Significant Constraints of SnO₂, SnS₂, and SnS₂/SnO₂ Heterostructures on Mitigating Polysulfide Shuttle Effects in Lithium‐Sulfur Batteries

Abstract

Lithium-sulfur batteries (LSBs) are considered to be promising candidates for next-generation energy storage devices because of high theoretical capacity of 1675 mAh g À 1 . However, LSBs have failed to be put into practical applications mainly due to their shuttle effect. SnO 2 and SnS 2 stand out among many metal oxides and sulfides, and are frequently applied to LSBs research given their characteristics of easy preparation and good chemical stability. In particular, SnO 2 has a strong chemical adsorption effect on polysulfides through the SÀ SnÀ O chemical bonds; SnS 2 can effectively reduce the electrochemical polarization and improve the redox efficiency of polysulfides. This Minireview summarizes and evaluates the latest research progress of SnO 2 , SnS 2 , and SnO 2 /SnS 2 heterostructures applied in LSBs including the cathode, separator, and interlayer. The three materials show excellent electrochemical performance and can serve as viable candidates for polysulfide immobilizers to deal with the shuttle effect in LSBs.

Construction of SnS2-modified multi-hole carbon nanofibers with sulfur encapsulated as free-standing cathode electrode for lithium sulfur battery

“…Recently, introducing polar material (metal sulfides [26], metal oxides [27], metal nitrides [28], and so on [29,30]) into cathode material to strengthen the chemisorption of polysulfide has been received widely investigated. Among these polar compounds, SnS 2 stands out because of the enhanced chemical absorption interaction with polysulfide and the unique catalyst property, which can accelerate the transformation of long-chain polysulfides to Li 2 S/Li 2 S 2 and promote the kinetics of chemical reactions [31,32]. Wu et al [33] prepared SnS 2 /CNTs/S composites and the electrode displayed an excellent discharge capacity of 1308 mAh g −1 in the initial cycle and 1002 mAh g −1 at 0.1 C after 100 cycles.…”

Metal Nanoclusters as a Superior Polysulfides Immobilizer toward Highly Stable Lithium–Sulfur Batteries

“…LG Chem Ltd. successfully used LSBs in an aircraft that flew for 7 h in the stratosphere. [ 12 ] However, the commercial potential of LSBs is undermined by i) shuttle behavior of dissolved polysulfides between electrodes entailing loss of active sulfur, poor round‐trip Coulombic efficiency, and fast capacity loss, [ 13–16 ] ii) insulating character of Li and Li 2 S responsible for poor utilization of active materials, [ 17 ] iii) high volume expansion by ≈78% during lithiation of sulfur leading to the pulverization of electrodes, [ 18,19 ] and iv) uncontrolled growth of lithium dendrites caused by nonuniform plating/stripping behavior of lithium and culminating in internal short circuits. [ 20,21 ] Material electrochemists have been engaged in a constant effort to address the problems by preparing cathode composites such as carbon–sulfur, [ 22 ] N/S‐doped graphene, [ 23 ] S‐coated multiwalled carbon nanotubes, [ 24 ] transition metal nitrides/graphene, [ 25 ] S@MOF, [ 26 ] and COF/S.…”