Synergistic dual conversion reactions assisting Pb-S electrochemistry for energy storage

Abstract

Significance Based on the analysis of three thermodynamic parameters of various M-S systems (solubility of metal sulfides [M x S y ] in aqueous solution, volume change of the metal-sulfur [M-S] battery system, and the potential of S/M x S y cathode redox couple), an aqueous Pb-S battery operated by synergistic dual conversion reactions (cathode: S⇄PbS, anode: Pb 2+ ⇄PbO 2 ) has been officially reported. Benefitting from the inherent insolubility of PbS and a conversion-type counter electrode, the aqueous Pb-S battery exhibited two advantages: it is shuttle effect free and has a dendrite-free nature. Moreover, the practical value of the Pb-S battery was further certified by the prototype S|Pb(NO 3 ) 2 ǁZn(NO 3 ) 2 |Zn hybrid cell, which afforded an energy density of 930.9 Wh kg −1 sulfur .

Activating sulfur oxidation reactionviasix-electron redox mesocrystal NiS2 for sulfur-based aqueous batteries

“…Elemental sulfur features top-level specific capacity (typically >1000 mAh g −1 ) via two-electron transfer reactions. In studies of SABs, aqueous metal-sulfur batteries, including Cu-S [ 9–11 ], Fe-S [ 12 ], Zn-S [ 13 , 14 ], Pb-S [ 15 ], Ca-S [ 16 ], Li-S [ 17 ] and Na-S [ 18 ], have attracted much recent attention due to their high actual specific capacity in aqueous electrolytes. Despite some impressive results so far, the electrically insulated elemental sulfur (5 × 10 −30 S cm −1 ) inevitably undergoes a distinct volume expansion of at least ∼50% during discharging, accompanied by the conversion of dense S 8 (1.96 g cm −3 ) to M x S y (such as Li 2 S, Cu 2 S, and PbS) [ 19 ], leading to kinetics and reversibility limitations.…”

A Rechargeable K/Br Battery

“…Making such primary batteries rechargeable is apparently a good way to achieve higher energy secondary batteries, which is always a formidable challenge. [4][5][6][7][8][9][10] Very recently, the Dai group tackled this oxidized to form Br 2 , which is the main source of the reversible capacity. Overall, the K/Br battery in this work operates via redox reactions between Br 2 /Br − at the HCS cathode and K + /K at the K-metal anode, making it rechargeable.…”

“…Making such primary batteries rechargeable is apparently a good way to achieve higher energy secondary batteries, which is always a formidable challenge. [ 4–10 ] Very recently, the Dai group tackled this thorny problem and realized the rechargeability of Na (or Li)/SOCl 2 batteries for the first time. [ 11,12 ] Based on the primary chemistry of SOCl 2 reduction, the authors demonstrated that the transformation of NaCl film (produced in the initial discharge) to Na and Cl 2 was the main reaction during charging.…”

Optimizing NH4+ Storage Capability of Nickel Ferrocyanide by Regulating Coordination Anion in Aqueous Electrolytes

“…The large requirement for storing renewable energy from solar or wind calls for safe, low‐cost, and high‐performance rechargeable batteries [1–3] . Traditional lithium ion batteries are qualified for this practical application but encounter the scarcity of lithium minerals and the increasing price [4–8] .…”