Multidimensional Hybrid Architecture Encapsulating Cobalt Oxide Nanoparticles into Carbon Nanotube Branched Nitrogen-Doped Reduced Graphene Oxide Networks for Lithium–Sulfur Batteries

Energy & Environmental Materials

article

Jeong Seok Yeon¹  Young Hun Ko¹  Tae Ho Park¹  Hyunyoung Park³  Jongsoon Kim³  Ho Seok Park¹ 

[1] School of Chemical Engineering, College of Engineering, Sungkyunkwan University;Advanced Batteries Research Center, Korea Electronics Technology Institute;Department of Energy Science, Sungkyunkwan University;Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology ,(SAIHST), Sungkyunkwan University

关键词: graphene/CNT hybrid;    lithium–sulfur batteries;    multidimensional architecture;    nanoparticle encapsulation;    redox promoter;   

DOI  :  10.1002/eem2.12187

来源: Wiley

【 摘 要 】

Lithium–sulfur batteries (LSBs) are regarded as promising candidates for the next-generation energy storage devices owing to their high-theoretical capacity (1675 mAh g −1 ) and affordable cost. However, several limitations of LSBs such as the lithium polysulfide shuttle, large volume expansion, and low electrical conductivity of sulfur need to be resolved for practical applications. To address these limitations, herein, a multidimensional architectured hybrid (Co@CNT/nG), where Co 3 O 4 nanoparticles are encapsulated into three-dimensional (3D) porous N-doped reduced graphene oxide interconnected with carbon nanotube (CNT) branches, is synthesized through a simple pyrolysis method. The synergistic effect achieved through the homogeneously distributed and encapsulated Co 3 O 4 nanoparticles, the interconnected CNT branches, and the 3D hierarchical porous structure and N-doping of Co@CNT/nG significantly suppresses the shuttle effect of lithium polysulfides and enhances the conversion redox kinetics for the improved sulfur utilization. We validate this effect through various measurements including symmetric cells, Li 2 S nucleation, shuttle currents, Tafel slopes, diffusion coefficients, and post-mortem analyses. Importantly, Co@CNT/nG-70S-based LSB cells achieve a high-specific capacity of 1193.1 mAh g −1 at 0.1 C and a low capacity decay rate of 0.030% per cycle for 700 cycles at 5 C, delivering a high areal capacity of 5.62 mAh cm −2 even with a loading of 6.5 mg cm −2 .

【 授权许可】

Unknown