Boosting solid–solid conversion kinetics of sulfurized polyacrylonitrile via MoS₂ doping for high‐rate and long‐life Li‐S batteries

Abstract

Sulfurized polyacrylonitrile (SPAN) with a "solid-solid" conversion mechanism in carbonated-based electrolyte eradicating the polysulfides shutting issue is considered as an ideal cathode for stabilizing lithium-sulfur (Li-S) batteries. However, the sluggish reaction kinetics and less sulfur content of the SPAN limit its practical application. Herein, the MoS 2 doped SPAN (MoS 2 @SPAN) is demonstrated to rapidly accelerate the solid-solid conversion kinetics of SPAN for remarkably boosting high-power and long-life Li-S batteries. Benefitting from the accelerated lithium-ion (Li + ) transfer rate, a fast ion transport channel and enhanced redox reaction kinetics of sulfur to Li 2 S 2 /Li 2 S is realized via MoS 2 catalysis, and excellent electrochemical performance is achieved. Consequently, MoS 2 @SPAN delivers a high capacity of 626 mAh g −1 at 0.1 A g −1 , and simultaneously shows ultralong cycling life of 500 cycles with only 0.089% capacity decay rate at 2 A g −1 . Moreover, a superb capacity of 321 mAh g −1 at ultrahigh current density of 5 A g −1 is offered, outperforming most of the reported SPAN cathodes. This work provides a general and reliable strategy on the reliable design of SPAN cathode for high-rate and long-term Li-S batteries.

SnS2 nanoparticles embedded in sulfurized polyacrylonitrile composite fibers for high‐performance potassium‐ion batteries

“…The former two peaks correspond to S 2p 3/2 and S 2p 1/2 , while the latter two peaks are related to S─S and C─S, respectively. [54] As shown in Figure 3E, the Sn 3d spectrum exhibits a typical pair of Sn 3d 3/2 and Sn 3d 5/2 peaks at 494.9 and 486.5 eV, respectively, suggesting the successful synthesis of SnS 2 rather than SnS.…”

Quantum Spin Exchange Interactions to Accelerate the Redox Kinetics in Li–S Batteries

“…4 g). MgPc@FCNT can provide high area capacity of 5.1 mAh cm −2 after 100 cycles indicating the potential commercial application compared with other materials [ 61 , 62 ].…”

Soft–Rigid Heterostructures with Functional Cation Vacancies for Fast‐Charging and High‐Capacity Sodium Storage

“…In addition, the specific surface areas measured using the Brunauer–Emmett–Teller (BET) method were all approximate to 40 m 2 g −1 for Co 9 S 8 /S‐Gr, MoS 2 /S‐Gr, and d‐Co 9 S 8 @MoS 2 /S‐Gr (Figure 2d, Figure S11, Supporting Information). [ 17 ] The three materials also have mesoporous structures identified with an average pore size of 4.0 nm (Figure 2e). In Figure 2f, a comparison of Raman spectra shows that the intensity ratio (1.05) of the defect (D) band to the graphitized (G) band ( I D / I G ) for d‐Co 9 S 8 @MoS 2 /S‐Gr is smaller than those for Co 9 S 8 /S‐Gr (1.08) and MoS 2 /S‐Gr (1.45), reflecting the high ratio of graphitic carbon with less defects formed in the d‐Co 9 S 8 @MoS 2 /S‐Gr which can boost the electronic diffusion kinetics as an external pathway.…”