Improving electrochemical performance of LiNi0.5Mn1.5O4 positive electrodes via regulated cathode electrolyte interphase

LiNi 0.5 Mn 1.5 O 4 has been thoroughly investigated as one of the most promising high-voltage positive materials for Li-ion batteries, owing to its low cost, high energy density and good stability. Nonetheless, the limited reversible capacity and poor cycle efficiency limit its use to the high-end digital domain. Herein, the SmF 3 cathode electrolyte interphase modified strategy has been first explored for LiNi 0.5 Mn 1.5 O 4 , which demonstrated outstanding electrochemical performance. The surface regulated sample demonstrates a preferred initial discharge-specific capacity of 137.85 mAh  g −1 at a 1 C rate and sustains a discharge capacity of 110.21 mAh  g −1 after 200 cycles. More importantly, SmF 3 can successfully reduce the occurrence of adverse reactions while producing a thin and homogenous CEI layer. The basic understanding of cathode electrolyte interphase alteration on surface morphology, crystal structure, and chemical components of the modified samples are revealed through means of various testing methods. The surface modification with SmF 3 can effectively mitigate the formation of generated by-products and enhance the transport of Li + . This technique of modifying the cathode electrolyte interphase with SmF 3 serves as a starting point for further research into the performance degradation process and opens up a new avenue for improving the electrochemical performance of the spinel positive materials.