Inhibiting Mn-ions dissolution and enhancing Li+ migration mechanism of spinel LiMn2O4 via dual-functional LaNiO3 perovskite coating

Spinel lithium manganate (LiMn 2 O 4 ) is a promising cathode material for lithium-ion batteries (LIBs) due to its non-toxicity, cost-effectiveness, and recyclability. However, its development is hindered by rapid capacity degradation and structural collapse caused by Jahn-Teller distortion and Mn-ions dissolution. In this work, a dual-functional LaNiO 3 coating on LiMn 2 O 4 particles was introduced to prevent direct contact with the F-containing electrolyte, meanwhile, apply compressive stress on the surface of LiMn 2 O 4 , suppressing surface MnO 6 octahedra distortion and preserving cubic symmetry during deep charge-discharge cycles. The strong La–O bonds can strengthen interface Mn–O bonds and increase the activation energy for Mn-ions disproportionation and acid erosion, thus reducing Mn-ions dissolution. Additionally, LaNiO 3 can serve as a conductive synapse to improve conductivity of LiMn 2 O 4 and optimize the Li + migration pathway at the electrode-electrolyte interface, reducing the migration potential barrier of Li + . Electrochemical tests show that the 1 wt% LaNiO 3 -coated LiMn 2 O 4 cathode achieves an initial discharge capacity of 130.37 mAh/g with a capacity retention of 92.27% after 600 cycles. This performance is significantly superior to that of the unmodified LiMn 2 O 4 , which only exhibits an initial capacity of 115.63 mAh/g and a retention of 79.55%. This work offers an effective strategy to enhance LiMn 2 O 4 stability and capacity and provides a theoretical basis for using perovskite materials in surface modification.