Reactivation of dead sulfide species in lithium polysulfide flow battery for grid scale energy storage

Yang Jin,Kai Liu,Yi Cui,Rufan Zhang,Jie Zhao,Wei Chen,Feifei Shi,Yayuan Liu,Chenxi Zu,Guangmin Zhou,Xuanyi Huang,Denys Zhuo

doi:10.1038/s41467-017-00537-0

Abstract

Lithium polysulfide batteries possess several favorable attributes including low cost and high energy density for grid energy storage. However, the precipitation of insoluble and irreversible sulfide species on the surface of carbon and lithium (called “dead” sulfide species) leads to continuous capacity degradation in high mass loading cells, which represents a great challenge. To address this problem, herein we propose a strategy to reactivate dead sulfide species by reacting them with sulfur powder with stirring and heating (70 °C) to recover the cell capacity, and further demonstrate a flow battery system based on the reactivation approach. As a result, ultrahigh mass loading (0.125 g cm–3, 2 g sulfur in a single cell), high volumetric energy density (135 Wh L–1), good cycle life, and high single-cell capacity are achieved. The high volumetric energy density indicates its promising application for future grid energy storage.

Highlights

Lithium polysulfide batteries possess several favorable attributes including low cost and high energy density for grid energy storage
To address the above challenges, we propose a method for the reactivation of dead sulfide species in the cell through stirring and heating them with sulfur at a relatively low temperature (70 °C)
To address the problem of dead sulfide species deposition on the lithium and carbon electrodes, reactivation via heating and stirring at a relatively low temperature (70 °C) was conducted to recycle the dead sulfide species by reacting them with sulfur powder in order to recover the cell capacity. We hypothesize that such activation is possible since it is similar to how we prepare polysulfide solution by using Li2S and sulfur powder mixed in ether solvent at elevated temperature[28, 31]

Summary

Introduction

Lithium polysulfide batteries possess several favorable attributes including low cost and high energy density for grid energy storage. The precipitation of insoluble and irreversible sulfide species on the surface of carbon and lithium (called “dead” sulfide species) leads to continuous capacity degradation in high mass loading cells, which represents a great challenge To address this problem, we propose a strategy to reactivate dead sulfide species by reacting them with sulfur powder with stirring and heating (70 °C) to recover the cell capacity, and further demonstrate a flow battery system based on the reactivation approach. Hot plate the design of various carbon–sulfur cathodes or other architectures to confine sulfur[16,17,18,19,20], exploration of new electrolytes or additives[21, 22], modification of battery configuration[23, 24], and protection of the metallic lithium anode[25,26,27] These strategies can achieve improved electrochemical performance, these issues have still not been entirely solved, and new directions for Li-S batteries are still in development[28,29,30]

Methods

Results

Conclusion