Long-Lifespan Lithium Metal Batteries Enabled by a Hybrid Artificial Solid Electrolyte Interface Layer

Lithium metal batteries based on metallic Li anodes have been recognized as competitive substitutes for current energy storage technologies due to their exceptional advantage in energy density. Nevertheless, their practical applications are greatly hindered by the safety concerns caused by lithium dendrites. Herein, we fabricate an artificial solid electrolyte interface (SEI) via a simple replacement reaction for the lithium anode (designated as LNA-Li) and demonstrate its effectiveness in suppressing the formation of lithium dendrites. The SEI is composed of LiF and nano-Ag. The former can facilitate the horizontal deposition of Li, while the latter can guide the uniform and dense lithium deposition. Benefiting from the synergetic effect of LiF and Ag, the LNA-Li anode exhibits excellent stability during long-term cycling. For example, the LNA-Li//LNA-Li symmetric cell can cycle stably for 1300 and 600 h at the current densities of 1 and 10 mA cm–2, respectively. Impressively, when matching with LiFePO4, the full cells can steadily cycle for 1000 times without obvious capacity attenuation. In addition, the modified LNA-Li anode coupled with the NCM cathode also exhibits good cycling performance

Cage-like Silicene/CNT Microspheres Synthesized by a Topochemical Reaction as Anodes for Enhanced Stable Lithium-Ion Batteries

Silicene has recently received increasing attention as an anode material in lithium-ion batteries (LIBs) due to its unique architectural properties. However, the synthesis of silicene still remains challenging, which limits its practical applications. In this work, silicene nanosheets with multilayer stacks are synthesized by the topochemical method and successfully combined with carbon nanotubes (CNTs) to form a cage-like structure composite. Benefiting from the hierarchical structure and two-dimensional active material, the cage-like silicene/CNTs increases the ionic and electric conductivity while reducing the volume expansion and relieving swelling stress. In addition, calculation also indicates a lower diffusion energy barrier of lithium ions in silicene than that in bulk silicon, which ultimately enhances the rate and cycling performance of the battery. The as-obtained electrodes exhibit a capacity of 690 mA h g–1 at 1 A g–1 after 500 cycles. This work not only introduces a facile topochemical method to prepare materials with two-dimensional multilayer silicene but also provides a new strategy for the application of silicene in LIBs