Spinel LiMn2O4 with Remarkable Electrochemical Performances by Synergistic Enhancement of Double-Cation (Sm3+, Mo6+) Doping for Li-Ion Batteries

Lithium ion spinel lithium manganate (LiMn 2 O 4 ) is a promising positive material due to its typical three-dimensional network as well as abundant manganese sources. However, the electrodes suffer from severe capacity degradation on account of the Jahn–Teller effect and spontaneous disproportionation reactions. In this work, we have fabricated Sm 3+ , Mo 6+ dual-doped LiMn 2 O 4 -positive materials using a facile solid phase strategy. Electrochemical test results show that the discharge capacity and capacity retention of the LMO-Sm&Mo material reaches 101.30 mAh g −1 and 88.08% after 200 cycles (85.69 mAh g −1 and 76.32% for LMO) at 1 C, which results from the synergistic enhancement of the double-cation (Sm 3+ , Mo 6+ ) doping strategy. Even at 10 C, LMO-Sm&Mo still exhibits a promising specific discharge capacity of 98.71 mAh g −1 . Moreover, ICP analysis indicates that the manganese dissolution of LMO-Sm&Mo in organic electrolyte is much lower than that of the undoped sample (LMO). Overall, the results indicate that the Sm 3+ , Mo 6+ co-doping is an effective strategy for enhancing the structural stability and electrochemical properties of spinel Mn-based positive electrodes.