Model Membrane-Free Li-S Batteries for Enhanced Performance and Cycle Life.

Kenville E Hendrickson,Lynden A Archer,Gil Cohn,Lin Ma,Yingying Lu

doi:10.1002/advs.201500068

Abstract

The success of the rechargeable Li-S cell is limited in part by the dissolution of lithium-polysulfide in the electrolyte. Remarkably, it is found that removal of the conventional membrane separator in a Li-S cell improves sulfur utilization and cycling performance, whether the sulfur is initially contained in the cathode or electrolyte. An optimized cell design yields discharge capacities as high as 980 mA h g-1 after 100 cycles.

Highlights

Advanced energy storage systems are increasingly reliant on rechargeable lithium ion batteries (LIBs)
Secondary batteries with significantly higher energy densities compared to current LIBs are required for meeting these needs
We studied the surface of the carbon cathode exposed to chemically synthesized high-order lithium polysulfide intermediates (Li-PS) species in the presence of LiTFSI

Summary

Introduction

Advanced energy storage systems are increasingly reliant on rechargeable lithium ion batteries (LIBs). We reported that integration of nitrile-containing additives in the sulfur cathode of a Li–S cell limits Li-PS loss to the electrolyte via strong interactions between Li+ and the lone pair of electrons on nitrogen containing species.[23] Figure 3 compares the galvanostatic cycling performance and discharge profiles at a fixed rate of C/5 of conventional Li–S cells in which the cathode is a physical mixture of 50 wt% sulfur, 40% carbon, and 10% binder and a conventional polypropylene material as separator.

Results

Conclusion