鋰和鎳的半徑相近，才會產(chǎn)生大量混排，使得鎳在interslab中起到支撐作用，才能實現(xiàn)高容量。然而這本身就是一種缺陷結(jié)構(gòu)，高電壓下鋰離子脫出較多，就會形成NiO巖鹽或尖晶石結(jié)構(gòu)。過渡金屬溶解不太了解，文獻(xiàn)中看到說錳在低價態(tài)時能溶解，高價鎳應(yīng)該是氧化性很強(qiáng)吧。

高電壓下，一般電解液不匹配，造成材料與電解液副反應(yīng)增多，材料結(jié)構(gòu)變化

高鎳的氧化性較高，材料與電解液形成的固液界面發(fā)生反應(yīng)。

這個主題很好，坐聽高手回答

氧和鎳的能級重疊，與電解液反應(yīng)失去氧形成巖鹽相NiO，導(dǎo)致性能衰減。

Highly reactive Ni4+ will be predominant at the end of charge leading to undesired side reactions with the electrolyte solution. This will eventually lead to a consumption of active material, gas evolution and capacity fading. Furthermore, the high temperature stability of the material will decrease with higher nickel contents leading to serious safety concerns
Just like in pure LNO high nickel contents in NCM will lead to a Li/Ni cation mixing. This will lead to a spinel formation on the surface and eventually to the formation of the inactive Fm(-)3m phase and capacity fade.
Starting with NCM811 a prolonged cycling will lead to cracks in the secondary particles along the grain boundaries. This leads to a continuous increase in surface area and hence more active sites for parasitic reactions.
我只是文獻(xiàn)的搬運工，

It is well known that Li[NixCoyMnz]O2, especially with x > 0.6,readily reacts with air, resulting in the formation of Li2CO3 and LiOH on the cathode surface [18,19]. The formed LiOH reacts with LiPF6
and generates acidic HF in the electrolyte. In addition, Li2CO3 gives rise to severe swelling upon storage at high temperatures, especially in the charged state [20]. Table 2 exhibits the total residual
lithium amounts (LiOH and Li2CO3) on the cathode surfaces. The total residual lithium amount increased with increasing Ni content in Li[NixCoyMnz]O2 and increased drastically at Ni contents (x)
above 0.7.