Recent Progress of Anode Protection in Li–S Batteries

Abstract

Lithium-ion batteries have gradually reached their theoretical limits. To meet the growing demand for higher energy storage technology, finding alternative battery chemistries has become the major concern. Fortunately, lithium-sulfur batteries are considered the most promising next-generation energy storage technology due to being cost-effective and having high theoretical energy density. However, the further commercialization of lithium-sulfur batteries is hindered due to the growth of lithium dendrites and the shuttle effect of soluble lithium polysulfides. This review provides an overview of the challenges facing lithium-sulfur batteries. Furthermore, a comprehensive overview of lithium metal protection strategies is provided including electrolyte optimization, construction of artificial solid electrolyte layers, utilization of hosting materials, and design of separators, as well as a theoretical understanding and analysis of the underlying methods. This review puts forward general conclusions and prospects for the practical application of lithium-sulfur batteries in the future and the promotion of technology development of lithium metal batteries.

Kinetically Favorable Li–S Battery Electrolytes

“…156 To this end, it is imperative to engineer the Li anode configuration instead of Li foil, wherein a Li alloy and 3D skeleton are recognized as two promising candidates. 157 In this respect, high lithiophilicity is a prerequisite for inducing favorable Li nucleation and growth. Besides, they are expected to afford uniform current distribution to alleviate the formation of Li dendrites.…”

“…Apart from high reactivity, Li metal anodes also suffer from large volume changes during Li plating/stripping processes . To this end, it is imperative to engineer the Li anode configuration instead of Li foil, wherein a Li alloy and 3D skeleton are recognized as two promising candidates . In this respect, high lithio­philicity is a prerequisite for inducing favorable Li nucleation and growth.…”

Multifunctional Asymmetric Separator Constructed by Polyacrylonitrile-Derived Nanofibers for Lithium–Sulfur Batteries

“…Since a continuously mounting and increasing demand for energy, the needs for high-performance novel electronic devices have been upsurging, and lithium-ion batteries (LIBs) can hardly satisfy the commercial technology requirements because of their low theoretical energy density. In contrast, lithium–sulfur (Li–S) batteries have become one of the most competitive candidates for high-energy rechargeable batteries, showing the relatively high theoretical capacity (1675 mA h g –1 ) and the theoretical energy density of 2600 W h kg –1 , which is about 5 times higher than that of commercial LIBs. − However, the notorious shuttle effect of lithium sulfides has been preventing the commercial applications of Li–S batteries, which would lead to rapid loss of the active sulfur, terrible cyclability, low Coulombic efficiency, as well as poor electrochemical kinetics . Tremendous attempts have been carried out to alleviate the shuttling effects, including electrode functionalization, − electrolyte optimization, − and separator modification. − …”

“…1−4 However, the notorious shuttle effect of lithium sulfides has been preventing the commercial applications of Li−S batteries, which would lead to rapid loss of the active sulfur, terrible cyclability, low Coulombic efficiency, as well as poor electrochemical kinetics. 5 Tremendous attempts have been carried out to alleviate the shuttling effects, including electrode functionalization, 6−8 electrolyte optimization, 9−11 and separator modification. 12−15 Particularly, lots of researchers have shifted their focus to advanced modified separators, which play a key role in enhancing ion transport and suppressing polysulfide migration.…”

Nitro-functionalized Fe-MOFs for lithium-sulfur batteries

“…Lithium-sulfur batteries have trouble holding on to polysul des because of the typical emphasis on the cathode [14][15][16][17]. The constant breakdown of sulfur in the electrolyte and the subsequent decline in critical capacity are inevitabilities over time, particularly over extended cycles [18][19][20].…”