Long‐Life Room‐Temperature Sodium–Sulfur Batteries by Virtue of Transition‐Metal‐Nanocluster–Sulfur Interactions

Abstract

Room‐temperature sodium–sulfur (RT‐Na/S) batteries hold significant promise for large‐scale application because of low cost of both sodium and sulfur. However, the dissolution of polysulfides into the electrolyte limits practical application. Now, the design and testing of a new class of sulfur hosts as transition‐metal (Fe, Cu, and Ni) nanoclusters (ca. 1.2 nm) wreathed on hollow carbon nanospheres (S@M‐HC) for RT‐Na/S batteries is reported. A chemical couple between the metal nanoclusters and sulfur is hypothesized to assist in immobilization of sulfur and to enhance conductivity and activity. S@Fe‐HC exhibited an unprecedented reversible capacity of 394 mAh g−1 despite 1000 cycles at 100 mA g−1, together with a rate capability of 220 mAh g−1 at a high current density of 5 A g−1. DFT calculations underscore that these metal nanoclusters serve as electrocatalysts to rapidly reduce Na2S4 into short‐chain sulfides and thereby obviate the shuttle effect.

Dual Play of Chitin‐Derived N‐Doped Carbon Nanosheets Enabling High‐Performance Na‐SeS2 Half/Full Cells

“…After 50 cycles, capacities of ∼450 mAh g −1 and ∼400 mAh g −1 are retained with SeS 2 loadings of 2.3 and 3.3 mg cm −2 , respectively. Figure S10a and Figure S10b (Supporting Information) show the comparisons of the rate performance with other reported Na−S and related battery systems . Table S2 (Supporting Information) displays the contrast of cycling performance.…”

Beyond Lithium-Based Batteries

“…The energy storage mechanism for all metal-sulfur batteries follows a conversion type mechanism [13,[150][151][152][153][154]. A simple version of this reaction occurs for lithium, sodium and magnesium [151][152][153][154][155][156][157][158][159][160][161][162][163][164][165][166]. In this mechanism the sulfur in the cathode is reduced and forms a metal sulfide complex with the metal ions from the electrolyte solution, as in Equation 22.…”

Recent Advances in Cathode Materials for Room‐Temperature Sodium−Sulfur Batteries

“…It should be pointed out that, although Co could partly promote the discharge process, there is still quite a portion of Na 2 S stayed unreversible due to its insulating nature and inert reactivity. Furthermore, other transition‐metals (M = Fe, Cu, and Ni) have been loaded on hollow carbon nanospheres (HC) as electrocatalyst for improving the performance of RT−Na/S batteries . Among three transition‐metals, Fe was demonstrated to be the most effective catalyst for immobilizing polysulfides and promoting the transformation from Na 2 S 4 to Na 2 S 2 .…”