Moderate Temperature Sodium Cells: I . Transition Metal Disulfide Cathodes

Abstract

A moderate temperature, rechargeable Na cell having the configurationnormalLiquid Na/β‐Al2O3/Na+‐normalconducting electrolyte/normalTransition metal disulfideis described. The cell operates at ∼130°C. Three transition metal disulfides, TiS2 , VS2 , and Nb1.1S2 , have been evaluated as cathode materials. A 1M solution of normalNaI in 1,2‐Bis(2‐methoxy‐ethoxy)ethane, (triglyme), served as the electrolyte. The mechanism of discharge in all the three cathode materials involves Na intercalation. Experimental results are presented on cathode capacity, rate capability, and rechargeability.

High-performance Na2Ti2O5 nanowire arrays coated with VS2 nanosheets for sodium-ion storage

“…The cathodic/anodic peaks at 1.08 / 0.96 V contributed by the layered sodium titanium oxides may overlap with the Na-intercalation/deintercalation processes of VS 2 , limiting their visibility. Consequently, we propose a possible sodium-storage mechanism in the NTO-VS 2 composite electrode at the initial discharge as follows [19,30,35]: …”

“…Aside from its intrinsically metallic behavior, VS 2 monolayer also has a higher theoretical capacity of 466 mA h g -1 for lithium storage and a lower or similar lithium diffusion barrier compared to MoS 2 and graphite, which makes it a highly attractive anode candidate for energy storage [29]. VS 2 was first reported as a cathode with the Na system in the 1980s, and it intercalated up to one Na per VS 2 during first discharge as a cathode [30,31].…”

Comparative electrochemical sodium insertion/extraction behavior in layered NaxVS2 and NaxTiS2

“…In spite of several early reports on the Na intercalation of layered NaMS 2 (M = transition metal) [14,15], these layered sulfides are conspicuously absent in the battery literature. This absence is understandable considering the history of Li-ion battery development, where layered sulfide electrodes were replaced by layered oxide cathodes and carbon anodes.…”

Sodium/Beta”-Alumina/Organosulfur Batteries Operating at Intermediate Temperatures

“…Accordingly, various efforts have been made to offer alternative high specific energy/power batteries operating at reduced temperatures [ 1,2,3 ]. However, since electrode kinetics and mass transport processes in batteries are thermally activated, lower temperature systems often present a compromise between lower power output, and enhanced reliability, safety, and economic factors.…”