Nanoscale metal oxide-based composite membranes with fast ion channel for Li metal protection

It is widely considered that lithium metal is the most ideal anode for the next-generation rechargeable batteries with high energy and power density. The growth of lithium dendrite and low coulombic efficiency, however, result in a sluggish pace for the real application of lithium metal anode. Here, the lithiophilic coating, like the metal oxide-based composite membrane, can be readily reacted with lithium ions to form multi-phase interface, leading to a uniform fast pathway for lithium ion transport. Through the metal oxide-based composite membrane, the Li dendrite can be suppressed effectively and the excellent cycling stability of the Li anode can be achieved. The life of Li–Li symmetric cells can be improved significantly from less than 240 h to more than 3200 h (0.5 mA cm −2 , 1 mAh cm −2 ), and the Li-Cu cells can maintain a coulombic efficiency of 98.7% after 250 cycles. The composite membrane can also improve the electrochemical performance of the Li/NCM cells. Finally, the mechanism of dendrite suppression by the composite membrane is also discussed in detail.