High-performance room-temperature sodium–sulfur battery enabled by electrocatalytic sodium polysulfides full conversion

Abstract

Developing novel gold nanoclusters as an electrocatalyst can facilitate a completely reversible reaction between S and Na, achieving advanced high-energy-density room-temperature sodium–sulfur batteries.

General Synthesis of Single‐Atom Catalysts for Hydrogen Evolution Reactions and Room‐Temperature Na‐S Batteries

“…Chemie capacities of 699 mA hg À1 and 575 mA hg À1 ,respectively,but they showed aq uick capacity fading to 140 mA hg À1 and 101 mA hg À1 after 1000 cycles.T he capacity loss of the Ru 1 @NC@S and Pt 1 @NC@S is due to the dissolved longchain polysulfides, [20] which are the main discharge products of noble single-atom decorated samples.A lso,t he charge plateaus of Fe 1 @NC@S from the first cycle to the 1300th cycles can be clearly found to lie below 2V ,w hich is attributed to the formation of short-chain polysulfides (Figure 6B). This performance comparison of the synthesized samples indicates that the reduction to long-chain polysulfides is irreversible and unstable due to shuttle effect while the short-chain polysulfides are repeatable and of benefit to the cycling stability.Owing to the excellent catalytic ability of Fe single atoms,the Fe 1 @NC@S delivers not only the highest specific capacity,but also the most outstanding rate capability compared with the other samples ( Figure 6C).…”

“…The Fe 1 @NC@S shows average capacities of 850, 522, 444, 392, 323, 250, and 205 mA hg À1 at the corresponding current densities of 0.2, 0.3, 0.5, 1, 2, 5, and 10 Ag À1 .Impressively,the capacity could be recovered to 542 mA hg À1 when the applied the current density was reversed to 0.2 Ag À1 .A lso,w ith ag radually increased rate,t he charge/discharge curves of Fe 1 @NC@S only show as mall polarization ( Figure 6D), meaning that the Fe 1 single atom is very effective for polysulfide immobilization and conversion even at high current rate.Acomparison of the reversible capacity versus the cycling stability of Fe 1 @NC@S with the state-of-the-art reports in the literature is presented in Figure 6E.I ti s impressive that the Fe 1 @NC@S shows an excellent capacity with ultra-stable cycling performance. [20,[23][24][34][35][36] Moreover, the retention of reversible capacity is very significant for the design of high-energy density batteries as well as its real use. Thesample Fe 1 @NC@S presented the high capacity retention of 76 %ofits initial reversible capacity,which is much higher than for the previously reported metal catalysts (inset image in Figure 6E).…”

“…[17] Thek ey challenge of the RT-Na/S batteries is the sluggish Sr edox reactions with Na, which is getting worse along with the migration of polysulfide intermediates. [18] Innovatively,v arious polar catalysts,s uch as transition metals, [19] noble metals, [20] metal sulfides, [21] and metal oxides, [22] are developed to improve the efficiencyo f polysulfide immobilization and conversion. Zhang et al found that different transition metals nanoclusters,i ncluding Fe,N i, and Cu, showed varied catalytic efficiencyo n polysulfide conversion due to different intrinsic sulfiphilic properties.…”

Na‐Ion Batteries—Approaching Old and New Challenges

“…For example, the practical discharge capacity of RT Na-S cells is far below the theoretical capacity (1672 mAh g −1 , corresponding to the final discharge product of Na 2 S), and the sluggish conversion reaction kinetics exacerbates the "shuttle effect", resulting in poor reversibility of Na 2 S. Those problems accelerate the exploration of electrocatalytic effects on the full conversion of sodium polysulfides and the novel design of cathode hosts. [163] Furthermore, it is imperative to realize highly Figure 13. Theoretical and practical energy densities of select rechargeable batteries, including NIB-sodium-ion battery, LIB-lithium-ion battery, HT Na-S-high-temperature sodium-sulfur battery, RT Na-S-room-temperature sodium-sulfur battery, Li-S-lithium-sulfur battery, Na-O 2 -sodium-oxygen battery, and Li-O 2 -lithium-oxygen battery.…”

Electrocatalytic Assisted Performance Enhancement for the Na-S Battery in Nitrogen-Doped Carbon Nanospheres Loaded with Fe

“…Considerable developments have been made in the RT Na-S battery since 2012 [21]. Extensive efforts, such as embedding the S species in a functional matrix and coating or modification of separator and passivation of the anode have been made to minimize the shuttle effect [26][27][28][29][30][31][32]. For example, Ma et al designed a freestanding C/S/BaTiO 3 @TiO 2 electrode and used it as the cathode for the RT Na-S battery [30].…”