Covalent sulfur for advanced room temperature sodium-sulfur batteries

Amorphous MoS 3 as the sulfur-equivalent cathode material for room-temperature Li–S and Na–S batteries

“…2F). It was worth noting that the sulfur content measured here was no lower than many conventional sulfur composite materials containing 40 wt % S or even lower) that were designed to trap polysulfides (19,(56)(57)(58)(59)(60).…”

Long Cycle Life, Low Self‐Discharge Sodium–Selenium Batteries with High Selenium Loading and Suppressed Polyselenide Shuttling

“…[14][15][16][17][18] Thus, development of viable room-temperature sodium-ion batteries is attracting increasing attention. [25][26][27][28][29][30] However, the practical applications of RT NaS batteries are facing two major challenges: (i) sulfur has a low electronic conductivity (5 × 10 −30 S cm −1 at 25 °C), thus leading to sluggish electrochemical reaction processes and low utilization of the active sulfur in the electrode; (ii) severe "polysulfide shuttle effect," i.e., migration of dissolved polysulfide intermediate products through the porous separator between the cathode and the anode, which leads to rapid capacity fade during cycling. [25][26][27][28][29][30] However, the practical applications of RT NaS batteries are facing two major challenges: (i) sulfur has a low electronic conductivity (5 × 10 −30 S cm −1 at 25 °C), thus leading to sluggish electrochemical reaction processes and low utilization of the active sulfur in the electrode; (ii) severe "polysulfide shuttle effect," i.e., migration of dissolved polysulfide intermediate products through the porous separator between the cathode and the anode, which leads to rapid capacity fade during cycling.…”

“…[19][20][21][22][23][24] Recently, room-temperature (RT) sodium-sulfur (NaS) batteries, based on the conversion reaction chemistry, have triggered extensive research interest due to the high charge-storage capacity and the abundance of both sodium and sulfur. [31] Many approaches have been pursued to mitigate these issues, including employing modified separators, [30] porous carbon matrix, [26] etc. [31] Many approaches have been pursued to mitigate these issues, including employing modified separators, [30] porous carbon matrix, [26] etc.…”

Flexible Na batteries

“…It was reported that dopamine was able to self-polymerize on the surface of fewwalled carbon nanotubes in alkaline aqueous solutions, and the loading of polydopamine could be controlled by adjusting the reaction time and concentration of dopamine molecules. [43][44][45][46] A sulfurized polyacrylonitrile nanofiber web was prepared by a simple pyrolysis process as a cathode for a low-cost and flexible Na-S battery, which exhibited good electrochemical properties, high flexibility and bendability, even to 180 without fracture. Using in/ex situ methods to prepare composite electrode materials can enable improved electrochemical performance due to the rapid charge transfer and efficient Na + ion diffusion, as well as the stronger covalent linkage between organic and carbon materials, suppressing the dissolution of organic molecules.…”

“…A carbon matrix with good electronic conductivity and excellent flexibility could be a promising scaffold to support sulfur cathodes. [43][44][45][46] A sulfurized polyacrylonitrile nanofiber web was prepared by a simple pyrolysis process as a cathode for a low-cost and flexible Na-S battery, which exhibited good electrochemical properties, high flexibility and bendability, even to 180 without fracture. 43,44 Carbonaceous substrates are also widely used as cathode active materials in Li/Na-O 2 batteries for their good electrocatalytic activity.…”