Improved Performance of All-Solid-State Lithium Metal Batteries via Physical and Chemical Interfacial Control.

Lithium metal batteries (LMBs) show several limitations, such as high flammability and Li dendrite growth. All-solid-state LMBs (ASSLMBs) are promising alternatives to conventional liquid electrolyte (LE)-based LMBs. However, it is challenging to prepare a solid electrolyte with both high ionic conductivity and low electrode-electrolyte interfacial resistance. In this study, to overcome these problems, a solid composite electrolyte (SCE) consisting of Li6.25 La3 Zr2 Al0.25 O12 and polyvinylidene fluoride-co-hexafluoropropylene is used, which has attracted considerable attention in recent years as a solid-state electrolyte. To operate LMBs without an LE, optimization of the electrode-solid-electrolyte interface is crucial. To achieve this, physical and chemical treatments are performed, i.e., direct growth of each layer by drop casting and thermal evaporation, and plasma treatment before the Li evaporation process, respectively. The optimized ASSLMB (amorphous V2 O5- x (1 µm)/SCE (30 µm)/Li film (10 µm)) has a high discharge capacity of 136.13 mAh g-1 (at 50 °C and 5 C), which is 90% of that of an LMB with an LE. It also shows good cycling performance (>99%) over 1000 cycles. Thus, the proposed design minimizes the electrode-solid-electrolyte interfacial resistance, and is expected to be suitable for integration with existing commercial processes.

Solar-to-Steam Generation via Porous Black Membranes with Tailored Pore Structures.

Solar-to-steam generation is a powerful, intense, and efficient method to harvest solar energy. Many efforts have been devoted to the development of a durable, affordable, and easy-to-manufacture solar steam device. In this study, we use a versatile polydimethylsiloxane material to fabricate an open porous black membrane with different pore structures using a simple salt water etching process and vapor deposition polymerization of pyrrole into a matrix. The porous black membrane absorbed radiation from a broad section of the light spectrum from near-infrared to ultraviolet and retained its initial pore structures and floating ability. We found that our black membrane with a tailored pore structure and surface exhibits excellent solar-to-steam generation efficiency of up to 72% at five sun irradiation. Also, a series of analyses including density functional theory calculation was used to prove the outstanding efficiency of solar-to-steam generation.