Lithiophilic and Antioxidative Copper Current Collectors for Highly Stable Lithium Metal Batteries

Designing copper (Cu) current collectors is a convenient way to stabilize lithium (Li) metal anodes. However, Cu current collectors and their derived Li/Cu anodes still face several obstacles, including lithiophobic and oxidizable Cu surface, cumbersome anode fabrication process, and low Li utilization. Here, a formate-treatment strategy is presented to reconstruct Cu current collectors with a passivation layer covered Cu(110) surface. This method can easily be generalized to increase the lithiophilicity and oxidation resistibility of Cu current collectors. Using the formate-treated Cu nanowire network as an anode current collector, the full cell consisting of a LiFePO4 cathode and Li/Cu anode with a low negative/positive capacity ratio delivers an excellent cycling performance with 74.8% capacity retention after 1000 cycles at 1 C. In addition, a concept of an upper current collector is introduced to simplify the manufacturing procedure of Li/Cu anodes. This work provides new insights into the design and construction of high-performance Li/Cu anodes.

Automated summary

The study introduces a formate-treatment strategy to reconstruct Cu current collectors for increased lithiophilicity and oxidation resistibility. The full cell using these treated Cu nanowires as anode current collectors shows excellent cycling performance, and the concept of an upper current collector simplifies the manufacturing process of Li/Cu anodes.