Ether-Induced Phase Transition toward Stabilized Layered Structure of MoS₂ with Extraordinary Sodium Storage Performance

Abstract

Ether-based electrolytes have long been proven to be advantageous over ether-based electrolytes in sodium ion batteries (SIBs), but the understanding of their effect on the phase transition of electrode materials during electrochemical cycling is very limited. In this work, we study the phase transition and electrochemical performance of 2H-MoS2 in ether- and ester-based electrolytes. Interestingly, we find that the MoS2 anode develops MoS2/diglyme-Na+ superlattices induced by cointercalation of Na+ and an ether solvent in an ether-based electrolyte, rather than the conversion reaction observed in ester-based electrolytes. The superlattices consist of mixed semiconductive 2H and metallic 1T phases, and are structurally stable and kinetically favorable for the repeated sodiation, which greatly enhances the capacity, cycling, and rate performance of MoS2. Specifically, the three-dimensional MoS2 nanoflowers deliver an ultrahigh capacity of 446.5 mAh g–1 at 5 A g–1 with no capacity fading after more than 3700 cycles in an ether-based electrolyte.

1D Insertion Chains Induced Small‐Polaron Collapse in MoS2 2D Layers Toward Fast‐Charging Sodium‐Ion Batteries

“…This process may include the formation of a cointercalation compound composed of Mo 2 S 3 , Na + , and ether solvent, which has recently been observed in an ether‐based electrolyte and has proven to be kinetically favorable for repeated sodiation. [ 59 ] In the following anodic scan, the distinct peak located at 1.74 V is ascribed to the reverse conversion process to form Mo 2 S 3 . With overall CV curves overlapping well after the first cycle, it can be concluded that Mo 2 S 3 has reversible redox chemistry and low polarization.…”

Carbon-coated ReS2 hierarchical nanospheres to inhibit polysulfide dissolution in ether-based electrolytes for high-performance Na-ion batteries

“…On the other hand, ether-based electrolytes (EBEs) are attracting increasing attention for SIBs, as they have numerous advantages including high ion transport, a stable solvation structure of Na + , high lowest unoccupied molecular orbital (LUMO) levels of solvated Na + to form a stable solid electrolyte interphase (SEI) layer, and highly reversible solvent co-intercalation reactions. [29][30][31][32][33][34][35] Therefore, utilization of EBEs is expected to be an effective strategy to improve the sodium storage performance of ReS 2 . Nevertheless, it was pointed out that the shuttling effect of polysulfides is encountered in EBEs for metal sulfide anodes during the discharge/charge processes, giving rise to the under-voltage failure phenomenon.…”

Honeycomb‐Structured MoSe2/rGO Composites as High‐Performance Anode Materials for Sodium‐Ion Batteries

“…[1][2][3][4] In terms of batteries, sodium-ion batteries (SIBs) are attracting increasing DOI: 10.1002/smll.202304124 interest due to the low cost and abundant resource of sodium, and its similar chemical properties with lithium. [5][6][7][8][9][10][11] Unfortunately, the relatively large radius of sodium ions (Na + : 1.02 Å vs Li + : 0.76 Å) may cause the electrode to undergo severe structural expansion and slow redox kinetics during the Na + intercalation/extraction reaction, resulting in unsatisfactory cycle durability and low rate performance. [12][13][14][15][16][17] Therefore, it is crucial to develop appropriate anode materials that can provide high sodium storage and excellent rate performance in order to achieve broad practical applications of SIBs.…”