High-Performance Lithium Sulfur Batteries Based on Multidimensional Graphene-CNT-Nanosulfur Hybrid Cathodes

Álvaro Doñoro,Vinodkumar Etacheri,Álvaro Muñoz-Mauricio

doi:10.3390/batteries7020026

Álvaro Doñoro, Vinodkumar Etacheri + Show 1 more

Open Access

https://doi.org/10.3390/batteries7020026

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Abstract

Although lithium-sulfur (Li-S) batteries are one of the promising candidates for next-generation energy storage, their practical implementation is limited by rapid capacity fading due to lithium polysulfide (LiPSs) formation and the low electronic conductivity of sulfur. Herein, we report a high-performance lithium-sulfur battery based on multidimensional cathode architecture consisting of nanosulfur, graphene nanoplatelets (2D) and multiwalled carbon nanotubes (1D). The ultrasonic synthesis method results in the generation of sulfur nanoparticles and their intercalation into the multilayered graphene nanoplatelets. The optimized multidimensional graphene-sulfur-CNT hybrid cathode (GNS58-CNT10) demonstrated a high specific capacity (1067 mAh g−1 @ 50 mA g−1), rate performance (539 @ 1 A g−1), coulombic efficiency (~95%) and cycling stability (726 mAh g−1 after 100 cycles @ 200 mA g−1) compared to the reference cathode. Superior electrochemical performances are credited to the encapsulation of nanosulfur between the individual layers of graphene nanoplatelets with high electronic conductivity, and effective polysulfide trapping by MWCNT bundles.

Highlights

Multiwalled carbon nanotubes (MWCNTs) bundles were used as an additive to further improve the electrochemical performance
In addition to providing the increased electronic conductivity, graphene nanoplatelets act as a host for the incorporation of sulfur nanoparticles, and MWCNT bundles double up as polysulfide trap
A Li-S battery based on the optimized hybrid cathode exhibited an excellent specific capacity, rate performance, coulombic efficiency and cycling stability compared to carbon nanotubes (CNTs)-free composite electrodes

Summary

Introduction

Its performance matrices are not sufficient for many applications, including long range driving [5]. Many approaches, such as designing high-capacity electrodes, engineering electrolyte compositions and design optimizations, have been investigated previously for improving the electrochemical performance of Li-ion batteries [6,7]. Lithium-sulfur (Li-S) batteries are potential candidates for overcoming the gravimetric and volumetric energy density limitations of current generation Li-ion batteries [8,9,10]. The high theoretical capacities of sulfur cathode (1675 mAh g−1 ) and lithium metal anode (3861 mAh g−1 ) result in a high theoretical energy density of 2600 Wh kg−1 , which greatly exceeds that of commercial Li-ion batteries [11]

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Results

Conclusion