High Performance Room Temperature Sodium–Sulfur Battery by Eutectic Acceleration in Tellurium-Doped Sulfurized Polyacrylonitrile

Abstract

Room temperature (RT) sodium–sulfur batteries suffer from slow reaction kinetics and polysulfide dissolution, resulting in poor performance. Sulfurized polyacrylonitrile is a unique sulfur cathode which is suggested to involve only S3–4 and shows high specific capacity. Herein, the designed Te0.04S0.96@pPAN with 4 mol % Te used as eutectic accelerator exhibits significantly enhanced reaction kinetics and excellent sulfur utilization, leading to a high performance RT Na–S battery. Te0.04S0.96@pPAN delivers capacities of 1236 and 629 mA h g–1 and 1111 and 601 mA h g–1 at 0.1 and 6 A g–1 in carbonate and ether electrolytes, respectively. Furthermore, UV–vis spectra and the shuttle current test reveal diminished sodium polysulfides in ether electrolyte, attributed to the fast kinetics enabled by Te doping. More significantly, the spectral technique and electrochemical analysis demonstrate a two-step reaction pathway in which Na2S3 and Na2S are the main intermediate and final discharge product, respectively. This method provides a promising approach toward applicable RT Na–S batteries.

Metal‐Tellurium Batteries: A Rising Energy Storage System

“…Xie and co-workers have reported Te as eutectic accelerator in room temperature Na-S batteries for the enhancement of reaction kinetics and excellent sulfur utilization. [27] Wang and co-workers successfully integrated Te on the surface of nickel-rich layered oxide to significantly improve the structural stability and electrochemical performance of electrode for LIBs. [101] Currently, there are few reports on Te doping, and the related works are worthy of more exploration.…”

“…In addition, the current Te doping technologies are mostly based on the ball milling of Te with active materials, which results in the relatively large size of the doped Te in system, so the feature of Te with high conductivity cannot be fully exhibited. [27] Te doping at the nanoscale and even smaller atomic scales is highly desirable for better performance in energy storage areas.…”

“…batteries. [25][26][27] We take a summary of the whole development in metal-Te batteries ( Table 1), and some promising possibilities have been put forward in this review. Te-based batteries, as a rising energy storage system, deserve more attention and researches in its potential for next-generation energy storage devices.…”

Prospect of Sulfurized Pyrolyzed Poly(acrylonitrile) (S@pPAN) Cathode Materials for Rechargeable Lithium Batteries

“…[28] Similarly,S ea nd tellurium (Te) were investigated as eutectic accelerators to enhance the reaction kinetics of S@pPAN composites for room temperature Na-S batteries. [52] As mall amount of Se or Te at the molecular level results in significant enhancement of electron conductivity.…”

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

“…Similar with lithium sulfur batteries, the operation of RT Na−S batteries face the same critical challenges including the insulating properties of sulfur, volume expansion during discharge and notorious shuttle effect . Many strategies have been pursued to mitigate these problems according to the components of the battery, including entrapping active materials into conductive matrix, synthesizing covalent sulfur composites, employing functionalized interlayers or modified separators, optimizing the electrolyte and binders . Although certain improvements of electrochemical performance have been garnered, the low utilization of the active materials, low Coulombic efficiency and rapid capacity fade during cycling still restrict the development of Na−S battery.…”