Na superionic conductor (NASICON)-type Li_1.5Al_0.5Ge_0.5P₃O₁₂ (LAGP) solid state electrolytes (SSEs) have attracted significant interests thanks to the prominent ionic conductivity (> 10^–4 S·cm^–1) at room temperature and superb stability in air. Unfortunately, its application has been hindered by the lithium dendrites and the intrinsic interfacial instability of LAGP towards metallic Li, etc. Herein, by magnetron sputtering (MS), an ultrathin Al film is deposited on the surface of the LAGP pellet (Al-LAGP). By in-situ alloying reaction, the spontaneously formed LiAl buffer layer inhibits the side reaction between LAGP SSEs and Li metal, and induces the uniform distribution of interfacial electric field as well. Density functional theory (DFT) calculations demonstrate that the LiAl alloy surface promotes the diffusion of lithium atoms due to the lower energy barrier, thereby inhibiting the formation of lithium dendrites. Consequently, the Li/Al-LAGP-Al/Li symmetric cells show a low resistance of 210 Ω and a durable lifespan over 1,200 h at a high current density of 0.1 mA·cm^–2. Assembled all solid state lithium metal batteries (ASSLMBs) with LiFePO₄ (LFP) cathode significantly improve cycle stability and rate performance, proving a promising stabilization strategy towards the NASIOCN type electrolyte/anode interface in solid state Li metal batteries.

Rechargeable Li-O₂ batteries (LOBs) have been receiving intensive attention because of their ultra-high theoretical energy density close to the gasoline. Herein, Ag modified urchin-like α-MnO₂ (Ag-MnO₂) material with hierarchical porous structure is obtained by a facile one-step hydrothermal method. Ag-MnO₂ possesses thick nanowires and presents hierarchical porous structure of mesopores and macropores. The unique structure can expose more active sites, and provide continuous pathways for O₂ and discharge products as well. The doping of Ag leads to the change of electronic distribution in α-MnO₂ (i.e., more oxygen vacancies), which play important roles in improving their intrinsic catalytic activity and conductivity. As a result, LOBs with Ag-MnO₂ catalysts exhibit lower overpotential, higher discharge specific capacity and much better cycle stability compared to pure α-MnO₂. LOBs with Ag-MnO₂ catalysts exhibit a superior discharge specific capacity of 13,131 mA·h·g^-1 at a current density of 200 mA·g^-1, a good cycle stability of 500 cycles at the capacity of 500 mA·h·g^-1. When current density is increased to 400 mA·g^-1, LOBs still retain a long lifespan of 170 cycles at a limited capacity of 1,000 mA·h·g^-1.

Silicon is considered an exceptionally promising alternative to the most commonly used material, graphite, as an anode for next-generation lithium-ion batteries, as it has high energy density owing to its high theoretical capacity and abundant storage. Here, microsized walnut-like porous silicon/reduced graphene oxide (P-Si/rGO) core–shell composites are successfully prepared via in situ reduction followed by a dealloying process. The composites show specific capacities of more than 2, 100 mAh·g^-1 at a current density of 1, 000 mA·g^-1, 1, 600 mAh·g^-1 at 2, 000 mA·g^-1, 1, 500 mAh·g^-1 at 3, 000 mA·g^-1, 1, 200 mAh·g^-1 at 4, 000 mA·g^-1, and 950 mAh·g^-1 at 5, 000 mA·g^-1, and maintain a value of 1, 258 mAh·g^-1 after 300 cycles at a current density of 1, 000 mA·g^-1. Their excellent rate performance and cycling stability can be attributed to the unique structural design: 1) The graphene shell dramatically improves the conductivity and stabilizes the solid– electrolyte interface layers; 2) the inner porous structure supplies sufficient space for silicon expansion; 3) the nanostructure of silicon can prevent the pulverization resulting from volume expansion stress. Notably, this in situ reduction method can be applied as a universal formula to coat graphene on almost all types of metals and alloys of various sizes, shapes, and compositions without adding any reagents to afford energy storage materials, graphene-based catalytic materials, graphene-enhanced composites, etc.