Operational Strategies to Improve the Performance and Long‐Term Cyclability of Intermediate Temperature Sodium‐Sulfur Batteries

Abstract

Based on the preliminary investigation of the intermediate temperature sodium-sulfur (IT-NaS) battery (150°C), herein we advance this energy storage system, by retuning the catholyte formulation; namely i) concentration, ii) layer thickness, and iii) cutoff limits during galvanostatic charge-discharge cycling, lowering the operating temperature and improving cell design. The systematic implementation of these strategies boosted the cell performance significantly, delivering 112 mAh/g-sulfur, 90 % of its theoretical specific capacity (125 mAh/g-sulfur), and 50 deep reversible charge-discharge cycles with coulombic and round-trip energy efficiencies of 97 � 3 % and 73 � 4 %, respectively. Along with the stability and improvement of cycle life, this study demonstrates, for the first time, the practicality of the tubular IT-NaS technology at a temperature as low as 125°C.

Effective Ways to Stabilize Polysulfide Ions for High‐Capacity Li−S Batteries Based on Organic Chalcogenide Catholytes

“…Examples include aerospace applications such as HAPS (High‐Altitude Pseudo‐Satellite) drones and marine, [10] while companies such as Oxis Energy, Zhongke Paisi and Sion Power have streamlined 400 Wh Kg −1 Li−S batteries for kWh‐level applications [11] . These cells comprise a carbon‐sulfur (C/S) cathode, a separator with an active or solid‐state electrolyte [12] tailored with a ceramic composite [13] that enables ionic diffusion, and at the anode, passivated metallic lithium. The electrolyte is the heaviest component of the cell and represents the most critical lever in the cell‘s specific energy [14] .…”

Nanostructure Engineering Strategies of Cathode Materials for Room-Temperature Na–S Batteries

“…21,22 Although the intermediate temperatures are able to lower the safety risks to some extent, the safety risks cannot be completely eliminated, and there still exists much possibility to trigger unforeseen accidents, as the metallic Na anode is present in the molten state at such temperatures. 23 In contrast, RT Na−S batteries can avert the safety issues through adopting ambient operation temperatures as well as offering an energy density considerably higher than those of the high temperature and intermediate temperature.…”

“…Among emerging energy storage systems like sodium-ion batteries, potassium-ion batteries, and lithium–sulfur batteries, sodium–sulfur (Na–S) batteries are very promising to become a good alternative of LIBs, as Na–S batteries not only integrate high elemental abundance and inexpensive prices of both elemental Na and S but also exhibit outstanding theoretical energy densities of 1274 W h kg –1 based the final product Na 2 S, which is relatively lower than that of Li–S batteries (2600 W h kg –1 , the final product is Li 2 S) but higher than that of LIBs. , The sodium–sulfur batteries are usually classified into high-temperature sodium–sulfur batteries (150–350 °C), intermediate-temperature sodium–sulfur batteries (150–200 °C), and room-temperature sodium–sulfur (RT Na–S) batteries (25–60 °C), according to the range of operating temperatures. − The high-temperature sodium–sulfur batteries possess high theoretical energy densities but bring in huge and uncontrollable safety hazards, possibly leading to a fire and even explosion. , Although the intermediate temperatures are able to lower the safety risks to some extent, the safety risks cannot be completely eliminated, and there still exists much possibility to trigger unforeseen accidents, as the metallic Na anode is present in the molten state at such temperatures . In contrast, RT Na–S batteries can avert the safety issues through adopting ambient operation temperatures as well as offering an energy density considerably higher than those of the high temperature and intermediate temperature.…”

Cover Feature: Effective Ways to Stabilize Polysulfide Ions for High‐Capacity Li−S Batteries Based on Organic Chalcogenide Catholytes (ChemElectroChem 18/2022)

“…Examples include aerospace applications such as HAPS (High-Altitude Pseudo-Satellite) drones and marine, [10] while companies such as Oxis Energy, Zhongke Paisi and Sion Power have streamlined 400 Wh Kg À 1 LiÀ S batteries for kWh-level applications. [11] These cells comprise a carbon-sulfur (C/S) cathode, a separator with an active or solid-state electrolyte [12] tailored with a ceramic composite [13] that enables ionic diffusion, and at the anode, passivated metallic lithium. The electrolyte is the heaviest component of the cell and represents the most critical lever in the cell's specific energy.…”