Hierarchically Porous SnO₂ Nanoparticle-Anchored Polypyrrole Nanotubes as a High-Efficient Sulfur/Polysulfide Trap for High-Performance Lithium–Sulfur Batteries

Abstract

Conductive supports could improve the electrical conductivity of the electrode in lithium–sulfur (Li–S) batteries but suffer from the shuttle effect originated from the polysulfide dissolution, while the hydrophilic metal oxides could avoid the shuttle effect but with poor conductivity. Herein, a facile approach was developed to fabricate hierarchically porous tin oxide (SnO2) nanoparticle-anchored tubular polypyrrole (T-PPy) as a sulfur host, in order to integrate the advantages of conductive supports and metal oxides but overcome their shortcomings. In the unique structure, the T-PPy nanotubes acted as a conductive network to not only improve the electrical conductivity of cathodes but also accommodate the volume expansion of the sulfur cathode during cycling as well as relatively confine the polysulfide diffusion, while the SnO2 nanoparticles served as a high-efficient polysulfide trap to mitigate the shuttle effect due to the chemical bond between SnO2 and polysulfides. Moreover, the hierarchically porous structure and therefore large surface area of the proposed S/(T-PPy)@SnO2 cathode were favorable for the accommodation of sulfur and lithium sulfides. Consequently, S/(T-PPy)@SnO2 with 64.7% sulfur mass content exhibited excellent cyclic stability with a decay rate of only 0.05% per cycle along with 500 cycles at 1 C, rate capability of 383.7 mA h/g at 5 C, and Coulombic efficiency above 90%, outstanding among most of the reported PPy-based sulfur cathodes and PPy-based ternary sulfur cathodes.

A review on electronically conducting polymers for lithium-sulfur battery and lithium-selenium battery: Progress and prospects

“…The S@Co 3 O 4 and S@Co 3 O 4 /PPy cathode showed an initial discharge specific capacity of 909.2 and 1094.9 mAh g À1 , respectively, and maintained a capacity of 150.1 and 370.6 mAh g À1 after 1000 cycles at 0.5 C, respectively. Wei et al [133] anchored the tin oxides (SnO 2 ) nanoparticles onto the tubular PPy (T-PPy) surface and then sulfur deposited on them formed the S/(T-PPy)@SnO 2 composite. Because of the chemical bond between SnO 2 and lithium polysulfides, the hierarchically porous SnO 2 was mainly used as an effective lithium polysulfide trap to reduce their ''shuttle effect".…”

Recent Progresses on Applications of Conducting Polymers for Modifying Electrode of Rechargeable Batteries

“…[ 108 ] Under the synergistic effect of H‐TiO x and PPy, the composite delivered capacity retention rate of 59.4% after 1000 cycles at 1C. Wei et al reported a facile approach to synthesis the SnO 2 @tubular PPy (T‐PPy@SnO 2 ) as the host of S. [ 109 ] The T‐PPy nanotubes with large surface area could accommodate the volume expansion of S, and anchor polysulfides to exhibit the long‐cycle stability with a high capacity retention rate of 75% after 500 cycles at 1C.…”

Significant Constraints of SnO2, SnS2, and SnS2/SnO2 Heterostructures on Mitigating Polysulfide Shuttle Effects in Lithium‐Sulfur Batteries

“…The conductivity of SnO 2 is better than that of most other oxides in the porous structure. [37] SnO 2 -decoration of the porous nanomaterials has aroused spreading interest. 2D nanomaterials benefit from its ultra-thin layered structure, large specific surface area, excellent photoelectric and mechanical properties, easy interface transmission and short diffusion, displaying very suitable features for being used in energy storage devices.…”

“…Among them, SnO 2 nanoparticles with the characteristics of environmental friendliness, easy preparation, chemical stability, and high energy density are widely concerned. [13,14,37] As a Sn-based compound, SnO 2 inherits the unique performance advantages of the Sn element in the following section: 1) Sn-based materials with high conductivity has been widely used in the electrochemical field because of their excellent ability to accommodate Li + . 2) Sn is an ecofriendly element with low biological toxicity and no pollution to the environment.…”