The adoption of metallic lithium anode in place of graphite anode for rechargeable batteries represents high theoretical specific capacity (3860 mAh g^-1) and low redox potential (3.04V vs H/H⁺). However, the formation of lithium dendrite which is possible to penetrate the separator, causing the short circuit and even fire hazard reacting with the flammable and organic electrolyte, impedes the practical application of Li-ion batteries.

To address the aforementioned safety concerns, artificial layer has attracted much attention as a research direction to solve the issue of Li-ion batteries. Ideally, the artificial layer should 1) suppress the lithium dendrite formation or growth to protect the structure of battery and 2) maintain good electrochemical performance of lithium batteries. Extensive studies have been carried out to research different types of anode artificial layer. In principle, the artificial layer of anode can be roughly divided into two categories, mechanical suppress and regulation of lithium deposition.

For mechanical suppress, artificial layer with proper mechanical strength can efficiently inhibit the growth of lithium dendrite. Nevertheless, the optimal material with strong mechanical properties has still been studied and investigated.

For the other type of artificial layer, it tensely associates with the formation principle of lithium dendrite. The lithium metal plating onto the bare copper current collector produces a large nucleation barrier, which results in a higher overpotential. When lithium deposits on the existing Li nuclei, dendritic morphology generates on the surface. If the overpotential between lithium anode and copper current collector can be dismissed, it can decrease the lithium dendrite formation from principle with high efficiency. Some articles revealed Ag nanoparticles and Ag composite can reduce the overpotential, efficiently inhibiting the formation of dendrite.

Antiperovskite Ag₃SI with lithiophilicity, high ionic conductivity and low electronic conductivity, has been utilized as artificial layer for lithium anode in this experiment, to regulate the lithium layer, limit the growth of lithium dendrite, stabilize the performance of the lithium batteries.

Ag₃SI is applied on the lithium anode as artificial protective layer. Copper foil is used as current collector. During charge and discharge cycling tests, Li-ion can transport through Ag₃SI via hopping mechanism. The crystallographic structure of Ag₃SI is moderate distortion with considerable defects, resulting in high ionic conductivity, which provides accurate possibility for Li-ion hopping. The overpotential of Cu foil and Li metal can be reduced by lithiophilic Ag₃SI layer, regulating the uniformity of Li deposition. Moreover, the Li-ions do not deposit on the Ag₃SI surface, because the low electronic conductivity of Ag₃SI represents an impressive amount of electrons for the reduction of Li-ions to Li metal are not available.

The rechargeable lithium battery based on antiperovskite Ag₃SI proposes superior electrochemical performance and stable cyclability after long cycling tests, compared with the bare lithium battery.