Application of Carbon Nanotube-Based Materials as Interlayers in High-Performance Lithium-Sulfur Batteries: A Review

Abstract

With the ever-increasing demands of electrochemical energy storage, lithium-sulfur (Li-S) batteries have drawn more attention because of their superior theoretical energy density and high specific capacity. However, practical applications of Li-S batteries suffer from problems such as low conductivity of sulfur and discharged products, severe polysulfide shuttling effect, and large volume change of sulfur during cycling, resulting in sluggish rate performance, and unsatisfactory cycle life. Various nanostructured carbon materials have been served as barrier layers to overcome these problems. In particular, carbon nanotubes (CNTs) with unique 1D nanostructure, have been introduced to Li-S batteries as the intermediate layers because of its superior flexibility, excellent electrical conductivity, and good chemical stability. Moreover, CNTs and CNTs-based barrier layers could also curb lithium polysulfides shuttling. In the minireview, we summarize recent works of CNTs-based materials as modifying interlayers for Li-S batteries. In addition, the strategies to enhance electrochemical performances of the batteries are summarized and discussed. Finally, the challenges and prospects for future research of CNTs-based materials as interlayer are proposed. We hope this review will be useful for designing and fabricating high-performance Li-S batteries and boost their practical applications.

3D x-ray microtomography investigations on the bimodal porosity and high sulfur impregnation in 3D carbon foam for Li–S battery application

“…Modifying separator with the coating of MWCNTs helps in the retention of capacity due to the binding of polysulfides with the functional groups on the surface of MWCNTs [18][19][20]60]. In the present work, to improve capacity retention and mitigate the polysulfide dissolution the separator was coated with f-MWCNT.…”

“…Various conductive carbon materials such as carbon nanofibers (CNFs) [7][8][9][10], carbon nanotubes (CNTs) [11][12][13][14][15][16][17][18][19][20], micro-mesoporous carbon [21][22][23][24][25][26][27][28][29], and graphene [4,22,[28][29][30][31] have been utilized to either impregnate sulfur to design positive electrode or to trap polysulfides species for the Li-S batteries. High sulfur content and high mass loading are the crucial factors to obtain higher energy density, long cycle life and active utilization [16,18,32,33].…”

“…a) shows the CV carried out at a scan rate of 0.05 mV s −1 exhibiting two distinct reduction peaks, the first peak at 2.25 V corresponds to the formation of long-chain polysulfides Li 2 S n , (4 ⩽ n ⩽ 8) and the second peak at ∼2.0 V corresponds to the further reduction of long-chain polysulfides to the short-chain Li 2 S 2 /Li 2 S[19,24,29,58,59]. The oxidation peak at 2.5 V is attributed to the formation of long-chain polysulfides from the short-chain polysulfides and then to form the S 8 .…”

Growth Mechanism of Micro/Nano Metal Dendrites and Cumulative Strategies for Countering Its Impacts in Metal Ion Batteries: A Review

“…Similarly, phosphide-based transition metals as host separators in Li-S batteries improve the operating performance due to the excellent catalytic activity and high conductivity of phosphides [151]. Carbon materials have strong potential to reduce the polysulfide shuttle effect as they adsorb firmly with Li-polysulfides and possess high conductivity [152,153]. A core-shell encapsulated sulfur cathode with nanoparticles reduces the polysulfide shuttle.…”

Investigating Multiscale Spatial Distribution of Sulfur in a CNT Scaffold and Its Impact on Li–S Cell Performance

“…Carbon nanotubes (CNTs) are superior among different types of carbon host matrix because of their large aspect ratio, decent electrical conductivity, stable chemical and thermal properties, and excellent flexibility . Therefore, CNTs have been broadly used to fabricate binder-free sulfur cathodes. − However, reviewing the literature in the field indicates that there is a limitation of improving the sulfur loading to an optimized value. Most studies focus on using the sulfur loading <1 mg/cm 2 at the laboratory level to ensure a reasonable galvanostatic cycling performance .…”