The dissolution, migration and deposition (DMD process) of transition metal ions during cycling is a well-known phenomenon reported in literature especially concerning high manganese spinel cathode material. The main approach to solve this issue consists in coating or doping the particles surface with electrochemically inert cations and/or anions. In this study, we describe a DMD process mechanism which happens in the silicon-graphite/lithium rich layered oxide (Si-Gr/Li_1.2Ni_0.2Mn_0.6O₂) systems. This phenomenon leads to a sudden death effect of the cell after 25 cycles. AlF₃ coating is envisaged to limit the cation dissolution from the positive electrode: we highlight that our synthesis finally results in improving the electrochemical performances of lithium rich layered oxides by offering an Al/F doped surface. Despite this improvement, the coating fails, on the other hand, to stop the transition metal cations dissolution, especially in Li-ion cells (Si-Gr as anode).

循环过程中过渡金属离子的溶解、迁移和沉积（DMD 过程）是文献中报道的众所周知的现象，尤其是关于高锰尖晶石正极材料。解决这个问题的主要方法在于用电化学惰性的阳离子和/或阴离子涂覆或掺杂颗粒表面。在这项研究中，我们描述了发生在硅石墨/富锂层状氧化物 (Si-Gr/Li _1.2 Ni _0.2 Mn _0.6 O ₂ ) 系统中的 DMD 工艺机制。这种现象导致细胞在 25 个循环后出现猝死效应。铝₃涂层旨在限制正极的阳离子溶解：我们强调，我们的合成最终通过提供 Al/F 掺杂表面改善了富锂层状氧化物的电化学性能。尽管有这种改进，但另一方面，涂层无法阻止过渡金属阳离子溶解，尤其是在锂离子电池（Si-Gr 作为阳极）中。