Graphene oxide coated nanosheet‐like γ‐MnS @ KB‐S fabricated by spray drying for high energy density Li‐S batteries

Abstract

In order to prohibit the shuttle influence of lithium polysulfides in lithium sulfur battery, a kind of graphene oxide (GO) coated γ-MnS@KB-S (GO@MKB-S) composite cathode material was successfully fabricated. First of all, the γ-MnS@KB (MKB) composite powders were prepared via a solvothermal reaction, then a spray drying method was used to obtain GO@MKB-S composites, which displays core/shell nanostructure. SEM, TEM, XRD as well as Raman spectrum are implemented to look into the microstructures and the functions of the 2D nanosheet-like γ-MnS in setting in KB on the battery performance were carefully analyzed. It is demonstrated that electrochemical discharge capacity and rate performance are clearly improved by using GO@MKB-S composites compared to the cathode electrode of the GO coated KB-S (GO@KB-S). With a sulfur loading of 5 mg cm −2 , the cathode electrode of GO@MKB-S shows a considerable discharge capacity of 749.9 mAh g −1 at 0.36 C. Additionally, the Li-S battery cycle retention of GO@MKB-S sample maintains 97.36% after 100 cycles and 78.69% after 200 cycles.

Alleviating the polysulfides “shuttling” and improving the sulfur utilization ably by the micropores of MOFs materials

“…Recently, targeted research has focused on introducing sulfur into microporous structure, which facilitates the immobilization of small sulfur molecules (S 2‐4 ) and confining polysulfides by the limited pore size 40‐45 . Interestingly, the storage of S 2‐4 in micropores is able to avoid the unnecessary conversion between S 8 to S 6 2− and S 4 2− , efficaciously improving active material utilization and alleviating the “shuttle effect” 46‐48 . Therefore, it is urgent to take measures to utilize the micropores of MOFs to confine and immobilize S and polysulfides, thereby increasing the sulfur utilization 49,50 …”

Preparation and Application of Nanorod FeOOH/CNT@S Composites for High-Performance Lithium–Sulfur Batteries

“…Carbon materials, such as conductive carbon black, graphene, and carbon nanotubes (CNTs), which improve the electronic conductivity during the charge/discharge process, were introduced for Li–S batteries . Guo et al reported a graphene oxide-coated γ-MnS@KB composite material via a solvothermal method. The synthesized electrode displays excellent electrochemical performance due to the high conductivity of carbon materials.…”