Sulfur Mismatch Substitution in Layered Double Hydroxides as Efficient Oxygen Electrocatalysts for Flexible Zinc–Air Batteries

Abstract

Although layered double hydroxides (LDHs) are extensively investigated for oxygen electrocatalysis, their development is hampered by their limited active sites and sluggish reaction kinetics. Here, sulfur mismatch substitution of NiFe-LDH (S-LDH) is demonstrated, which are in-situ deposited on nitrogen-doped graphene (S-LDH/NG). This atomic-level sulfur incorporation leads to the construction of the tailored topological microstructure and the modulated electronic structure for the improved catalytic activity and durability of bifunctional electrocatalysts. The combined computational and experimental results clarify that the electron transfer between the sulfur anion and Fe 3+ generates the high-valence Fe 4+ species, while the mismatch substitution of the sulfur anion induces the metallic conductivity, an increased carrier density, and the reduced reaction barrier. Consequently, the as-fabricated Zn-air battery achieves a high power density of 165 mW cm -2 , a large energy density of 772 Wh kg Zn -1 at 5 mA cm -2 , and long cycle stability for 120 h, demonstrating its real-life operation.

A Prussian‐Blue Bifunctional Interface Membrane for Enhanced Flexible Al–Air Batteries

“…PDOS of the two interfaces is also analyzed to investigate the contribution of each atomic orbital to the DOS. [ 42 ] As shown in Figure S5 (Supporting Information), the orbital p dominates the interfacial molecular interaction of Al(1 1 1)‐H 2 O and Al(1 1 1)‐PB interface. Moreover, the strength of atomic bonding by the orbital p in the Al(1 1 1)‐PB interface is higher than Al(1 1 1)‐H 2 O due to the larger pseudogap value of 0.113 Ha for the former interface, as shown in Figure 5c.…”

Sustainable zinc–air battery chemistry: advances, challenges and prospects

“…To further improve the oxygen catalytic activity, Han et al demonstrated that S-incorporated NiFe-LDH on N-doped graphene (S-LDH/NG) acted as bifunctional oxygen electrocatalyst for rechargeable ZABs. 157 The mismatch substitution of introduced S species led to a tailored topological microstructure and optimized electronic structure for boosting the activity and durability. Consequently, the as-fabricated ZABs with the S-LDH/NG cathode achieved a high P max of 165 mW cm −2 , large energy density of 772 W h kg −1 , and long cycle stability of 120 h. Yu et al tuned the proportion and valence state of metal ions in Ni–Fe–Co oxide/hydroxide to significantly modify its electronic structure.…”

Cobalt(ii)-bridged triphenylamine and terpyridine-based donor–acceptor coordination polymer as an efficient trifunctional electrocatalyst

“…But the chemistry of materials with inherent limitations makes it difficult to meet the growing needs. [1][2][3][4][5][6][7] Electrochemical redox reactions such as the oxygen reduction reaction (ORR), 8,9 oxygen evolution reaction (OER), 10,11 and hydrogen evolution reaction (HER) 12,13 occur at the electrodes of these devices. The electrocatalyst should promote the ORR in fuel cells, OER in metal-air batteries, and HER for dihydrogen fuel generation.…”