High voltage LiNi_0.5Mn_1.5O₄ cathodes are of prime importance for the development of next generation lithium-ion batteries (LIBs) with high energy density. LiNi_0.5Mn_1.5O₄, however, always was attacked by the generated HF from the electrolyte decomposition during cycling, leading to instable surface structure and poor Li⁺ diffusion kinetic property. In this regard, YF₃ with good thermal stability and excellent structural stability in the HF containing electrolyte, is chosen as coating layer to modify the surface of LiNi_0.5Mn_1.5O₄. Ex-situ electrochemical impedance spectroscopy study and inductively coupled plasma analysis indicate that YF₃ coating layer on the surface of LiNi_0.5Mn_1.5O₄ could act as protect medium to effectively suppress side reactions between the LiNi_0.5Mn_1.5O₄ surface and electrolyte, and thus enhance its structural stability and kinetics properties during repeated electrochemical reactions. As a result, LiNi_0.5Mn_1.5O₄ after YF₃ modification shows the improved capacity retention of 84% after 100 cycles at 0.1C, and 78 mAh g⁻¹ could be obtained at 2C, much higher than those of the pristine LiNi_0.5Mn_1.5O₄ cathode (78%, 24 mAh g⁻¹). Furthermore, differential scanning calorimetry result confirms the enhanced thermal stability of LiNi_0.5Mn_1.5O₄ after YF₃ coating. These findings open up chance to prepare high performance LiNi_0.5Mn_1.5O₄ cathode and promote development of LIBs with high energy density.

高压LiNi _0.5 Mn _1.5 O ₄阴极对于开发高能量密度的下一代锂离子电池（LIB）至关重要。然而，LiNi _0.5 Mn _1.5 O ₄总是受到循环过程中电解质分解产生的HF的侵蚀，导致表面结构不稳定和不良的Li ⁺扩散动力学性能。在这方面，选择在含HF的电解质中具有良好的热稳定性和优异的结构稳定性的YF ₃作为涂层以改性LiNi _0.5 Mn _1.5 O ₄的表面。。异位电化学阻抗谱研究和电感耦合等离子体分析表明，LiNi _0.5 Mn _1.5 O ₄表面的YF ₃涂层可作为保护介质，有效抑制LiNi _0.5 Mn _1.5 O ₄表面与电解质之间的副反应，因此在重复的电化学反应过程中增强了其结构稳定性和动力学性质。结果，YF ₃改性后的LiNi _0.5 Mn _1.5 O ₄表现出在0.1C 100次循环后的容量保持率提高了84％，以及78 mAh g ^-1可以在2C下获得，远高于原始的LiNi _0.5 Mn _1.5 O ₄阴极（78％，24 mAh g ^-1）。此外，差示扫描量热法结果证实了YF ₃涂覆之后LiNi _0.5 Mn _1.5 O ₄的增强的热稳定性。这些发现为制备高性能LiNi _0.5 Mn _1.5 O ₄阴极和促进具有高能量密度的LIB的发展提供了机会。