Highly Li‐ion conductive Li4(BH4)3I@SBA‐15 is synthesized by confining the LiI doped LiBH4 into mesoporous silica SBA‐15. Uniform nanoconfinement of P63 mc phase Li4(BH4)3I in SBA‐15 mesopores leads to a significantly enhanced conductivity of 2.5 × 10−4 S cm−1 with a Li‐ion transference number of 0.97 at 35 °C. The super Li‐ion mobility in the interface layer with a thickness of 1.2 nm between Li4(BH4)3I and SBA‐15 is believed to be responsible for the fast Li‐ion conduction in Li4(BH4)3I@SBA‐15. Additionally, Li4(BH4)3I@SBA‐15 also exhibits a wide apparent electrochemical stability window (0 to 5 V vs Li/Li+) and a superior Li dendrite suppression capability (critical current density 2.6 mA cm−2 at 55 °C) due to the formation of stable interphases. More importantly, Li4(BH4)3I@SBA‐15‐based Li batteries using either high‐capacity sulfur cathode or high‐voltage oxide cathode show excellent electrochemical performances, making Li4(BH4)3I@SBA‐15 a very attractive electrolyte for next‐generation all‐solid‐state Li batteries.

All-solid-state lithium batteries are promising next-generation energy storage devices that have gained increasing attention in the past decades due to their huge potential towards higher energy density and safety. As a key component, solid electrolytes have also attracted significant attention and have experienced major breakthroughs, especially in terms of Li-ion conductivity. However, the poor electrode compatibility of solid electrolytes can lead to the degradation of electrolyte/electrode interfaces, which is the major cause for failure in all-solid-state lithium batteries. To address this, this review will summarize the indepth understanding of physical and chemical interactions between electrolytes and electrodes with a focus on the contact, charge transfer and Li dendrite formation occurring at electrolyte/electrode interfaces. Based on mechanistic analyses, this review will also briefly present corresponding strategies to enhance electrolyte/electrode interfaces through compositional modifications and structural designs. Overall, the comprehensive insights into electrolyte/electrode interfaces provided by this review can guide the future investigation of all-solid-state lithium batteries.

Room-temperature sodium−sulfur (RT Na−S) batteries are widely considered as one of the alternative energystorage systems with low cost and high energy density. However, the both poor cycle stability and capacity are two critical issues arising from low conversion kinetics and sodium polysulfides (NaPSs) dissolution for sulfur cathodes during the charge/discharge process. Herein, we report a highly stable RT Na−S battery cathode via building heterostructures in multichannel carbon fibers. The TiN-TiO 2 @MCCFs, fabricated by electrospinning and nitriding techniques, are loaded with the active material S, forming S/TiN-TiO 2 @MCCFs as the cathode in a RT Na−S battery. At 0.1 A g −1 , the cathode produces the capacity of more than 640 mAh g −1 within 100 cycles with a high Coulombic efficiency of nearly 100%. Even at 5 A g −1 , the battery still exhibites a capacity of 257.1 mAh g −1 after 1000 cycles. Combining structural and electrochemical analyses with the first-principles calculations reveals that the incorporation of the highly electrocatalytic activity of TiN with the powerful chemisorption of TiO 2 well stabilizes S and also alleviates the shuttle effects of polysulfides. This work with simple processes and low cost is expected to promote the further development and application of metal−S batteries.

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