ZnO Nanoparticles Anchored on a N-Doped Graphene-Coated Separator for High Performance Lithium/Sulfur Batteries

Abstract

Fabrication of a nanocrystalline zinc oxide (ZnO)/nitrogen-doped graphene (NDG) composite using a novel and facile in situ sol-gel technique is demonstrated in this study. A two-dimensional nanostructured morphology with uniform ZnO nanoparticles (average diameter of 10 ± 4 nm) anchored on NDG nanosheets was observed via electron microscopy. The polar heteroatoms on the graphene sheets provided abundant sites for polysulfide absorption. More importantly, the strong chemical interaction between ZnO and polysulfides efficiently hindered the transport of polysulfides. Consequently, the lithium/sulfur (Li/S) battery with the ZnO/NDG composite-coated separator exhibited enhanced performance in terms of discharge capacity and cycling stability compared to the cell with a conventional separator. With the modified separator, the Li/S battery achieved a discharge capacity of 942 mAh·g−1 after the first cycle and exhibited a capacity retention of 90.02% after the 200th charge/discharge test at 0.1 C. These results indicate that suppression of the shuttling of polysulfides efficiently improves the performance of the Li/S battery.

Inhibition of Polysulfide Shuttles in Li–S Batteries: Modified Separators and Solid‐State Electrolytes

“…GO and RGO are usually combined with metal oxides because metal oxides have a strong polar surface exposing numerous unsaturated anions (O 2− ) and metal cations, thus having the ability to form polar‐polar bonding with polysulfides. The reported oxides applied as coatings cover MnO, [ 66 ] ZnO, [ 67,68 ] ZrO, [ 69 ] TiO, [ 70 ] MnO 2 , [ 71–74 ] TiO 2 , [ 63,75,76 ] CeO 2 , [ 77 ] SnO 2 , [ 78 ] MoO 3 , [ 79 ] In 2 O 3 , [ 80 ] La 2 O 3 , [ 81 ] Y 2 O 3 , [ 82 ] Al 2 O 3 , [ 32,83–85 ] Nb 2 O 5 , [ 86 ] Fe 3 O 4 , [ 64 ] NiCo 2 O 4 , [ 87 ] and MgAl 2 O 4 . [ 88 ]…”

Influence of Nd-MOF/CNF-derived Nd2O3-C/CNF composite on lithium–sulfur batteries

“…13 In addition to the above methods, there is separation modification, which serves as an intermediate layer between the positive and negative electrodes, and its modification can not only inhibit polysulfide shuttling but also act as a secondary collector to improve the utilization rate of active substances. So far, separator modification materials mainly include carbon materials, [14][15][16] polar metal compounds, [17][18][19] and new MOF materials. [20][21][22] For instance, carbon nanotubes, porous carbon, graphene, and graphene oxide as well as other carbon materials are considered advantageous in the realm of carbon nanofibers.…”

S−ZnO/CNTs Microspheres Prepared by Spray Drying for Improved Cathodes in Lithium‐Sulfur Batteries

“…Wang et al. prepared ZnO/nitrogen‐doped graphene with obvious adsorption capability of lithium polysulfide . However, the preparation of stably dispersed ZnO nanoparticles by simple steps then effectively compounding them with carbon materials is still challenging.…”