scholarly journals Three-Dimensionally Ordered Macro/Mesoporous Nb2O5/Nb4N5 Heterostructure as Sulfur Host for High-Performance Lithium/Sulfur Batteries

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1531
Author(s):  
Haoxian Chen ◽  
Jiayi Wang ◽  
Yan Zhao ◽  
Qindan Zeng ◽  
Guofu Zhou ◽  
...  

The severe shuttle effect of soluble polysulfides hinders the development of lithium–sulfur batteries. Herein, we develop a three-dimensionally ordered macro/mesoporous (3DOM) Nb2O5/Nb4N5 heterostructure, which combines the strong adsorption of Nb2O5 and remarkable catalysis effect of Nb4N5 by the promotion “adsorption-transformation” mechanism in sulfur reaction. Furthermore, the high electrocatalytic activity of Nb4N5 facilitates ion/mass transfer during the charge/discharge process. As a result, cells with the S-Nb2O5/Nb4N5 electrode delivered outstanding cycling stability and higher discharge capacity than its counterparts. Our work demonstrates a new routine for the multifunctional sulfur host design, which offers great potential for commercial high-performance lithium–sulfur batteries.

2021 ◽  
Author(s):  
Dongke Zhang ◽  
Ting Huang ◽  
Pengfei Zhao ◽  
Ze Zhang ◽  
Xingtao Qi ◽  
...  

Abstract Due to the low conductivity of sulfur and the dissolution of polysulfides, the research and application of lithium-sulfur (Li-S) batteries have encountered certain resistance. Increasing conductivity and introducing polarity into the sulfur host can effectively overcome these long-standing problems. Herein, We first prepared Co3W3C@ C@ CNTs / S material and used it in the cathode of lithium-sulfur batteries, The existence of carboxylated CNTs can form a conductive network, accelerate the transmission of electrons and improve the rate performance, and polar Co3W3C can form a strong interaction with polysulfide intermediates, effectively inhibiting its shuttle effect, improving the utilization of sulfur cathode electrodes, and improving the capacity and cycle stability. The Co3W3C@C@CNTs / S electrode material has a capacity of 1,093 mA h g-1 at a 0.1 A g− 1 and 482 mA h g-1 at 5 A g− 1. Even after 500 cycles of 2 A g− 1, the capacity of each cycle is only reduced by 0.08%. The excellent stability of this material can provide a new idea for the future development of lithium-sulfur batteries.


NANO ◽  
2021 ◽  
pp. 2150029
Author(s):  
Qian Zhang ◽  
Renxia Zhu ◽  
Chenyu Zhao ◽  
Runze Fan ◽  
Yong Zhang ◽  
...  

Application of lithium-sulfur battery has been limited due to polysulfide dissolution, the insulating nature of sulfur and the volumetric strain produced during charge and discharge process. To improve the performance of Li-S batteries, two kinds of bimetallic sulfides of NiCo2S4 with flaky (F-NiCo2S4) and sea urchin-like (S-NiCo2S4) structures were synthesized by using simple hydrothermal method, which were used as sulfur carriers in lithium-sulfur batteries and showed excellent electrochemical properties. At 0.2[Formula: see text]C, both electrodes of F-NiCo2S4/S and S-NiCo2S4/S have high pristine discharge specific capacities of 986[Formula: see text]mAh[Formula: see text]g[Formula: see text] and 959[Formula: see text]mAh[Formula: see text]g[Formula: see text]. At high current density of 4[Formula: see text]C, the F-NiCo2S4/S electrode still has a high pristine discharge specific capacity of 673[Formula: see text]mAh[Formula: see text]g[Formula: see text] and a coulombic efficiency of 97.00%. The specific capacity can remain at 526[Formula: see text]mAh[Formula: see text]g[Formula: see text] with a low average attenuation of 0.17% even after 130 cycles. The excellent electrochemical performances of the cathode material can be ascribed to the synergistic effect of tubular morphology, good electrical conductivity and strong adsorption ability of NiCo2S4 matrix for polysulfide. The job provides a new scheme and material for application of lithium-sulfur batteries with high performance.


Author(s):  
Chenhui WANG ◽  
Nobuyuki Sakai ◽  
Yasuo Ebina ◽  
Takayuki KIKUCHI ◽  
Monika Snowdon ◽  
...  

Lithium-sulfur batteries have high promise for application in next-generation energy storage. However, further advances have been hindered by various intractable challenges, particularly three notorious problems: the “shuttle effect”, sluggish kinetics...


Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 255
Author(s):  
Ben Hu ◽  
Bing Ding ◽  
Chong Xu ◽  
Zengjie Fan ◽  
Derong Luo ◽  
...  

The shuttling effect of polysulfides is one of the major problems of lithium–sulfur (Li–S) batteries, which causes rapid capacity fading during cycling. Modification of the commercial separator with a functional interlayer is an effective strategy to address this issue. Herein, we modified the commercial Celgard separator of Li–S batteries with one-dimensional (1D) covalent triazine framework (CTF) and a carbon nanotube (CNT) composite as a functional interlayer. The intertwined CTF/CNT can provide a fast lithium ionic/electronic transport pathway and strong adsorption capability towards polysulfides. The Li–S batteries with the CTF/CNT/Celgard separator delivered a high initial capacity of 1314 mAh g−1 at 0.1 C and remained at 684 mAh g−1 after 400 cycles−1 at 1 C. Theoretical calculation and static-adsorption experiments indicated that the triazine ring in the CTF skeleton possessed strong adsorption capability towards polysulfides. The work described here demonstrates the potential for CTF-based permselective membranes as separators in Li–S batteries.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Mengjiao Shi ◽  
Su Zhang ◽  
Yuting Jiang ◽  
Zimu Jiang ◽  
Longhai Zhang ◽  
...  

AbstractThe development of lithium–sulfur batteries (LSBs) is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect. Herein, an N, O co-doped graphene layered block (NOGB) with many dents on the graphene sheets is designed as effective sulfur host for high-performance LSBs. The sulfur platelets are physically confined into the dents and closely contacted with the graphene scaffold, ensuring structural stability and high conductivity. The highly doped N and O atoms can prevent the shuttle effect of sulfur species by strong chemical adsorption. Moreover, the micropores on the graphene sheets enable fast Li+ transport through the blocks. As a result, the obtained NOGB/S composite with 76 wt% sulfur content shows a high capacity of 1413 mAh g−1 at 0.1 C, good rate performance of 433 mAh g−1 at 10 C, and remarkable stability with 526 mAh g−1 at after 1000 cycles at 1 C (average decay rate: 0.038% per cycle). Our design provides a comprehensive route for simultaneously improving the conductivity, ion transport kinetics, and preventing the shuttle effect in LSBs.


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