Enable High-Energy LiNi<sub>0.5</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>O<sub>2</sub> by Ultra-Thin Coating through Wet Impregnation
oleh: Xin Su, Xiaoping Wang, Javier Bareno, Yan Qin, Frederic Aguesse, Wenquan Lu
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2022-09-01 |
Deskripsi
A high cut-off voltage is required for nickel-rich layered oxide LiNi<i><sub>x</sub></i>Co<i><sub>y</sub></i>Mn<i><sub>z</sub></i>O<sub>2</sub> (NCM) to meet the high energy density requirement of lithium-ion batteries in electric vehicles. However, such a high voltage application leads to an unstable interface between NCM and liquid electrolytes. To stabilize the interface, the facile wet impregnation method has been developed to apply an ultra-thin Al<sub>2</sub>O<sub>3</sub> coating layer on the NCM particles. This coating layer was found to have a strong interaction with the NCM and resulted in Al-doped NCM at the surface structure of NCM. The change of surface structure can not only reduce the surface resistance of lithium diffusion of LiNi<sub>0.5</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>O<sub>2</sub> (NCM523), but also stabilize the solid electrolyte interface between NCM523 and the electrolyte with the cut-off voltage of 4.5 V vs. Li/Li<sup>+</sup>. Compared to other coating methods, wet impregnation coating can provide an ultra-thin and uniform coating with surface doping on NCM particles. Furthermore, this scalable coating method can be applied to various electrode materials without adding much additional cost.