A novel two‐step surface modification method that includes atomic layer deposition (ALD) of TiO₂ followed by post‐annealing treatment on spinel LiNi_0.5Mn_1.5O₄ (LNMO) cathode material is developed to optimize the performance. The performance improvement can be attributed to the formation of a TiMn₂O₄ (TMO)‐like spinel phase resulting from the reaction of TiO₂ with the surface LNMO. The Ti incorporation into the tetrahedral sites helps to combat the impedance growth that stems from continuous irreversible structural transition. The TMO‐like spinel phase also alleviates the electrolyte decomposition during electrochemical cycling. 25 ALD cycles of TiO₂ growth are found to be the optimized parameter toward capacity, Coulombic efficiency, stability, and rate capability enhancement. A detailed understanding of this surface modification mechanism has been demonstrated. This work provides a new insight into the atomic‐scale surface structural modification using ALD and post‐treatment, which is of great importance for the future design of cathode materials.

中文翻译：

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多位点钛作为高性能阴极对尖晶石锂镍锰锰氧化物表面的纳米处理

为了优化性能，开发了一种新颖的两步表面改性方法，该方法包括TiO _2的原子层沉积（ALD），然后在尖晶石LiNi _0.5 Mn _1.5 O ₄（LNMO）阴极材料上进行后退火处理。性能的提高归因于TiO ₂与表面LNMO的反应形成了类似TiMn ₂ O ₄（TMO）的尖晶石相。Ti掺入四面体位点有助于抵抗由于连续不可逆结构转变而引起的阻抗增长。类似于TMO的尖晶石相还可以减轻电化学循环过程中的电解质分解。TiO的25个ALD循环发现_2个增长是朝向容量，库仑效率，稳定性和速率能力增强的优化参数。已经证明了对该表面改性机理的详细理解。这项工作为使用ALD和后处理的原子级表面结构改性提供了新的见解，这对于阴极材料的未来设计非常重要。