N-Doped C/ZnO-Modified Cu Foil Current Collector for a Stable Anode of Lithium-Metal Batteries

The security concerns and poor stability caused by lithium (Li) dendrites and volume changes are the main obstacles posed by the Li-metal batteries (LMBs). These serious issues need to be addressed before LMBs can be commercialized. Herein, a simple way to process the ZIF-8 precursor was designed to oxidize Zn to ZnO; at the same time, the surface of ZnO was coated with a layer of N-doped carbon material to prepare N-doped C/ZnO (NCZ) composite anode. As a lithiophilic framework, the NCZ composite anode acts as a steady Li "host" during the deposition/stripping process of Li. N doping not only improves the conductivity but also provides additional active sites for the deposition of Li. The LiZn alloy formed by ZnO and Li+ promotes the uniform deposition and distribution of Li and mitigates the Li dendrite formation caused by an uneven Li-ion distribution. The conductive carbon interconnection framework provides convenient electron/ion transmission channels and alleviates the volume change. Combined with the above strengths, the Li/CF@NCZ composite symmetrical cell has a good cycle endurance of over 1600 h with an ultralow voltage hysteresis (22 mV) at 5 mA cm–2 with 5 mAh cm–2. This study presents a facile strategy for developing dendrite-free Li-metal anodes.