Interface engineering of LiMn₂O₄ (LMO) is a promising strategy to enhance the lithium storage capability and cycling stability of cathode materials in Li-ion batteries (LIBs). This is because the strategy prevents structural degradation; however, Li storage kinetics remains unsatisfactory, resulting in poor ultrafast cycling performance. Therefore, we fabricated an Nb-doped TiO₂ (NTO) functional layer as a conductive passivation layer on the LMO surface by horizontal ultrasonic spray pyrolysis deposition. The NTO functional layer suppressed the volume expansion of LMO and exhibited high electrical and ionic conductivity, which resulted in improved structural stability of LMO (related to cycling stability) and increased electron/ion transfer rate (related to ultrafast cycling performance). In the TiO₂ structure, Ti⁴⁺ ions were replaced by Nb⁵⁺ ions, which possess high electrical conductivity and a wide c-axis as a Li-ion diffusion route. As a result, the NTO-coated LMO cathode material showed an outstanding specific capacity of 112.7 mAh/g with a remarkable capacity retention of 96.2% after 100 cycles at a current density of 1 C and excellent ultrafast cycling capacity and stability of 70.0 mAh/g after 500 cycles at a current density of 10 C.

LiMn ₂ O ₄（LMO）的界面工程是一种有前途的策略，可以提高锂离子电池（LIB）中正极材料的锂存储能力和循环稳定性。这是因为该策略可防止结构退化；然而，锂的存储动力学仍然不能令人满意，导致差的超快速循环性能。因此，我们制备了Nb掺杂的TiO ₂（NTO）功能层通过水平超声喷涂热解沉积法在LMO表面上作为导电钝化层。NTO功能层抑制了LMO的体积膨胀并显示出高电导率和离子电导率，从而提高了LMO的结构稳定性（与循环稳定性有关）并提高了电子/离子传输速率（与超快速循环性能有关）。在TiO ₂结构中，Ti ⁴⁺离子被Nb ⁵⁺取代离子具有高电导率和宽的c轴作为锂离子扩散途径。结果，涂有NTO的LMO正极材料在11 C的电流密度下经过100次循环后，具有112.7 mAh / g的出色比容量和96.2％的显着容量保持率，以及超快的循环容量和70.0 mAh / g的稳定性。在10 C的电流密度下经过500次循环后的g。