The 5 V lithium-insertion material of Li[Ni_1/2Mn_3/2]O₄ (LiNiMO) is a promising positive electrode material for lithium-ion batteries. Therefore, several approaches toward improving the cyclability of LiNiMO have been undertaken. To understand the origin of the capacity fading of LiNiMO during cycling, we examined long-term cycle tests of LiNiMO with different particle sizes under varying temperatures. We observed that the cyclability of LiNiMO is strongly dependent on its particle size; LiNiMO with a large particle size exhibits high capacity retention and slow polarization increasing rate. Cycle tests of LiNiMO electrodes at various temperatures indicated that the capacity fading is faster at higher temperatures. The polarization increasing rate of the LiNiMO electrodes follows the Arrhenius equation. From the cycle tests, a correlation between the capacity fading of the LiNiMO electrodes and their polarization increasing rate was observed, that is, the larger the polarization increasing rate, the faster is the capacity fading. This indicates that the capacity fading of the LiNiMO electrode is caused by an increase in the polarization of the LiNiMO-positive electrode during cycling.

Li[Ni _1/2 Mn _3/2 ]O ₄ 5 V嵌锂材料（LiNiMO）是一种很有前途的锂离子电池正极材料。因此，已经采取了多种方法来提高 LiNiMO 的可循环性。为了了解循环过程中 LiNiMO 容量衰减的原因，我们检查了在不同温度下具有不同粒径的 LiNiMO 的长期循环测试。我们观察到 LiNiMO 的循环性强烈依赖于其粒径；大粒径的 LiNiMO 表现出高容量保持率和缓慢的极化增长率。LiNiMO 电极在不同温度下的循环测试表明，在较高温度下容量衰减更快。LiNiMO 电极的极化增长率遵循 Arrhenius 方程。从循环测试来看，观察到LiNiMO电极的容量衰减与其极化增长率之间存在相关性，即极化增长率越大，容量衰减越快。这表明 LiNiMO 电极的容量衰减是由循环过程中 LiNiMO 正极极化的增加引起的。