The Li-rich manganese-based oxides (LRMO) with high operating voltage and large reversible capacities can demonstrate comprehensive advantages of intrinsic safety and high energy density when employed in all-solid-state lithium batteries (ASSLBs). However, severe interfacial incompatibility with solid electrolytes (SEs) arising from unstable lattice oxygen and sluggish Li+ ionic transport hinders their practical application. In this contribution, the gradient-modified structure containing S, Zr co-doping near-surface and amorphous Zr(SO4)2 coating is simultaneously established onto LRMO cathode by a one-step mechano-fusion process. The synergistic co-functionalization stabilizes the oxygen framework, enhances charge transport, and suppresses oxygen dimerization under high potential. Besides, the amorphous Zr(SO4)2 coating evenly adhering onto LRMO bulk ensures long-term intimate contact with SEs to guarantee electrochemical activities and restrains interfacial parasitic reactions. Consequently, the optimized A-LRMO cathode exhibits a high discharge capacity of 292 mAh/g at 0.1 C and 81.8% capacity retention after 2000 cycles at 1 C. Pouch cells delivered an areal capacity of 8.5 mAh/cm2 with >99.6% Coulombic efficiency. This gradient-modification strategy offers an effective pathway to improve interfacial stability and accelerate the practical application of LRMO-based ASSLBs.
Chen et al. (Wed,) studied this question.