Whether lithium–sulfur batteries succeed hinges largely on taming sulfur's complex electrochemistry, over which, choice of electrolyte exerts an equally complex influence.

Energy production and storage are critical research domains where the demands for improved energy devices and the requirement for greener energy resources are increasing. There is particularly intense interest in Lithium (Li)-ion batteries for all kinds of electrochemical energy storage. Li-ion batteries are currently the primary energy storage devices in the communications, transportation and renewable-energy sectors. However, scaling up the Liion battery technology to meet current increasing demands is still problematic and issues such as safety, costs, and electrode materials with higher performance are under intense investigation. The Li-sulphur (S) battery is a promising electrochemical system as a highenergy secondary battery, particularly for large-scale applications, due to its low cost, theoretically large specific capacity, theoretically high specific energy, and its ecofriendly footprint. The Li-S battery exhibits excellent potential and has attracted the attention of battery developers in large scale production in recent years. This review aims to highlight recent advances in the Li-S battery, providing an overview of the Li-ion battery applications in energy storage, then detailing the challenges facing Li-S battery and current applied strategies for improvement in its efficiency.

Utilization of permselective membranes holds tremendous promise for retention of the electrode-active material in electrochemical devices that suffer from electrode instability issues. In a rechargeable Li−S batterya strong contender to outperform the Li-ion technologymigration of lithium polysulfides from the sulfur cathode has been linked to rapid capacity fading and lower Coulombic efficiency. However, the current approaches for configuring Li−S cells with permselective membranes suffer from large ohmic polarization, resulting in low capacity and poor rate capability. To overcome these issues, we report the facile fabrication of a high-flux graphene oxide membrane directly onto the sulfur cathode by shear alignment of discotic nematic liquid crystals of graphene oxide (GO). In conjunction with a carbon-coated separator, the highly ordered structure of the thin (∼0.75 μm) membrane and its inherent surface charge retain a majority of the polysulfides, enabling the cells to deliver very high initial discharge capacities of 1063 and 1182 mAh g electrode −1for electrodes with 70 and 80% sulfur content, respectively, at the practical 0.5 C rate. The very high sulfur utilization and impressive capacity retentions of the high sulfur content electrodes result in some of the highest performance metrics in the literature of Li−S (e.g., electrode capacity of 835 mAh g electrode −1after 100 cycles at 0.5 C with a sulfur content of 80%). We show that the structural order of the shear-aligned GO membrane is key in maintaining good kinetics of the charge transfer processes in Li−S batteries.

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