Prelithiated Li-Enriched Gradient Interphase toward Practical High-Energy NMC–Silicon Full Cell
Xiaoxiao Liu, Tongchao Liu, Rui Wang, Zhao Cai, Wenyu Wang, Yifei Yuan, Reza Shahbazian‐Yassar, Xiaocheng Li, Songru Wang, Enyuan Hu, Xiao‐Qing Yang, Yinguo Xiao, Khalil Amine, Jun Lü, Yongming Sun
Abstract
It is highly desirable to realize high-energy-density lithium-ion batteries consisting of nickel-rich layered oxide cathodes (Ni-rich NMC) and Si-based anodes. A critical challenge for Ni-rich NMC is its fast capacity degradation. In addition, the low initial Coulombic efficiency of the Si-based anode consumes the electrochemically active lithium from the cathode and decreases the energy density of full batteries considerably. We consider cathode and anode as a whole to simultaneously resolve the issues of both sides. Ni-rich LiNi0.65Mn0.20Co0.15O2 (LR-Ni65) consisting of a lithium-enriched gradient interphase layer (∼20 nm) is designed to supply excess electrochemically active lithium to compensate lithium loss at the anode and enhance cycling stability through regulating Li/Ni disorder in the cathode structure. We show that a LR-Ni65||Si/graphite pouch cell displays a capacity (3.29 Ah) greater than that for the counterpart using pristine Ni-rich NMC (2.95 Ah), as well as enhanced cycling stability with 88% capacity retention. The good compatibility with current Ni-rich NMC processing and facile synthesis make the as-fabricated cathode material promising for practical commercial application.