

Abstract

Although Li-rich layered oxides (LLOs) can achieve high capacity (>300 mAh g^–1) and thereby enhance energy density of Li-ion battery cathodes, they encounter persistent challenges, including low initial Coulombic efficiency (ICE), poor cycling performance, and bad rate capability. In the present study, the layered–spinel heterostructure is constructed on the surface of single-crystalline LLO materials by Mo doping with a facile sol–gel method. The Li-rich layered–spinel heterostructure can provide 3D Li-ion channels and restrain the growth of the SEI film and oxygen release. Additionally, the larger ionic radius of Mo⁶⁺ also can contribute to enhancing the discharge specific capacity and improving Li⁺ diffusion kinetics. Benefiting from these collaborative contributions of solid oxygen framework and unique layered–spinel heterostructure, the as-prepared material shows good electrochemical properties, including a high ICE of 93.44%, an outstanding initial discharge specific capacity of 302.01 mAh g^–1, an excellent capacity retention of 92.55% after 100 cycles under 1 C, and a remarkable rate capability.