Interfacial-engineering-enabled high-performance Li-rich cathodes

Li-rich layered oxides (LLOs) with high energy density and low cost are regarded as the most promising cathode materials for the next generation Li-ion batteries (LIBs). However, the rapid capacity decline and voltage fading impede their practical application. Herein, an OVs(oxygen vacancies)-spinel functional layer with rich-OVs and surface spinel phase is constructed on the surface of Li1.2Mn0.56Ni0.16Co0.08O2 (LLMO) through Y2O3 and ZrO2 co-modification. The interface OVs effectively stabilize lattice oxygen evolution and suppress structural distortion by storing O2 or O(2-n)- released from LLMO within these OVs, while the formation of spinel phase in the subsurface motivates rapid Li+ transfer. The comprehensive effect of this OVs-spinel layer synergistically inhibits irreversible oxygen release, mitigates electrolyte decomposition, and accelerates Li+ ions diffusion kinetics. The corresponding cathode with Y2O3 and ZrO2 co-modification (Y&Zr-LLMO) exhibits an average attenuation voltage of 2.5 mV per cycle (vs. 3.3 mV), and a capacity retention rate of 95.4 % after 100 cycles at 1C (vs. 86.5 %). Remarkably, the pouch cell (Y&Zr-LLMO/graphite) also demonstrates excellent cycling stability, retaining 71.4 % capacity after 600 cycles at 0.5C. This finding pioneers multifunctional interface layer designs for high energy density LIBs.