Small amounts of fluorine substituting for oxygen deficiencies could reduce Mn dissolution, enhancing the cyclability in spinel-type lithium nickel manganese oxides (LiNi_0.5Mn_1.5O₄). Fluorine anion incorporation simultaneously enhances the C-rate capability and specific capacity fading. We used experimental and theoretical approaches to obtain a full picture of the mixed-anion effects for LiNi_0.5Mn_1.5O_4−xF_x cathode materials. The fluorine anion reduced the activation barrier for lithium-ion hopping along the most energetically preferable 8a-16c-8a route, enhancing the C-rate capability. Simultaneously, the coordination bond of the linear F⁻–Mn³⁺–F⁻ (Mn@2F diagonal) arrangement increased the oxidation potential to 5.1 V (vs Li⁺/Li). This hampered full extraction of Li⁺ from the spinel lattice, which was triggered by the oxidation of Mn³⁺ below the cutoff voltage (3.5–4.8 V (vs Li⁺/Li)), leading to a capacity loss.

少量的氟替代氧不足会减少Mn的溶解，从而增强尖晶石型锂镍锰氧化物（LiNi _0.5 Mn _1.5 O ₄）的循环能力。氟阴离子的掺入同时增强了C速率能力和比容量衰减。我们使用实验和理论方法来获得LiNi _0.5 Mn _1.5 O _{4− x} F _x阴极材料的混合阴离子效应的全貌。氟阴离子降低锂离子沿着最大力，优选8跳频激活屏障一个-16 Ç -8一个路线，提高了C费率功能。同时，线性F的配位键^- -Mn ³⁺ -F ^- （锰@ 2F对角线）布置增加的氧化电势为5.1 V（相对于Li ⁺ / Li）的。这阻碍了尖晶石晶格中Li ^+的完全提取，这是由低于截止电压（3.5–4.8 V（vs Li ⁺ / Li））的Mn ³⁺的氧化触发的，从而导致容量损失。