Dendrite-free lithium metal anode enabled by separator engineering via uniform loading of lithiophilic nucleation sites

Despite promising high-capacity of lithium metal anode, one major obstacle for its wide application is the uncontrolled dendrite growth, causing low Coulombic efficiency (CE), irreversible capacity loss and short circuit. Here, we report a facile separator engineering to suppress Li dendrites growth through single-side deposition of magnesium (Mg) nanoparticles. The lithiophilic Mg nanoparticles on the separator, servering as heterogeneous nucleation sites, exhibits a strong guiding effect to form inerratic Li crystal seeds in the early plating process, resulting in a dense Li anode with dendrite-free morphology after long cycling. The unique characteristics of this functional separator are further demonstrated in Li|LiCoO2 full cells with a high capacity retention (>80% after 400 cycles). Accordingly, our strategy offers a scalable low-cost and efficient approach for advanced rechargeable Li metal batteries.