Spinel LiMn₂O₄ has become one of the most attractive cathode materials for electric vehicles due to its low cost, non-toxicity, and good electrochemical performance of high C-rates. While the rapid decay of capacity at high temperature limits its further development. In this article, it is demonstrated that Gd modification can achieve the dual-modification of bulk structure and surface to effectively improve the electrochemical performance of LiMn₂O₄ at high temperature. It is found that Gd modification can decrease the lattice parameters and strengthens the stability of Mn–O bonds, which can efficiently improve the capacity stability by inhibiting the dissolution of Mn³⁺ from the electrode to the electrolyte. Besides, the Gd modification also enables the formation of the Gd₂O₃ coating layer on the material surface, which can significantly reduce the interfacial impedance and lower the diffusion activation energy of lithium-ion. Therefore, Gd-modified samples show a better rate capability and longer cycle life, especially at high temperature. Among them, the sample with Gd of 6000 ppm exhibited the most excellent capacity retention ratio of 82.6% after 300 cycles at 55 °C, 1C (1C = 148 mA·g^-1) in the voltage range of 3.0–4.3 V, with an initial discharge capacity of 124.9 mAh·g⁻¹.

尖晶石LiMn ₂ O ₄ 因其低成本、无毒、高C率的良好电化学性能而成为最具吸引力的电动汽车正极材料之一。而高温下容量的快速衰减限制了它的进一步发展。本文论证了Gd改性可以实现体结构和表面的双重改性，有效提高LiMn ₂ O ₄的高温电化学性能。发现Gd修饰可以降低晶格参数，增强Mn-O键的稳定性，通过抑制Mn ^{3+的溶解可以有效提高容量稳定性。}从电极到电解液。此外，Gd改性还可以在材料表面形成Gd ₂ O ₃涂层，可以显着降低界面阻抗，降低锂离子的扩散活化能。因此，Gd 改性样品表现出更好的倍率性能和更长的循环寿命，尤其是在高温下。其中，Gd 为 6000 ppm 的样品在3.0-4.3 V 电压范围内，在 55 ℃、1C（1C = 148 mA·g ^-1 ）循环 300 次后表现出最优异的容量保持率，达到 82.6%。初始放电容量为124.9 mAh·g ^-1。