Stable Li deposition of 3D highstrength-lithiophilicity-porous CuZn current collector with gradient structure

The growth and volume changes of dendrites caused by irregular Li deposition hinder the commercial application of Li metal anodes. Here, we design a bottom-up current collector with a gradient layered structure to fabricate dendrite-free Li metal anode and achieve high stability of the cycle. The high strength support layer stabilizes the volume change of the repeated Li plating/stripping process, and the lithiophilic CuZn alloy layer and porous Cu surface enable Li to uniformly nucleate and stably deposit inside the pore structure, thus efficiently suppressing the growth of Li dendrites. Due to the unique gradient structure of current collector, the symmetrical cell achieved a long cycle life of over 560 h at Li plating/stripping capacity of 1 mAh cm−2 and a current density of 1 mA cm−2, approximately four times and twice as long as plane Cu and porous Cu. In the full cells with LiFePO4 cathode, the capacity retention increased from 33.2 % (plane Cu) to 80 % after 200 cycles, and achieved excellent rate performance. This gradient design deepens the understanding of the nucleation and growth of Li in the integrated lithiophilic matrix and 3D porous structure, and provides an optional idea for the development of high-performance Li metal anode.