Lithium−sulfur (Li−S) batteries have received intense interest as next-generation electrochemical energy storage systems because of their high specific energy and natural abundance potential. However, its practical reality is seriously limited by the safety concerns from heterogeneous lithium deposition and the so-called "shuttle effect". Herein, this work reports a novel gel−polymer−inorganic separator specifically for the lithium−sulfur battery, which could enable homogeneous lithium deposition and inhibit the diffusion of polysulfides, simultaneously. The composite separator exhibits a superior electrochemical performance up to 500 cycles at 0.5 C with a capacity retention of 718.2 mA h g −1 . It is worth noting that the corresponding fade rate for 1000 cycles was 0.04%/cycle even tested at 2 C. This outstanding cycling stability can be attributed to the strong anchoring effect of polar carboxymethylcellulose sodium to polysulfides, which is confirmed by the permeation experiments and X-ray photoelectron spectroscopy analyses. Besides, the Al 2 O 3 coating layer on the anode side could achieve relatively uniform lithium deposition and inhibit the growth of dendrite to some extent. As a result, this study may provide a novel strategy for the effective design of separators toward the practical reality of the high-performance lithium−sulfur battery.

A hybrid electrolyte, by uniting aqueous and organic electrolyte with a water‐stable lithium super ionic conductor ceramic (LISICON) plate, was proposed to circumvent the drawbacks of nonaqueous Li‐air batteries, such as corrosion of metallic Li from humidity, decomposition of organic solvents and insoluble discharge products clogging air electrode. However, safety issues deteriorate when the brittle ceramic plate fails to separate organic and aqueous solutions. This study aimed to improve the safety of the hybrid electrolyte based Li‐air battery, by designing a liquid anode of lithium biphenyl (LiBP) replacing the lithium metal as the mild reaction between LiBP and aqueous electrolyte without combustion. Moreover, sputtering Ti layer onto the anodic side of the ceramic plate can improve chemical stability of interface between the liquid anode and solid electrolyte. In this system, the cell exhibited a relatively high discharge voltage of 2.81 V at the current density of 0.5 mA cm−2, as well as a specific power of 1638 W kg−1 at the current density of 6 mA cm−2 by using this liquid anode. The cycling life exceeded over 120 cycles at the current density of 0.5 mA cm−2. The ex situ Raman spectrometry and in situ GC‐MS analyses reveal that the redox reaction of BP−/BP and OH−/O2 in anolyte and catholyte respectively can deliver large capacity during cycling.

A schematic diagram of Li extraction from seawater by electrolysis with a hybrid electrolyte is shown. NiO@SP herein shows a satisfactory balance between the performance and cost for lithium recovery from seawater.