Grafting polymer from oxygen-vacancy-rich nanoparticles to enable protective layers for stable lithium metal anode
Sipei Li, Tong Liu, Jiajun Yan, Jacob A. Flum, Han Wang, Francesca Lorandi, Zongyu Wang, Liye Fu, Leiming Hu, Yuqi Zhao, Rui Yuan, Mingkang Sun, Jay Whitacre, Krzysztof Matyjaszewski
Abstract
Fabricating an artificial solid electrolyte interface (SEI) is a promising approach to improve cycling stability of lithium metal batteries. In this work, a new category of artificial SEI based on oxygen vacancy-rich hybrid nanoparticles was prepared by covalently grafting polymers from yttria–stabilized zirconia (YSZ) nanoparticles via surface-initiated atom transfer radical polymerization (SI-ATRP). The hairy nanoparticles had high dispersibility in dimethylsulfoxide, and were solution casted into uniform thin films with high inorganic content, high ionic conductivity (>1 × 10−4 S/cm at r.t.), and good mechanical properties (Young's modulus 7.56 GPa). No dendrite formation was observed by in-situ optical microscopy on a lithium metal protected by such artificial SEI. Protected anodes were stably cycled at 3 mA/cm2 and 3 mA h/cm2 with low overpotentials (20 mV) for >2500 h. LiNi0.8Co0.15Al0.05O2 (NCA)|Li full cells with protected Li anode showed much higher specific discharge capacity at various rates and improved capacity retention compared to unprotected Li anode.