A modification engineering to form two kinds of truncated octahedrons by in situ LaBO3 coating for high-performance LiMn2O4 cathode material

Rapid capacity fade of spinel LiMn 2 O 4 cathode material limits the application of lithium-ion batteries. Herein, the introduction of La/B elements achieves the dual-modification of surface coating and single-crystal truncated morphology, ensuring the compatibility of rate capability and cycling stability. The La and B introduction enables the in situ formation of LaBO 3 coating layer. Both the LaBO 3 coating and truncated morphology prevent the direct exposure of the cathode to the electrolyte, decreasing the Mn dissolution and providing the additional Li + diffusion channels. The increase of La and B modification partially restrains the development of {110} crystal planes. The refinement manifests that the La 3+ /B 3+ doping partially replaces Mn 3+ of the LiMn 2 O 4 , inhibiting the Jahn-Teller effect and stabilizing the [MnO 6 ] skeleton. Consequently, the optimized LiMn 2 O 4 @0.04LaBO 3 with the favorable LaBO 3 coating thickness and two truncated octahedrons exhibits the excellent electrochemical properties at high current rate. The first discharge capacities of 109.1, 104.2 and 96.9 mAh⋅g −1 are obtained, whilst the capacity retentions of 64.8 % (after 2000 cycles), 65.8 % (after 2000 cycles) and 80.5 % (after 1000 cycles) can be maintained at 5 C, 10 C and 20 C, respectively. Even at 5 C and 55 °C, the high initial discharge capacity of 113.6 mAh⋅g −1 and good cycling lifespans can be achieved. This modification strategy provides valuable insight for preparing the advanced LiMn 2 O 4 cathode materials for lithium-ion batteries.