Mixed ionic/electronic conducting nanosheet arrays for stable lithium storage.

Lithium metal batteries (LMBs) have received extensive attention and research interest as high specific energy systems. However, the issues of Li dendrites growth in LMBs restrict their practical applications. The development of lithiophilic collectors can effectively solve the issues of Li dendrites growth. This study reports excellent lithium storage performance of lithiophilic nanosheet arrays which consist of electronic conductor Ni and ionic conductor Li2O (Ni-LONSs) on Ni foil (NF) fabricated via a simple preparation method for LMBs. The ionic conductor Li2O of the Ni-LONSs layer is lithiophilic and can induce uniform Li deposition on the Ni-LONSs collector. In addition, the nanosheet array structure of the Ni-LONSs collector is beneficial to slow down the volume change of the Li plating/stripping. In comparison with the NF collector, due to the specific nanosheet array structure of Ni-LONSs collector, the Ni-LONSs collector demonstrates excellent coulombic efficiency of 97.2% after 280 cycles (95.7% after 100 cycles of NF collector) and satisfactory cycling lifespan of 340 h (about 120 h of NF collector) at 0.5 mA cm-2with 1.0 mAh cm-2. Furthermore, the Ni-LONSs collector shows superior electrochemical performance in Ni-LONS/Li∣LiFePO4full cells. The excellent lithium storage performance of Ni-LONSs collector with mixed ionic/electronic conductor is conducive to the development and practical applications of LMBs.