In this work, 4-(Trifluoromethyl)-benzonitrile (4-TB) is used as a novel electrolyte additive for LiNi_0.5Mn_1.5O₄ cathode of high voltage lithium ion battery. Charge–discharge tests show that the cyclic stability of LiNi_0.5Mn_1.5O₄ is significantly improved by using 0.5 wt.% 4-TB. With using 4-TB, LiNi_0.5Mn_1.5O₄ delivers an initial capacity of 133 mAh g⁻¹ and maintains 121 mAh g⁻¹ after 300 cycles with a capacity retention of 91%, compared to the 75% of that using base electrolyte (1 M LiPF₆ in ethylene carbonate(EC)/dimethyl carbonate(DMC)). The results from linear sweep voltammetry, density functional theory calculations, electrochemical impedance spectroscopy, scanning electron microscope, energy dispersive spectroscopy, Fourier transform infrared, and inductively coupled plasma, indicate that 4-TB has lower oxidative stability than EC and DMC, and is preferentially oxidized on LiNi_0.5Mn_1.5O₄ forming a low-impedance protective film, which prevents the subsequent oxidation decomposition of the electrolyte and suppresses the manganese dissolution from LiNi_0.5Mn_1.5O₄.

在这项工作中，将4-（三氟甲基）-苄腈（4-TB）用作高压锂离子电池LiNi _0.5 Mn _1.5 O ₄阴极的新型电解质添加剂。充放电测试表明，使用0.5 wt。％的4-TB可以显着改善LiNi _0.5 Mn _1.5 O ₄的循环稳定性。使用4-TB时，LiNi _0.5 Mn _1.5 O ₄的初始容量为133 mAh g ^-1，在300次循环后保持121 mAh g ^-1，容量保持率为91％，而使用基础电解质的为75％ （1 M LiPF ₆在碳酸亚乙酯（EC）/碳酸二甲酯（DMC）中）。线性扫描伏安法，密度泛函理论计算，电化学阻抗谱，扫描电子显微镜，能量色散谱，傅里叶变换红外光谱和电感耦合等离子体的结果表明，4-TB的氧化稳定性低于EC和DMC，并且优先考虑在LiNi _0.5 Mn _1.5 O ₄上氧化形成低阻抗保护膜，从而防止电解质随后的氧化分解，并抑制锰从LiNi _0.5 Mn _1.5 O ₄溶解。